fileshare (#5414)

Co-authored-by: ConnorYoh <[email protected]>
Co-authored-by: Connor Yoh <[email protected]>
Co-authored-by: EthanHealy01 <[email protected]>
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

app/proprietary/src/main/java/stirling/software/proprietary/security/configuration/DatabaseConfig.java

@@ -28,9 +28,16 @@ import stirling.software.common.model.exception.UnsupportedProviderException;
         basePackages = {
             "stirling.software.proprietary.security.database.repository",
             "stirling.software.proprietary.security.repository",
-            "stirling.software.proprietary.repository"
+            "stirling.software.proprietary.repository",
+            "stirling.software.proprietary.storage.repository",
+            "stirling.software.proprietary.workflow.repository"
         })
-@EntityScan({"stirling.software.proprietary.security.model", "stirling.software.proprietary.model"})
+@EntityScan({
+    "stirling.software.proprietary.security.model",
+    "stirling.software.proprietary.model",
+    "stirling.software.proprietary.storage.model",
+    "stirling.software.proprietary.workflow.model"
+})
 public class DatabaseConfig {
 
     public final String DATASOURCE_DEFAULT_URL;

app/proprietary/src/main/java/stirling/software/proprietary/security/configuration/ProprietaryWebMvcConfig.java

@@ -0,0 +1,22 @@
+package stirling.software.proprietary.security.configuration;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.proprietary.security.filter.ParticipantRateLimitInterceptor;
+
+@Configuration
+@RequiredArgsConstructor
+public class ProprietaryWebMvcConfig implements WebMvcConfigurer {
+
+    private final ParticipantRateLimitInterceptor participantRateLimitInterceptor;
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(participantRateLimitInterceptor)
+                .addPathPatterns("/api/v1/workflow/participant/**");
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/security/controller/api/AdminSettingsController.java

@@ -612,6 +612,7 @@ public class AdminSettingsController {
             case "endpoints" -> applicationProperties.getEndpoints();
             case "metrics" -> applicationProperties.getMetrics();
             case "mail" -> applicationProperties.getMail();
+            case "storage" -> applicationProperties.getStorage();
             case "premium" -> applicationProperties.getPremium();
             case "processexecutor", "processExecutor" -> applicationProperties.getProcessExecutor();
             case "autopipeline", "autoPipeline" -> applicationProperties.getAutoPipeline();
@@ -633,6 +634,7 @@ public class AdminSettingsController {
                     "endpoints",
                     "metrics",
                     "mail",
+                    "storage",
                     "premium",
                     "processExecutor",
                     "processexecutor",

app/proprietary/src/main/java/stirling/software/proprietary/security/controller/api/UserController.java

@@ -18,6 +18,7 @@ import org.springframework.security.core.session.SessionInformation;
 import org.springframework.security.core.userdetails.UserDetails;
 import org.springframework.security.oauth2.core.user.OAuth2User;
 import org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
@@ -33,6 +34,7 @@ import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.annotations.api.UserApi;
 import stirling.software.common.model.ApplicationProperties;
+import stirling.software.common.model.api.security.UserSummaryDTO;
 import stirling.software.common.model.enumeration.Role;
 import stirling.software.common.model.exception.UnsupportedProviderException;
 import stirling.software.proprietary.audit.AuditEventType;
@@ -775,6 +777,7 @@ public class UserController {
 
     @PreAuthorize("hasRole('ROLE_ADMIN')")
     @PostMapping("/admin/deleteUser/{username}")
+    @Audited(type = AuditEventType.USER_PROFILE_UPDATE, level = AuditLevel.BASIC)
     public ResponseEntity<?> deleteUser(
             @PathVariable("username") String username, Authentication authentication) {
         if (!userService.usernameExistsIgnoreCase(username)) {
@@ -964,4 +967,34 @@ public class UserController {
                     .body("Failed to complete initial setup");
         }
     }
+
+    /**
+     * List all enabled users for selection in signing workflows.
+     *
+     * @param principal The authenticated user
+     * @return List of user summaries
+     */
+    @GetMapping("/users")
+    public ResponseEntity<List<UserSummaryDTO>> listUsers(Principal principal) {
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        }
+
+        List<UserSummaryDTO> users =
+                userRepository.findAll().stream()
+                        .filter(User::isEnabled)
+                        .map(this::toUserSummaryDTO)
+                        .collect(java.util.stream.Collectors.toList());
+
+        return ResponseEntity.ok(users);
+    }
+
+    private UserSummaryDTO toUserSummaryDTO(User user) {
+        return new UserSummaryDTO(
+                user.getId(),
+                user.getUsername(),
+                user.getUsername(), // Use username as displayName
+                user.getTeam() != null ? user.getTeam().getName() : null,
+                user.isEnabled());
+    }
 }

app/proprietary/src/main/java/stirling/software/proprietary/security/filter/ParticipantRateLimitInterceptor.java

@@ -0,0 +1,73 @@
+package stirling.software.proprietary.security.filter;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+import org.springframework.web.servlet.HandlerInterceptor;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+
+import lombok.extern.slf4j.Slf4j;
+
+/** Per-IP rate limiter for the unauthenticated participant token endpoints. */
+@Slf4j
+@Component
+public class ParticipantRateLimitInterceptor implements HandlerInterceptor {
+
+    private static final int MAX_REQUESTS_PER_MINUTE = 20;
+    private static final long WINDOW_MS = 60_000L;
+
+    // value: [requestCount, windowStartMs]
+    private final ConcurrentHashMap<String, long[]> requestCounts = new ConcurrentHashMap<>();
+
+    @Override
+    public boolean preHandle(
+            HttpServletRequest request, HttpServletResponse response, Object handler)
+            throws Exception {
+
+        String ip = getClientIp(request);
+        long now = System.currentTimeMillis();
+
+        long[] entry =
+                requestCounts.compute(
+                        ip,
+                        (key, existing) -> {
+                            if (existing == null || now - existing[1] >= WINDOW_MS) {
+                                return new long[] {1, now};
+                            }
+                            existing[0]++;
+                            return existing;
+                        });
+
+        if (entry[0] > MAX_REQUESTS_PER_MINUTE) {
+            log.warn(
+                    "Rate limit exceeded for IP {} on participant endpoint {}",
+                    ip,
+                    request.getRequestURI());
+            response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
+            response.setHeader("Retry-After", "60");
+            response.setContentType("application/json");
+            response.getWriter()
+                    .write("{\"error\":\"Rate limit exceeded. Try again in 60 seconds.\"}");
+            return false;
+        }
+        return true;
+    }
+
+    private String getClientIp(HttpServletRequest request) {
+        // Do not trust X-Forwarded-For: it is user-controlled and trivially spoofed,
+        // which would allow an attacker to bypass this rate limiter by rotating fake IPs.
+        // Operators who deploy behind a trusted reverse proxy should configure Spring's
+        // RemoteIpFilter / ForwardedHeaderFilter at the framework level instead.
+        return request.getRemoteAddr();
+    }
+
+    @Scheduled(fixedDelay = 300_000)
+    public void cleanupExpiredWindows() {
+        long cutoff = System.currentTimeMillis() - WINDOW_MS;
+        requestCounts.entrySet().removeIf(e -> e.getValue()[1] < cutoff);
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/security/model/User.java

@@ -40,6 +40,7 @@ public class User implements UserDetails, Serializable {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @Column(name = "user_id")
+    @EqualsAndHashCode.Include
     private Long id;
 
     @Column(name = "username", unique = true)

app/proprietary/src/main/java/stirling/software/proprietary/security/service/UserService.java

@@ -41,6 +41,7 @@ import stirling.software.common.service.UserServiceInterface;
 import stirling.software.common.util.RegexPatternUtils;
 import stirling.software.proprietary.model.Team;
 import stirling.software.proprietary.security.database.repository.AuthorityRepository;
+import stirling.software.proprietary.security.database.repository.PersistentLoginRepository;
 import stirling.software.proprietary.security.database.repository.UserRepository;
 import stirling.software.proprietary.security.model.AuthenticationType;
 import stirling.software.proprietary.security.model.Authority;
@@ -48,6 +49,16 @@ import stirling.software.proprietary.security.model.User;
 import stirling.software.proprietary.security.repository.TeamRepository;
 import stirling.software.proprietary.security.saml2.CustomSaml2AuthenticatedPrincipal;
 import stirling.software.proprietary.security.session.SessionPersistentRegistry;
+import stirling.software.proprietary.storage.model.FileShare;
+import stirling.software.proprietary.storage.model.StorageCleanupEntry;
+import stirling.software.proprietary.storage.model.StoredFile;
+import stirling.software.proprietary.storage.repository.FileShareAccessRepository;
+import stirling.software.proprietary.storage.repository.FileShareRepository;
+import stirling.software.proprietary.storage.repository.StorageCleanupEntryRepository;
+import stirling.software.proprietary.storage.repository.StoredFileRepository;
+import stirling.software.proprietary.workflow.repository.WorkflowParticipantRepository;
+import stirling.software.proprietary.workflow.repository.WorkflowSessionRepository;
+import stirling.software.proprietary.workflow.service.UserServerCertificateService;
 
 @Service
 @Slf4j
@@ -68,6 +79,15 @@ public class UserService implements UserServiceInterface {
 
     private final ApplicationProperties.Security.OAUTH2 oAuth2;
 
+    private final PersistentLoginRepository persistentLoginRepository;
+    private final UserServerCertificateService userServerCertificateService;
+    private final WorkflowParticipantRepository workflowParticipantRepository;
+    private final WorkflowSessionRepository workflowSessionRepository;
+    private final StoredFileRepository storedFileRepository;
+    private final StorageCleanupEntryRepository storageCleanupEntryRepository;
+    private final FileShareRepository fileShareRepository;
+    private final FileShareAccessRepository fileShareAccessRepository;
+
     @Transactional
     public void processSSOPostLogin(
             String username,
@@ -200,19 +220,78 @@ public class UserService implements UserServiceInterface {
         return userOpt.isPresent() && apiKey.equals(userOpt.get().getApiKey());
     }
 
+    @Transactional
     public void deleteUser(String username) {
         Optional<User> userOpt = findByUsernameIgnoreCase(username);
         if (userOpt.isPresent()) {
-            for (Authority authority : userOpt.get().getAuthorities()) {
+            User user = userOpt.get();
+            for (Authority authority : user.getAuthorities()) {
                 if (authority.getAuthority().equals(Role.INTERNAL_API_USER.getRoleId())) {
                     return;
                 }
             }
-            userRepository.delete(userOpt.get());
+            deleteUserRelatedData(user);
+            userRepository.delete(user);
+            persistentLoginRepository.deleteByUsername(username);
         }
         invalidateUserSessions(username);
     }
 
+    private void deleteUserRelatedData(User user) {
+        log.info("Deleting all associated data for user: {}", user.getUsername());
+
+        // Delete server certificate (non-nullable OneToOne → User)
+        userServerCertificateService.deleteUserCertificate(user.getId());
+
+        // Delete FileShareAccess records where this user is the accessor
+        fileShareAccessRepository.deleteByUser(user);
+
+        // Delete FileShare records where this user is the recipient (shared with them by others).
+        // FileShareAccess for those shares must be cleared first (no cascade from FileShare side).
+        List<FileShare> sharesTargetingUser = fileShareRepository.findBySharedWithUser(user);
+        sharesTargetingUser.forEach(fileShareAccessRepository::deleteByFileShare);
+        fileShareRepository.deleteAll(sharesTargetingUser);
+
+        // Null out WorkflowParticipant.user for sessions this user participates in but does not
+        // own.
+        // The participant record is retained to preserve the workflow audit trail.
+        workflowParticipantRepository.clearUserReferences(user);
+
+        // Break circular FK: null out stored_files.workflow_session_id before deleting sessions
+        storedFileRepository.clearWorkflowSessionReferencesByOwner(user);
+
+        // Delete WorkflowSessions (CascadeType.ALL cascades to WorkflowParticipant)
+        workflowSessionRepository.deleteAll(
+                workflowSessionRepository.findByOwnerOrderByCreatedAtDesc(user));
+
+        // Collect storage keys for physical cleanup before deleting DB records
+        List<StoredFile> files = storedFileRepository.findAllByOwner(user);
+        List<String> storageKeys =
+                files.stream()
+                        .flatMap(
+                                f ->
+                                        java.util.stream.Stream.of(
+                                                f.getStorageKey(),
+                                                f.getHistoryStorageKey(),
+                                                f.getAuditLogStorageKey()))
+                        .filter(k -> k != null && !k.isBlank())
+                        .toList();
+
+        // Clear FileShareAccess per share (no cascade from FileShare), then delete StoredFiles
+        // (CascadeType.ALL on StoredFile.shares cascades to FileShare)
+        for (StoredFile file : files) {
+            file.getShares().forEach(fileShareAccessRepository::deleteByFileShare);
+        }
+        storedFileRepository.deleteAll(files);
+
+        // Schedule physical deletion of all storage blobs; StorageCleanupService handles retry
+        for (String key : storageKeys) {
+            StorageCleanupEntry entry = new StorageCleanupEntry();
+            entry.setStorageKey(key);
+            storageCleanupEntryRepository.save(entry);
+        }
+    }
+
     public boolean usernameExists(String username) {
         return findByUsername(username).isPresent();
     }

app/proprietary/src/main/java/stirling/software/proprietary/storage/config/StorageProviderConfig.java

@@ -0,0 +1,74 @@
+package stirling.software.proprietary.storage.config;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Locale;
+import java.util.Optional;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.configuration.InstallationPathConfig;
+import stirling.software.common.model.ApplicationProperties;
+import stirling.software.proprietary.storage.provider.DatabaseStorageProvider;
+import stirling.software.proprietary.storage.provider.LocalStorageProvider;
+import stirling.software.proprietary.storage.provider.StorageProvider;
+import stirling.software.proprietary.storage.repository.StoredFileBlobRepository;
+
+@Configuration
+@RequiredArgsConstructor
+@Slf4j
+public class StorageProviderConfig {
+
+    private final ApplicationProperties applicationProperties;
+    private final StoredFileBlobRepository storedFileBlobRepository;
+
+    @Bean
+    public StorageProvider storageProvider() {
+        boolean storageEnabled = applicationProperties.getStorage().isEnabled();
+        String providerName =
+                Optional.ofNullable(applicationProperties.getStorage().getProvider())
+                        .orElse("local")
+                        .trim()
+                        .toLowerCase(Locale.ROOT);
+        if ("database".equals(providerName)) {
+            return new DatabaseStorageProvider(storedFileBlobRepository);
+        }
+        if (!"local".equals(providerName)) {
+            throw new IllegalStateException("Storage provider not supported: " + providerName);
+        }
+        String basePathValue = applicationProperties.getStorage().getLocal().getBasePath();
+        if (basePathValue == null || basePathValue.isBlank()) {
+            if (storageEnabled) {
+                throw new IllegalStateException("Storage base path is not configured");
+            }
+            basePathValue = InstallationPathConfig.getPath() + "storage";
+        }
+        Path basePath = Paths.get(basePathValue).toAbsolutePath().normalize();
+        Path installRoot = Paths.get(InstallationPathConfig.getPath()).toAbsolutePath().normalize();
+        if (!basePath.startsWith(installRoot)) {
+            // Warn rather than hard-fail: admins may legitimately point storage at an external
+            // volume, but an unexpected path could indicate a misconfiguration or traversal
+            // attempt.
+            log.warn(
+                    "Storage basePath '{}' is outside the installation directory '{}'. "
+                            + "Verify this is intentional.",
+                    basePath,
+                    installRoot);
+        }
+        if (storageEnabled) {
+            try {
+                Files.createDirectories(basePath);
+            } catch (IOException e) {
+                throw new IllegalStateException(
+                        "Unable to create storage base directory: " + basePath, e);
+            }
+        }
+        return new LocalStorageProvider(basePath);
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/controller/FileStorageController.java

