feat(security): add RFC 3161 PDF timestamp tool (#5855)

Co-authored-by: Anthony Stirling <[email protected]>

app/common/src/main/java/stirling/software/SPDF/config/EndpointConfiguration.java

@@ -356,6 +356,7 @@ public class EndpointConfiguration {
         addEndpointToGroup("Security", "cert-sign");
         addEndpointToGroup("Security", "remove-cert-sign");
         addEndpointToGroup("Security", "sanitize-pdf");
+        addEndpointToGroup("Security", "timestamp-pdf");
         addEndpointToGroup("Security", "auto-redact");
         addEndpointToGroup("Security", "validate-signature");
         addEndpointToGroup("Security", "add-stamp");
@@ -472,6 +473,7 @@ public class EndpointConfiguration {
         addEndpointToGroup("Java", "auto-rename");
         addEndpointToGroup("Java", "auto-split-pdf");
         addEndpointToGroup("Java", "sanitize-pdf");
+        addEndpointToGroup("Java", "timestamp-pdf");
         addEndpointToGroup("Java", "crop");
         addEndpointToGroup("Java", "get-info-on-pdf");
         addEndpointToGroup("Java", "pdf-to-single-page");

app/common/src/main/java/stirling/software/common/model/ApplicationProperties.java

@@ -251,6 +251,7 @@ public class ApplicationProperties {
         private String customGlobalAPIKey;
         private Jwt jwt = new Jwt();
         private Validation validation = new Validation();
+        private Timestamp timestamp = new Timestamp();
         private String xFrameOptions = "DENY";
 
         public Boolean isAltLogin() {
@@ -569,6 +570,12 @@ public class ApplicationProperties {
                 private boolean hardFail = false;
             }
         }
+
+        @Data
+        public static class Timestamp {
+            private String defaultTsaUrl = "http://timestamp.digicert.com";
+            private List<String> customTsaUrls = new ArrayList<>();
+        }
     }
 
     @Data

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ConfigController.java

@@ -17,6 +17,7 @@ import lombok.extern.slf4j.Slf4j;
 import stirling.software.SPDF.config.EndpointConfiguration;
 import stirling.software.SPDF.config.EndpointConfiguration.EndpointAvailability;
 import stirling.software.SPDF.config.InitialSetup;
+import stirling.software.SPDF.controller.api.security.TimestampController;
 import stirling.software.common.annotations.api.ConfigApi;
 import stirling.software.common.configuration.AppConfig;
 import stirling.software.common.model.ApplicationProperties;
@@ -245,6 +246,13 @@ public class ConfigController {
             // Premium/Enterprise settings
             configData.put("premiumEnabled", applicationProperties.getPremium().isEnabled());
 
+            // Timestamp TSA settings — single source of truth for presets + admin URLs
+            ApplicationProperties.Security.Timestamp tsConfig =
+                    applicationProperties.getSecurity().getTimestamp();
+            configData.put("timestampDefaultTsaUrl", tsConfig.getDefaultTsaUrl());
+            configData.put("timestampCustomTsaUrls", tsConfig.getCustomTsaUrls());
+            configData.put("timestampTsaPresets", TimestampController.TSA_PRESETS);
+
             // Server certificate settings
             configData.put(
                     "serverCertificateEnabled",

app/core/src/main/java/stirling/software/SPDF/controller/api/security/TimestampController.java

