UFAL/fix: S3 presigned-URL Content-Disposition — spaces became '+', raw non-ASCII in filename param

dspace-api/src/main/java/org/dspace/storage/bitstore/S3DirectDownloadServiceImpl.java

@@ -10,6 +10,7 @@
 import java.io.IOException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.text.Normalizer;
 import java.time.Instant;
 import java.util.Date;
 
@@ -79,20 +80,60 @@ public String generatePresignedUrl(String bucket, String key, int expirationSeco
                 .withMethod(HttpMethod.GET)
                 .withExpiration(expiration);
         // Add custom response header for filename - to download the file with the desired name
-        // Remove CRLF and quotes to prevent header injection
-        String safeName = desiredFilename.replaceAll("[\\r\\n\"]", "_");
-        // RFC-5987: percent-encode UTF-8, e.g. filename*=UTF-8''%E2%82%ACrates.txt
-        String encoded = URLEncoder.encode(desiredFilename, StandardCharsets.UTF_8);
-        String contentDisposition = String.format(
-                "attachment; filename=\"%s\"; filename*=UTF-8''%s",
-                safeName, encoded);
-
-        request.addRequestParameter("response-content-disposition", contentDisposition);
+        request.addRequestParameter("response-content-disposition",
+                buildContentDisposition(desiredFilename));
         try {
             return s3Client.generatePresignedUrl(request).toString();
         } catch (Exception e) {
             log.error("Failed to generate presigned URL for bucket: {}, key: {}", bucket, key, e);
             throw new RuntimeException("Failed to generate presigned URL", e);
         }
     }
+
+    /**
+     * Build the Content-Disposition value the way vanilla's HttpHeadersInitializer does: an ASCII
+     * fallback in {@code filename} for clients that predate RFC 5987, plus the real UTF-8 name in
+     * {@code filename*} for everyone else. S3 direct download has no upstream counterpart, so the
+     * logic is copied from vanilla rather than shared.
+     */
+    private String buildContentDisposition(String name) {
+        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                createFallbackAsciiName(name), createEncodedUtf8Name(name));
+    }
+
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        // Two deviations from vanilla, both of them behaviour this class already had: CR/LF are
+        // dropped so a crafted name cannot inject a header, and \ and " are escaped so a name
+        // containing a quote cannot close the quoted-string early.
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "")
+                .replaceAll("[\\r\\n]", "")
+                .replace("\\", "\\\\")
+                .replace("\"", "\\\"");
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        return URLEncoder.encode(originalFilename, StandardCharsets.UTF_8).replace("+", "%20");
+    }
 }

dspace-api/src/test/java/org/dspace/storage/bitstore/S3DirectDownloadServiceTest.java

@@ -139,6 +139,19 @@ public void weirdFilename() throws Exception {
         assertTrue(cd.contains("UTF-8"));
     }
 
+    // Spaces must be %20 in filename*, not '+' — URLEncoder is form-encoding and differs from RFC 5987 here
+    @Test
+    public void spacesAndDiacriticsInFilename() throws Exception {
+        URL fake = new URL("https://spaces");
+        when(amazonS3.generatePresignedUrl(any(GeneratePresignedUrlRequest.class))).thenReturn(fake);
+
+        s3DirectDownloadService.generatePresignedUrl("b", "k", 60, "Příliš žluťoučký kůň.txt");
+        String cd = captureRequest().getRequestParameters().get("response-content-disposition");
+
+        assertEquals("attachment; filename=\"Prilis zlutoucky kun.txt\"; "
+                + "filename*=UTF-8''P%C5%99%C3%ADli%C5%A1%20%C5%BElu%C5%A5ou%C4%8Dk%C3%BD%20k%C5%AF%C5%88.txt", cd);
+    }
+
     // Underlying AmazonS3 throws → IllegalArgumentException
     @Test(expected = IllegalArgumentException.class)
     public void nullFilename() throws Exception {

dspace-server-webapp/src/main/java/org/dspace/app/rest/BitstreamByHandleRestController.java

@@ -15,6 +15,7 @@
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
+import java.text.Normalizer;
 import java.util.List;
 import java.util.Objects;
 import javax.servlet.http.HttpServletRequest;
@@ -279,25 +280,50 @@ private void redirectToS3DownloadUrl(String bitName, String bitInternalId,
     }
 
     /**
-     * Build a Content-Disposition header value using RFC 5987 encoding.
-     * Includes both {@code filename} (ASCII fallback) and {@code filename*}
-     * (UTF-8 percent-encoded) so that curl -J and browsers can save files
-     * with non-ASCII characters in the name correctly.
-     *
-     * @param name the original filename
-     * @return the Content-Disposition header value
+     * Build the Content-Disposition value the way vanilla's HttpHeadersInitializer does: an ASCII
+     * fallback in {@code filename} for clients that predate RFC 5987, plus the real UTF-8 name in
+     * {@code filename*} for everyone else. This endpoint has no upstream counterpart, so the logic
+     * is copied from vanilla rather than shared, to keep it tracking upstream's behaviour.
+     * curl -J on Windows cannot create files with non-ASCII characters from a raw UTF-8 header,
+     * which is why this endpoint needs it too.
      */
     private String buildContentDisposition(String name) {
-        // RFC 5987 percent-encoding for filename*
-        String encoded = URLEncoder.encode(name, StandardCharsets.UTF_8)
-                .replace("+", "%20");
-        // ASCII fallback: replace non-ASCII chars with underscore, escape quotes.
-        // Modern clients use filename* (RFC 5987 / RFC 6266) with real UTF-8 name.
-        String asciiFallback = name.replaceAll("[^\\x20-\\x7E]", "_")
+        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                createFallbackAsciiName(name), createEncodedUtf8Name(name));
+    }
+
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        // Deviates from vanilla by escaping \ and ": the value is a quoted-string, and a name
+        // containing a quote closes it early. That is the bug #1267 fixed; vanilla still has it.
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "")
                 .replace("\\", "\\\\")
                 .replace("\"", "\\\"");
-        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
-                asciiFallback, encoded);
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        return URLEncoder.encode(originalFilename, StandardCharsets.UTF_8).replace("+", "%20");
     }
 