@@ -0,0 +1,270 @@
+package stirling.software.proprietary.storage.controller;
+
+import java.util.List;
+import java.util.Locale;
+
+import org.springframework.http.ContentDisposition;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RequestPart;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.server.ResponseStatusException;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.FileShare;
+import stirling.software.proprietary.storage.model.StoredFile;
+import stirling.software.proprietary.storage.model.api.CreateShareLinkRequest;
+import stirling.software.proprietary.storage.model.api.ShareLinkAccessResponse;
+import stirling.software.proprietary.storage.model.api.ShareLinkMetadataResponse;
+import stirling.software.proprietary.storage.model.api.ShareLinkResponse;
+import stirling.software.proprietary.storage.model.api.ShareWithUserRequest;
+import stirling.software.proprietary.storage.model.api.StoredFileResponse;
+import stirling.software.proprietary.storage.service.FileStorageService;
+
+@RestController
+@RequestMapping("/api/v1/storage")
+@RequiredArgsConstructor
+public class FileStorageController {
+
+    private final FileStorageService fileStorageService;
+
+    @PostMapping(
+            value = "/files",
+            consumes = MediaType.MULTIPART_FORM_DATA_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public StoredFileResponse uploadFile(
+            @RequestPart("file") MultipartFile file,
+            @RequestPart(name = "historyBundle", required = false) MultipartFile historyBundle,
+            @RequestPart(name = "auditLog", required = false) MultipartFile auditLog) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        return fileStorageService.storeFileResponse(user, file, historyBundle, auditLog);
+    }
+
+    @PutMapping(
+            value = "/files/{fileId}",
+            consumes = MediaType.MULTIPART_FORM_DATA_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public StoredFileResponse updateFile(
+            @PathVariable Long fileId,
+            @RequestPart("file") MultipartFile file,
+            @RequestPart(name = "historyBundle", required = false) MultipartFile historyBundle,
+            @RequestPart(name = "auditLog", required = false) MultipartFile auditLog) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        return fileStorageService.updateFileResponse(user, fileId, file, historyBundle, auditLog);
+    }
+
+    @GetMapping(value = "/files", produces = MediaType.APPLICATION_JSON_VALUE)
+    public List<StoredFileResponse> listFiles() {
+        User user = fileStorageService.requireAuthenticatedUser();
+        return fileStorageService.listAccessibleFileResponses(user);
+    }
+
+    @GetMapping(value = "/files/{fileId}", produces = MediaType.APPLICATION_JSON_VALUE)
+    public StoredFileResponse getFileMetadata(@PathVariable Long fileId) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        return fileStorageService.getAccessibleFileResponse(user, fileId);
+    }
+
+    @GetMapping("/files/{fileId}/download")
+    public ResponseEntity<org.springframework.core.io.Resource> downloadFile(
+            @PathVariable Long fileId,
+            @RequestParam(name = "inline", defaultValue = "false") boolean inline) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getAccessibleFile(user, fileId);
+        fileStorageService.requireReadAccess(user, file);
+        return buildFileResponse(file, inline);
+    }
+
+    @DeleteMapping("/files/{fileId}")
+    public ResponseEntity<Void> deleteFile(@PathVariable Long fileId) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getOwnedFile(user, fileId);
+        fileStorageService.deleteFile(user, file);
+        return ResponseEntity.noContent().build();
+    }
+
+    @PostMapping(
+            value = "/files/{fileId}/shares/users",
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public StoredFileResponse shareWithUser(
+            @PathVariable Long fileId, @RequestBody ShareWithUserRequest request) {
+        User owner = fileStorageService.requireAuthenticatedUser();
+        if (request == null || request.getUsername() == null || request.getUsername().isBlank()) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Username is required");
+        }
+        return fileStorageService.shareWithUserResponse(
+                owner,
+                fileId,
+                request.getUsername(),
+                fileStorageService.normalizeShareRole(request.getAccessRole()));
+    }
+
+    @DeleteMapping("/files/{fileId}/shares/users/{username}")
+    public ResponseEntity<Void> revokeUserShare(
+            @PathVariable Long fileId, @PathVariable String username) {
+        User owner = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getOwnedFile(owner, fileId);
+        fileStorageService.revokeUserShare(owner, file, username);
+        return ResponseEntity.noContent().build();
+    }
+
+    @DeleteMapping("/files/{fileId}/shares/self")
+    public ResponseEntity<Void> leaveUserShare(@PathVariable Long fileId) {
+        User user = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getAccessibleFile(user, fileId);
+        fileStorageService.leaveUserShare(user, file);
+        return ResponseEntity.noContent().build();
+    }
+
+    @PostMapping(
+            value = "/files/{fileId}/shares/links",
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public ShareLinkResponse createShareLink(
+            @PathVariable Long fileId, @RequestBody CreateShareLinkRequest request) {
+        User owner = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getOwnedFile(owner, fileId);
+        FileShare share =
+                fileStorageService.createShareLink(
+                        owner,
+                        file,
+                        fileStorageService.normalizeShareRole(
+                                request != null ? request.getAccessRole() : null));
+        return ShareLinkResponse.builder()
+                .token(share.getShareToken())
+                .accessRole(
+                        share.getAccessRole() != null
+                                ? share.getAccessRole().name().toLowerCase(Locale.ROOT)
+                                : null)
+                .createdAt(share.getCreatedAt())
+                .expiresAt(share.getExpiresAt())
+                .build();
+    }
+
+    @DeleteMapping("/files/{fileId}/shares/links/{token}")
+    public ResponseEntity<Void> revokeShareLink(
+            @PathVariable Long fileId, @PathVariable String token) {
+        User owner = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getOwnedFile(owner, fileId);
+        fileStorageService.revokeShareLink(owner, file, token);
+        return ResponseEntity.noContent().build();
+    }
+
+    @GetMapping("/share-links/{token}")
+    public ResponseEntity<org.springframework.core.io.Resource> downloadShareLink(
+            @PathVariable String token,
+            Authentication authentication,
+            @RequestParam(name = "inline", defaultValue = "false") boolean inline) {
+        fileStorageService.ensureShareLinksEnabled();
+        FileShare share = fileStorageService.getShareByToken(token);
+        if (!fileStorageService.canAccessShareLink(share, authentication)) {
+            HttpStatus status =
+                    isAuthenticated(authentication)
+                            ? HttpStatus.FORBIDDEN
+                            : HttpStatus.UNAUTHORIZED;
+            String message =
+                    status == HttpStatus.FORBIDDEN
+                            ? "Access denied for this share link"
+                            : "Authentication required for this share link";
+            throw new ResponseStatusException(status, message);
+        }
+        fileStorageService.requireReadAccess(share);
+        fileStorageService.recordShareAccess(share, authentication, inline);
+        StoredFile file = share.getFile();
+        return buildFileResponse(file, inline);
+    }
+
+    @GetMapping("/share-links/{token}/metadata")
+    public ShareLinkMetadataResponse getShareLinkMetadata(
+            @PathVariable String token, Authentication authentication) {
+        fileStorageService.ensureShareLinksEnabled();
+        FileShare share = fileStorageService.getShareByToken(token);
+        if (!fileStorageService.canAccessShareLink(share, authentication)) {
+            HttpStatus status =
+                    isAuthenticated(authentication)
+                            ? HttpStatus.FORBIDDEN
+                            : HttpStatus.UNAUTHORIZED;
+            String message =
+                    status == HttpStatus.FORBIDDEN
+                            ? "Access denied for this share link"
+                            : "Authentication required for this share link";
+            throw new ResponseStatusException(status, message);
+        }
+        StoredFile file = share.getFile();
+        User currentUser = fileStorageService.requireAuthenticatedUser();
+        boolean ownedByCurrentUser =
+                currentUser != null
+                        && file.getOwner() != null
+                        && currentUser.getId().equals(file.getOwner().getId());
+        return ShareLinkMetadataResponse.builder()
+                .shareToken(share.getShareToken())
+                .fileId(file.getId())
+                .fileName(file.getOriginalFilename())
+                .owner(file.getOwner() != null ? file.getOwner().getUsername() : null)
+                .ownedByCurrentUser(ownedByCurrentUser)
+                .accessRole(
+                        share.getAccessRole() != null
+                                ? share.getAccessRole().name().toLowerCase(Locale.ROOT)
+                                : null)
+                .createdAt(share.getCreatedAt())
+                .expiresAt(share.getExpiresAt())
+                .build();
+    }
+
+    @GetMapping("/share-links/accessed")
+    public List<ShareLinkMetadataResponse> listAccessedShareLinks() {
+        fileStorageService.ensureShareLinksEnabled();
+        User user = fileStorageService.requireAuthenticatedUser();
+        return fileStorageService.listAccessedShareLinkResponses(user);
+    }
+
+    @GetMapping("/files/{fileId}/shares/links/{token}/accesses")
+    public List<ShareLinkAccessResponse> listShareAccesses(
+            @PathVariable Long fileId, @PathVariable String token) {
+        fileStorageService.ensureShareLinksEnabled();
+        User owner = fileStorageService.requireAuthenticatedUser();
+        StoredFile file = fileStorageService.getOwnedFile(owner, fileId);
+        return fileStorageService.listShareAccessResponses(owner, file, token);
+    }
+
+    private ResponseEntity<org.springframework.core.io.Resource> buildFileResponse(
+            StoredFile file, boolean inline) {
+        org.springframework.core.io.Resource resource = fileStorageService.loadFile(file);
+        String contentType =
+                file.getContentType() == null
+                        ? MediaType.APPLICATION_OCTET_STREAM_VALUE
+                        : file.getContentType();
+        ContentDisposition disposition =
+                ContentDisposition.builder(inline ? "inline" : "attachment")
+                        .filename(file.getOriginalFilename())
+                        .build();
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentDisposition(disposition);
+        try {
+            headers.setContentType(MediaType.parseMediaType(contentType));
+        } catch (IllegalArgumentException ex) {
+            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
+        }
+        headers.setContentLength(file.getSizeBytes());
+        return ResponseEntity.ok().headers(headers).body(resource);
+    }
+
+    private boolean isAuthenticated(Authentication authentication) {
+        return authentication != null
+                && authentication.isAuthenticated()
+                && !"anonymousUser".equals(authentication.getPrincipal());
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/converter/JsonMapConverter.java

@@ -0,0 +1,81 @@
+package stirling.software.proprietary.storage.converter;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import jakarta.persistence.AttributeConverter;
+import jakarta.persistence.Converter;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * JPA AttributeConverter for storing Map<String, Object> as JSON in database columns.
+ *
+ * <p>Converts between Java Map objects and JSON strings for PostgreSQL JSONB or TEXT columns.
+ * Includes backward compatibility handling for legacy double-encoded JSON data.
+ */
+@Converter
+@Slf4j
+public class JsonMapConverter implements AttributeConverter<Map<String, Object>, String> {
+
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    public String convertToDatabaseColumn(Map<String, Object> attribute) {
+        if (attribute == null || attribute.isEmpty()) {
+            return null;
+        }
+
+        try {
+            return objectMapper.writeValueAsString(attribute);
+        } catch (JsonProcessingException e) {
+            log.error("Failed to convert map to JSON", e);
+            throw new RuntimeException("Failed to convert map to JSON", e);
+        }
+    }
+
+    @Override
+    public Map<String, Object> convertToEntityAttribute(String dbData) {
+        if (dbData == null || dbData.isBlank()) {
+            return new HashMap<>();
+        }
+
+        try {
+            // Try normal parsing first
+            return objectMapper.readValue(dbData, new TypeReference<Map<String, Object>>() {});
+        } catch (JsonProcessingException e) {
+            // Fallback: try double-parsing for legacy double-encoded data
+            // This handles data that was stored as JSON strings instead of JSON objects
+            log.debug("Attempting double-decode fallback for legacy metadata format");
+            try {
+                JsonNode node = objectMapper.readTree(dbData);
+                if (node.isTextual()) {
+                    log.warn(
+                            "╔════════════════════════════════════════════════════════════════════╗");
+                    log.warn(
+                            "║ WARNING: DOUBLE-ENCODED JSON DETECTED - LEGACY DATA FOUND         ║");
+                    log.warn(
+                            "║ This should not occur in newly created records.                   ║");
+                    log.warn(
+                            "║ Data preview: {}",
+                            dbData.length() > 100 ? dbData.substring(0, 100) + "..." : dbData);
+                    log.warn(
+                            "╚════════════════════════════════════════════════════════════════════╝");
+                    return objectMapper.readValue(
+                            node.asText(), new TypeReference<Map<String, Object>>() {});
+                }
+            } catch (JsonProcessingException e2) {
+                log.error("Failed to parse metadata even with double-decode fallback", e2);
+            }
+
+            // If all parsing fails, return empty map to prevent application errors
+            log.error("Unable to parse JSON metadata, returning empty map", e);
+            return new HashMap<>();
+        }
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/FilePurpose.java

@@ -0,0 +1,19 @@
+package stirling.software.proprietary.storage.model;
+
+/**
+ * Defines the purpose classification for stored files. Used to categorize files based on their role
+ * in the system.
+ */
+public enum FilePurpose {
+    /** Regular file sharing - generic uploaded files */
+    GENERIC,
+
+    /** Original PDF in a signing session - the document to be signed */
+    SIGNING_ORIGINAL,
+
+    /** Final signed PDF - the completed document with all signatures applied */
+    SIGNING_SIGNED,
+
+    /** Audit trail for signing session - history and metadata */
+    SIGNING_HISTORY
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/FileShare.java

@@ -0,0 +1,77 @@
+package stirling.software.proprietary.storage.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+import jakarta.persistence.UniqueConstraint;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import stirling.software.proprietary.security.model.User;
+
+/** Represents a file sharing relationship between a file and a user or token. */
+@Entity
+@Table(
+        name = "file_shares",
+        uniqueConstraints = {
+            @UniqueConstraint(
+                    name = "uk_file_share_user",
+                    columnNames = {"stored_file_id", "shared_with_user_id"}),
+            @UniqueConstraint(
+                    name = "uk_file_share_token",
+                    columnNames = {"share_token"})
+        },
+        indexes = {
+            @Index(name = "idx_file_shares_file_id", columnList = "stored_file_id"),
+            @Index(name = "idx_file_shares_share_token", columnList = "share_token")
+        })
+@NoArgsConstructor
+@Getter
+@Setter
+public class FileShare implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "file_share_id")
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "stored_file_id", nullable = false)
+    private StoredFile file;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "shared_with_user_id")
+    private User sharedWithUser;
+
+    @Column(name = "share_token", unique = true)
+    private String shareToken;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "access_role")
+    private ShareAccessRole accessRole;
+
+    @Column(name = "expires_at")
+    private LocalDateTime expiresAt;
+
+    @CreationTimestamp
+    @Column(name = "created_at", updatable = false)
+    private LocalDateTime createdAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/FileShareAccess.java

@@ -0,0 +1,64 @@
+package stirling.software.proprietary.storage.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import stirling.software.proprietary.security.model.User;
+
+@Entity
+@Table(
+        name = "file_share_accesses",
+        indexes = {
+            @Index(name = "idx_share_access_file_share", columnList = "file_share_id"),
+            @Index(name = "idx_share_access_user", columnList = "user_id"),
+            @Index(
+                    name = "idx_share_access_file_share_accessed",
+                    columnList = "file_share_id, accessed_at")
+        })
+@NoArgsConstructor
+@Getter
+@Setter
+public class FileShareAccess implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "file_share_access_id")
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "file_share_id", nullable = false)
+    private FileShare fileShare;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "access_type", nullable = false)
+    private FileShareAccessType accessType;
+
+    @CreationTimestamp
+    @Column(name = "accessed_at", updatable = false)
+    private LocalDateTime accessedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/FileShareAccessType.java

@@ -0,0 +1,6 @@
+package stirling.software.proprietary.storage.model;
+
+public enum FileShareAccessType {
+    VIEW,
+    DOWNLOAD
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/ShareAccessRole.java

@@ -0,0 +1,7 @@
+package stirling.software.proprietary.storage.model;
+
+public enum ShareAccessRole {
+    EDITOR,
+    COMMENTER,
+    VIEWER
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/StorageCleanupEntry.java

@@ -0,0 +1,47 @@
+package stirling.software.proprietary.storage.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+import org.hibernate.annotations.UpdateTimestamp;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Table(name = "storage_cleanup_entries")
+@NoArgsConstructor
+@Getter
+@Setter
+public class StorageCleanupEntry implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "cleanup_entry_id")
+    private Long id;
+
+    @Column(name = "storage_key", nullable = false, length = 128)
+    private String storageKey;
+
+    @Column(name = "attempt_count")
+    private int attemptCount;
+
+    @CreationTimestamp
+    @Column(name = "created_at", updatable = false)
+    private LocalDateTime createdAt;
+
+    @UpdateTimestamp
+    @Column(name = "updated_at")
+    private LocalDateTime updatedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/StoredFile.java

@@ -0,0 +1,116 @@
+package stirling.software.proprietary.storage.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.hibernate.annotations.CreationTimestamp;
+import org.hibernate.annotations.UpdateTimestamp;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+
+@Entity
+@Table(
+        name = "stored_files",
+        indexes = {
+            @Index(name = "idx_stored_files_owner", columnList = "owner_id"),
+            @Index(name = "idx_stored_files_workflow", columnList = "workflow_session_id")
+        })
+@NoArgsConstructor
+@Getter
+@Setter
+public class StoredFile implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "stored_file_id")
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "owner_id", nullable = false)
+    private User owner;
+
+    @Column(name = "original_filename", nullable = false)
+    private String originalFilename;
+
+    @Column(name = "content_type")
+    private String contentType;
+
+    @Column(name = "size_bytes")
+    private long sizeBytes;
+
+    @Column(name = "storage_key", nullable = false, unique = true)
+    private String storageKey;
+
+    @Column(name = "history_filename")
+    private String historyFilename;
+
+    @Column(name = "history_content_type")
+    private String historyContentType;
+
+    @Column(name = "history_size_bytes")
+    private Long historySizeBytes;
+
+    @Column(name = "history_storage_key", unique = true)
+    private String historyStorageKey;
+
+    @Column(name = "audit_log_filename")
+    private String auditLogFilename;
+
+    @Column(name = "audit_log_content_type")
+    private String auditLogContentType;
+
+    @Column(name = "audit_log_size_bytes")
+    private Long auditLogSizeBytes;
+
+    @Column(name = "audit_log_storage_key", unique = true)
+    private String auditLogStorageKey;
+
+    // Link to workflow if this file is part of a workflow
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "workflow_session_id")
+    private WorkflowSession workflowSession;
+
+    // Purpose classification
+    @Column(name = "file_purpose")
+    @Enumerated(EnumType.STRING)
+    private FilePurpose purpose;
+
+    @OneToMany(
+            mappedBy = "file",
+            fetch = FetchType.LAZY,
+            cascade = CascadeType.ALL,
+            orphanRemoval = true)
+    private Set<FileShare> shares = new HashSet<>();
+
+    @CreationTimestamp
+    @Column(name = "created_at", updatable = false)
+    private LocalDateTime createdAt;
+
+    @UpdateTimestamp
+    @Column(name = "updated_at")
+    private LocalDateTime updatedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/StoredFileBlob.java

@@ -0,0 +1,31 @@
+package stirling.software.proprietary.storage.model;
+
+import java.io.Serializable;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Lob;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Table(name = "stored_file_blobs")
+@NoArgsConstructor
+@Getter
+@Setter
+public class StoredFileBlob implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @Column(name = "storage_key", nullable = false, length = 128)
+    private String storageKey;
+
+    @Lob
+    @Column(name = "data", nullable = false, columnDefinition = "BYTEA")
+    private byte[] data;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/CreateShareLinkRequest.java

@@ -0,0 +1,12 @@
+package stirling.software.proprietary.storage.model.api;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@NoArgsConstructor
+public class CreateShareLinkRequest {
+    private String accessRole;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/ShareLinkAccessResponse.java

@@ -0,0 +1,14 @@
+package stirling.software.proprietary.storage.model.api;
+
+import java.time.LocalDateTime;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class ShareLinkAccessResponse {
+    private final String username;
+    private final String accessType;
+    private final LocalDateTime accessedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/ShareLinkMetadataResponse.java

@@ -0,0 +1,20 @@
+package stirling.software.proprietary.storage.model.api;
+
+import java.time.LocalDateTime;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class ShareLinkMetadataResponse {
+    private final String shareToken;
+    private final Long fileId;
+    private final String fileName;
+    private final String owner;
+    private final boolean ownedByCurrentUser;
+    private final String accessRole;
+    private final LocalDateTime createdAt;
+    private final LocalDateTime expiresAt;
+    private final LocalDateTime lastAccessedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/ShareLinkResponse.java

@@ -0,0 +1,15 @@
+package stirling.software.proprietary.storage.model.api;
+
+import java.time.LocalDateTime;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class ShareLinkResponse {
+    private final String token;
+    private final String accessRole;
+    private final LocalDateTime createdAt;
+    private final LocalDateTime expiresAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/ShareWithUserRequest.java

@@ -0,0 +1,13 @@
+package stirling.software.proprietary.storage.model.api;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@NoArgsConstructor
+public class ShareWithUserRequest {
+    private String username;
+    private String accessRole;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/SharedUserResponse.java

@@ -0,0 +1,11 @@
+package stirling.software.proprietary.storage.model.api;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class SharedUserResponse {
+    private final String username;
+    private final String accessRole;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/model/api/StoredFileResponse.java

@@ -0,0 +1,25 @@
+package stirling.software.proprietary.storage.model.api;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class StoredFileResponse {
+    private final Long id;
+    private final String fileName;
+    private final String contentType;
+    private final long sizeBytes;
+    private final String owner;
+    private final boolean ownedByCurrentUser;
+    private final String accessRole;
+    private final LocalDateTime createdAt;
+    private final LocalDateTime updatedAt;
+    private final List<String> sharedWithUsers;
+    private final List<SharedUserResponse> sharedUsers;
+    private final List<ShareLinkResponse> shareLinks;
+    private final String filePurpose;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/provider/DatabaseStorageProvider.java

@@ -0,0 +1,53 @@
+package stirling.software.proprietary.storage.provider;
+
+import java.io.IOException;
+import java.util.UUID;
+
+import org.springframework.core.io.ByteArrayResource;
+import org.springframework.core.io.Resource;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.StoredFileBlob;
+import stirling.software.proprietary.storage.repository.StoredFileBlobRepository;
+
+@RequiredArgsConstructor
+public class DatabaseStorageProvider implements StorageProvider {
+
+    private final StoredFileBlobRepository storedFileBlobRepository;
+
+    @Override
+    public StoredObject store(User owner, MultipartFile file) throws IOException {
+        String storageKey = UUID.randomUUID().toString();
+        StoredFileBlob blob = new StoredFileBlob();
+        blob.setStorageKey(storageKey);
+        blob.setData(file.getBytes());
+        storedFileBlobRepository.save(blob);
+
+        return StoredObject.builder()
+                .storageKey(storageKey)
+                .originalFilename(file.getOriginalFilename())
+                .contentType(file.getContentType())
+                .sizeBytes(file.getSize())
+                .build();
+    }
+
+    @Override
+    public Resource load(String storageKey) throws IOException {
+        StoredFileBlob blob =
+                storedFileBlobRepository
+                        .findById(storageKey)
+                        .orElseThrow(() -> new IOException("File not found"));
+        return new ByteArrayResource(blob.getData());
+    }
+
+    @Override
+    public void delete(String storageKey) throws IOException {
+        if (!storedFileBlobRepository.existsById(storageKey)) {
+            return;
+        }
+        storedFileBlobRepository.deleteById(storageKey);
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/provider/LocalStorageProvider.java