@@ -0,0 +1,264 @@
+package stirling.software.SPDF.controller.api.security;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.math.BigInteger;
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.SecureRandom;
+import java.security.Security;
+import java.util.Calendar;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.apache.pdfbox.cos.COSName;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.interactive.digitalsignature.PDSignature;
+import org.bouncycastle.asn1.ASN1ObjectIdentifier;
+import org.bouncycastle.asn1.nist.NISTObjectIdentifiers;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.tsp.TimeStampRequest;
+import org.bouncycastle.tsp.TimeStampRequestGenerator;
+import org.bouncycastle.tsp.TimeStampResponse;
+import org.bouncycastle.tsp.TimeStampToken;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.multipart.MultipartFile;
+
+import io.swagger.v3.oas.annotations.Operation;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.SPDF.config.swagger.StandardPdfResponse;
+import stirling.software.SPDF.model.api.security.TimestampPdfRequest;
+import stirling.software.common.annotations.AutoJobPostMapping;
+import stirling.software.common.annotations.api.SecurityApi;
+import stirling.software.common.model.ApplicationProperties;
+import stirling.software.common.service.CustomPDFDocumentFactory;
+import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.WebResponseUtils;
+
+@Slf4j
+@SecurityApi
+@RequiredArgsConstructor
+public class TimestampController {
+
+    static {
+        Security.addProvider(new BouncyCastleProvider());
+    }
+
+    /** Built-in TSA presets with labels — single source of truth for backend + frontend. */
+    public static final List<Map<String, String>> TSA_PRESETS =
+            List.of(
+                    Map.of("label", "DigiCert", "url", "http://timestamp.digicert.com"),
+                    Map.of("label", "Sectigo", "url", "http://timestamp.sectigo.com"),
+                    Map.of("label", "SSL.com", "url", "http://ts.ssl.com"),
+                    Map.of("label", "FreeTSA", "url", "https://freetsa.org/tsr"),
+                    Map.of("label", "MeSign", "url", "http://tsa.mesign.com"));
+
+    private static final Set<String> ALLOWED_TSA_PRESET_URLS =
+            TSA_PRESETS.stream().map(p -> p.get("url")).collect(Collectors.toUnmodifiableSet());
+
+    private static final int MAX_TSA_RESPONSE_SIZE = 1024 * 1024; // 1 MB
+    private static final SecureRandom SECURE_RANDOM = new SecureRandom();
+
+    private final CustomPDFDocumentFactory pdfDocumentFactory;
+    private final ApplicationProperties applicationProperties;
+
+    @AutoJobPostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/timestamp-pdf")
+    @StandardPdfResponse
+    @Operation(
+            summary = "Add RFC 3161 document timestamp to a PDF",
+            description =
+                    "Contacts a trusted Time Stamp Authority (TSA) server and embeds an RFC 3161"
+                            + " document timestamp into the PDF. Only a SHA-256 hash of the"
+                            + " document is sent to the TSA — the PDF itself never leaves the"
+                            + " server. Input:PDF Output:PDF Type:SISO")
+    public ResponseEntity<byte[]> timestampPdf(@ModelAttribute TimestampPdfRequest request)
+            throws Exception {
+        MultipartFile inputFile = request.getFileInput();
+        ApplicationProperties.Security.Timestamp tsConfig =
+                applicationProperties.getSecurity().getTimestamp();
+
+        // Determine effective TSA URL: use request value if provided, otherwise config default
+        String tsaUrl =
+                (request.getTsaUrl() != null && !request.getTsaUrl().isBlank())
+                        ? request.getTsaUrl()
+                        : tsConfig.getDefaultTsaUrl();
+
+        // Build allowed set: built-in presets + admin-configured custom URLs
+        // Filter null/blank entries and validate protocol (TASK-6)
+        Set<String> allowedUrls = new HashSet<>(ALLOWED_TSA_PRESET_URLS);
+        if (tsConfig.getDefaultTsaUrl() != null
+                && !tsConfig.getDefaultTsaUrl().isBlank()
+                && isValidTsaUrlProtocol(tsConfig.getDefaultTsaUrl())) {
+            allowedUrls.add(tsConfig.getDefaultTsaUrl());
+        }
+        List<String> customUrls = tsConfig.getCustomTsaUrls();
+        if (customUrls != null) {
+            customUrls.stream()
+                    .filter(u -> u != null && !u.isBlank() && isValidTsaUrlProtocol(u))
+                    .forEach(allowedUrls::add);
+        }
+
+        // Normalize for case-insensitive comparison (TASK-12)
+        Set<String> normalizedAllowed =
+                allowedUrls.stream()
+                        .map(TimestampController::normalizeTsaUrl)
+                        .collect(Collectors.toSet());
+
+        // Validate TSA URL against allowed set to prevent SSRF
+        if (!normalizedAllowed.contains(normalizeTsaUrl(tsaUrl))) {
+            throw new IllegalArgumentException(
+                    "TSA URL is not in the allowed list. Contact your administrator to add it"
+                            + " via settings.yml (security.timestamp.customTsaUrls).");
+        }
+
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+
+        try (PDDocument document = pdfDocumentFactory.load(inputFile)) {
+            PDSignature signature = new PDSignature();
+            signature.setType(COSName.DOC_TIME_STAMP);
+            signature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE);
+            signature.setSubFilter(COSName.getPDFName("ETSI.RFC3161"));
+            signature.setSignDate(Calendar.getInstance());
+
+            document.addSignature(signature, content -> requestTimestampToken(content, tsaUrl));
+
+            document.saveIncremental(outputStream);
+        }
+
+        return WebResponseUtils.bytesToWebResponse(
+                outputStream.toByteArray(),
+                GeneralUtils.generateFilename(inputFile.getOriginalFilename(), "_timestamped.pdf"));
+    }
+
+    private byte[] requestTimestampToken(InputStream content, String tsaUrl) throws IOException {
+        HttpURLConnection connection = null;
+        try {
+            // Hash the PDF content byte range with SHA-256
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            byte[] buffer = new byte[8192];
+            int read;
+            while ((read = content.read(buffer)) != -1) {
+                digest.update(buffer, 0, read);
+            }
+            byte[] hash = digest.digest();
+
+            // Build the RFC 3161 timestamp request
+            TimeStampRequestGenerator generator = new TimeStampRequestGenerator();
+            generator.setCertReq(true);
+            BigInteger nonce = BigInteger.valueOf(SECURE_RANDOM.nextLong() & Long.MAX_VALUE);
+            ASN1ObjectIdentifier digestAlgorithm = NISTObjectIdentifiers.id_sha256;
+            TimeStampRequest tsaRequest = generator.generate(digestAlgorithm, hash, nonce);
+            byte[] requestBytes = tsaRequest.getEncoded();
+
+            // Contact the TSA server (redirects disabled to prevent SSRF via redirect)
+            connection = (HttpURLConnection) URI.create(tsaUrl).toURL().openConnection();
+            connection.setInstanceFollowRedirects(false);
+            connection.setDoOutput(true);
+            connection.setDoInput(true);
+            connection.setRequestMethod("POST");
+            connection.setRequestProperty("Content-Type", "application/timestamp-query");
+            connection.setRequestProperty("Content-Length", String.valueOf(requestBytes.length));
+            connection.setConnectTimeout(30_000);
+            connection.setReadTimeout(30_000);
+
+            try (OutputStream out = connection.getOutputStream()) {
+                out.write(requestBytes);
+            }
+
+            int responseCode = connection.getResponseCode();
+            if (responseCode != HttpURLConnection.HTTP_OK) {
+                // Read error stream for debugging (TASK-5)
+                String errorBody = readErrorStream(connection);
+                throw new IOException(
+                        "TSA server returned HTTP "
+                                + responseCode
+                                + " for URL: "
+                                + tsaUrl
+                                + (errorBody.isEmpty() ? "" : " — " + errorBody));
+            }
+
+            // Read response with size limit to prevent OOM (TASK-4)
+            byte[] responseBytes;
+            try (InputStream in = connection.getInputStream()) {
+                responseBytes = in.readNBytes(MAX_TSA_RESPONSE_SIZE);
+                if (in.read() != -1) {
+                    throw new IOException(
+                            "TSA response exceeds maximum allowed size of "
+                                    + MAX_TSA_RESPONSE_SIZE
+                                    + " bytes");
+                }
+            }
+
+            // Parse and validate the TSA response
+            TimeStampResponse tsaResponse = new TimeStampResponse(responseBytes);
+            tsaResponse.validate(tsaRequest);
+
+            TimeStampToken token = tsaResponse.getTimeStampToken();
+            if (token == null) {
+                throw new IOException(
+                        "TSA server did not return a timestamp token. Status: "
+                                + tsaResponse.getStatus());
+            }
+
+            log.info(
+                    "RFC 3161 timestamp obtained from {} at {}",
+                    tsaUrl,
+                    token.getTimeStampInfo().getGenTime());
+
+            return token.getEncoded();
+
+        } catch (IOException e) {
+            throw e;
+        } catch (Exception e) {
+            throw new IOException(
+                    "Failed to obtain RFC 3161 timestamp from " + tsaUrl + ": " + e.getMessage(),
+                    e);
+        } finally {
+            // Always disconnect to release the underlying socket (TASK-1)
+            if (connection != null) {
+                connection.disconnect();
+            }
+        }
+    }
+
+    private static boolean isValidTsaUrlProtocol(String url) {
+        String lower = url.toLowerCase(Locale.ROOT);
+        return lower.startsWith("http://") || lower.startsWith("https://");
+    }
+
+    private static String normalizeTsaUrl(String url) {
+        try {
+            URI uri = URI.create(url.trim());
+            String scheme = uri.getScheme() == null ? "" : uri.getScheme().toLowerCase(Locale.ROOT);
+            String host = uri.getHost() == null ? "" : uri.getHost().toLowerCase(Locale.ROOT);
+            int port = uri.getPort();
+            String path = uri.getPath() == null ? "" : uri.getPath();
+            return scheme + "://" + host + (port == -1 ? "" : ":" + port) + path;
+        } catch (Exception e) {
+            return url.toLowerCase(Locale.ROOT);
+        }
+    }
+
+    private static String readErrorStream(HttpURLConnection connection) {
+        try (InputStream err = connection.getErrorStream()) {
+            if (err == null) return "";
+            byte[] body = err.readNBytes(2048);
+            return new String(body, StandardCharsets.UTF_8).trim();
+        } catch (IOException e) {
+            return "";
+        }
+    }
+}

app/core/src/main/java/stirling/software/SPDF/model/api/security/TimestampPdfRequest.java

@@ -0,0 +1,24 @@
+package stirling.software.SPDF.model.api.security;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+import stirling.software.common.model.api.PDFFile;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+public class TimestampPdfRequest extends PDFFile {
+
+    @Schema(
+            description =
+                    "URL of the RFC 3161 Time Stamp Authority (TSA) server."
+                            + " Must be one of the built-in presets (DigiCert, Sectigo, SSL.com,"
+                            + " FreeTSA, MeSign) or an admin-configured URL in"
+                            + " settings.yml (security.timestamp.customTsaUrls)."
+                            + " If omitted, the server default is used.",
+            defaultValue = "http://timestamp.digicert.com",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED)
+    private String tsaUrl;
+}

app/core/src/main/resources/settings.yml.template

@@ -65,7 +65,7 @@ security:
     enableKeyRotation: true # Set to 'true' to enable key pair rotation
     enableKeyCleanup: true # Set to 'true' to enable key pair cleanup
     tokenExpiryMinutes: 1440 # JWT access token lifetime in minutes for web clients (1 day).
-    desktopTokenExpiryMinutes: 43200 # JWT access token lifetime in minutes for desktop clients (30 days). 
+    desktopTokenExpiryMinutes: 43200 # JWT access token lifetime in minutes for desktop clients (30 days).
     allowedClockSkewSeconds: 60 # Allowed JWT validation clock skew in seconds to tolerate small client/server time drift.
     refreshGraceMinutes: 15 # Allow refresh using an expired access token only within this many minutes after expiry.
   validation: # PDF signature validation settings
@@ -84,6 +84,9 @@ security:
     revocation:
       mode: none # Revocation checking mode: 'none' (disabled), 'ocsp' (OCSP only), 'crl' (CRL only), 'ocsp+crl' (OCSP with CRL fallback)
       hardFail: false # Fail validation if revocation status cannot be determined (true=strict, false=soft-fail)
+  timestamp:
+    defaultTsaUrl: http://timestamp.digicert.com # Default TSA server for RFC 3161 document timestamps
+    customTsaUrls: [] # Admin-configured additional TSA URLs (e.g. ['https://internal-tsa.corp.com/timestamp']). Users can only select from built-in presets and these URLs.
   xFrameOptions: DENY # X-Frame-Options header value. Options: 'DENY' (default, prevents all framing), 'SAMEORIGIN' (allows framing from same domain), 'DISABLED' (no X-Frame-Options header sent). Note: automatically set to DISABLED when login is disabled
 
 premium:

app/core/src/test/java/stirling/software/SPDF/controller/api/security/TimestampControllerTest.java

@@ -0,0 +1,288 @@
+package stirling.software.SPDF.controller.api.security;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import java.io.ByteArrayOutputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.junit.jupiter.MockitoSettings;
+import org.mockito.quality.Strictness;
+import org.springframework.http.MediaType;
+import org.springframework.mock.web.MockMultipartFile;
+
+import stirling.software.SPDF.model.api.security.TimestampPdfRequest;
+import stirling.software.common.model.ApplicationProperties;
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@DisplayName("TimestampController security tests")
+@ExtendWith(MockitoExtension.class)
+@MockitoSettings(strictness = Strictness.LENIENT)
+class TimestampControllerTest {
+
+    @Mock private CustomPDFDocumentFactory pdfDocumentFactory;
+    @Mock private ApplicationProperties applicationProperties;
+
+    @InjectMocks private TimestampController controller;
+
+    private ApplicationProperties.Security security;
+    private ApplicationProperties.Security.Timestamp tsConfig;
+    private MockMultipartFile mockPdfFile;
+
+    @BeforeEach
+    void setUp() {
+        security = new ApplicationProperties.Security();
+        tsConfig = new ApplicationProperties.Security.Timestamp();
+        security.setTimestamp(tsConfig);
+
+        when(applicationProperties.getSecurity()).thenReturn(security);
+
+        mockPdfFile =
+                new MockMultipartFile(
+                        "fileInput",
+                        "test.pdf",
+                        MediaType.APPLICATION_PDF_VALUE,
+                        new byte[] {0x25, 0x50, 0x44, 0x46}); // %PDF header
+    }
+
+    private TimestampPdfRequest createRequest(String tsaUrl) {
+        TimestampPdfRequest request = new TimestampPdfRequest();
+        request.setFileInput(mockPdfFile);
+        request.setTsaUrl(tsaUrl);
+        return request;
+    }
+
+    @Nested
+    @DisplayName("URL Allowlist Validation")
+    class AllowlistTests {
+
+        @ParameterizedTest
+        @DisplayName("Should accept built-in preset URLs")
+        @ValueSource(
+                strings = {
+                    "http://timestamp.digicert.com",
+                    "http://timestamp.sectigo.com",
+                    "http://ts.ssl.com",
+                    "https://freetsa.org/tsr",
+                    "http://tsa.mesign.com"
+                })
+        void shouldAcceptPresetUrls(String presetUrl) throws Exception {
+            // Mock PDF loading to avoid actual TSA call — we only test validation here
+            PDDocument mockDoc = mock(PDDocument.class);
+            when(pdfDocumentFactory.load(any(MockMultipartFile.class))).thenReturn(mockDoc);
+            doAnswer(
+                            inv -> {
+                                ByteArrayOutputStream baos = inv.getArgument(0);
+                                baos.write(new byte[] {0x25, 0x50, 0x44, 0x46});
+                                return null;
+                            })
+                    .when(mockDoc)
+                    .saveIncremental(any(ByteArrayOutputStream.class));
+            doNothing().when(mockDoc).close();
+
+            TimestampPdfRequest request = createRequest(presetUrl);
+
+            // The method should NOT throw IllegalArgumentException for preset URLs
+            // It may throw IOException when contacting the TSA — that's expected
+            try {
+                controller.timestampPdf(request);
+            } catch (IllegalArgumentException e) {
+                fail("Preset URL should be in the allowlist: " + presetUrl);
+            } catch (Exception e) {
+                // IOException from TSA contact is expected in test env — validation passed
+                assertFalse(
+                        e instanceof IllegalArgumentException,
+                        "Should not reject preset URL: " + presetUrl);
+            }
+        }
+
+        @Test
+        @DisplayName("Should reject arbitrary URL not in allowlist")
+        void shouldRejectArbitraryUrl() {
+            TimestampPdfRequest request = createRequest("http://evil.internal.corp/ssrf");
+
+            IllegalArgumentException ex =
+                    assertThrows(
+                            IllegalArgumentException.class, () -> controller.timestampPdf(request));
+            assertTrue(ex.getMessage().contains("not in the allowed list"));
+        }
+
+        @ParameterizedTest
+        @DisplayName("Should reject SSRF-prone URLs")
+        @ValueSource(
+                strings = {
+                    "http://localhost/timestamp",
+                    "http://127.0.0.1:8080/internal",
+                    "http://192.168.1.1/admin",
+                    "http://10.0.0.1/metadata",
+                    "http://169.254.169.254/latest/meta-data",
+                    "file:///etc/passwd",
+                    "ftp://internal-server/data",
+                    "gopher://internal:25/",
+                })
+        void shouldRejectSsrfUrls(String ssrfUrl) {
+            TimestampPdfRequest request = createRequest(ssrfUrl);
+
+            assertThrows(
+                    IllegalArgumentException.class,
+                    () -> controller.timestampPdf(request),
+                    "Should reject SSRF URL: " + ssrfUrl);
+        }
+
+        @Test
+        @DisplayName("Should accept admin-configured custom URL")
+        void shouldAcceptAdminCustomUrl() throws Exception {
+            String customUrl = "https://internal-tsa.corp.com/timestamp";
+            tsConfig.setCustomTsaUrls(new ArrayList<>(List.of(customUrl)));
+
+            PDDocument mockDoc = mock(PDDocument.class);
+            when(pdfDocumentFactory.load(any(MockMultipartFile.class))).thenReturn(mockDoc);
+            doNothing().when(mockDoc).close();
+
+            TimestampPdfRequest request = createRequest(customUrl);
+
+            try {
+                controller.timestampPdf(request);
+            } catch (IllegalArgumentException e) {
+                fail("Admin-configured custom URL should be accepted: " + customUrl);
+            } catch (Exception e) {
+                // IOException from TSA contact is expected
+                assertFalse(e instanceof IllegalArgumentException);
+            }
+        }
+
+        @Test
+        @DisplayName("Should reject URL not in admin custom list")
+        void shouldRejectUrlNotInAdminList() {
+            tsConfig.setCustomTsaUrls(
+                    new ArrayList<>(List.of("https://allowed-tsa.corp.com/timestamp")));
+
+            TimestampPdfRequest request =
+                    createRequest("https://not-allowed-tsa.evil.com/timestamp");
+
+            assertThrows(IllegalArgumentException.class, () -> controller.timestampPdf(request));
+        }
+    }
+
+    @Nested
+    @DisplayName("Default TSA URL Fallback")
+    class DefaultFallbackTests {
+
+        @Test
+        @DisplayName("Should use config default when tsaUrl is null")
+        void shouldFallbackToConfigDefault() throws Exception {
+            tsConfig.setDefaultTsaUrl("http://timestamp.digicert.com");
+
+            PDDocument mockDoc = mock(PDDocument.class);
+            when(pdfDocumentFactory.load(any(MockMultipartFile.class))).thenReturn(mockDoc);
+            doNothing().when(mockDoc).close();
+
+            TimestampPdfRequest request = createRequest(null);
+
+            // Should not throw IllegalArgumentException — default is in presets
+            try {
+                controller.timestampPdf(request);
+            } catch (IllegalArgumentException e) {
+                fail("Default TSA URL should be accepted");
+            } catch (Exception e) {
+                // IOException expected
+            }
+        }
+
+        @Test
+        @DisplayName("Should use config default when tsaUrl is blank")
+        void shouldFallbackToConfigDefaultWhenBlank() throws Exception {
+            tsConfig.setDefaultTsaUrl("http://timestamp.digicert.com");
+
+            PDDocument mockDoc = mock(PDDocument.class);
+            when(pdfDocumentFactory.load(any(MockMultipartFile.class))).thenReturn(mockDoc);
+            doNothing().when(mockDoc).close();
+
+            TimestampPdfRequest request = createRequest("   ");
+
+            try {
+                controller.timestampPdf(request);
+            } catch (IllegalArgumentException e) {
+                fail("Should fallback to config default when blank");
+            } catch (Exception e) {
+                // IOException expected
+            }
+        }
+    }
+
+    @Nested
+    @DisplayName("Config URL Validation (TASK-6)")
+    class ConfigValidationTests {
+
+        @Test
+        @DisplayName("Should filter blank entries from admin custom URLs")
+        void shouldFilterBlankCustomUrls() {
+            List<String> customUrls = new ArrayList<>(List.of("", "  ", "http://valid-tsa.com/ts"));
+            tsConfig.setCustomTsaUrls(customUrls);
+
+            TimestampPdfRequest request = createRequest("http://evil.com/ssrf");
+
+            // Blank entries should not expand the allowlist
+            assertThrows(IllegalArgumentException.class, () -> controller.timestampPdf(request));
+        }
+
+        @Test
+        @DisplayName("Should reject file:// protocol in admin config")
+        void shouldRejectFileProtocolInConfig() {
+            tsConfig.setDefaultTsaUrl("file:///etc/passwd");
+            tsConfig.setCustomTsaUrls(new ArrayList<>());
+
+            TimestampPdfRequest request = createRequest(null);
+
+            // file:// default should be filtered out, leaving no valid default
+            // The request falls back to "file:///etc/passwd" which is not in allowed set
+            assertThrows(Exception.class, () -> controller.timestampPdf(request));
+        }
+
+        @Test
+        @DisplayName("Should reject ftp:// protocol in custom URLs")
+        void shouldRejectFtpProtocolInCustomUrls() {
+            tsConfig.setCustomTsaUrls(new ArrayList<>(List.of("ftp://internal-server/timestamp")));
+
+            TimestampPdfRequest request = createRequest("ftp://internal-server/timestamp");
+
+            assertThrows(IllegalArgumentException.class, () -> controller.timestampPdf(request));
+        }
+    }
+
+    @Nested
+    @DisplayName("Case-insensitive URL matching (TASK-12)")
+    class CaseInsensitiveTests {
+
+        @Test
+        @DisplayName("Should match URLs regardless of case")
+        void shouldMatchCaseInsensitive() throws Exception {
+            PDDocument mockDoc = mock(PDDocument.class);
+            when(pdfDocumentFactory.load(any(MockMultipartFile.class))).thenReturn(mockDoc);
+            doNothing().when(mockDoc).close();
+
+            TimestampPdfRequest request = createRequest("HTTP://TIMESTAMP.DIGICERT.COM");
+
+            try {
+                controller.timestampPdf(request);
+            } catch (IllegalArgumentException e) {
+                fail("Case-insensitive URL should match preset");
+            } catch (Exception e) {
+                // IOException expected
+                assertFalse(e instanceof IllegalArgumentException);
+            }
+        }
+    }
+}