@@ -0,0 +1,82 @@
+package stirling.software.proprietary.storage.provider;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import java.util.Optional;
+import java.util.UUID;
+
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.io.Resource;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.proprietary.security.model.User;
+
+@RequiredArgsConstructor
+public class LocalStorageProvider implements StorageProvider {
+
+    private final Path basePath;
+
+    @Override
+    public StoredObject store(User owner, MultipartFile file) throws IOException {
+        String originalFilename = sanitizeFilename(file.getOriginalFilename());
+        String storageKey =
+                owner.getId()
+                        + "/"
+                        + UUID.randomUUID()
+                        + "_"
+                        + Optional.ofNullable(originalFilename).orElse("file");
+        Path targetPath = basePath.resolve(storageKey).normalize();
+
+        if (!targetPath.startsWith(basePath)) {
+            throw new IOException("Resolved storage path is outside the storage directory");
+        }
+
+        Files.createDirectories(targetPath.getParent());
+        try (InputStream inputStream = file.getInputStream()) {
+            Files.copy(inputStream, targetPath, StandardCopyOption.REPLACE_EXISTING);
+        }
+
+        return StoredObject.builder()
+                .storageKey(storageKey)
+                .originalFilename(originalFilename)
+                .contentType(file.getContentType())
+                .sizeBytes(file.getSize())
+                .build();
+    }
+
+    @Override
+    public Resource load(String storageKey) throws IOException {
+        Path targetPath = basePath.resolve(storageKey).normalize();
+        if (!targetPath.startsWith(basePath)) {
+            throw new IOException("Resolved storage path is outside the storage directory");
+        }
+
+        if (!Files.exists(targetPath)) {
+            throw new IOException("File not found");
+        }
+
+        return new FileSystemResource(targetPath.toFile());
+    }
+
+    @Override
+    public void delete(String storageKey) throws IOException {
+        Path targetPath = basePath.resolve(storageKey).normalize();
+        if (!targetPath.startsWith(basePath)) {
+            throw new IOException("Resolved storage path is outside the storage directory");
+        }
+        Files.deleteIfExists(targetPath);
+    }
+
+    private String sanitizeFilename(String filename) {
+        if (filename == null || filename.isBlank()) {
+            return "file";
+        }
+        return Paths.get(filename).getFileName().toString();
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/provider/StorageProvider.java

@@ -0,0 +1,16 @@
+package stirling.software.proprietary.storage.provider;
+
+import java.io.IOException;
+
+import org.springframework.core.io.Resource;
+import org.springframework.web.multipart.MultipartFile;
+
+import stirling.software.proprietary.security.model.User;
+
+public interface StorageProvider {
+    StoredObject store(User owner, MultipartFile file) throws IOException;
+
+    Resource load(String storageKey) throws IOException;
+
+    void delete(String storageKey) throws IOException;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/provider/StoredObject.java

@@ -0,0 +1,13 @@
+package stirling.software.proprietary.storage.provider;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class StoredObject {
+    private final String storageKey;
+    private final String originalFilename;
+    private final String contentType;
+    private final long sizeBytes;
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/repository/FileShareAccessRepository.java

@@ -0,0 +1,34 @@
+package stirling.software.proprietary.storage.repository;
+
+import java.util.List;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.FileShare;
+import stirling.software.proprietary.storage.model.FileShareAccess;
+
+public interface FileShareAccessRepository extends JpaRepository<FileShareAccess, Long> {
+    @Query(
+            "SELECT a FROM FileShareAccess a "
+                    + "LEFT JOIN FETCH a.user "
+                    + "WHERE a.fileShare = :fileShare "
+                    + "ORDER BY a.accessedAt DESC")
+    List<FileShareAccess> findByFileShareWithUserOrderByAccessedAtDesc(
+            @Param("fileShare") FileShare fileShare);
+
+    void deleteByFileShare(FileShare fileShare);
+
+    void deleteByUser(User user);
+
+    @Query(
+            "SELECT a FROM FileShareAccess a "
+                    + "JOIN FETCH a.fileShare s "
+                    + "JOIN FETCH s.file f "
+                    + "LEFT JOIN FETCH f.owner "
+                    + "WHERE a.user = :user "
+                    + "ORDER BY a.accessedAt DESC")
+    List<FileShareAccess> findByUserWithShareAndFile(@Param("user") User user);
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/repository/FileShareRepository.java

@@ -0,0 +1,39 @@
+package stirling.software.proprietary.storage.repository;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.FileShare;
+import stirling.software.proprietary.storage.model.StoredFile;
+
+public interface FileShareRepository extends JpaRepository<FileShare, Long> {
+    Optional<FileShare> findByFileAndSharedWithUser(StoredFile file, User sharedWithUser);
+
+    Optional<FileShare> findByShareToken(String shareToken);
+
+    @Query(
+            "SELECT s FROM FileShare s "
+                    + "JOIN FETCH s.file f "
+                    + "LEFT JOIN FETCH f.owner "
+                    + "WHERE s.shareToken = :shareToken")
+    Optional<FileShare> findByShareTokenWithFile(@Param("shareToken") String shareToken);
+
+    @Query("SELECT s FROM FileShare s WHERE s.file = :file AND s.shareToken IS NOT NULL")
+    List<FileShare> findShareLinks(@Param("file") StoredFile file);
+
+    List<FileShare> findBySharedWithUser(User sharedWithUser);
+
+    List<FileShare> findByExpiresAtBeforeAndShareTokenNotNull(java.time.LocalDateTime now);
+
+    @Query(
+            "SELECT s FROM FileShare s "
+                    + "JOIN FETCH s.file f "
+                    + "WHERE s.sharedWithUser = :user AND f IN :files")
+    List<FileShare> findBySharedWithUserAndFileIn(
+            @Param("user") User user, @Param("files") List<StoredFile> files);
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/repository/StorageCleanupEntryRepository.java

@@ -0,0 +1,11 @@
+package stirling.software.proprietary.storage.repository;
+
+import java.util.List;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import stirling.software.proprietary.storage.model.StorageCleanupEntry;
+
+public interface StorageCleanupEntryRepository extends JpaRepository<StorageCleanupEntry, Long> {
+    List<StorageCleanupEntry> findTop50ByOrderByUpdatedAtAsc();
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/repository/StoredFileBlobRepository.java

@@ -0,0 +1,7 @@
+package stirling.software.proprietary.storage.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import stirling.software.proprietary.storage.model.StoredFileBlob;
+
+public interface StoredFileBlobRepository extends JpaRepository<StoredFileBlob, String> {}

app/proprietary/src/main/java/stirling/software/proprietary/storage/repository/StoredFileRepository.java

@@ -0,0 +1,69 @@
+package stirling.software.proprietary.storage.repository;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.transaction.annotation.Transactional;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.StoredFile;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+
+public interface StoredFileRepository extends JpaRepository<StoredFile, Long> {
+    Optional<StoredFile> findByIdAndOwner(Long id, User owner);
+
+    @Query(
+            "SELECT DISTINCT f FROM StoredFile f "
+                    + "LEFT JOIN FETCH f.owner "
+                    + "LEFT JOIN FETCH f.shares s "
+                    + "LEFT JOIN FETCH s.sharedWithUser "
+                    + "WHERE f.id = :id AND f.owner = :owner")
+    Optional<StoredFile> findByIdAndOwnerWithShares(
+            @Param("id") Long id, @Param("owner") User owner);
+
+    @Query(
+            "SELECT DISTINCT f FROM StoredFile f "
+                    + "LEFT JOIN FETCH f.owner "
+                    + "LEFT JOIN FETCH f.shares s "
+                    + "LEFT JOIN FETCH s.sharedWithUser "
+                    + "WHERE f.id = :id")
+    Optional<StoredFile> findByIdWithShares(@Param("id") Long id);
+
+    @Query(
+            "SELECT DISTINCT f FROM StoredFile f "
+                    + "LEFT JOIN FETCH f.owner "
+                    + "LEFT JOIN FETCH f.shares s "
+                    + "LEFT JOIN FETCH s.sharedWithUser "
+                    + "WHERE f.owner = :user "
+                    + "OR s.sharedWithUser = :user")
+    List<StoredFile> findAccessibleFiles(@Param("user") User user);
+
+    @Query(
+            "SELECT COALESCE(SUM(f.sizeBytes + COALESCE(f.historySizeBytes, 0) "
+                    + "+ COALESCE(f.auditLogSizeBytes, 0)), 0) "
+                    + "FROM StoredFile f WHERE f.owner = :owner")
+    long sumStorageBytesByOwner(@Param("owner") User owner);
+
+    @Query(
+            "SELECT COALESCE(SUM(f.sizeBytes + COALESCE(f.historySizeBytes, 0) "
+                    + "+ COALESCE(f.auditLogSizeBytes, 0)), 0) "
+                    + "FROM StoredFile f")
+    long sumStorageBytesTotal();
+
+    /** Finds all files associated with a workflow session. */
+    List<StoredFile> findByWorkflowSession(WorkflowSession workflowSession);
+
+    List<StoredFile> findAllByOwner(User owner);
+
+    @Modifying
+    @Transactional
+    @Query(
+            "UPDATE StoredFile sf SET sf.workflowSession = null "
+                    + "WHERE sf.workflowSession IN "
+                    + "(SELECT ws FROM WorkflowSession ws WHERE ws.owner = :user)")
+    void clearWorkflowSessionReferencesByOwner(@Param("user") User user);
+}

app/proprietary/src/main/java/stirling/software/proprietary/storage/service/StorageCleanupService.java

@@ -0,0 +1,73 @@
+package stirling.software.proprietary.storage.service;
+
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.proprietary.storage.model.StorageCleanupEntry;
+import stirling.software.proprietary.storage.provider.StorageProvider;
+import stirling.software.proprietary.storage.repository.FileShareRepository;
+import stirling.software.proprietary.storage.repository.StorageCleanupEntryRepository;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class StorageCleanupService {
+
+    private static final int MAX_CLEANUP_ATTEMPTS = 10;
+
+    private final StorageProvider storageProvider;
+    private final StorageCleanupEntryRepository cleanupEntryRepository;
+    private final FileShareRepository fileShareRepository;
+
+    @Scheduled(fixedDelay = 1, timeUnit = TimeUnit.DAYS)
+    public void cleanupOrphanedStorage() {
+        List<StorageCleanupEntry> entries = cleanupEntryRepository.findTop50ByOrderByUpdatedAtAsc();
+        if (entries.isEmpty()) {
+            return;
+        }
+        for (StorageCleanupEntry entry : entries) {
+            try {
+                storageProvider.delete(entry.getStorageKey());
+                cleanupEntryRepository.delete(entry);
+            } catch (IOException ex) {
+                int attempts = entry.getAttemptCount() + 1;
+                if (attempts >= MAX_CLEANUP_ATTEMPTS) {
+                    log.error(
+                            "Abandoning cleanup for storage key {} after {} failed attempts."
+                                    + " The blob may be orphaned and require manual removal.",
+                            entry.getStorageKey(),
+                            attempts,
+                            ex);
+                    cleanupEntryRepository.delete(entry);
+                } else {
+                    entry.setAttemptCount(attempts);
+                    cleanupEntryRepository.save(entry);
+                    log.warn(
+                            "Failed to cleanup storage key {} (attempt {}/{})",
+                            entry.getStorageKey(),
+                            attempts,
+                            MAX_CLEANUP_ATTEMPTS,
+                            ex);
+                }
+            }
+        }
+    }
+
+    @Scheduled(fixedDelay = 1, timeUnit = TimeUnit.DAYS)
+    public void cleanupExpiredShareLinks() {
+        List<stirling.software.proprietary.storage.model.FileShare> expired =
+                fileShareRepository.findByExpiresAtBeforeAndShareTokenNotNull(LocalDateTime.now());
+        if (expired.isEmpty()) {
+            return;
+        }
+        fileShareRepository.deleteAll(expired);
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/controller/SigningSessionController.java

@@ -0,0 +1,408 @@
+package stirling.software.proprietary.workflow.controller;
+
+import java.security.Principal;
+import java.util.List;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import jakarta.validation.constraints.NotBlank;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.SPDF.config.swagger.StandardPdfResponse;
+import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.WebResponseUtils;
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.security.service.UserService;
+import stirling.software.proprietary.workflow.dto.ParticipantRequest;
+import stirling.software.proprietary.workflow.dto.WorkflowCreationRequest;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+import stirling.software.proprietary.workflow.service.SigningFinalizationService;
+import stirling.software.proprietary.workflow.service.WorkflowSessionService;
+
+@Slf4j
+@RestController
+@RequestMapping("/api/v1/security")
+@Tag(name = "Security", description = "Security APIs - Signing Workflows")
+@RequiredArgsConstructor
+public class SigningSessionController {
+
+    private final WorkflowSessionService workflowSessionService;
+    private final UserService userService;
+    private final SigningFinalizationService signingFinalizationService;
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Operation(summary = "List all signing sessions for current user")
+    @Transactional(readOnly = true)
+    @GetMapping(value = "/cert-sign/sessions")
+    public ResponseEntity<?> listSessions(Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User user = getCurrentUser(principal);
+            List<stirling.software.proprietary.workflow.model.WorkflowSession> sessions =
+                    workflowSessionService.listUserSessions(user);
+            List<stirling.software.proprietary.workflow.dto.WorkflowSessionResponse> responses =
+                    sessions.stream()
+                            .map(
+                                    stirling.software.proprietary.workflow.util.WorkflowMapper
+                                            ::toResponse)
+                            .collect(java.util.stream.Collectors.toList());
+            return ResponseEntity.ok(responses);
+        } catch (Exception e) {
+            log.error("Error listing sessions for user {}", principal.getName(), e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("Error listing sessions");
+        }
+    }
+
+    @PostMapping(
+            consumes = {MediaType.MULTIPART_FORM_DATA_VALUE},
+            value = "/cert-sign/sessions",
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    @Operation(
+            summary = "Create a shared signing session",
+            description =
+                    "Starts a collaboration session, distributes share links, and optionally notifies"
+                            + " participants. Input:PDF Output:JSON Type:SISO")
+    public ResponseEntity<?> createSession(
+            @org.springframework.web.bind.annotation.RequestParam("file")
+                    org.springframework.web.multipart.MultipartFile file,
+            @ModelAttribute WorkflowCreationRequest request,
+            Principal principal)
+            throws Exception {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+
+        try {
+            User owner = getCurrentUser(principal);
+            WorkflowSession session = workflowSessionService.createSession(owner, file, request);
+            return ResponseEntity.ok(
+                    stirling.software.proprietary.workflow.util.WorkflowMapper.toResponse(session));
+        } catch (Exception e) {
+            log.error("Error creating signing session", e);
+            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Fetch signing session details")
+    @Transactional(readOnly = true)
+    @GetMapping(value = "/cert-sign/sessions/{sessionId}")
+    public ResponseEntity<?> getSession(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            WorkflowSession session = workflowSessionService.getSessionForOwner(sessionId, owner);
+            // Include wet signatures in response for owner preview
+            return ResponseEntity.ok(
+                    stirling.software.proprietary.workflow.util.WorkflowMapper.toResponse(
+                            session, objectMapper));
+        } catch (Exception e) {
+            log.error("Error fetching session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Access denied or session not found");
+        }
+    }
+
+    @Operation(summary = "Delete a signing session")
+    @DeleteMapping(value = "/cert-sign/sessions/{sessionId}")
+    public ResponseEntity<?> deleteSession(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            workflowSessionService.deleteSession(sessionId, owner);
+            return ResponseEntity.noContent().build();
+        } catch (Exception e) {
+            log.error("Error deleting session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Cannot delete session: " + e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Add participants to an existing session")
+    @PostMapping(value = "/cert-sign/sessions/{sessionId}/participants")
+    public ResponseEntity<?> addParticipants(
+            @PathVariable("sessionId") @NotBlank String sessionId,
+            @RequestBody List<ParticipantRequest> participants,
+            Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            workflowSessionService.addParticipants(sessionId, participants, owner);
+            WorkflowSession session =
+                    workflowSessionService.getSessionWithParticipantsForOwner(sessionId, owner);
+            return ResponseEntity.ok(
+                    stirling.software.proprietary.workflow.util.WorkflowMapper.toResponse(session));
+        } catch (Exception e) {
+            log.error("Error adding participants to session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Cannot add participants: " + e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Remove a participant from a session")
+    @DeleteMapping(value = "/cert-sign/sessions/{sessionId}/participants/{participantId}")
+    public ResponseEntity<?> removeParticipant(
+            @PathVariable("sessionId") @NotBlank String sessionId,
+            @PathVariable("participantId") Long participantId,
+            Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            workflowSessionService.removeParticipant(sessionId, participantId, owner);
+            return ResponseEntity.noContent().build();
+        } catch (Exception e) {
+            log.error("Error removing participant {} from session {}", participantId, sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Cannot remove participant: " + e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Get session PDF for participant view")
+    @GetMapping(value = "/cert-sign/sessions/{sessionId}/pdf")
+    public ResponseEntity<byte[]> getSessionPdf(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            workflowSessionService.getSessionForOwner(sessionId, owner);
+            byte[] pdfBytes = workflowSessionService.getOriginalFile(sessionId);
+            return WebResponseUtils.bytesToWebResponse(pdfBytes, "document.pdf");
+        } catch (Exception e) {
+            log.error("Error fetching PDF for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
+        }
+    }
+
+    @PostMapping(value = "/cert-sign/sessions/{sessionId}/finalize")
+    @Operation(
+            summary = "Finalize signing session",
+            description =
+                    "Applies collected wet signatures and digital certificates, then returns the"
+                            + " signed document.")
+    @StandardPdfResponse
+    public ResponseEntity<byte[]> finalizeSession(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal)
+            throws Exception {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        }
+
+        try {
+            User owner = getCurrentUser(principal);
+            WorkflowSession session =
+                    workflowSessionService.getSessionWithParticipantsForOwner(sessionId, owner);
+
+            byte[] originalPdf = workflowSessionService.getOriginalFile(sessionId);
+            byte[] pdf = signingFinalizationService.finalizeDocument(session, originalPdf);
+
+            String filename = session.getDocumentName().replace(".pdf", "") + "_shared_signed.pdf";
+            workflowSessionService.storeProcessedFile(session, pdf, filename);
+            workflowSessionService.finalizeSession(sessionId, owner);
+            workflowSessionService.deleteOriginalFile(session);
+
+            try {
+                signingFinalizationService.clearSensitiveMetadata(session);
+            } catch (Exception e) {
+                log.error(
+                        "SECURITY: Failed to clear sensitive metadata for session {} "
+                                + "(participants: {}). Keystore credentials may remain in the "
+                                + "database until manual cleanup.",
+                        sessionId,
+                        session.getParticipants() != null
+                                ? session.getParticipants().stream().map(p -> p.getEmail()).toList()
+                                : "unknown",
+                        e);
+                throw new ResponseStatusException(
+                        HttpStatus.INTERNAL_SERVER_ERROR,
+                        "Document signed successfully but post-signing cleanup failed. "
+                                + "Contact your administrator to complete the cleanup.");
+            }
+
+            return WebResponseUtils.bytesToWebResponse(pdf, filename);
+        } catch (Exception e) {
+            log.error("Error finalizing session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
+        }
+    }
+
+    @Operation(summary = "Get signed PDF from finalized session")
+    @GetMapping(value = "/cert-sign/sessions/{sessionId}/signed-pdf")
+    @StandardPdfResponse
+    public ResponseEntity<byte[]> getSignedPdf(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        }
+        try {
+            User owner = getCurrentUser(principal);
+            byte[] signedPdf = workflowSessionService.getProcessedFile(sessionId, owner);
+            if (signedPdf == null) {
+                return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                        .body("Session not finalized".getBytes());
+            }
+            WorkflowSession session = workflowSessionService.getSessionForOwner(sessionId, owner);
+            return WebResponseUtils.bytesToWebResponse(
+                    signedPdf,
+                    GeneralUtils.generateFilename(session.getDocumentName(), "_shared_signed.pdf"));
+        } catch (Exception e) {
+            log.error("Error fetching signed PDF for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
+        }
+    }
+
+    // ===== SIGN REQUESTS (Participant View) =====
+
+    @Operation(summary = "List sign requests for authenticated user")
+    @Transactional(readOnly = true)
+    @GetMapping(value = "/cert-sign/sign-requests")
+    public ResponseEntity<?> listSignRequests(Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User user = getCurrentUser(principal);
+            return ResponseEntity.ok(workflowSessionService.listSignRequests(user));
+        } catch (Exception e) {
+            log.error("Error listing sign requests for user {}", principal.getName(), e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("Cannot list sign requests: " + e.getMessage());
+        }
+    }
+
+    @Transactional(readOnly = true)
+    @Operation(summary = "Get sign request detail for participant")
+    @GetMapping(value = "/cert-sign/sign-requests/{sessionId}")
+    public ResponseEntity<?> getSignRequestDetail(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User user = getCurrentUser(principal);
+            return ResponseEntity.ok(workflowSessionService.getSignRequestDetail(sessionId, user));
+        } catch (Exception e) {
+            log.error("Error fetching sign request detail for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Access denied or sign request not found: " + e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Get document for sign request")
+    @GetMapping(value = "/cert-sign/sign-requests/{sessionId}/document")
+    public ResponseEntity<byte[]> getSignRequestDocument(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
+        }
+        try {
+            User user = getCurrentUser(principal);
+            byte[] document = workflowSessionService.getSignRequestDocument(sessionId, user);
+            return WebResponseUtils.bytesToWebResponse(document, "document.pdf");
+        } catch (Exception e) {
+            log.error("Error fetching document for sign request {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
+        }
+    }
+
+    @Operation(summary = "Sign a document with certificate and optional wet signature")
+    @PostMapping(
+            value = "/cert-sign/sign-requests/{sessionId}/sign",
+            consumes = {
+                MediaType.MULTIPART_FORM_DATA_VALUE,
+                MediaType.APPLICATION_FORM_URLENCODED_VALUE
+            })
+    public ResponseEntity<?> signDocument(
+            @PathVariable("sessionId") @NotBlank String sessionId,
+            @ModelAttribute stirling.software.proprietary.workflow.dto.SignDocumentRequest request,
+            Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User user = getCurrentUser(principal);
+            workflowSessionService.signDocument(sessionId, user, request);
+            return ResponseEntity.noContent().build();
+        } catch (IllegalArgumentException e) {
+            log.error("Invalid sign request for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(e.getMessage());
+        } catch (Exception e) {
+            log.error("Error signing document for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("Cannot sign document: " + e.getMessage());
+        }
+    }
+
+    @Operation(summary = "Decline a sign request")
+    @PostMapping(value = "/cert-sign/sign-requests/{sessionId}/decline")
+    public ResponseEntity<?> declineSignRequest(
+            @PathVariable("sessionId") @NotBlank String sessionId, Principal principal) {
+        workflowSessionService.ensureSigningEnabled();
+        if (principal == null) {
+            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body("Authentication required");
+        }
+        try {
+            User user = getCurrentUser(principal);
+            workflowSessionService.declineSignRequest(sessionId, user);
+            return ResponseEntity.noContent().build();
+        } catch (Exception e) {
+            log.error("Error declining sign request for session {}", sessionId, e);
+            return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                    .body("Cannot decline sign request: " + e.getMessage());
+        }
+    }
+
+    // ===== HELPER METHODS =====
+
+    private User getCurrentUser(Principal principal) {
+        return userService
+                .findByUsernameIgnoreCase(principal.getName())
+                .orElseThrow(
+                        () -> new ResponseStatusException(HttpStatus.UNAUTHORIZED, "Unauthorized"));
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/controller/WorkflowParticipantController.java

@@ -0,0 +1,328 @@
+package stirling.software.proprietary.workflow.controller;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.http.ContentDisposition;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.proprietary.workflow.dto.ParticipantResponse;
+import stirling.software.proprietary.workflow.dto.SignatureSubmissionRequest;
+import stirling.software.proprietary.workflow.dto.WetSignatureMetadata;
+import stirling.software.proprietary.workflow.dto.WorkflowSessionResponse;
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+import stirling.software.proprietary.workflow.model.WorkflowParticipant;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+import stirling.software.proprietary.workflow.repository.WorkflowParticipantRepository;
+import stirling.software.proprietary.workflow.service.MetadataEncryptionService;
+import stirling.software.proprietary.workflow.service.WorkflowSessionService;
+import stirling.software.proprietary.workflow.util.WorkflowMapper;
+
+import tools.jackson.core.type.TypeReference;
+import tools.jackson.databind.ObjectMapper;
+
+/**
+ * REST controller for workflow participant actions. Handles participant-facing operations like
+ * viewing sessions, submitting signatures, and updating participant status.
+ *
+ * <p>Access is controlled via share tokens, not requiring authentication.
+ */
+@Slf4j
+@RestController
+@RequestMapping("/api/v1/workflow/participant")
+@Tag(name = "Workflow Participant", description = "Participant Action APIs")
+@RequiredArgsConstructor
+public class WorkflowParticipantController {
+
+    private final WorkflowSessionService workflowSessionService;
+    private final WorkflowParticipantRepository participantRepository;
+    private final ObjectMapper objectMapper;
+    private final MetadataEncryptionService metadataEncryptionService;
+
+    @Operation(
+            summary = "Get workflow session details by participant token",
+            description = "Allows participants to view session details using their share token")
+    @GetMapping(value = "/session", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<WorkflowSessionResponse> getSessionByToken(
+            @RequestParam("token") @NotBlank String token) {
+
+        workflowSessionService.ensureSigningEnabled();
+
+        WorkflowParticipant participant =
+                participantRepository
+                        .findByShareToken(token)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.FORBIDDEN,
+                                                "Invalid or expired participant token"));
+
+        // Check if participant is expired
+        if (participant.isExpired()) {
+            throw new ResponseStatusException(HttpStatus.FORBIDDEN, "Participant access expired");
+        }
+
+        // Mark as viewed if not already
+        if (participant.getStatus() == ParticipantStatus.PENDING
+                || participant.getStatus() == ParticipantStatus.NOTIFIED) {
+            workflowSessionService.updateParticipantStatus(
+                    participant.getId(), ParticipantStatus.VIEWED);
+        }
+
+        WorkflowSession session = participant.getWorkflowSession();
+        return ResponseEntity.ok(WorkflowMapper.toResponse(session));
+    }
+
+    @Operation(
+            summary = "Get participant details by token",
+            description = "Returns participant-specific information")
+    @GetMapping(value = "/details", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<ParticipantResponse> getParticipantDetails(
+            @RequestParam("token") @NotBlank String token) {
+
+        workflowSessionService.ensureSigningEnabled();
+
+        WorkflowParticipant participant =
+                participantRepository
+                        .findByShareToken(token)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.FORBIDDEN,
+                                                "Invalid or expired participant token"));
+
+        return ResponseEntity.ok(WorkflowMapper.toParticipantResponse(participant));
+    }
+
+    @Operation(
+            summary = "Submit signature (wet signature and/or certificate)",
+            description =
+                    "Participants submit their signature data and certificate information for signing")
+    @PostMapping(
+            value = "/submit-signature",
+            consumes = MediaType.MULTIPART_FORM_DATA_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<ParticipantResponse> submitSignature(
+            @ModelAttribute SignatureSubmissionRequest request) {
+
+        workflowSessionService.ensureSigningEnabled();
+
+        if (request.getParticipantToken() == null || request.getParticipantToken().isBlank()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Participant token is required");
+        }
+
+        WorkflowParticipant participant =
+                participantRepository
+                        .findByShareToken(request.getParticipantToken())
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.FORBIDDEN,
+                                                "Invalid or expired participant token"));
+
+        // Check if participant can still submit
+        if (participant.isExpired()) {
+            throw new ResponseStatusException(HttpStatus.FORBIDDEN, "Participant access expired");
+        }
+
+        if (participant.hasCompleted()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Participant has already completed their action");
+        }
+
+        if (!participant.getWorkflowSession().isActive()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Workflow session is no longer active");
+        }
+
+        try {
+            // Build metadata map with certificate and wet signature data
+            Map<String, Object> metadata = buildSubmissionMetadata(request);
+            participant.setParticipantMetadata(metadata);
+
+            // Update status to SIGNED
+            participant.setStatus(ParticipantStatus.SIGNED);
+            participant = participantRepository.save(participant);
+
+            log.info(
+                    "Participant {} submitted signature for session {}",
+                    participant.getEmail(),
+                    participant.getWorkflowSession().getSessionId());
+
+            return ResponseEntity.ok(WorkflowMapper.toParticipantResponse(participant));
+
+        } catch (Exception e) {
+            log.error("Error submitting signature for participant {}", participant.getEmail(), e);
+            throw new ResponseStatusException(
+                    HttpStatus.INTERNAL_SERVER_ERROR, "Failed to submit signature", e);
+        }
+    }
+
+    @Operation(
+            summary = "Decline participation",
+            description = "Participant declines to sign or participate in the workflow")
+    @PostMapping(value = "/decline", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<ParticipantResponse> declineParticipation(
+            @RequestParam("token") @NotBlank String token,
+            @RequestParam(value = "reason", required = false) @Size(max = 500) String reason) {
+
+        workflowSessionService.ensureSigningEnabled();
+
+        WorkflowParticipant participant =
+                participantRepository
+                        .findByShareToken(token)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.FORBIDDEN,
+                                                "Invalid or expired participant token"));
+
+        if (participant.hasCompleted()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Participant has already completed their action");
+        }
+
+        // Update status to DECLINED
+        participant.setStatus(ParticipantStatus.DECLINED);
+
+        // Add decline reason to notifications
+        if (reason != null && !reason.isBlank()) {
+            workflowSessionService.addParticipantNotification(
+                    participant.getId(), "Declined: " + reason);
+        } else {
+            workflowSessionService.addParticipantNotification(
+                    participant.getId(), "Declined participation");
+        }
+
+        participant = participantRepository.save(participant);
+
+        log.info(
+                "Participant {} declined workflow session {}",
+                participant.getEmail(),
+                participant.getWorkflowSession().getSessionId());
+
+        return ResponseEntity.ok(WorkflowMapper.toParticipantResponse(participant));
+    }
+
+    @Operation(
+            summary = "Get original PDF for review",
+            description = "Participant downloads the original document")
+    @GetMapping(value = "/document", produces = MediaType.APPLICATION_PDF_VALUE)
+    public ResponseEntity<byte[]> getDocument(@RequestParam("token") @NotBlank String token) {
+
+        workflowSessionService.ensureSigningEnabled();
+
+        WorkflowParticipant participant =
+                participantRepository
+                        .findByShareToken(token)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.FORBIDDEN,
+                                                "Invalid or expired participant token"));
+
+        if (participant.isExpired()) {
+            throw new ResponseStatusException(HttpStatus.FORBIDDEN, "Participant access expired");
+        }
+
+        try {
+            WorkflowSession session = participant.getWorkflowSession();
+            byte[] pdf = workflowSessionService.getOriginalFile(session.getSessionId());
+
+            return ResponseEntity.ok()
+                    .header(
+                            HttpHeaders.CONTENT_DISPOSITION,
+                            ContentDisposition.attachment()
+                                    .filename(session.getDocumentName(), StandardCharsets.UTF_8)
+                                    .build()
+                                    .toString())
+                    .contentType(org.springframework.http.MediaType.APPLICATION_PDF)
+                    .body(pdf);
+
+        } catch (IOException e) {
+            log.error("Error retrieving document for participant", e);
+            throw new ResponseStatusException(
+                    HttpStatus.INTERNAL_SERVER_ERROR, "Failed to retrieve document", e);
+        }
+    }
+
+    /**
+     * Builds metadata map from signature submission request. Includes certificate submission and
+     * wet signature data.
+     */
+    private Map<String, Object> buildSubmissionMetadata(SignatureSubmissionRequest request)
+            throws IOException {
+        Map<String, Object> metadata = new HashMap<>();
+
+        // Add certificate submission if provided
+        if (request.getCertType() != null) {
+            Map<String, Object> certSubmission = new HashMap<>();
+            certSubmission.put("certType", request.getCertType());
+            certSubmission.put(
+                    "password", metadataEncryptionService.encrypt(request.getPassword()));
+            certSubmission.put("showSignature", request.getShowSignature());
+            certSubmission.put("pageNumber", request.getPageNumber());
+            certSubmission.put("location", request.getLocation());
+            certSubmission.put("reason", request.getReason());
+            certSubmission.put("showLogo", request.getShowLogo());
+
+            // Store certificate files as base64
+            if (request.getP12File() != null && !request.getP12File().isEmpty()) {
+                certSubmission.put(
+                        "p12Keystore",
+                        java.util.Base64.getEncoder()
+                                .encodeToString(request.getP12File().getBytes()));
+            }
+            if (request.getJksFile() != null && !request.getJksFile().isEmpty()) {
+                certSubmission.put(
+                        "jksKeystore",
+                        java.util.Base64.getEncoder()
+                                .encodeToString(request.getJksFile().getBytes()));
+            }
+
+            metadata.put("certificateSubmission", certSubmission);
+        }
+
+        // Add wet signatures data if provided - parse once and store as List directly
+        if (request.getWetSignaturesData() != null && !request.getWetSignaturesData().isBlank()) {
+            if (request.getWetSignaturesData().length() > 5 * 1024 * 1024) {
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST, "Wet signatures data exceeds maximum allowed size");
+            }
+            @SuppressWarnings("unchecked")
+            java.util.List<Map<String, Object>> wetSigs =
+                    objectMapper.readValue(
+                            request.getWetSignaturesData(),
+                            new TypeReference<java.util.List<Map<String, Object>>>() {});
+            if (wetSigs.size() > WetSignatureMetadata.MAX_SIGNATURES_PER_PARTICIPANT) {
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST, "Too many wet signatures submitted");
+            }
+            metadata.put("wetSignatures", wetSigs);
+        }
+
+        return metadata;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/CertificateSubmission.java

@@ -0,0 +1,46 @@
+package stirling.software.proprietary.workflow.dto;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+/**
+ * Certificate submission details extracted from a participant's stored metadata. Contains the
+ * certificate type, optional keystore bytes (decoded from base64), password, and per-participant
+ * signature appearance overrides.
+ */
+@Getter
+@Setter
+@NoArgsConstructor
+public class CertificateSubmission {
+
+    /** Certificate type: P12, JKS, SERVER, or USER_CERT */
+    private String certType;
+
+    /**
+     * Keystore password. Stored encrypted at rest; decrypted by MetadataEncryptionService before
+     * use. Cleared from the database after finalization.
+     */
+    private String password;
+
+    /** PKCS12 keystore bytes, decoded from the base64 stored in participant metadata. */
+    private byte[] p12Keystore;
+
+    /** JKS keystore bytes, decoded from the base64 stored in participant metadata. */
+    private byte[] jksKeystore;
+
+    /** Whether to show a visible digital signature block on the page. */
+    private Boolean showSignature;
+
+    /** 1-indexed page number for the digital signature block (session-level default). */
+    private Integer pageNumber;
+
+    /** Participant's location when signing (included in digital signature metadata). */
+    private String location;
+
+    /** Participant's reason for signing (included in digital signature metadata). */
+    private String reason;
+
+    /** Whether to show the Stirling logo in the digital signature block. */
+    private Boolean showLogo;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/ParticipantRequest.java

@@ -0,0 +1,43 @@
+package stirling.software.proprietary.workflow.dto;
+
+import java.time.LocalDateTime;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.storage.model.ShareAccessRole;
+
+/**
+ * Request DTO for adding or configuring a workflow participant. Supports both registered users and
+ * external email participants.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class ParticipantRequest {
+
+    /** User ID if participant is a registered user */
+    private Long userId;
+
+    /** Email address (required for external users, optional for registered users) */
+    private String email;
+
+    /** Display name for the participant */
+    private String name;
+
+    /** Access role for the participant (EDITOR, COMMENTER, VIEWER) */
+    private ShareAccessRole accessRole;
+
+    /** Optional expiration timestamp for participant access */
+    private LocalDateTime expiresAt;
+
+    /** Participant-specific metadata (JSON string) */
+    private String participantMetadata;
+
+    /** Whether to send notification immediately */
+    private boolean sendNotification = true;
+
+    /** Owner-set default reason for this participant's signature */
+    private String defaultReason;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/ParticipantResponse.java

@@ -0,0 +1,34 @@
+package stirling.software.proprietary.workflow.dto;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.storage.model.ShareAccessRole;
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+
+/**
+ * Response DTO for workflow participant details. Used in API responses to provide participant
+ * information.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class ParticipantResponse {
+
+    private Long id;
+    private Long userId;
+    private String email;
+    private String name;
+    private ParticipantStatus status;
+    private String shareToken;
+    private ShareAccessRole accessRole;
+    private LocalDateTime expiresAt;
+    private LocalDateTime lastUpdated;
+    private boolean hasCompleted;
+    private boolean isExpired;
+    private List<WetSignatureMetadata> wetSignatures;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/SignDocumentRequest.java

@@ -0,0 +1,72 @@
+package stirling.software.proprietary.workflow.dto;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Request object for signing a document. Combines certificate submission data with optional wet
+ * signature (visual signature) metadata. Supports multiple wet signatures.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class SignDocumentRequest {
+
+    // Certificate-related fields
+    @NotNull(message = "Certificate type is required")
+    @Pattern(
+            regexp = "SERVER|USER_CERT|UPLOAD|PEM|PKCS12|PFX|JKS",
+            message = "Invalid certificate type")
+    private String certType;
+
+    private MultipartFile p12File;
+    private String password;
+    private MultipartFile privateKeyFile;
+    private MultipartFile certFile;
+
+    // Signature metadata (participant can override owner defaults)
+    private String reason; // Participant's reason for signing
+    private String location; // Participant's location when signing
+
+    // Wet signatures as JSON string (from frontend FormData)
+    private String wetSignaturesData;
+
+    // Parsed wet signatures (populated by controller/service)
+    private List<WetSignatureMetadata> wetSignatures;
+
+    /**
+     * Checks if this request includes wet signature metadata.
+     *
+     * @return true if wet signatures list is not empty
+     */
+    public boolean hasWetSignatures() {
+        return wetSignatures != null && !wetSignatures.isEmpty();
+    }
+
+    /**
+     * Extracts and validates wet signature metadata.
+     *
+     * @return List of validated WetSignatureMetadata objects
+     */
+    public List<WetSignatureMetadata> extractWetSignatureMetadata() {
+        List<WetSignatureMetadata> signatures = new ArrayList<>();
+
+        if (hasWetSignatures()) {
+            for (WetSignatureMetadata signature : wetSignatures) {
+                signature.validate();
+                signatures.add(signature);
+            }
+        }
+
+        return signatures;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/SignRequestDetailDTO.java

@@ -0,0 +1,27 @@
+package stirling.software.proprietary.workflow.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+
+/** DTO for sign request detail (participant view) */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class SignRequestDetailDTO {
+    private String sessionId;
+    private String documentName;
+    private String ownerUsername;
+    private String message;
+    private String dueDate;
+    private String createdAt;
+    private ParticipantStatus myStatus;
+    // Signature appearance settings (read-only, configured by owner)
+    private Boolean showSignature;
+    private Integer pageNumber;
+    private String reason;
+    private String location;
+    private Boolean showLogo;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/SignRequestSummaryDTO.java

@@ -0,0 +1,20 @@
+package stirling.software.proprietary.workflow.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+
+/** DTO for sign request summary (participant view) */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class SignRequestSummaryDTO {
+    private String sessionId;
+    private String documentName;
+    private String ownerUsername;
+    private String createdAt;
+    private String dueDate;
+    private ParticipantStatus myStatus;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/SignatureSubmissionRequest.java

@@ -0,0 +1,34 @@
+package stirling.software.proprietary.workflow.dto;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Request DTO for submitting a signature (wet signature or certificate). Used when a participant
+ * completes their signing action. Supports multiple wet signatures.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class SignatureSubmissionRequest {
+
+    // Certificate submission fields
+    private String certType; // P12, JKS, SERVER, USER_CERT
+    private String password;
+    private MultipartFile p12File;
+    private MultipartFile jksFile;
+    private Boolean showSignature;
+    private Integer pageNumber;
+    private String location;
+    private String reason;
+    private Boolean showLogo;
+
+    // Wet signatures (JSON array string with coordinates and image data)
+    private String wetSignaturesData;
+
+    // Participant identification
+    private String participantToken;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/WetSignatureMetadata.java