frontend/public/locales/en-GB/translation.toml

@@ -3773,6 +3773,11 @@ desc = "Adds signature to PDF by drawing, text or image"
 tags = "signature,autograph,e-sign,electronic signature,digital signature,sign document,approval,signoff,authorize,endorse,ink signature,handwriting"
 title = "Sign"
 
+[home.timestampPdf]
+desc = "Add an RFC 3161 document timestamp to prove when your PDF existed"
+tags = "timestamp,RFC 3161,TSA,time stamp authority,document timestamp,proof of existence,timestamp token,trusted timestamp,sign timestamp,notarise"
+title = "Timestamp PDF"
+
 [home.split]
 desc = "Split PDFs into multiple documents"
 tags = "divide,separate,break,split,extract pages,separate pages,divide document,break apart,separate files,unbind,split by page,divide by chapter"
@@ -5718,6 +5723,32 @@ text = "Rotate your PDF pages clockwise or anticlockwise in 90-degree increments
 [rotate.tooltip.header]
 title = "Rotate Settings Overview"
 
+[timestampPdf]
+completed = "PDF timestamped successfully"
+desc = "Add an RFC 3161 document timestamp to your PDF using a trusted Time Stamp Authority (TSA) server."
+filenamePrefix = "timestamped"
+results = "Timestamp Results"
+submit = "Apply Timestamp"
+title = "Timestamp PDF"
+
+[timestampPdf.error]
+failed = "An error occurred while timestamping the PDF."
+generic = "Timestamping failed"
+
+[timestampPdf.files]
+placeholder = "Select a PDF file in the main view to get started"
+
+[timestampPdf.options]
+note = "Only a SHA-256 hash of your document is sent to the TSA server; the PDF file itself is never sent to the TSA server."
+title = "Timestamp Server (TSA)"
+
+[timestampPdf.options.tsaUrl]
+desc = "Pick a trusted Time Stamp Authority"
+label = "Select a TSA server"
+
+[timestampPdf.steps]
+settings = "Settings"
+
 [sanitize]
 completed = "Sanitisation completed successfully"
 desc = "Remove potentially harmful elements from PDF files."