@@ -0,0 +1,112 @@
+package stirling.software.proprietary.workflow.dto;
+
+import jakarta.validation.constraints.DecimalMax;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
+import jakarta.validation.constraints.Positive;
+import jakarta.validation.constraints.PositiveOrZero;
+import jakarta.validation.constraints.Size;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Data Transfer Object for wet signature (visual signature) metadata. Contains information about a
+ * signature annotation placed by a participant on the PDF. This data is used to overlay the
+ * signature on the PDF during finalization.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class WetSignatureMetadata {
+
+    /** Maximum number of wet signatures allowed per participant submission. */
+    public static final int MAX_SIGNATURES_PER_PARTICIPANT = 50;
+
+    /** Type of wet signature: "canvas" (drawn), "image" (uploaded), or "text" (typed) */
+    @NotNull(message = "Wet signature type is required")
+    @Pattern(
+            regexp = "canvas|image|text",
+            message = "Wet signature type must be canvas, image, or text")
+    private String type;
+
+    /**
+     * Base64-encoded image data or text content for the signature. For canvas/image types:
+     * data:image/png;base64,... format For text type: plain text string
+     */
+    @NotNull(message = "Wet signature data is required")
+    @Size(max = 5_000_000, message = "Wet signature data exceeds maximum size of 5MB")
+    private String data;
+
+    /** Zero-indexed page number where the signature is placed */
+    @NotNull(message = "Page number is required")
+    @PositiveOrZero(message = "Page number must be zero or positive")
+    private Integer page;
+
+    /** X position as a fraction (0–1) of page width, measured from left edge */
+    @NotNull(message = "X coordinate is required")
+    @PositiveOrZero(message = "X coordinate must be zero or positive")
+    @DecimalMax(value = "1.0", message = "X coordinate must not exceed 1.0 (page width)")
+    private Double x;
+
+    /**
+     * Y position as a fraction (0–1) of page height, measured from top edge. Note: This is UI
+     * coordinate system (top-left origin). Will be converted to PDF coordinate system (bottom-left
+     * origin) during overlay.
+     */
+    @NotNull(message = "Y coordinate is required")
+    @PositiveOrZero(message = "Y coordinate must be zero or positive")
+    @DecimalMax(value = "1.0", message = "Y coordinate must not exceed 1.0 (page height)")
+    private Double y;
+
+    /** Width of the signature rectangle as a fraction (0–1) of page width */
+    @NotNull(message = "Width is required")
+    @Positive(message = "Width must be positive")
+    @DecimalMax(value = "1.0", message = "Width must not exceed 1.0 (page width)")
+    private Double width;
+
+    /** Height of the signature rectangle as a fraction (0–1) of page height */
+    @NotNull(message = "Height is required")
+    @Positive(message = "Height must be positive")
+    @DecimalMax(value = "1.0", message = "Height must not exceed 1.0 (page height)")
+    private Double height;
+
+    /**
+     * Validates that the wet signature data is properly formatted based on type. For image types,
+     * ensures data starts with data:image prefix.
+     *
+     * @return true if validation passes
+     * @throws IllegalArgumentException if validation fails
+     */
+    public boolean validate() {
+        if (type.equals("canvas") || type.equals("image")) {
+            if (!data.startsWith("data:image/")) {
+                throw new IllegalArgumentException(
+                        "Image wet signature data must start with data:image/ prefix");
+            }
+        }
+        if (x != null && width != null && x + width > 1.0) {
+            throw new IllegalArgumentException(
+                    "Signature extends beyond the right edge of the page (x + width > 1.0)");
+        }
+        if (y != null && height != null && y + height > 1.0) {
+            throw new IllegalArgumentException(
+                    "Signature extends beyond the bottom edge of the page (y + height > 1.0)");
+        }
+        return true;
+    }
+
+    /**
+     * Extracts just the base64 data portion from a data URL. Removes the "data:image/png;base64,"
+     * prefix.
+     *
+     * @return pure base64 string without data URL prefix
+     */
+    public String extractBase64Data() {
+        if (data != null && data.contains(",")) {
+            return data.substring(data.indexOf(",") + 1);
+        }
+        return data;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/WorkflowCreationRequest.java

@@ -0,0 +1,43 @@
+package stirling.software.proprietary.workflow.dto;
+
+import java.util.List;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.workflow.model.WorkflowType;
+
+/**
+ * Request DTO for creating a new workflow session. Used to initialize workflow sessions with
+ * participants and settings.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class WorkflowCreationRequest {
+
+    /** Type of workflow to create (SIGNING, REVIEW, APPROVAL) */
+    private WorkflowType workflowType;
+
+    /** Display name for the document in the workflow */
+    private String documentName;
+
+    /** Owner's email address (optional, used for notifications) */
+    private String ownerEmail;
+
+    /** Message/instructions for participants */
+    private String message;
+
+    /** Due date for workflow completion (flexible string format) */
+    private String dueDate;
+
+    /** List of participant user IDs (for registered users) */
+    private List<Long> participantUserIds;
+
+    /** List of participant email addresses (for external/unregistered users) */
+    private List<String> participantEmails;
+
+    /** Workflow-specific metadata (JSON string) */
+    private String workflowMetadata;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/dto/WorkflowSessionResponse.java

@@ -0,0 +1,40 @@
+package stirling.software.proprietary.workflow.dto;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import stirling.software.proprietary.workflow.model.WorkflowStatus;
+import stirling.software.proprietary.workflow.model.WorkflowType;
+
+/**
+ * Response DTO for workflow session details. Used in API responses to provide session information
+ * to clients.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class WorkflowSessionResponse {
+
+    private String sessionId;
+    private Long ownerId;
+    private String ownerUsername;
+    private WorkflowType workflowType;
+    private String documentName;
+    private String ownerEmail;
+    private String message;
+    private String dueDate;
+    private WorkflowStatus status;
+    private boolean finalized;
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+    private List<ParticipantResponse> participants;
+    private int participantCount;
+    private int signedCount;
+    private boolean hasProcessedFile;
+    private Long originalFileId;
+    private Long processedFileId;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/CertificateType.java

@@ -0,0 +1,6 @@
+package stirling.software.proprietary.workflow.model;
+
+public enum CertificateType {
+    AUTO_GENERATED,
+    USER_UPLOADED
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/ParticipantStatus.java

@@ -0,0 +1,22 @@
+package stirling.software.proprietary.workflow.model;
+
+/**
+ * Defines the status of a participant in a workflow session. Tracks participant progress through
+ * the workflow lifecycle.
+ */
+public enum ParticipantStatus {
+    /** Participant has been added but not yet notified */
+    PENDING,
+
+    /** Participant has been notified via email or other means */
+    NOTIFIED,
+
+    /** Participant has viewed the document */
+    VIEWED,
+
+    /** Participant has completed their action (e.g., signed the document) */
+    SIGNED,
+
+    /** Participant has declined to participate or rejected the action */
+    DECLINED
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/UserServerCertificateEntity.java

@@ -0,0 +1,73 @@
+package stirling.software.proprietary.workflow.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+import org.hibernate.annotations.UpdateTimestamp;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+import jakarta.persistence.*;
+
+import lombok.*;
+
+import stirling.software.proprietary.security.model.User;
+
+@Entity
+@Table(name = "user_server_certificates")
+@NoArgsConstructor
+@Getter
+@Setter
+@EqualsAndHashCode(onlyExplicitlyIncluded = true)
+@ToString(onlyExplicitlyIncluded = true)
+public class UserServerCertificateEntity implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    @EqualsAndHashCode.Include
+    @ToString.Include
+    private Long id;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id", unique = true, nullable = false)
+    @JsonIgnore
+    private User user;
+
+    @Lob
+    @Basic(fetch = FetchType.EAGER)
+    @Column(name = "keystore_data", nullable = false, columnDefinition = "bytea")
+    @JsonIgnore
+    private byte[] keystoreData;
+
+    @Column(name = "keystore_password", nullable = false)
+    @JsonIgnore
+    private String keystorePassword;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "certificate_type", nullable = false, length = 50)
+    private CertificateType certificateType;
+
+    @Column(name = "subject_dn", length = 500)
+    private String subjectDn;
+
+    @Column(name = "issuer_dn", length = 500)
+    private String issuerDn;
+
+    @Column(name = "valid_from")
+    private LocalDateTime validFrom;
+
+    @Column(name = "valid_to")
+    private LocalDateTime validTo;
+
+    @CreationTimestamp
+    @Column(name = "created_at", updatable = false)
+    private LocalDateTime createdAt;
+
+    @UpdateTimestamp
+    @Column(name = "updated_at")
+    private LocalDateTime updatedAt;
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/WorkflowParticipant.java

@@ -0,0 +1,141 @@
+package stirling.software.proprietary.workflow.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.hibernate.annotations.UpdateTimestamp;
+
+import jakarta.persistence.CollectionTable;
+import jakarta.persistence.Column;
+import jakarta.persistence.ElementCollection;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.ShareAccessRole;
+
+/**
+ * Represents a participant in a workflow session. Replaces SigningParticipantEntity with broader
+ * workflow support.
+ *
+ * <p>Integrates with FileShare for access control - each participant gets a FileShare entry linked
+ * to this participant record for unified access control.
+ */
+@Entity
+@Table(
+        name = "workflow_participants",
+        indexes = {
+            @Index(name = "idx_workflow_participants_session", columnList = "workflow_session_id"),
+            @Index(name = "idx_workflow_participants_token", columnList = "share_token"),
+            @Index(name = "idx_workflow_participants_user", columnList = "user_id")
+        })
+@NoArgsConstructor
+@Getter
+@Setter
+public class WorkflowParticipant implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "workflow_session_id", nullable = false)
+    private WorkflowSession workflowSession;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id")
+    private User user;
+
+    @Column(name = "email")
+    private String email;
+
+    @Column(name = "name")
+    private String name;
+
+    // Workflow progress tracking
+    @Enumerated(EnumType.STRING)
+    @Column(name = "status", nullable = false, length = 20)
+    private ParticipantStatus status = ParticipantStatus.PENDING;
+
+    // Access control (unified with FileShare)
+    @Column(name = "share_token", unique = true, length = 36)
+    private String shareToken;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "access_role", nullable = false, length = 20)
+    private ShareAccessRole accessRole;
+
+    @Column(name = "expires_at")
+    private LocalDateTime expiresAt;
+
+    // Workflow-specific data stored as JSON for flexibility
+    // For signing: wet signature coordinates, signature appearance settings
+    // For review: assigned review sections, comment preferences
+    // For approval: decision criteria, approval authority level
+    @org.hibernate.annotations.JdbcTypeCode(org.hibernate.type.SqlTypes.JSON)
+    @Column(name = "participant_metadata", columnDefinition = "jsonb")
+    private Map<String, Object> participantMetadata = new HashMap<>();
+
+    // Notification history
+    @ElementCollection(fetch = FetchType.LAZY)
+    @CollectionTable(
+            name = "participant_notifications",
+            joinColumns = @JoinColumn(name = "participant_id"))
+    @Column(name = "notification_message", columnDefinition = "text")
+    private List<String> notifications = new ArrayList<>();
+
+    @UpdateTimestamp
+    @Column(name = "last_updated")
+    private LocalDateTime lastUpdated;
+
+    // Helper methods
+
+    public void addNotification(String message) {
+        notifications.add(message);
+    }
+
+    public boolean isExpired() {
+        return expiresAt != null && LocalDateTime.now().isAfter(expiresAt);
+    }
+
+    public boolean hasCompleted() {
+        return status == ParticipantStatus.SIGNED || status == ParticipantStatus.DECLINED;
+    }
+
+    /**
+     * Determines the effective access role based on participant status. After completion
+     * (signed/declined), downgrade to VIEWER.
+     */
+    public ShareAccessRole getEffectiveRole() {
+        if (hasCompleted()) {
+            return ShareAccessRole.VIEWER;
+        }
+        return accessRole;
+    }
+
+    public boolean canEdit() {
+        return !hasCompleted()
+                && !isExpired()
+                && (accessRole == ShareAccessRole.EDITOR
+                        || accessRole == ShareAccessRole.COMMENTER);
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/WorkflowSession.java

@@ -0,0 +1,143 @@
+package stirling.software.proprietary.workflow.model;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import org.hibernate.annotations.CreationTimestamp;
+import org.hibernate.annotations.UpdateTimestamp;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Index;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.StoredFile;
+
+/**
+ * Represents a workflow session for multi-participant document processing. Replaces
+ * SigningSessionEntity with a more generic workflow abstraction that supports signing, review,
+ * approval, and other collaborative workflows.
+ *
+ * <p>This entity coordinates the workflow lifecycle and links to StoredFile for actual document
+ * storage (no more direct BLOBs).
+ */
+@Entity
+@Table(
+        name = "workflow_sessions",
+        indexes = {
+            @Index(name = "idx_workflow_sessions_owner", columnList = "owner_id"),
+            @Index(name = "idx_workflow_sessions_session_id", columnList = "session_id")
+        })
+@NoArgsConstructor
+@Getter
+@Setter
+public class WorkflowSession implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "session_id", unique = true, nullable = false, length = 36)
+    private String sessionId = UUID.randomUUID().toString();
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "owner_id", nullable = false)
+    private User owner;
+
+    @Column(name = "workflow_type", nullable = false, length = 20)
+    @Enumerated(EnumType.STRING)
+    private WorkflowType workflowType;
+
+    @Column(name = "document_name", nullable = false)
+    private String documentName;
+
+    // Replaces BLOB storage with StoredFile reference
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "original_file_id", nullable = false)
+    private StoredFile originalFile;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "processed_file_id")
+    private StoredFile processedFile;
+
+    @Column(name = "owner_email")
+    private String ownerEmail;
+
+    @Column(name = "message", columnDefinition = "text")
+    private String message;
+
+    @Column(name = "due_date", length = 50)
+    private String dueDate;
+
+    @Column(name = "status", nullable = false, length = 20)
+    @Enumerated(EnumType.STRING)
+    private WorkflowStatus status = WorkflowStatus.IN_PROGRESS;
+
+    @Column(name = "finalized", nullable = false)
+    private boolean finalized = false;
+
+    @OneToMany(
+            mappedBy = "workflowSession",
+            cascade = CascadeType.ALL,
+            orphanRemoval = true,
+            fetch = FetchType.LAZY)
+    private List<WorkflowParticipant> participants = new ArrayList<>();
+
+    // Workflow-specific settings stored as JSON for flexibility
+    // For signing: signature appearance settings, wet signature metadata
+    // For review: review guidelines, comment templates
+    // For approval: approval criteria, decision options
+    @org.hibernate.annotations.JdbcTypeCode(org.hibernate.type.SqlTypes.JSON)
+    @Column(name = "workflow_metadata", columnDefinition = "jsonb")
+    private Map<String, Object> workflowMetadata = new HashMap<>();
+
+    @CreationTimestamp
+    @Column(name = "created_at", updatable = false)
+    private LocalDateTime createdAt;
+
+    @UpdateTimestamp
+    @Column(name = "updated_at")
+    private LocalDateTime updatedAt;
+
+    // Helper methods
+
+    public void addParticipant(WorkflowParticipant participant) {
+        participants.add(participant);
+        participant.setWorkflowSession(this);
+    }
+
+    public void removeParticipant(WorkflowParticipant participant) {
+        participants.remove(participant);
+        participant.setWorkflowSession(null);
+    }
+
+    public boolean isActive() {
+        return status == WorkflowStatus.IN_PROGRESS && !finalized;
+    }
+
+    public boolean hasProcessedFile() {
+        return processedFile != null;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/WorkflowStatus.java

@@ -0,0 +1,16 @@
+package stirling.software.proprietary.workflow.model;
+
+/**
+ * Defines the overall status of a workflow session. Tracks the lifecycle from creation through
+ * completion or cancellation.
+ */
+public enum WorkflowStatus {
+    /** Workflow is active and awaiting participant actions */
+    IN_PROGRESS,
+
+    /** Workflow has been successfully completed by all participants */
+    COMPLETED,
+
+    /** Workflow has been cancelled by the owner or system */
+    CANCELLED
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/model/WorkflowType.java

@@ -0,0 +1,16 @@
+package stirling.software.proprietary.workflow.model;
+
+/**
+ * Defines the type of workflow being executed. Determines the business logic and lifecycle for the
+ * workflow session.
+ */
+public enum WorkflowType {
+    /** Document signing workflow - participants sign a PDF with digital certificates */
+    SIGNING,
+
+    /** Document review workflow - participants review and comment on a document */
+    REVIEW,
+
+    /** Document approval workflow - participants approve or reject a document */
+    APPROVAL
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/repository/UserServerCertificateRepository.java

@@ -0,0 +1,23 @@
+package stirling.software.proprietary.workflow.repository;
+
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+
+import stirling.software.proprietary.workflow.model.UserServerCertificateEntity;
+
+@Repository
+public interface UserServerCertificateRepository
+        extends JpaRepository<UserServerCertificateEntity, Long> {
+
+    @Query("SELECT c FROM UserServerCertificateEntity c WHERE c.user.id = :userId")
+    Optional<UserServerCertificateEntity> findByUserId(@Param("userId") Long userId);
+
+    @Query("SELECT c FROM UserServerCertificateEntity c WHERE c.user.username = :username")
+    Optional<UserServerCertificateEntity> findByUsername(@Param("username") String username);
+
+    boolean existsByUserId(Long userId);
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/repository/WorkflowParticipantRepository.java

@@ -0,0 +1,75 @@
+package stirling.software.proprietary.workflow.repository;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+import org.springframework.transaction.annotation.Transactional;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+import stirling.software.proprietary.workflow.model.WorkflowParticipant;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+
+@Repository
+public interface WorkflowParticipantRepository extends JpaRepository<WorkflowParticipant, Long> {
+
+    /** Find participant by share token */
+    Optional<WorkflowParticipant> findByShareToken(String shareToken);
+
+    /** Find all participants in a workflow session */
+    List<WorkflowParticipant> findByWorkflowSession(WorkflowSession session);
+
+    /** Find participant by session and user */
+    Optional<WorkflowParticipant> findByWorkflowSessionAndUser(WorkflowSession session, User user);
+
+    /** Find participant by session and email */
+    Optional<WorkflowParticipant> findByWorkflowSessionAndEmail(
+            WorkflowSession session, String email);
+
+    /** Find all participants with a specific status in a session */
+    List<WorkflowParticipant> findByWorkflowSessionAndStatus(
+            WorkflowSession session, ParticipantStatus status);
+
+    /** Find all sessions where a user is a participant */
+    List<WorkflowParticipant> findByUserOrderByLastUpdatedDesc(User user);
+
+    /** Find all sessions where an email is a participant */
+    List<WorkflowParticipant> findByEmailOrderByLastUpdatedDesc(String email);
+
+    /** Check if a participant exists by share token */
+    boolean existsByShareToken(String shareToken);
+
+    /** Count participants in a session by status */
+    long countByWorkflowSessionAndStatus(WorkflowSession session, ParticipantStatus status);
+
+    /** Find expired participants that haven't completed */
+    @Query(
+            "SELECT p FROM WorkflowParticipant p WHERE p.expiresAt < CURRENT_TIMESTAMP AND p.status NOT IN ('SIGNED', 'DECLINED')")
+    List<WorkflowParticipant> findExpiredIncompleteParticipants();
+
+    /** Find all participants pending notification */
+    @Query(
+            "SELECT p FROM WorkflowParticipant p WHERE p.status = 'PENDING' AND p.workflowSession.status = 'IN_PROGRESS'")
+    List<WorkflowParticipant> findPendingNotifications();
+
+    /** Delete participant by ID and session owner (for authorization) */
+    @Query(
+            "DELETE FROM WorkflowParticipant p WHERE p.id = :participantId AND p.workflowSession.owner = :owner")
+    void deleteByIdAndSessionOwner(
+            @Param("participantId") Long participantId, @Param("owner") User owner);
+
+    /**
+     * Null out the user reference for all participants linked to the given user. Used during user
+     * deletion to preserve workflow audit history while removing the personal data link.
+     * Participants in sessions owned by others are retained but de-linked from the deleted account.
+     */
+    @Modifying
+    @Transactional
+    @Query("UPDATE WorkflowParticipant wp SET wp.user = null WHERE wp.user = :user")
+    void clearUserReferences(@Param("user") User user);
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/repository/WorkflowSessionRepository.java

@@ -0,0 +1,61 @@
+package stirling.software.proprietary.workflow.repository;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+import stirling.software.proprietary.workflow.model.WorkflowStatus;
+import stirling.software.proprietary.workflow.model.WorkflowType;
+
+@Repository
+public interface WorkflowSessionRepository extends JpaRepository<WorkflowSession, Long> {
+
+    /** Find workflow session by unique session ID */
+    Optional<WorkflowSession> findBySessionId(String sessionId);
+
+    /** Find workflow session by unique session ID with participants eagerly loaded */
+    @Query(
+            "SELECT ws FROM WorkflowSession ws LEFT JOIN FETCH ws.participants WHERE ws.sessionId = :sessionId")
+    Optional<WorkflowSession> findBySessionIdWithParticipants(@Param("sessionId") String sessionId);
+
+    /** Find all workflow sessions owned by a specific user */
+    List<WorkflowSession> findByOwnerOrderByCreatedAtDesc(User owner);
+
+    /** Find all workflow sessions of a specific type for a user */
+    List<WorkflowSession> findByOwnerAndWorkflowTypeOrderByCreatedAtDesc(
+            User owner, WorkflowType workflowType);
+
+    /** Find all workflow sessions with a specific status */
+    List<WorkflowSession> findByStatusOrderByCreatedAtDesc(WorkflowStatus status);
+
+    /** Find all active (non-finalized, in-progress) sessions for a user */
+    @Query(
+            "SELECT ws FROM WorkflowSession ws WHERE ws.owner = :owner AND ws.status = 'IN_PROGRESS' AND ws.finalized = false ORDER BY ws.createdAt DESC")
+    List<WorkflowSession> findActiveSessionsByOwner(@Param("owner") User owner);
+
+    /** Find all finalized sessions for a user */
+    List<WorkflowSession> findByOwnerAndFinalizedTrueOrderByCreatedAtDesc(User owner);
+
+    /** Check if a session exists by session ID */
+    boolean existsBySessionId(String sessionId);
+
+    /** Find sessions that need cleanup (e.g., old cancelled sessions) */
+    @Query(
+            "SELECT ws FROM WorkflowSession ws WHERE ws.status = 'CANCELLED' AND ws.updatedAt < :cutoffDate")
+    List<WorkflowSession> findCancelledSessionsOlderThan(
+            @Param("cutoffDate") java.time.LocalDateTime cutoffDate);
+
+    /** Count active sessions for a user */
+    @Query(
+            "SELECT COUNT(ws) FROM WorkflowSession ws WHERE ws.owner = :owner AND ws.status = 'IN_PROGRESS' AND ws.finalized = false")
+    long countActiveSessionsByOwner(@Param("owner") User owner);
+
+    /** Delete session by session ID and owner (for authorization) */
+    void deleteBySessionIdAndOwner(String sessionId, User owner);
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/service/MetadataEncryptionService.java

@@ -0,0 +1,119 @@
+package stirling.software.proprietary.workflow.service;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.SecureRandom;
+import java.util.Arrays;
+import java.util.Base64;
+
+import javax.crypto.Cipher;
+import javax.crypto.spec.GCMParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import org.springframework.stereotype.Service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.model.ApplicationProperties;
+
+/**
+ * Provides AES-256-GCM encryption for sensitive fields stored in JSONB metadata columns (e.g.
+ * keystore passwords). The encryption key is derived from the application's
+ * AutomaticallyGenerated.key, which is persisted in settings on first run.
+ *
+ * <p>Encrypted values are prefixed with {@value #ENC_PREFIX} so that legacy plaintext values
+ * written before this service was introduced can still be decrypted transparently.
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class MetadataEncryptionService {
+
+    static final String ENC_PREFIX = "enc:";
+    private static final String ALGORITHM = "AES/GCM/NoPadding";
+    private static final int GCM_IV_LENGTH = 12;
+    private static final int GCM_TAG_LENGTH = 128; // bits
+
+    private final ApplicationProperties applicationProperties;
+
+    // ── Public API ──────────────────────────────────────────────────────────
+
+    /**
+     * Encrypts {@code plaintext} with AES-256-GCM and returns a Base64-encoded ciphertext prefixed
+     * with {@value #ENC_PREFIX}.
+     */
+    public String encrypt(String plaintext) {
+        if (plaintext == null) {
+            return null;
+        }
+        try {
+            SecretKeySpec keySpec = deriveKey();
+            byte[] iv = generateIv();
+
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.ENCRYPT_MODE, keySpec, new GCMParameterSpec(GCM_TAG_LENGTH, iv));
+
+            byte[] cipherBytes = cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));
+
+            // Prepend IV to ciphertext for storage: [12-byte IV][ciphertext+tag]
+            byte[] combined = new byte[iv.length + cipherBytes.length];
+            System.arraycopy(iv, 0, combined, 0, iv.length);
+            System.arraycopy(cipherBytes, 0, combined, iv.length, cipherBytes.length);
+
+            return ENC_PREFIX + Base64.getEncoder().encodeToString(combined);
+        } catch (Exception e) {
+            throw new IllegalStateException("Failed to encrypt metadata field", e);
+        }
+    }
+
+    /**
+     * Decrypts a value produced by {@link #encrypt}. If the value does not start with {@value
+     * #ENC_PREFIX} it is returned as-is to preserve backwards compatibility with plaintext values
+     * written before this service existed.
+     */
+    public String decrypt(String value) {
+        if (value == null) {
+            return null;
+        }
+        if (!value.startsWith(ENC_PREFIX)) {
+            // Legacy plaintext – return unchanged
+            return value;
+        }
+        try {
+            SecretKeySpec keySpec = deriveKey();
+            byte[] combined = Base64.getDecoder().decode(value.substring(ENC_PREFIX.length()));
+
+            byte[] iv = Arrays.copyOfRange(combined, 0, GCM_IV_LENGTH);
+            byte[] cipherBytes = Arrays.copyOfRange(combined, GCM_IV_LENGTH, combined.length);
+
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.DECRYPT_MODE, keySpec, new GCMParameterSpec(GCM_TAG_LENGTH, iv));
+
+            return new String(cipher.doFinal(cipherBytes), StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            throw new IllegalStateException("Failed to decrypt metadata field", e);
+        }
+    }
+
+    // ── Internals ───────────────────────────────────────────────────────────
+
+    private SecretKeySpec deriveKey() throws Exception {
+        String rawKey = applicationProperties.getAutomaticallyGenerated().getKey();
+        if (rawKey == null || rawKey.isBlank()) {
+            throw new IllegalStateException(
+                    "AutomaticallyGenerated.key is not initialised — cannot derive encryption key");
+        }
+        // SHA-256 of the raw key gives a stable 32-byte AES-256 key
+        byte[] hash =
+                MessageDigest.getInstance("SHA-256")
+                        .digest(rawKey.getBytes(StandardCharsets.UTF_8));
+        return new SecretKeySpec(hash, "AES");
+    }
+
+    private static byte[] generateIv() {
+        byte[] iv = new byte[GCM_IV_LENGTH];
+        new SecureRandom().nextBytes(iv);
+        return iv;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/service/UnifiedAccessControlService.java

@@ -0,0 +1,233 @@
+package stirling.software.proprietary.workflow.service;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.FileShare;
+import stirling.software.proprietary.storage.model.ShareAccessRole;
+import stirling.software.proprietary.storage.model.StoredFile;
+import stirling.software.proprietary.storage.repository.FileShareRepository;
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+import stirling.software.proprietary.workflow.model.WorkflowParticipant;
+import stirling.software.proprietary.workflow.repository.WorkflowParticipantRepository;
+
+/**
+ * Unified access control service that consolidates validation logic for both generic file shares
+ * and workflow participants.
+ *
+ * <p>This service bridges the gap between the file sharing infrastructure and workflow-specific
+ * access control.
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+@Transactional(readOnly = true)
+public class UnifiedAccessControlService {
+
+    private final FileShareRepository fileShareRepository;
+    private final WorkflowParticipantRepository workflowParticipantRepository;
+
+    /**
+     * Validates a share token and returns access validation result. Works for both generic file
+     * shares and workflow participant shares.
+     */
+    public AccessValidationResult validateToken(String token, User user) {
+        log.debug("Validating access token: {}", token);
+
+        // First try as file share token
+        Optional<FileShare> fileShareOpt = fileShareRepository.findByShareTokenWithFile(token);
+        if (fileShareOpt.isPresent()) {
+            return validateGenericShare(fileShareOpt.get(), user);
+        }
+
+        // Try as workflow participant token
+        Optional<WorkflowParticipant> participantOpt =
+                workflowParticipantRepository.findByShareToken(token);
+        if (participantOpt.isPresent()) {
+            return validateParticipant(participantOpt.get(), user);
+        }
+
+        log.warn("Invalid or expired token: {}", token);
+        return AccessValidationResult.denied("Invalid or expired access token");
+    }
+
+    /** Validates a generic file share (non-workflow) */
+    private AccessValidationResult validateGenericShare(FileShare share, User user) {
+        // Check expiration
+        if (share.getExpiresAt() != null && LocalDateTime.now().isAfter(share.getExpiresAt())) {
+            log.warn("Share token expired: {}", share.getShareToken());
+            return AccessValidationResult.denied("Access link has expired");
+        }
+
+        // Check if user matches (if share is user-specific)
+        if (share.getSharedWithUser() != null && !share.getSharedWithUser().equals(user)) {
+            log.warn(
+                    "User mismatch for share: expected {}, got {}",
+                    share.getSharedWithUser().getId(),
+                    user != null ? user.getId() : "null");
+            return AccessValidationResult.denied("Access denied for this user");
+        }
+
+        return AccessValidationResult.allowed(share.getFile(), share.getAccessRole(), null, false);
+    }
+
+    /** Validates a workflow participant by token */
+    private AccessValidationResult validateParticipant(WorkflowParticipant participant, User user) {
+        // Check expiration
+        if (participant.isExpired()) {
+            log.warn("Workflow participant access expired: {}", participant.getShareToken());
+            return AccessValidationResult.denied("Workflow access has expired");
+        }
+
+        // Check if workflow is still active
+        if (!participant.getWorkflowSession().isActive()) {
+            log.info(
+                    "Workflow session no longer active: {}",
+                    participant.getWorkflowSession().getSessionId());
+            return AccessValidationResult.denied("Workflow session is no longer active");
+        }
+
+        // Check user authorization
+        if (participant.getUser() != null && !participant.getUser().equals(user)) {
+            log.warn(
+                    "User mismatch for participant: expected {}, got {}",
+                    participant.getUser().getId(),
+                    user != null ? user.getId() : "null");
+            return AccessValidationResult.denied("Access denied for this user");
+        }
+
+        // Get effective role based on participant status
+        ShareAccessRole effectiveRole = getEffectiveRole(participant);
+
+        // Get the file from the workflow session
+        StoredFile file = participant.getWorkflowSession().getOriginalFile();
+
+        return AccessValidationResult.allowed(file, effectiveRole, participant, true);
+    }
+
+    /**
+     * Maps participant status to effective access role. After completion (signed/declined),
+     * downgrade to VIEWER.
+     */
+    public ShareAccessRole getEffectiveRole(WorkflowParticipant participant) {
+        ParticipantStatus status = participant.getStatus();
+
+        switch (status) {
+            case SIGNED:
+            case DECLINED:
+                // After action completed, downgrade to read-only
+                return ShareAccessRole.VIEWER;
+            case PENDING:
+            case NOTIFIED:
+            case VIEWED:
+                // Active participants retain their assigned role
+                return participant.getAccessRole();
+            default:
+                log.warn("Unknown participant status: {}", status);
+                return ShareAccessRole.VIEWER;
+        }
+    }
+
+    /** Checks if a user can access a specific file */
+    public boolean canAccessFile(User user, StoredFile file) {
+        // Owner always has access
+        if (file.getOwner().equals(user)) {
+            return true;
+        }
+
+        // Check for file share
+        Optional<FileShare> share = fileShareRepository.findByFileAndSharedWithUser(file, user);
+        if (share.isPresent() && !isExpired(share.get())) {
+            return true;
+        }
+
+        // Check for workflow participant access
+        if (file.getWorkflowSession() != null) {
+            Optional<WorkflowParticipant> participant =
+                    workflowParticipantRepository.findByWorkflowSessionAndUser(
+                            file.getWorkflowSession(), user);
+            return participant.isPresent()
+                    && !participant.get().isExpired()
+                    && participant.get().getWorkflowSession().isActive();
+        }
+
+        return false;
+    }
+
+    private boolean isExpired(FileShare share) {
+        return share.getExpiresAt() != null && LocalDateTime.now().isAfter(share.getExpiresAt());
+    }
+
+    /** Result of access validation */
+    public static class AccessValidationResult {
+        private final boolean allowed;
+        private final String denialReason;
+        private final StoredFile file;
+        private final ShareAccessRole role;
+        private final WorkflowParticipant participant;
+        private final boolean isWorkflowAccess;
+
+        private AccessValidationResult(
+                boolean allowed,
+                String denialReason,
+                StoredFile file,
+                ShareAccessRole role,
+                WorkflowParticipant participant,
+                boolean isWorkflowAccess) {
+            this.allowed = allowed;
+            this.denialReason = denialReason;
+            this.file = file;
+            this.role = role;
+            this.participant = participant;
+            this.isWorkflowAccess = isWorkflowAccess;
+        }
+
+        public static AccessValidationResult allowed(
+                StoredFile file,
+                ShareAccessRole role,
+                WorkflowParticipant participant,
+                boolean isWorkflowAccess) {
+            return new AccessValidationResult(
+                    true, null, file, role, participant, isWorkflowAccess);
+        }
+
+        public static AccessValidationResult denied(String reason) {
+            return new AccessValidationResult(false, reason, null, null, null, false);
+        }
+
+        public boolean isAllowed() {
+            return allowed;
+        }
+
+        public String getDenialReason() {
+            return denialReason;
+        }
+
+        public StoredFile getFile() {
+            return file;
+        }
+
+        public ShareAccessRole getRole() {
+            return role;
+        }
+
+        public WorkflowParticipant getParticipant() {
+            return participant;
+        }
+
+        public boolean isWorkflowAccess() {
+            return isWorkflowAccess;
+        }
+
+        public boolean canEdit() {
+            return allowed && (role == ShareAccessRole.EDITOR || role == ShareAccessRole.COMMENTER);
+        }
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/service/UserServerCertificateService.java

@@ -0,0 +1,258 @@
+package stirling.software.proprietary.workflow.service;
+
+import java.io.*;
+import java.math.BigInteger;
+import java.security.*;
+import java.security.cert.Certificate;
+import java.security.cert.X509Certificate;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.Date;
+import java.util.Optional;
+
+import org.bouncycastle.asn1.x500.X500Name;
+import org.bouncycastle.asn1.x509.BasicConstraints;
+import org.bouncycastle.asn1.x509.ExtendedKeyUsage;
+import org.bouncycastle.asn1.x509.Extension;
+import org.bouncycastle.asn1.x509.KeyPurposeId;
+import org.bouncycastle.asn1.x509.KeyUsage;
+import org.bouncycastle.cert.X509CertificateHolder;
+import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
+import org.bouncycastle.cert.jcajce.JcaX509ExtensionUtils;
+import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.operator.ContentSigner;
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.proprietary.security.database.repository.UserRepository;
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.workflow.model.CertificateType;
+import stirling.software.proprietary.workflow.model.UserServerCertificateEntity;
+import stirling.software.proprietary.workflow.repository.UserServerCertificateRepository;
+
+@Service
+@Slf4j
+@RequiredArgsConstructor
+public class UserServerCertificateService {
+
+    private static final String KEYSTORE_ALIAS = "stirling-pdf-user-cert";
+    private static final String DEFAULT_PASSWORD_PREFIX = "stirling-user-cert-";
+    private static final int VALIDITY_DAYS = 365;
+
+    private final UserServerCertificateRepository certificateRepository;
+    private final UserRepository userRepository;
+    private final MetadataEncryptionService metadataEncryptionService;
+
+    static {
+        Security.addProvider(new BouncyCastleProvider());
+    }
+
+    /** Get or create user certificate (auto-generate if not exists) */
+    @Transactional
+    public UserServerCertificateEntity getOrCreateUserCertificate(Long userId) throws Exception {
+        Optional<UserServerCertificateEntity> existing = certificateRepository.findByUserId(userId);
+        if (existing.isPresent()) {
+            return existing.get();
+        }
+
+        User user =
+                userRepository
+                        .findById(userId)
+                        .orElseThrow(() -> new IllegalArgumentException("User not found"));
+        return generateUserCertificate(user);
+    }
+
+    /** Generate new certificate for user */
+    @Transactional
+    public UserServerCertificateEntity generateUserCertificate(User user) throws Exception {
+        log.info("Generating server certificate for user: {}", user.getUsername());
+
+        // Generate key pair
+        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA", "BC");
+        keyPairGenerator.initialize(2048, new SecureRandom());
+        KeyPair keyPair = keyPairGenerator.generateKeyPair();
+
+        // Certificate details with username
+        String username = user.getUsername();
+        X500Name subject = new X500Name("CN=" + username + ", O=Stirling-PDF User, C=US");
+        BigInteger serialNumber = BigInteger.valueOf(System.currentTimeMillis());
+        Date notBefore = new Date();
+        Date notAfter =
+                new Date(notBefore.getTime() + ((long) VALIDITY_DAYS * 24 * 60 * 60 * 1000));
+
+        // Build certificate
+        JcaX509v3CertificateBuilder certBuilder =
+                new JcaX509v3CertificateBuilder(
+                        subject, serialNumber, notBefore, notAfter, subject, keyPair.getPublic());
+
+        // Add PDF-specific certificate extensions
+        JcaX509ExtensionUtils extUtils = new JcaX509ExtensionUtils();
+
+        // End-entity certificate, not a CA
+        certBuilder.addExtension(Extension.basicConstraints, true, new BasicConstraints(false));
+
+        // Key usage for PDF digital signatures
+        certBuilder.addExtension(
+                Extension.keyUsage,
+                true,
+                new KeyUsage(KeyUsage.digitalSignature | KeyUsage.nonRepudiation));
+
+        // Extended key usage for document signing
+        certBuilder.addExtension(
+                Extension.extendedKeyUsage,
+                false,
+                new ExtendedKeyUsage(KeyPurposeId.id_kp_codeSigning));
+
+        // Subject Key Identifier
+        certBuilder.addExtension(
+                Extension.subjectKeyIdentifier,
+                false,
+                extUtils.createSubjectKeyIdentifier(keyPair.getPublic()));
+
+        // Authority Key Identifier for self-signed cert
+        certBuilder.addExtension(
+                Extension.authorityKeyIdentifier,
+                false,
+                extUtils.createAuthorityKeyIdentifier(keyPair.getPublic()));
+
+        // Sign certificate
+        ContentSigner signer =
+                new JcaContentSignerBuilder("SHA256WithRSA")
+                        .setProvider("BC")
+                        .build(keyPair.getPrivate());
+
+        X509CertificateHolder certHolder = certBuilder.build(signer);
+        X509Certificate cert =
+                new JcaX509CertificateConverter().setProvider("BC").getCertificate(certHolder);
+
+        // Create keystore
+        KeyStore keyStore = KeyStore.getInstance("PKCS12");
+        keyStore.load(null, null);
+        String password = generateUserPassword(user.getId());
+        keyStore.setKeyEntry(
+                KEYSTORE_ALIAS,
+                keyPair.getPrivate(),
+                password.toCharArray(),
+                new Certificate[] {cert});
+
+        // Store keystore bytes
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        keyStore.store(baos, password.toCharArray());
+        byte[] keystoreBytes = baos.toByteArray();
+
+        // Create entity
+        UserServerCertificateEntity entity = new UserServerCertificateEntity();
+        entity.setUser(user);
+        entity.setKeystoreData(keystoreBytes);
+        entity.setKeystorePassword(metadataEncryptionService.encrypt(password));
+        entity.setCertificateType(CertificateType.AUTO_GENERATED);
+        entity.setSubjectDn(cert.getSubjectX500Principal().getName());
+        entity.setIssuerDn(cert.getIssuerX500Principal().getName());
+        entity.setValidFrom(
+                LocalDateTime.ofInstant(cert.getNotBefore().toInstant(), ZoneId.systemDefault()));
+        entity.setValidTo(
+                LocalDateTime.ofInstant(cert.getNotAfter().toInstant(), ZoneId.systemDefault()));
+
+        return certificateRepository.save(entity);
+    }
+
+    /** Upload user-provided certificate */
+    @Transactional
+    public UserServerCertificateEntity uploadUserCertificate(
+            User user, InputStream p12Stream, String password) throws Exception {
+        log.info("Uploading user certificate for user: {}", user.getUsername());
+
+        // Validate keystore
+        byte[] keystoreBytes = p12Stream.readNBytes(10 * 1024 * 1024 + 1); // read at most 10 MB + 1
+        if (keystoreBytes.length > 10 * 1024 * 1024) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Keystore file exceeds maximum allowed size of 10 MB");
+        }
+        KeyStore keyStore = KeyStore.getInstance("PKCS12");
+        keyStore.load(new ByteArrayInputStream(keystoreBytes), password.toCharArray());
+
+        // Extract certificate info
+        String alias = keyStore.aliases().nextElement();
+        X509Certificate cert = (X509Certificate) keyStore.getCertificate(alias);
+
+        if (cert == null) {
+            throw new IllegalArgumentException("No certificate found in keystore");
+        }
+
+        // Create or update entity
+        UserServerCertificateEntity entity =
+                certificateRepository
+                        .findByUserId(user.getId())
+                        .orElse(new UserServerCertificateEntity());
+
+        entity.setUser(user);
+        entity.setKeystoreData(keystoreBytes);
+        entity.setKeystorePassword(metadataEncryptionService.encrypt(password));
+        entity.setCertificateType(CertificateType.USER_UPLOADED);
+        entity.setSubjectDn(cert.getSubjectX500Principal().getName());
+        entity.setIssuerDn(cert.getIssuerX500Principal().getName());
+        entity.setValidFrom(
+                LocalDateTime.ofInstant(cert.getNotBefore().toInstant(), ZoneId.systemDefault()));
+        entity.setValidTo(
+                LocalDateTime.ofInstant(cert.getNotAfter().toInstant(), ZoneId.systemDefault()));
+
+        return certificateRepository.save(entity);
+    }
+
+    /** Get user's KeyStore for signing operations */
+    @Transactional(readOnly = true)
+    public KeyStore getUserKeyStore(Long userId) throws Exception {
+        UserServerCertificateEntity cert =
+                certificateRepository
+                        .findByUserId(userId)
+                        .orElseThrow(
+                                () -> new IllegalArgumentException("User certificate not found"));
+
+        KeyStore keyStore = KeyStore.getInstance("PKCS12");
+        keyStore.load(
+                new ByteArrayInputStream(cert.getKeystoreData()),
+                metadataEncryptionService.decrypt(cert.getKeystorePassword()).toCharArray());
+        return keyStore;
+    }
+
+    /** Get user's keystore password */
+    @Transactional(readOnly = true)
+    public String getUserKeystorePassword(Long userId) {
+        UserServerCertificateEntity cert =
+                certificateRepository
+                        .findByUserId(userId)
+                        .orElseThrow(
+                                () -> new IllegalArgumentException("User certificate not found"));
+        return metadataEncryptionService.decrypt(cert.getKeystorePassword());
+    }
+
+    /** Delete user certificate */
+    @Transactional
+    public void deleteUserCertificate(Long userId) {
+        certificateRepository.findByUserId(userId).ifPresent(certificateRepository::delete);
+    }
+
+    /** Check if user has certificate */
+    @Transactional(readOnly = true)
+    public boolean hasUserCertificate(Long userId) {
+        return certificateRepository.findByUserId(userId).isPresent();
+    }
+
+    /** Get certificate info (without keystore data) */
+    @Transactional(readOnly = true)
+    public Optional<UserServerCertificateEntity> getCertificateInfo(Long userId) {
+        return certificateRepository.findByUserId(userId);
+    }
+
+    /** Generate consistent password for user (based on user ID) */
+    private String generateUserPassword(Long userId) {
+        return DEFAULT_PASSWORD_PREFIX + userId;
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/service/WorkflowSessionService.java