frontend/public/locales/fr-FR/translation.toml

@@ -142,6 +142,10 @@ welcome = "Bienvenue"
 white = "Blanc"
 WorkInProgess = "En cours de développement, merci de nous remonter les problèmes que vous pourriez constater!"
 yes = "Oui"
+insufficientCredits = "Insufficient credits. Required: {{requiredCredits}}, Available: {{currentBalance}}, Shortfall: {{shortfall}}"
+loadingCredits = "Checking credits..."
+loadingProStatus = "Checking subscription status..."
+noticeTopUpOrPlan = "Not enough credits, please top up or upgrade to a plan"
 
 [account]
 accountSettings = "Paramètres du compte"
@@ -1557,6 +1561,13 @@ underline = "Souligner"
 undo = "Annuler"
 unsupportedType = "Ce type d’annotation n’est pas entièrement pris en charge pour l’édition."
 width = "Largeur"
+annotationStyle = "Annotation style"
+comment = "Comment"
+comments = "Comments"
+insertText = "Insert Text"
+lineArrow = "Arrow"
+polyline = "Polyline"
+replaceText = "Replace Text"
 
 [app]
 description = "L’alternative gratuite à Adobe Acrobat (10M+ téléchargements)"
@@ -2574,10 +2585,22 @@ title = "Réglage de la qualité"
 [compressPdfs]
 tags = "compresser,réduire,taille,squish,small,tiny"
 
+[config]
+plan = "Plan"
+
 [config.account.overview]
 guestDescription = "Vous êtes connecté en tant qu’invité. Envisagez de mettre à niveau votre compte ci-dessus."
 manageAccountPreferences = "Gérer les préférences de votre compte"
 title = "Paramètres du compte"
+confirmDelete = "Delete My Account"
+deleteAccount = "Delete Account"
+deleteAccountTitle = "Delete Account"
+deleteFailed = "Failed to delete account."
+deleteFailedTitle = "Unable to delete account"
+deleteWarning = "This action is permanent and cannot be undone. All your data will be deleted."
+enterEmailConfirm = "To confirm deletion, please type your email address ({{email}}) below:"
+label = "Overview"
+signedInAs = "Signed in as"
 
 [config.account.upgrade]
 description = "Liez votre compte pour préserver votre historique et accéder à davantage de fonctionnalités !"
@@ -2592,6 +2615,32 @@ socialLogin = "Mettre à niveau avec un compte social"
 title = "Mettre à niveau le compte invité"
 upgradeButton = "Mettre à niveau le compte"
 
+[config.account.profilePicture]
+description = "Upload an image to personalize your account."
+help = "PNG, JPG, or WebP up to 2MB."
+remove = "Remove"
+sizeError = "Please select an image smaller than 2MB."
+switchedToCustom = "Switched to custom picture. You can now upload your own."
+title = "Profile picture"
+upload = "Upload"
+useCustom = "Use custom picture"
+usingProvider = "Using {{provider}} profile picture"
+
+[config.account.profilePicture.cropper]
+cropError = "Failed to crop image. Please try again."
+invalidImage = "Invalid image file. Please select a valid PNG, JPG, or WebP file."
+processing = "Processing crop..."
+save = "Save Cropped Image"
+sizeErrorAfterCrop = "Cropped image is too large. Please zoom out or crop a smaller area."
+title = "Crop Profile Picture"
+zoom = "Zoom"
+
+[config.account.security]
+changePassword = "Change password"
+description = "Manage your password and security settings."
+title = "Passwords & Security"
+update = "Update password"
+
 [config.apiKeys]
 chartAriaLabel = "Utilisation des crédits : inclus {{includedUsed}} sur {{includedTotal}}, achetés {{purchasedUsed}} sur {{purchasedTotal}}"
 copyKeyAriaLabel = "Copier la clé API"
@@ -2614,6 +2663,7 @@ refreshAriaLabel = "Actualiser la clé API"
 schemaLink = "Référence du schéma API"
 totalCredits = "Crédits totaux"
 usage = "Incluez cette clé dans l’en-tête X-API-KEY pour toutes les requêtes API."
+creditsRemaining = "Credits Remaining"
 
 [config.apiKeys.alert]
 apiKeyErrorTitle = "Erreur de clé API"
@@ -2728,6 +2778,15 @@ webOptions = "Options Web vers PDF"
 wordDoc = "Document Word"
 wordDocExt = "Document Word (.docx)"
 zoomLevel = "Niveau de zoom"
+cbrToPdf = "CBR → PDF"
+cbzToPdf = "CBZ → PDF"
+ebookToPdf = "eBook → PDF"
+emlToPdf = "Email → PDF"
+fileToPdf = "Office/Document → PDF"
+pdfToCbr = "PDF → CBR"
+pdfToCbz = "PDF → CBZ"
+pdfToEpub = "PDF → EPUB"
+svgToPdf = "SVG → PDF"
 
 [convert.ebookOptions]
 ebookOptions = "Options eBook vers PDF"
@@ -3713,6 +3772,11 @@ desc = "Recherche et affiche tout JavaScript injecté dans un PDF."
 tags = "javascript,code,script"
 title = "Afficher le JavaScript"
 
+[home.timestampPdf]
+desc = "Ajoutez un horodatage RFC 3161 pour prouver la date d'existence de votre PDF"
+tags = "horodatage,RFC 3161,TSA,autorité de timestamp,horodatage de document,preuve d'existence,jeton d'horodatage,timestamp de confiance,signer horodatage,notariser"
+title = "Horodater le PDF"
+
 [home.sign]
 desc = "Ajoutez une signature au PDF avec un dessin, du texte ou une image."
 tags = "signature,autographe"
@@ -3920,6 +3984,13 @@ username = "Nom d’utilisateur"
 verifyingMfa = "Vérification..."
 verifyMfa = "Vérifier le code"
 youAreLoggedIn = "Vous êtes connecté !"
+backToSignIn = "Back to sign in"
+passwordUpdatedSuccess = "Your password has been updated successfully."
+resetHelp = "Enter your email to receive a secure link to reset your password. If the link has expired, please request a new one."
+resetYourPassword = "Reset your password"
+sendResetLink = "Send reset link"
+subtitle = "Sign back in to Stirling PDF"
+updatePassword = "Update password"
 
 [login.slides.edit]
 alt = "Modifier des PDF"
@@ -4280,6 +4351,15 @@ rightRail = "Le <strong>rail de droite</strong> contient des actions rapides pou
 topBar = "La barre supérieure permet de basculer entre la <strong>Visionneuse</strong>, <strong>l’Éditeur de pages</strong> et <strong>les fichiers actifs</strong>."
 wrapUp = "Voilà les nouveautés de la V2. Ouvrez le menu <strong>Visites guidées</strong> à tout moment pour rejouer ceci, le parcours des outils ou le parcours Admin."
 