@@ -0,0 +1,869 @@
+package stirling.software.proprietary.workflow.service;
+
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.server.ResponseStatusException;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.model.ApplicationProperties;
+import stirling.software.proprietary.security.database.repository.UserRepository;
+import stirling.software.proprietary.security.model.User;
+import stirling.software.proprietary.storage.model.FilePurpose;
+import stirling.software.proprietary.storage.model.ShareAccessRole;
+import stirling.software.proprietary.storage.model.StoredFile;
+import stirling.software.proprietary.storage.provider.StorageProvider;
+import stirling.software.proprietary.storage.provider.StoredObject;
+import stirling.software.proprietary.storage.repository.StoredFileRepository;
+import stirling.software.proprietary.workflow.dto.ParticipantRequest;
+import stirling.software.proprietary.workflow.dto.WetSignatureMetadata;
+import stirling.software.proprietary.workflow.dto.WorkflowCreationRequest;
+import stirling.software.proprietary.workflow.model.ParticipantStatus;
+import stirling.software.proprietary.workflow.model.WorkflowParticipant;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+import stirling.software.proprietary.workflow.model.WorkflowStatus;
+import stirling.software.proprietary.workflow.repository.WorkflowParticipantRepository;
+import stirling.software.proprietary.workflow.repository.WorkflowSessionRepository;
+
+import tools.jackson.core.JacksonException;
+import tools.jackson.core.type.TypeReference;
+import tools.jackson.databind.ObjectMapper;
+
+/**
+ * Core service for workflow session management. Handles creation, participant management, and
+ * lifecycle coordination.
+ *
+ * <p>Delegates file storage to FileStorageService/StorageProvider and integrates with the file
+ * sharing infrastructure.
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+@Transactional
+public class WorkflowSessionService {
+
+    private final WorkflowSessionRepository workflowSessionRepository;
+    private final WorkflowParticipantRepository workflowParticipantRepository;
+    private final StoredFileRepository storedFileRepository;
+    private final UserRepository userRepository;
+    private final StorageProvider storageProvider;
+    private final ObjectMapper objectMapper;
+    private final ApplicationProperties applicationProperties;
+    private final MetadataEncryptionService metadataEncryptionService;
+
+    public void ensureSigningEnabled() {
+        if (!applicationProperties.getStorage().isEnabled()
+                || !applicationProperties.getStorage().getSigning().isEnabled()) {
+            throw new ResponseStatusException(HttpStatus.FORBIDDEN, "Group signing is disabled");
+        }
+    }
+
+    /**
+     * Creates a new workflow session with participants. Stores the original file using
+     * StorageProvider.
+     */
+    public WorkflowSession createSession(
+            User owner, MultipartFile file, WorkflowCreationRequest request) throws IOException {
+        log.info(
+                "Creating workflow session for user {} with type {}",
+                owner.getUsername(),
+                request.getWorkflowType());
+
+        // Validate request
+        if (file == null || file.isEmpty()) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "File is required");
+        }
+
+        if (request.getWorkflowType() == null) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Workflow type is required");
+        }
+
+        // Store original file using StorageProvider
+        StoredFile originalFile = storeWorkflowFile(owner, file, FilePurpose.SIGNING_ORIGINAL);
+
+        // Create workflow session
+        WorkflowSession session = new WorkflowSession();
+        session.setSessionId(UUID.randomUUID().toString());
+        session.setOwner(owner);
+        session.setWorkflowType(request.getWorkflowType());
+        session.setDocumentName(
+                request.getDocumentName() != null
+                        ? request.getDocumentName()
+                        : file.getOriginalFilename());
+        session.setOriginalFile(originalFile);
+        session.setOwnerEmail(request.getOwnerEmail());
+        session.setMessage(request.getMessage());
+        session.setDueDate(request.getDueDate());
+        session.setStatus(WorkflowStatus.IN_PROGRESS);
+
+        // Parse workflow metadata from JSON string to Map
+        if (request.getWorkflowMetadata() != null && !request.getWorkflowMetadata().isBlank()) {
+            try {
+                @SuppressWarnings("unchecked")
+                Map<String, Object> metadataMap =
+                        objectMapper.readValue(request.getWorkflowMetadata(), Map.class);
+                session.setWorkflowMetadata(metadataMap);
+            } catch (JacksonException e) {
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST,
+                        "Invalid workflowMetadata: must be a valid JSON object");
+            }
+        }
+
+        // Link file back to session
+        originalFile.setWorkflowSession(session);
+        originalFile.setPurpose(FilePurpose.SIGNING_ORIGINAL);
+
+        session = workflowSessionRepository.save(session);
+        storedFileRepository.save(originalFile);
+
+        // Add participants
+        List<ParticipantRequest> participants = new ArrayList<>();
+
+        if (request.getParticipantUserIds() != null) {
+            for (Long userId : request.getParticipantUserIds()) {
+                ParticipantRequest pr = new ParticipantRequest();
+                pr.setUserId(userId);
+                pr.setAccessRole(ShareAccessRole.EDITOR);
+                participants.add(pr);
+            }
+        }
+
+        if (request.getParticipantEmails() != null) {
+            for (String email : request.getParticipantEmails()) {
+                ParticipantRequest pr = new ParticipantRequest();
+                pr.setEmail(email);
+                pr.setAccessRole(ShareAccessRole.EDITOR);
+                participants.add(pr);
+            }
+        }
+
+        if (!participants.isEmpty()) {
+            addParticipantsToSession(session, participants);
+        }
+
+        log.info(
+                "Created workflow session {} with {} participants",
+                session.getSessionId(),
+                session.getParticipants().size());
+        return session;
+    }
+
+    /** Adds participants to a workflow session. */
+    private void addParticipantsToSession(
+            WorkflowSession session, List<ParticipantRequest> participantRequests) {
+        for (ParticipantRequest request : participantRequests) {
+            WorkflowParticipant participant = new WorkflowParticipant();
+            participant.setShareToken(UUID.randomUUID().toString());
+            participant.setAccessRole(
+                    request.getAccessRole() != null
+                            ? request.getAccessRole()
+                            : ShareAccessRole.EDITOR);
+            participant.setExpiresAt(request.getExpiresAt());
+
+            // Parse participant metadata from JSON string to Map
+            if (request.getParticipantMetadata() != null
+                    && !request.getParticipantMetadata().isBlank()) {
+                try {
+                    @SuppressWarnings("unchecked")
+                    Map<String, Object> metadataMap =
+                            objectMapper.readValue(request.getParticipantMetadata(), Map.class);
+                    participant.setParticipantMetadata(metadataMap);
+                } catch (JacksonException e) {
+                    log.warn(
+                            "Failed to parse participant metadata for {}, using empty map",
+                            request.getEmail(),
+                            e);
+                    participant.setParticipantMetadata(new HashMap<>());
+                }
+            }
+
+            // Store defaultReason in participant metadata if provided
+            if (request.getDefaultReason() != null && !request.getDefaultReason().isBlank()) {
+                Map<String, Object> metadata = participant.getParticipantMetadata();
+                if (metadata == null) {
+                    metadata = new HashMap<>();
+                }
+                metadata.put("defaultReason", request.getDefaultReason());
+                participant.setParticipantMetadata(metadata);
+                log.debug(
+                        "Set default reason for participant {}: {}",
+                        request.getEmail(),
+                        request.getDefaultReason());
+            }
+
+            participant.setStatus(ParticipantStatus.PENDING);
+
+            // Set user or email
+            if (request.getUserId() != null) {
+                User user =
+                        userRepository
+                                .findById(request.getUserId())
+                                .orElseThrow(
+                                        () ->
+                                                new ResponseStatusException(
+                                                        HttpStatus.NOT_FOUND,
+                                                        "User not found: " + request.getUserId()));
+                participant.setUser(user);
+                participant.setEmail(user.getUsername()); // User entity uses username, not email
+                participant.setName(user.getUsername());
+            } else if (request.getEmail() != null) {
+                participant.setEmail(request.getEmail());
+                participant.setName(
+                        request.getName() != null ? request.getName() : request.getEmail());
+            } else {
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST, "Participant must have either userId or email");
+            }
+
+            session.addParticipant(participant);
+            participant = workflowParticipantRepository.save(participant);
+        }
+    }
+
+    /** Stores a file as part of a workflow using the StorageProvider. */
+    private StoredFile storeWorkflowFile(User owner, MultipartFile file, FilePurpose purpose)
+            throws IOException {
+        // Store file content (storage provider generates the key)
+        StoredObject storedObject = storageProvider.store(owner, file);
+
+        // Create StoredFile entity
+        StoredFile storedFile = new StoredFile();
+        storedFile.setOwner(owner);
+        storedFile.setOriginalFilename(storedObject.getOriginalFilename());
+        storedFile.setContentType(storedObject.getContentType());
+        storedFile.setSizeBytes(storedObject.getSizeBytes());
+        storedFile.setStorageKey(storedObject.getStorageKey());
+        storedFile.setPurpose(purpose);
+
+        return storedFileRepository.save(storedFile);
+    }
+
+    /** Retrieves a workflow session by session ID. */
+    @Transactional(readOnly = true)
+    public WorkflowSession getSession(String sessionId) {
+        return workflowSessionRepository
+                .findBySessionId(sessionId)
+                .orElseThrow(
+                        () ->
+                                new ResponseStatusException(
+                                        HttpStatus.NOT_FOUND,
+                                        "Workflow session not found: " + sessionId));
+    }
+
+    /** Retrieves a workflow session with authorization check. */
+    @Transactional(readOnly = true)
+    public WorkflowSession getSessionForOwner(String sessionId, User owner) {
+        WorkflowSession session = getSession(sessionId);
+        if (!session.getOwner().equals(owner)) {
+            throw new ResponseStatusException(
+                    HttpStatus.FORBIDDEN, "Not authorized to access this workflow session");
+        }
+        return session;
+    }
+
+    /** Retrieves a workflow session with participants eagerly loaded for finalization. */
+    @Transactional(readOnly = true)
+    public WorkflowSession getSessionWithParticipants(String sessionId) {
+        return workflowSessionRepository
+                .findBySessionIdWithParticipants(sessionId)
+                .orElseThrow(
+                        () ->
+                                new ResponseStatusException(
+                                        HttpStatus.NOT_FOUND,
+                                        "Workflow session not found: " + sessionId));
+    }
+
+    /** Retrieves a workflow session with participants, with authorization check. */
+    @Transactional(readOnly = true)
+    public WorkflowSession getSessionWithParticipantsForOwner(String sessionId, User owner) {
+        WorkflowSession session = getSessionWithParticipants(sessionId);
+        if (!session.getOwner().equals(owner)) {
+            throw new ResponseStatusException(
+                    HttpStatus.FORBIDDEN, "Not authorized to access this workflow session");
+        }
+        return session;
+    }
+
+    /** Lists all workflow sessions owned by a user. */
+    @Transactional(readOnly = true)
+    public List<WorkflowSession> listUserSessions(User owner) {
+        return workflowSessionRepository.findByOwnerOrderByCreatedAtDesc(owner);
+    }
+
+    /** Lists active workflow sessions for a user. */
+    @Transactional(readOnly = true)
+    public List<WorkflowSession> listActiveSessions(User owner) {
+        return workflowSessionRepository.findActiveSessionsByOwner(owner);
+    }
+
+    /** Adds additional participants to an existing session. */
+    @Transactional
+    public void addParticipants(
+            String sessionId, List<ParticipantRequest> participants, User owner) {
+        WorkflowSession session = getSessionForOwner(sessionId, owner);
+
+        if (!session.isActive()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Cannot add participants to inactive workflow");
+        }
+
+        addParticipantsToSession(session, participants);
+        log.info("Added {} participants to session {}", participants.size(), sessionId);
+    }
+
+    /** Removes a participant from a workflow session. */
+    @Transactional
+    public void removeParticipant(String sessionId, Long participantId, User owner) {
+        WorkflowSession session = getSessionForOwner(sessionId, owner);
+
+        WorkflowParticipant participant =
+                workflowParticipantRepository
+                        .findById(participantId)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.NOT_FOUND,
+                                                "Participant not found: " + participantId));
+
+        if (!participant.getWorkflowSession().equals(session)) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Participant not in this workflow session");
+        }
+
+        session.removeParticipant(participant);
+        workflowParticipantRepository.delete(participant);
+        log.info("Removed participant {} from session {}", participantId, sessionId);
+    }
+
+    /** Updates participant status (e.g., NOTIFIED, VIEWED, SIGNED). */
+    public void updateParticipantStatus(Long participantId, ParticipantStatus newStatus) {
+        WorkflowParticipant participant =
+                workflowParticipantRepository
+                        .findById(participantId)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.NOT_FOUND,
+                                                "Participant not found: " + participantId));
+
+        participant.setStatus(newStatus);
+        workflowParticipantRepository.save(participant);
+        log.debug("Updated participant {} status to {}", participantId, newStatus);
+    }
+
+    /** Adds a notification message to a participant's history. */
+    public void addParticipantNotification(Long participantId, String message) {
+        WorkflowParticipant participant =
+                workflowParticipantRepository
+                        .findById(participantId)
+                        .orElseThrow(
+                                () ->
+                                        new ResponseStatusException(
+                                                HttpStatus.NOT_FOUND,
+                                                "Participant not found: " + participantId));
+
+        String timestampedMessage = LocalDateTime.now().toString() + ": " + message;
+        participant.addNotification(timestampedMessage);
+        workflowParticipantRepository.save(participant);
+    }
+
+    /** Stores the processed/finalized file for a workflow session. */
+    public void storeProcessedFile(WorkflowSession session, byte[] fileData, String filename)
+            throws IOException {
+        log.info("Storing processed file for session {}", session.getSessionId());
+
+        // Create a temporary multipart file wrapper
+        MultipartFile processedFile = new ByteArrayMultipartFile(fileData, filename);
+
+        // Store using StorageProvider
+        StoredFile storedFile =
+                storeWorkflowFile(session.getOwner(), processedFile, FilePurpose.SIGNING_SIGNED);
+
+        // Link to session
+        storedFile.setWorkflowSession(session);
+        session.setProcessedFile(storedFile);
+
+        storedFileRepository.save(storedFile);
+        workflowSessionRepository.save(session);
+    }
+
+    /** Marks a workflow session as finalized. */
+    public void finalizeSession(String sessionId, User owner) {
+        WorkflowSession session = getSessionForOwner(sessionId, owner);
+
+        if (session.isFinalized()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Workflow session already finalized");
+        }
+
+        session.setFinalized(true);
+        session.setStatus(WorkflowStatus.COMPLETED);
+        workflowSessionRepository.save(session);
+
+        log.info("Finalized workflow session {}", sessionId);
+    }
+
+    /** Retrieves the processed file data for a workflow session. */
+    @Transactional(readOnly = true)
+    public byte[] getProcessedFile(String sessionId, User owner) throws IOException {
+        WorkflowSession session = getSessionForOwner(sessionId, owner);
+
+        if (session.getProcessedFile() == null) {
+            throw new ResponseStatusException(
+                    HttpStatus.NOT_FOUND, "No processed file available for this session");
+        }
+
+        String storageKey = session.getProcessedFile().getStorageKey();
+        org.springframework.core.io.Resource resource = storageProvider.load(storageKey);
+        return resource.getContentAsByteArray();
+    }
+
+    /** Retrieves the original file data for a workflow session. */
+    @Transactional(readOnly = true)
+    public byte[] getOriginalFile(String sessionId) throws IOException {
+        WorkflowSession session = getSession(sessionId);
+        if (session.getOriginalFile() == null) {
+            throw new ResponseStatusException(
+                    HttpStatus.NOT_FOUND,
+                    "Original file no longer available (session may be finalized)");
+        }
+        String storageKey = session.getOriginalFile().getStorageKey();
+        org.springframework.core.io.Resource resource = storageProvider.load(storageKey);
+        return resource.getContentAsByteArray();
+    }
+
+    /** Deletes a workflow session and associated files. */
+    @Transactional
+    public void deleteSession(String sessionId, User owner) {
+        WorkflowSession session = getSessionForOwner(sessionId, owner);
+
+        if (session.isFinalized()) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST,
+                    "Cannot delete a finalized session. The signed PDF remains accessible from your session history.");
+        }
+
+        // Delete physical storage files (non-fatal; may already be absent)
+        try {
+            if (session.getOriginalFile() != null) {
+                storageProvider.delete(session.getOriginalFile().getStorageKey());
+            }
+            if (session.getProcessedFile() != null) {
+                storageProvider.delete(session.getProcessedFile().getStorageKey());
+            }
+        } catch (Exception e) {
+            log.error("Error deleting files for session {}", sessionId, e);
+        }
+
+        // Clear only the StoredFile → WorkflowSession back-reference before deleting.
+        //
+        // We do NOT null session.originalFile here because that would emit an UPDATE with
+        // original_file_id=NULL, violating the NOT NULL constraint.  There is no need to — a
+        // DELETE statement removes the row entirely, so the NOT NULL constraint never triggers.
+        //
+        // We DO null StoredFile.workflowSession (workflow_session_id IS nullable) so that
+        // Hibernate does not see a persistent StoredFile referencing a "removed" WorkflowSession
+        // during flush, which would throw TransientPropertyValueException.
+        StoredFile originalFile = session.getOriginalFile();
+        StoredFile processedFile = session.getProcessedFile();
+        if (originalFile != null) {
+            originalFile.setWorkflowSession(null);
+            storedFileRepository.save(originalFile);
+        }
+        if (processedFile != null) {
+            processedFile.setWorkflowSession(null);
+            storedFileRepository.save(processedFile);
+        }
+
+        // Delete the session row. Cascades to WorkflowParticipant via orphanRemoval=true.
+        workflowSessionRepository.delete(session);
+
+        // StoredFile rows can now be deleted — the workflow_sessions FK is gone.
+        if (originalFile != null) storedFileRepository.delete(originalFile);
+        if (processedFile != null) storedFileRepository.delete(processedFile);
+        log.info("Deleted workflow session {}", sessionId);
+    }
+
+    /**
+     * Deletes the original (presigned) file from storage after finalization. The original file is
+     * no longer needed once the signed document has been stored. Non-fatal: logs errors but does
+     * not fail finalization.
+     */
+    public void deleteOriginalFile(WorkflowSession session) {
+        if (session.getOriginalFile() == null) {
+            return;
+        }
+        try {
+            storageProvider.delete(session.getOriginalFile().getStorageKey());
+            StoredFile originalFile = session.getOriginalFile();
+            session.setOriginalFile(null);
+            workflowSessionRepository.save(session);
+            storedFileRepository.delete(originalFile);
+            log.info("Deleted original presigned file for session {}", session.getSessionId());
+        } catch (Exception e) {
+            log.error(
+                    "Failed to delete original file for session {}: {}",
+                    session.getSessionId(),
+                    e.getMessage());
+        }
+    }
+
+    // ===== SIGN REQUEST METHODS (Participant View) =====
+
+    /**
+     * List all sign requests where the user is a participant.
+     *
+     * @param user The participant user
+     * @return List of sign request summaries
+     */
+    @Transactional(readOnly = true)
+    public List<stirling.software.proprietary.workflow.dto.SignRequestSummaryDTO> listSignRequests(
+            User user) {
+        List<WorkflowParticipant> participations =
+                workflowParticipantRepository.findByUserOrderByLastUpdatedDesc(user);
+
+        return participations.stream()
+                .map(
+                        p -> {
+                            WorkflowSession session = p.getWorkflowSession();
+                            stirling.software.proprietary.workflow.dto.SignRequestSummaryDTO dto =
+                                    new stirling.software.proprietary.workflow.dto
+                                            .SignRequestSummaryDTO();
+                            dto.setSessionId(session.getSessionId());
+                            dto.setDocumentName(session.getDocumentName());
+                            dto.setOwnerUsername(session.getOwner().getUsername());
+                            dto.setCreatedAt(session.getCreatedAt().toString());
+                            dto.setDueDate(
+                                    session.getDueDate() != null
+                                            ? session.getDueDate().toString()
+                                            : null);
+                            dto.setMyStatus(p.getStatus());
+                            return dto;
+                        })
+                .collect(java.util.stream.Collectors.toList());
+    }
+
+    /**
+     * Get detailed information about a sign request.
+     *
+     * @param sessionId The session ID
+     * @param user The participant user
+     * @return Sign request detail
+     */
+    @Transactional(readOnly = true)
+    public stirling.software.proprietary.workflow.dto.SignRequestDetailDTO getSignRequestDetail(
+            String sessionId, User user) {
+        WorkflowSession session = getSession(sessionId);
+        WorkflowParticipant participant = getParticipantForUser(session, user);
+
+        stirling.software.proprietary.workflow.dto.SignRequestDetailDTO dto =
+                new stirling.software.proprietary.workflow.dto.SignRequestDetailDTO();
+        dto.setSessionId(session.getSessionId());
+        dto.setDocumentName(session.getDocumentName());
+        dto.setOwnerUsername(session.getOwner().getUsername());
+        dto.setMessage(session.getMessage());
+        dto.setDueDate(session.getDueDate());
+        dto.setCreatedAt(session.getCreatedAt().toString());
+        dto.setMyStatus(participant.getStatus());
+
+        // Load signature appearance settings from workflow metadata
+        Map<String, Object> metadata = session.getWorkflowMetadata();
+        if (metadata != null && !metadata.isEmpty()) {
+            dto.setShowSignature(
+                    metadata.containsKey("showSignature")
+                            ? (Boolean) metadata.get("showSignature")
+                            : false);
+            dto.setPageNumber(
+                    metadata.containsKey("pageNumber")
+                            ? ((Number) metadata.get("pageNumber")).intValue()
+                            : null);
+            dto.setReason(metadata.containsKey("reason") ? (String) metadata.get("reason") : null);
+            dto.setLocation(
+                    metadata.containsKey("location") ? (String) metadata.get("location") : null);
+            dto.setShowLogo(
+                    metadata.containsKey("showLogo") ? (Boolean) metadata.get("showLogo") : false);
+        } else {
+            // Default values if no metadata
+            dto.setShowSignature(false);
+            dto.setPageNumber(null);
+            dto.setReason(null);
+            dto.setLocation(null);
+            dto.setShowLogo(false);
+        }
+
+        // Update status to VIEWED if it was NOTIFIED
+        if (participant.getStatus() == ParticipantStatus.NOTIFIED) {
+            participant.setStatus(ParticipantStatus.VIEWED);
+            workflowParticipantRepository.save(participant);
+        }
+
+        return dto;
+    }
+
+    /**
+     * Get the document for a sign request.
+     *
+     * <p>After finalization, returns the signed document. Before finalization, returns the
+     * original.
+     *
+     * @param sessionId The session ID
+     * @param user The participant user
+     * @return PDF document bytes
+     */
+    @Transactional(readOnly = true)
+    public byte[] getSignRequestDocument(String sessionId, User user) {
+        WorkflowSession session = getSession(sessionId);
+        getParticipantForUser(session, user); // Verify participant access
+
+        // After finalization, serve the signed document instead of the original
+        StoredFile fileToServe =
+                (session.isFinalized() && session.getProcessedFile() != null)
+                        ? session.getProcessedFile()
+                        : session.getOriginalFile();
+
+        if (fileToServe == null) {
+            throw new ResponseStatusException(
+                    HttpStatus.NOT_FOUND, "Document not available for this session");
+        }
+
+        try {
+            org.springframework.core.io.Resource resource =
+                    storageProvider.load(fileToServe.getStorageKey());
+            return resource.getContentAsByteArray();
+        } catch (IOException e) {
+            log.error("Failed to retrieve document for session {}", sessionId, e);
+            throw new ResponseStatusException(
+                    HttpStatus.INTERNAL_SERVER_ERROR, "Failed to retrieve document");
+        }
+    }
+
+    /**
+     * Sign a document in a workflow session.
+     *
+     * @param sessionId The session ID
+     * @param user The participant user
+     * @param request Sign document request with certificate and optional wet signature
+     */
+    public void signDocument(
+            String sessionId,
+            User user,
+            stirling.software.proprietary.workflow.dto.SignDocumentRequest request) {
+        WorkflowSession session = getSession(sessionId);
+        WorkflowParticipant participant = getParticipantForUser(session, user);
+
+        if (participant.getStatus() == ParticipantStatus.SIGNED) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Document already signed by this user");
+        }
+
+        if (participant.getStatus() == ParticipantStatus.DECLINED) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Cannot sign after declining");
+        }
+
+        // Build metadata JSON containing certificate submission and wet signature data
+        // Merge with existing metadata if present (preserves owner-configured appearance
+        // settings)
+        Map<String, Object> metadata = new HashMap<>();
+
+        // Get existing metadata if present
+        Map<String, Object> existingMetadata = participant.getParticipantMetadata();
+        if (existingMetadata != null && !existingMetadata.isEmpty()) {
+            metadata = new HashMap<>(existingMetadata);
+        }
+
+        // 1. Store certificate submission data
+        Map<String, Object> certSubmission = new HashMap<>();
+        certSubmission.put("certType", request.getCertType());
+        certSubmission.put("password", metadataEncryptionService.encrypt(request.getPassword()));
+
+        // Store keystore files as base64 if provided
+        if (request.getP12File() != null && !request.getP12File().isEmpty()) {
+            try {
+                byte[] keystoreBytes = request.getP12File().getBytes();
+                String base64Keystore = java.util.Base64.getEncoder().encodeToString(keystoreBytes);
+                certSubmission.put("p12Keystore", base64Keystore);
+            } catch (IOException e) {
+                log.error("Failed to read P12 keystore file", e);
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST, "Failed to process certificate file");
+            }
+        }
+
+        // Note: Signature appearance settings (showSignature, pageNumber, location, reason,
+        // showLogo)
+        // may already be in metadata if owner configured them when adding participant.
+        // If not present, the finalization process will use defaults.
+
+        metadata.put("certificateSubmission", certSubmission);
+
+        // 2. Parse wet signatures from JSON string if provided
+        if (request.getWetSignaturesData() != null && !request.getWetSignaturesData().isBlank()) {
+            try {
+                List<WetSignatureMetadata> wetSigs =
+                        objectMapper.readValue(
+                                request.getWetSignaturesData(),
+                                new TypeReference<List<WetSignatureMetadata>>() {});
+                if (wetSigs.size() > WetSignatureMetadata.MAX_SIGNATURES_PER_PARTICIPANT) {
+                    throw new ResponseStatusException(
+                            HttpStatus.BAD_REQUEST, "Too many wet signatures submitted");
+                }
+                request.setWetSignatures(wetSigs);
+                log.info("Parsed {} wet signatures from wetSignaturesData", wetSigs.size());
+            } catch (JacksonException e) {
+                log.error("Failed to parse wetSignaturesData: {}", e.getMessage());
+                throw new ResponseStatusException(
+                        HttpStatus.BAD_REQUEST, "Invalid wet signatures data");
+            }
+        }
+
+        // 3. Store wet signatures metadata if provided (supports multiple signatures)
+        if (request.hasWetSignatures()) {
+            List<WetSignatureMetadata> wetSigs = request.extractWetSignatureMetadata();
+            List<Map<String, Object>> wetSignatures = new ArrayList<>();
+
+            for (WetSignatureMetadata wetSig : wetSigs) {
+                Map<String, Object> wetSignature = new HashMap<>();
+                wetSignature.put("type", wetSig.getType());
+                wetSignature.put("data", wetSig.getData());
+                wetSignature.put("page", wetSig.getPage());
+                wetSignature.put("x", wetSig.getX());
+                wetSignature.put("y", wetSig.getY());
+                wetSignature.put("width", wetSig.getWidth());
+                wetSignature.put("height", wetSig.getHeight());
+                wetSignatures.add(wetSignature);
+            }
+
+            // Always store as array
+            metadata.put("wetSignatures", wetSignatures);
+
+            log.info(
+                    "Stored {} wet signature(s) metadata for participant {}",
+                    wetSignatures.size(),
+                    user.getUsername());
+        }
+
+        // 4. Store metadata in participant (JPA converter handles JSON serialization)
+        participant.setParticipantMetadata(metadata);
+        log.info(
+                "Stored signature metadata for participant ID {}, email {}: {} wet signatures, cert type: {}",
+                participant.getId(),
+                user.getUsername(),
+                metadata.containsKey("wetSignatures")
+                        ? ((List<?>) metadata.get("wetSignatures")).size()
+                        : 0,
+                ((Map<?, ?>) metadata.get("certificateSubmission")).get("certType"));
+
+        // 5. Update participant status
+        participant.setStatus(ParticipantStatus.SIGNED);
+        workflowParticipantRepository.save(participant);
+
+        log.info(
+                "User {} signed document in session {} - certificate and signature data stored",
+                user.getUsername(),
+                sessionId);
+    }
+
+    /**
+     * Decline a sign request.
+     *
+     * @param sessionId The session ID
+     * @param user The participant user
+     */
+    public void declineSignRequest(String sessionId, User user) {
+        WorkflowSession session = getSession(sessionId);
+        WorkflowParticipant participant = getParticipantForUser(session, user);
+
+        if (participant.getStatus() == ParticipantStatus.SIGNED) {
+            throw new ResponseStatusException(
+                    HttpStatus.BAD_REQUEST, "Cannot decline after signing");
+        }
+
+        participant.setStatus(ParticipantStatus.DECLINED);
+        workflowParticipantRepository.save(participant); // updatedAt is auto-updated
+
+        log.info("User {} declined sign request for session {}", user.getUsername(), sessionId);
+    }
+
+    /**
+     * Get participant record for a user in a session.
+     *
+     * @param session The workflow session
+     * @param user The user
+     * @return Participant record
+     * @throws ResponseStatusException if user is not a participant
+     */
+    private WorkflowParticipant getParticipantForUser(WorkflowSession session, User user) {
+        return session.getParticipants().stream()
+                .filter(p -> p.getUser() != null && p.getUser().equals(user))
+                .findFirst()
+                .orElseThrow(
+                        () ->
+                                new ResponseStatusException(
+                                        HttpStatus.FORBIDDEN,
+                                        "User is not a participant in this session"));
+    }
+
+    /** Helper class to wrap byte array as MultipartFile. */
+    private static class ByteArrayMultipartFile implements MultipartFile {
+        private final byte[] content;
+        private final String filename;
+
+        public ByteArrayMultipartFile(byte[] content, String filename) {
+            this.content = content;
+            this.filename = filename;
+        }
+
+        @Override
+        public String getName() {
+            return "file";
+        }
+
+        @Override
+        public String getOriginalFilename() {
+            return filename;
+        }
+
+        @Override
+        public String getContentType() {
+            return "application/pdf";
+        }
+
+        @Override
+        public boolean isEmpty() {
+            return content == null || content.length == 0;
+        }
+
+        @Override
+        public long getSize() {
+            return content.length;
+        }
+
+        @Override
+        public byte[] getBytes() {
+            return content;
+        }
+
+        @Override
+        public java.io.InputStream getInputStream() {
+            return new java.io.ByteArrayInputStream(content);
+        }
+
+        @Override
+        public void transferTo(java.io.File dest) throws IOException {
+            java.nio.file.Files.write(dest.toPath(), content);
+        }
+    }
+}

app/proprietary/src/main/java/stirling/software/proprietary/workflow/util/WorkflowMapper.java

@@ -0,0 +1,169 @@
+package stirling.software.proprietary.workflow.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import stirling.software.proprietary.workflow.dto.ParticipantResponse;
+import stirling.software.proprietary.workflow.dto.WetSignatureMetadata;
+import stirling.software.proprietary.workflow.dto.WorkflowSessionResponse;
+import stirling.software.proprietary.workflow.model.WorkflowParticipant;
+import stirling.software.proprietary.workflow.model.WorkflowSession;
+
+/**
+ * Utility class for mapping workflow entities to DTOs. Centralizes conversion logic for consistent
+ * API responses.
+ */
+public class WorkflowMapper {
+
+    /** Converts a WorkflowSession entity to a response DTO. */
+    public static WorkflowSessionResponse toResponse(WorkflowSession session) {
+        return toResponse(session, null);
+    }
+
+    /**
+     * Converts a WorkflowSession entity to a response DTO with optional wet signature extraction.
+     *
+     * @param session The workflow session entity
+     * @param objectMapper ObjectMapper for JSON processing (null to skip wet signature extraction)
+     * @return WorkflowSessionResponse with participants (and wet signatures if objectMapper
+     *     provided)
+     */
+    public static WorkflowSessionResponse toResponse(
+            WorkflowSession session, ObjectMapper objectMapper) {
+        if (session == null) {
+            return null;
+        }
+
+        WorkflowSessionResponse response = new WorkflowSessionResponse();
+        response.setSessionId(session.getSessionId());
+        response.setOwnerId(session.getOwner().getId());
+        response.setOwnerUsername(session.getOwner().getUsername());
+        response.setWorkflowType(session.getWorkflowType());
+        response.setDocumentName(session.getDocumentName());
+        response.setOwnerEmail(session.getOwnerEmail());
+        response.setMessage(session.getMessage());
+        response.setDueDate(session.getDueDate());
+        response.setStatus(session.getStatus());
+        response.setFinalized(session.isFinalized());
+        response.setCreatedAt(session.getCreatedAt());
+        response.setUpdatedAt(session.getUpdatedAt());
+        response.setHasProcessedFile(session.hasProcessedFile());
+
+        if (session.getOriginalFile() != null) {
+            response.setOriginalFileId(session.getOriginalFile().getId());
+        }
+        if (session.getProcessedFile() != null) {
+            response.setProcessedFileId(session.getProcessedFile().getId());
+        }
+
+        // Convert participants (with wet signatures if objectMapper provided)
+        if (objectMapper != null) {
+            response.setParticipants(
+                    session.getParticipants().stream()
+                            .map(p -> toParticipantResponse(p, objectMapper))
+                            .collect(Collectors.toList()));
+        } else {
+            response.setParticipants(
+                    session.getParticipants().stream()
+                            .map(WorkflowMapper::toParticipantResponse)
+                            .collect(Collectors.toList()));
+        }
+
+        // Calculate participant counts
+        response.setParticipantCount(session.getParticipants().size());
+        response.setSignedCount(
+                (int)
+                        session.getParticipants().stream()
+                                .filter(
+                                        p ->
+                                                p.getStatus()
+                                                        == stirling.software.proprietary.workflow
+                                                                .model.ParticipantStatus.SIGNED)
+                                .count());
+
+        return response;
+    }
+
+    /** Converts a WorkflowParticipant entity to a response DTO. */
+    public static ParticipantResponse toParticipantResponse(WorkflowParticipant participant) {
+        if (participant == null) {
+            return null;
+        }
+
+        ParticipantResponse response = new ParticipantResponse();
+        response.setId(participant.getId());
+        if (participant.getUser() != null) {
+            response.setUserId(participant.getUser().getId());
+        }
+        response.setEmail(participant.getEmail());
+        response.setName(participant.getName());
+        response.setStatus(participant.getStatus());
+        response.setShareToken(participant.getShareToken());
+        response.setAccessRole(participant.getAccessRole());
+        response.setExpiresAt(participant.getExpiresAt());
+        response.setLastUpdated(participant.getLastUpdated());
+        response.setHasCompleted(participant.hasCompleted());
+        response.setExpired(
+                participant.isExpired()); // Lombok generates setExpired() for isExpired field
+
+        return response;
+    }
+
+    /**
+     * Converts a WorkflowParticipant entity to a response DTO with wet signatures extracted.
+     *
+     * @param participant The participant entity
+     * @param objectMapper ObjectMapper for JSON processing
+     * @return ParticipantResponse with wet signatures included
+     */
+    public static ParticipantResponse toParticipantResponse(
+            WorkflowParticipant participant, ObjectMapper objectMapper) {
+        ParticipantResponse response = toParticipantResponse(participant);
+        if (response != null) {
+            response.setWetSignatures(extractWetSignatures(participant, objectMapper));
+        }
+        return response;
+    }
+
+    /**
+     * Extracts wet signature metadata from a participant's metadata JSON field.
+     *
+     * @param participant The participant entity
+     * @param objectMapper ObjectMapper for JSON processing
+     * @return List of wet signatures, empty if none found
+     */
+    private static List<WetSignatureMetadata> extractWetSignatures(
+            WorkflowParticipant participant, ObjectMapper objectMapper) {
+        List<WetSignatureMetadata> signatures = new ArrayList<>();
+
+        Map<String, Object> metadata = participant.getParticipantMetadata();
+        if (metadata == null || metadata.isEmpty() || !metadata.containsKey("wetSignatures")) {
+            return signatures;
+        }
+
+        try {
+            // Convert metadata to JsonNode for processing
+            var node = objectMapper.valueToTree(metadata);
+            if (node.has("wetSignatures")) {
+                var wetSigsNode = node.get("wetSignatures");
+                if (wetSigsNode.isArray()) {
+                    for (var wetSigNode : wetSigsNode) {
+                        WetSignatureMetadata wetSig =
+                                objectMapper.treeToValue(wetSigNode, WetSignatureMetadata.class);
+                        signatures.add(wetSig);
+                    }
+                }
+            }
+        } catch (Exception e) {
+            // Log error but don't fail the entire response
+            // In production, you might want to use a logger here
+            return signatures;
+        }
+
+        return signatures;
+    }
+}