+[onboarding.freeTrial]
+afterTrialWithPayment = "Your Pro subscription will start automatically when the trial ends."
+afterTrialWithoutPayment = "After your trial ends, you'll continue with our free tier. Add a payment method to keep Pro access."
+body = "You have full access to Stirling PDF Pro features during your trial. Enjoy unlimited conversions, larger file sizes, and priority processing."
+daysRemaining = "{{days}} days remaining"
+daysRemainingSingular = "{{days}} day remaining"
+title = "Your 30-Day Pro Trial"
+trialEnds = "Trial ends {{date}}"
+
 [overlay-pdfs]
 desc = "Superposer un PDF sur un autre"
 header = "Incrustation de PDF"
@@ -4401,6 +4481,31 @@ dismiss = "Fermer"
 apply = "Appliquer les modifications"
 download = "Télécharger le PDF"
 
+[viewer.comments]
+addComment = "Add comment"
+addCommentPlaceholder = "Add comment..."
+addLink = "Add link"
+addReplyPlaceholder = "Add reply..."
+deleteAnnotationAndComment = "Delete annotation & comment"
+deleteDescription = "This annotation has a comment attached. You can remove just the comment from the sidebar while keeping the annotation, or delete everything."
+deleteTitle = "Remove annotation from comments?"
+goToLink = "Go to link"
+hint = "Place comments with the Comment, Insert Text, or Replace Text tools. They will appear here by page."
+locateAnnotation = "Locate in document"
+moreActions = "More actions"
+nComments = "{{count}} comments"
+oneComment = "1 comment"
+pageLabel = "Page {{page}}"
+placeholder = "Type your comment..."
+removeCommentOnly = "Remove comment only"
+saveReply = "Save reply"
+send = "Send"
+title = "Comments"
+typeComment = "Comment"
+typeInsertText = "Insert Text"
+typeReplaceText = "Replace Text"
+viewComment = "View comment"
+
 [rightRail]
 closeSelected = "Fermer les fichiers sélectionnés"
 selectAll = "Tout sélectionner"
@@ -4433,6 +4538,12 @@ exitRedaction = "Quitter le mode de caviardage"
 save = "Enregistrer"
 downloadAll = "Tout télécharger"
 saveAll = "Tout enregistrer"
+readAloud = "Read Aloud"
+readAloudLanguage = "Language"
+readAloudSpeed = "Speed"
+saveAs = "Save As"
+selectLanguage = "Select language"
+toggleComments = "Comments"
 
 [textAlign]
 left = "Gauche"
@@ -4980,6 +5091,9 @@ selectPlan = "Choisir un plan"
 showComparison = "Comparer toutes les fonctionnalités"
 upgrade = "Mettre à niveau"
 withServer = "+ Plan Server"
+purchase = "Purchase"
+selectCredits = "Select Credit Amount"
+totalCost = "Total Cost"
 
 [plan.activePlan]
 subtitle = "Détails de votre abonnement actuel"
@@ -5069,6 +5183,30 @@ successMessage = "Votre licence a été activée avec succès. Vous pouvez maint
 name = "Team"
 siteLicense = "Licence site"
 
+[plan.api]
+large = "5,000 Credits"
+medium = "1,000 Credits"
+small = "500 Credits"
+xsmall = "100 Credits"
+
+[plan.apiPackages]
+subtitle = "Purchase API credits for your applications"
+title = "API Credit Packages"
+
+[plan.trial]
+badge = "Trial"
+continueWithFree = "Continue with Free"
+daysRemaining = "Your trial ends in {{days}} days"
+endDate = "Expires: {{date}}"
+expired = "Your Trial Has Ended"
+expiredMessage = "Your 30-day Pro trial has expired. Subscribe to Pro to continue accessing premium features, or continue with our free tier."
+freeTierLimitations = "Free tier includes basic PDF tools with usage limits."
+message = ""
+subscribe = "Subscribe to Pro"
+subscribeToPro = "Subscribe to Pro"
+subscriptionScheduled = "Subscription scheduled - starts {{date}}"
+title = "Free Trial Active"
+
 [credits]
 enableOverageBilling = "Activer la facturation de dépassement"
 maybeLater = "Peut-être plus tard"
@@ -5631,6 +5769,32 @@ text = "Faites pivoter les pages de votre PDF dans le sens horaire ou antihorair
 [rotate.tooltip.header]
 title = "Aperçu des paramètres de rotation"
 
+[timestampPdf]
+completed = "PDF horodaté avec succès"
+desc = "Ajoutez un horodatage RFC 3161 à votre PDF via un serveur d'autorité d'horodatage (TSA) de confiance."
+filenamePrefix = "horodaté"
+results = "Résultats de l'horodatage"
+submit = "Appliquer l'horodatage"
+title = "Horodater le PDF"
+
+[timestampPdf.error]
+failed = "Une erreur est survenue lors de l'horodatage du PDF."
+generic = "Échec de l'horodatage"
+
+[timestampPdf.files]
+placeholder = "Sélectionnez un fichier PDF dans la vue principale pour commencer"
+
+[timestampPdf.options]
+note = "Seul le hash SHA-256 de votre document est envoyé au serveur TSA ; le fichier PDF lui-même n'est jamais envoyé au serveur TSA."
+title = "Serveur d'horodatage (TSA)"
+
+[timestampPdf.options.tsaUrl]
+desc = "Choisissez une autorité d'horodatage de confiance"
+label = "Sélectionner un serveur TSA"
+
+[timestampPdf.steps]
+settings = "Paramètres"
+
 [sanitize]
 completed = "Assainissement effectué avec succès"
 desc = "Supprimer les éléments potentiellement nuisibles des fichiers PDF."
@@ -5772,10 +5936,13 @@ logout = "Se déconnecter"
 server = "Serveur"
 title = "Mode de connexion"
 user = "Connecté en tant que"
+localDescription = "You are using the local backend without an account. Some tools requiring cloud processing or a self-hosted server are unavailable."
+signIn = "Sign In"
 
 [settings.connection.mode]
 saas = "Stirling Cloud"
 selfhosted = "Auto-hébergé"
+local = "Local Only"
 
 [settings.planBilling]
 currentPlan = "Offre actuelle"
@@ -5931,6 +6098,9 @@ title = "Politiques et confidentialité"
 [settings.preferences]
 title = "Préférences"
 
+[settings.search]
+placeholder = "Rechercher dans les paramètres…"
+
 [settings.security]
 description = "Mettez à jour votre mot de passe pour sécuriser votre compte."
 title = "Sécurité"
@@ -5988,6 +6158,7 @@ sso = "Authentification unique"
 submit = "Se connecter"
 subtitle = "Saisissez vos identifiants pour continuer"
 title = "Se connecter"
+skipSignIn = "Continue without signing in"
 
 [setup.login.email]
 label = "Email"
@@ -6023,6 +6194,13 @@ title = "Se connecter à Stirling"
 link = "ou connectez-vous à un compte auto-hébergé"
 subtitle = "Saisissez les identifiants du serveur"
 title = "Se connecter au serveur"
+switchToLocal = "Use local tools instead"
+
+[setup.selfhosted.unreachable]
+continueOffline = "Use local tools instead"
+message = "Could not reach {{url}}. Check that the server is running and accessible."
+retry = "Retry"
+title = "Cannot connect to server"
 
 [setup.server]
 subtitle = "Saisissez l’URL de votre serveur auto‑hébergé"
@@ -6036,6 +6214,7 @@ emptyUrl = "Veuillez saisir une URL de serveur"
 invalidUrl = "Format d’URL invalide. Veuillez saisir une URL valide comme https://your-server.com"
 testFailed = "Échec du test de connexion"
 unreachable = "Connexion au serveur impossible"
+configFetchError = "Failed to fetch server configuration: {{error}}"
 
 [setup.server.error.securityDisabled]
 body = "La connexion n'est pas activée sur ce serveur. Pour vous y connecter, vous devez activer l'authentification :"
@@ -6561,6 +6740,7 @@ showDetails = "Afficher les détails"
 unavailable = "Désactivé par l’administrateur du serveur :"
 unavailableDependency = "Indisponible - outil requis manquant sur le serveur :"
 unfavorite = "Retirer des favoris"
+selfHostedOffline = "Requires your Stirling-PDF server (currently offline):"
 
 [toolPanel.modePrompt]
 chooseFullscreen = "Utiliser le mode plein écran"
@@ -7534,3 +7714,37 @@ description = "Clé API Google pour Google Picker API depuis Google Cloud Consol
 [provider.googledrive.appId]
 label = "App ID"
 description = "App ID Google Drive depuis Google Cloud Console"
+
+[selfHosted.offline]
+hideTools = "Hide unavailable tools ▴"
+messageNoFallback = "Tools are unavailable until your server comes back online."
+messageWithFallback = "Some tools require a server connection."
+showTools = "View unavailable tools ▾"
+title = "Your Stirling-PDF server is unreachable"
+toolNotAvailableLocally = "Your Stirling-PDF server is offline and \"{{endpoint}}\" is not available on the local backend."
+
+[connectionMode.status]
+localOffline = "Offline mode running"
+localOnline = "Offline mode running"
+saas = "Connected to Stirling Cloud"
+selfhostedChecking = "Connected to self-hosted server (checking...)"
+selfhostedOffline = "Self-hosted server unreachable"
+selfhostedOnline = "Connected to self-hosted server"
+
+[localMode]
+toolUnavailable = "This tool requires an account. Sign in to Stirling Cloud or connect to a self-hosted server to use it."
+
+[localMode.banner]
+message = "Sign in to unlock all tools."
+signIn = "Sign In"
+title = "Running locally"
+
+[localMode.toolPicker]
+message = "Sign in to unlock all tools."
+signIn = "Sign In"
+
+[tool]
+endpointUnavailable = "This tool is unavailable on your server."
+endpointUnavailableClickable = "Not available in this mode. Click to sign in."
+invalidParams = "Fill in the required settings."
+noFiles = "Add a file to get started."

frontend/src/core/components/tools/timestampPdf/TimestampPdfSettings.tsx

@@ -0,0 +1,80 @@
+import { useEffect, useRef } from "react";
+import { Stack, Text, Select } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import {
+  TimestampPdfParameters,
+  FALLBACK_TSA_PRESETS,
+} from "@app/hooks/tools/timestampPdf/useTimestampPdfParameters";
+import { useAppConfig } from "@app/contexts/AppConfigContext";
+
+interface TimestampPdfSettingsProps {
+  parameters: TimestampPdfParameters;
+  onParameterChange: <K extends keyof TimestampPdfParameters>(
+    key: K,
+    value: TimestampPdfParameters[K]
+  ) => void;
+  disabled?: boolean;
+}
+
+const TimestampPdfSettings = ({
+  parameters,
+  onParameterChange,
+  disabled = false,
+}: TimestampPdfSettingsProps) => {
+  const { t } = useTranslation();
+  const { config } = useAppConfig();
+  const defaultApplied = useRef(false);
+
+  // Use backend presets (single source of truth) with fallback (TASK-10)
+  const presets = config?.timestampTsaPresets ?? FALLBACK_TSA_PRESETS;
+
+  // Build dropdown: presets + admin custom URLs, deduplicated (TASK-9)
+  const presetUrls = new Set(presets.map((p) => p.url));
+  const adminCustomUrls = (config?.timestampCustomTsaUrls ?? []).filter(
+    (url) => !presetUrls.has(url)
+  );
+  const selectData = [
+    ...presets.map((preset) => ({ value: preset.url, label: preset.label })),
+    ...adminCustomUrls.map((url) => ({ value: url, label: url })),
+  ];
+
+  // Apply admin default TSA URL on first config load (TASK-2)
+  useEffect(() => {
+    if (!defaultApplied.current && config?.timestampDefaultTsaUrl) {
+      defaultApplied.current = true;
+      const adminDefault = config.timestampDefaultTsaUrl;
+      if (adminDefault && adminDefault !== parameters.tsaUrl) {
+        onParameterChange("tsaUrl", adminDefault);
+      }
+    }
+  }, [config?.timestampDefaultTsaUrl]);
+
+  return (
+    <Stack gap="md">
+      <Text size="sm" fw={500}>
+        {t("timestampPdf.options.title", "Timestamp Server (TSA)")}
+      </Text>
+
+      <Select
+        label={t("timestampPdf.options.tsaUrl.label", "Select a TSA server")}
+        description={t(
+          "timestampPdf.options.tsaUrl.desc",
+          "Pick a trusted Time Stamp Authority"
+        )}
+        data={selectData}
+        value={parameters.tsaUrl}
+        onChange={(value) => onParameterChange("tsaUrl", value ?? presets[0].url)}
+        disabled={disabled}
+      />
+
+      <Text size="xs" c="dimmed">
+        {t(
+          "timestampPdf.options.note",
+          "Only a SHA-256 hash of your document is sent to the TSA server; the PDF file itself is never sent to the TSA server."
+        )}
+      </Text>
+    </Stack>
+  );
+};
+
+export default TimestampPdfSettings;

frontend/src/core/data/useTranslatedToolRegistry.tsx

@@ -43,6 +43,7 @@ import FormFill from "@app/tools/formFill/FormFill";
 import RemoveCertificateSign from "@app/tools/RemoveCertificateSign";
 import RemoveImage from "@app/tools/RemoveImage";
 import CertSign from "@app/tools/CertSign";
+import TimestampPdf from "@app/tools/TimestampPdf";
 import BookletImposition from "@app/tools/BookletImposition";
 import Flatten from "@app/tools/Flatten";
 import Rotate from "@app/tools/Rotate";
@@ -69,6 +70,7 @@ import { convertOperationConfig } from "@app/hooks/tools/convert/useConvertOpera
 import { removeCertificateSignOperationConfig } from "@app/hooks/tools/removeCertificateSign/useRemoveCertificateSignOperation";
 import { changePermissionsOperationConfig } from "@app/hooks/tools/changePermissions/useChangePermissionsOperation";
 import { certSignOperationConfig } from "@app/hooks/tools/certSign/useCertSignOperation";
+import { timestampPdfOperationConfig } from "@app/hooks/tools/timestampPdf/useTimestampPdfOperation";
 import { bookletImpositionOperationConfig } from "@app/hooks/tools/bookletImposition/useBookletImpositionOperation";
 import { mergeOperationConfig } from '@app/hooks/tools/merge/useMergeOperation';
 import { editTableOfContentsOperationConfig } from '@app/hooks/tools/editTableOfContents/useEditTableOfContentsOperation';
@@ -213,6 +215,19 @@ export function useTranslatedToolCatalog(): TranslatedToolCatalog {
         operationConfig: certSignOperationConfig,
         automationSettings: CertSignAutomationSettings,
       },
+      timestampPdf: {
+        icon: <LocalIcon icon="schedule-rounded" width="1.5rem" height="1.5rem" />,
+        name: t("home.timestampPdf.title", "Timestamp PDF"),
+        component: TimestampPdf,
+        description: t("home.timestampPdf.desc", "Add an RFC 3161 document timestamp to prove when your PDF existed"),
+        categoryId: ToolCategoryId.STANDARD_TOOLS,
+        subcategoryId: SubcategoryId.SIGNING,
+        maxFiles: -1,
+        endpoints: ["timestamp-pdf"],
+        operationConfig: timestampPdfOperationConfig,
+        automationSettings: null,
+        synonyms: getSynonyms(t, "timestampPdf"),
+      },
       sign: {
         icon: <LocalIcon icon="signature-rounded" width="1.5rem" height="1.5rem" />,
         name: t("home.sign.title", "Sign"),

frontend/src/core/hooks/tools/timestampPdf/useTimestampPdfOperation.ts

@@ -0,0 +1,33 @@
+import { useTranslation } from 'react-i18next';
+import { ToolType, useToolOperation } from '@app/hooks/tools/shared/useToolOperation';
+import { createStandardErrorHandler } from '@app/utils/toolErrorHandler';
+import { TimestampPdfParameters, defaultParameters } from '@app/hooks/tools/timestampPdf/useTimestampPdfParameters';
+
+export const buildTimestampPdfFormData = (parameters: TimestampPdfParameters, file: File): FormData => {
+  const formData = new FormData();
+  formData.append('fileInput', file);
+
+  formData.append('tsaUrl', parameters.tsaUrl);
+
+  return formData;
+};
+
+export const timestampPdfOperationConfig = {
+  toolType: ToolType.singleFile,
+  buildFormData: buildTimestampPdfFormData,
+  operationType: 'timestampPdf',
+  endpoint: '/api/v1/security/timestamp-pdf',
+  multiFileEndpoint: false,
+  defaultParameters,
+} as const;
+
+export const useTimestampPdfOperation = () => {
+  const { t } = useTranslation();
+
+  return useToolOperation<TimestampPdfParameters>({
+    ...timestampPdfOperationConfig,
+    getErrorMessage: createStandardErrorHandler(
+      t('timestampPdf.error.failed', 'An error occurred while timestamping the PDF.')
+    ),
+  });
+};

frontend/src/core/hooks/tools/timestampPdf/useTimestampPdfParameters.ts

@@ -0,0 +1,33 @@
+import { BaseParameters } from '@app/types/parameters';
+import { useBaseParameters, BaseParametersHook } from '@app/hooks/tools/shared/useBaseParameters';
+
+// Fallback presets used only when AppConfig hasn't loaded yet.
+// The real presets are served by the backend via /api/v1/config/app-config
+// (field: timestampTsaPresets) — single source of truth.
+export const FALLBACK_TSA_PRESETS = [
+  { label: 'DigiCert', url: 'http://timestamp.digicert.com' },
+  { label: 'Sectigo', url: 'http://timestamp.sectigo.com' },
+  { label: 'SSL.com', url: 'http://ts.ssl.com' },
+  { label: 'FreeTSA', url: 'https://freetsa.org/tsr' },
+  { label: 'MeSign', url: 'http://tsa.mesign.com' },
+] as const;
+
+export interface TimestampPdfParameters extends BaseParameters {
+  tsaUrl: string;
+}
+
+export const defaultParameters: TimestampPdfParameters = {
+  tsaUrl: FALLBACK_TSA_PRESETS[0].url,
+};
+
+export type TimestampPdfParametersHook = BaseParametersHook<TimestampPdfParameters>;
+
+export const useTimestampPdfParameters = (): TimestampPdfParametersHook => {
+  return useBaseParameters({
+    defaultParameters,
+    endpointName: 'timestamp-pdf',
+    validateFn: (params) => {
+      return params.tsaUrl.trim().length > 0;
+    },
+  });
+};

frontend/src/core/tools/TimestampPdf.tsx

@@ -0,0 +1,60 @@
+import { useTranslation } from "react-i18next";
+import { createToolFlow } from "@app/components/tools/shared/createToolFlow";
+import TimestampPdfSettings from "@app/components/tools/timestampPdf/TimestampPdfSettings";
+import { useTimestampPdfParameters } from "@app/hooks/tools/timestampPdf/useTimestampPdfParameters";
+import { useTimestampPdfOperation } from "@app/hooks/tools/timestampPdf/useTimestampPdfOperation";
+import { useBaseTool } from "@app/hooks/tools/shared/useBaseTool";
+import { BaseToolProps, ToolComponent } from "@app/types/tool";
+
+const TimestampPdf = (props: BaseToolProps) => {
+  const { t } = useTranslation();
+
+  const base = useBaseTool(
+    "timestampPdf",
+    useTimestampPdfParameters,
+    useTimestampPdfOperation,
+    props
+  );
+
+  return createToolFlow({
+    files: {
+      selectedFiles: base.selectedFiles,
+      isCollapsed: base.hasResults,
+    },
+    steps: [
+      {
+        title: t("timestampPdf.steps.settings", "Settings"),
+        isCollapsed: base.settingsCollapsed,
+        onCollapsedClick: base.settingsCollapsed ? base.handleSettingsReset : undefined,
+        content: (
+          <TimestampPdfSettings
+            parameters={base.params.parameters}
+            onParameterChange={base.params.updateParameter}
+            disabled={base.endpointLoading}
+          />
+        ),
+      },
+    ],
+    executeButton: {
+      text: t("timestampPdf.submit", "Apply Timestamp"),
+      isVisible: !base.hasResults,
+      loadingText: t("loading"),
+      onClick: base.handleExecute,
+      disabled:
+        !base.params.validateParameters() ||
+        !base.hasFiles ||
+        !base.endpointEnabled,
+    },
+    review: {
+      isVisible: base.hasResults,
+      operation: base.operation,
+      title: t("timestampPdf.results", "Timestamp Results"),
+      onFileClick: base.handleThumbnailClick,
+      onUndo: base.handleUndo,
+    },
+  });
+};
+
+TimestampPdf.tool = () => useTimestampPdfOperation;
+
+export default TimestampPdf as ToolComponent;

frontend/src/core/types/appConfig.ts

@@ -50,6 +50,9 @@ export interface AppConfig {
   googleDriveClientId?: string;
   googleDriveApiKey?: string;
   googleDriveAppId?: string;
+  timestampDefaultTsaUrl?: string;
+  timestampCustomTsaUrls?: string[];
+  timestampTsaPresets?: { label: string; url: string }[];
 }
 
 export type AppConfigBootstrapMode = 'blocking' | 'non-blocking';

frontend/src/core/types/toolId.ts

@@ -52,6 +52,7 @@ export const CORE_REGULAR_TOOL_IDS = [
   'overlayPdfs',
   'getPdfInfo',
   'validateSignature',
+  'timestampPdf',
   'replaceColor',
   'showJS',
   'bookletImposition',

frontend/src/proprietary/utils/creditCosts.ts

@@ -77,6 +77,7 @@ export const TOOL_CREDIT_COSTS: Record<ToolId, number> = {
   convert: CREDIT_COSTS.LARGE,
   ocr: CREDIT_COSTS.LARGE,
   certSign: CREDIT_COSTS.LARGE,
+  timestampPdf: CREDIT_COSTS.LARGE,
 
   // Extra large operations (10 credits)
   automate: CREDIT_COSTS.XLARGE,