     /**

dspace-server-webapp/src/main/java/org/dspace/app/rest/MetadataBitstreamController.java

@@ -11,7 +11,10 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
+import java.text.Normalizer;
 import java.util.List;
 import java.util.Objects;
 import java.util.UUID;
@@ -115,7 +118,7 @@ public void downloadFileZip(@PathVariable UUID uuid, @RequestParam("handleId") S
         // This bitstream is used to get it's item in the statistics tracker
         Bitstream bitstreamForStatistics = null;
         name = item.getName() + ".zip";
-        response.setHeader(HttpHeaders.CONTENT_DISPOSITION, String.format("attachment;filename=\"%s\"", name));
+        response.setHeader(HttpHeaders.CONTENT_DISPOSITION, buildContentDisposition(name));
         response.setContentType("application/zip");
         List<Bundle> bundles = item.getBundles("ORIGINAL");
 
@@ -143,4 +146,49 @@ public void downloadFileZip(@PathVariable UUID uuid, @RequestParam("handleId") S
         matomoBitstreamTracker.trackBitstreamDownload(context, request, bitstreamForStatistics, true);
         response.getOutputStream().flush();
     }
+
+    /**
+     * Build the Content-Disposition value the way vanilla's HttpHeadersInitializer does: an ASCII
+     * fallback in {@code filename} for clients that predate RFC 5987, plus the real UTF-8 name in
+     * {@code filename*} for everyone else. This endpoint has no upstream counterpart, so the logic
+     * is copied from vanilla rather than shared, to keep it tracking upstream's behaviour.
+     */
+    private String buildContentDisposition(String name) {
+        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                createFallbackAsciiName(name), createEncodedUtf8Name(name));
+    }
+
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        // Deviates from vanilla by escaping \ and ": the value is a quoted-string, and an item name
+        // containing a quote closes it early. That is the bug #1267 fixed; vanilla still has it.
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "")
+                .replace("\\", "\\\\")
+                .replace("\"", "\\\"");
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        return URLEncoder.encode(originalFilename, StandardCharsets.UTF_8).replace("+", "%20");
+    }
 }

dspace-server-webapp/src/main/java/org/dspace/app/rest/utils/HttpHeadersInitializer.java

@@ -9,9 +9,11 @@
 
 import static java.util.Objects.isNull;
 import static java.util.Objects.nonNull;
-import static javax.mail.internet.MimeUtility.encodeText;
 
 import java.io.IOException;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.text.Normalizer;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Objects;
@@ -171,9 +173,16 @@ public HttpHeaders initialiseHeaders() throws IOException {
 
         // distposition may be null here if contentType is null
         if (!isNullOrEmpty(disposition)) {
-            httpHeaders.put(CONTENT_DISPOSITION, Collections.singletonList(String.format(CONTENT_DISPOSITION_FORMAT,
-                                                                                         disposition,
-                                                                                         encodeText(fileName))));
+            String fallbackAsciiName = createFallbackAsciiName(this.fileName);
+            String encodedUtf8Name = createEncodedUtf8Name(this.fileName);
+
+            String headerValue = String.format(
+                "%s; filename=\"%s\"; filename*=UTF-8''%s",
+                disposition,
+                fallbackAsciiName,
+                encodedUtf8Name
+            );
+            httpHeaders.put(CONTENT_DISPOSITION, Collections.singletonList(headerValue));
         }
         log.debug("Content-Disposition : {}", disposition);
 
@@ -261,4 +270,41 @@ private static boolean matches(String matchHeader, String toMatch) {
         return Arrays.binarySearch(matchValues, toMatch) > -1 || Arrays.binarySearch(matchValues, "*") > -1;
     }
 
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "");
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        try {
+            String encoded = URLEncoder.encode(originalFilename, StandardCharsets.UTF_8.toString());
+            return encoded.replace("+", "%20");
+        } catch (java.io.UnsupportedEncodingException e) {
+            // Fallback to a simple ASCII name if encoding fails.
+            log.error("UTF-8 encoding not supported, which should not happen.", e);
+            return createFallbackAsciiName(originalFilename);
+        }
+    }
+
 }

dspace-server-webapp/src/test/java/org/dspace/app/rest/BitstreamByHandleRestControllerIT.java

@@ -260,8 +260,8 @@ public void downloadBitstreamByHandleUtf8Filename() throws Exception {
                         + "/M%C3%A9di%C3%A1%20(3).jfif")))
                 .andExpect(status().isOk())
                 .andExpect(header().string(HttpHeaders.CONTENT_DISPOSITION,
-                        // ASCII fallback replaces non-ASCII with underscore; filename* has UTF-8 encoding
-                        equalTo("attachment; filename=\"M_di_ (3).jfif\"; "
+                        // ASCII fallback transliterates the diacritics away; filename* keeps the real name
+                        equalTo("attachment; filename=\"Media (3).jfif\"; "
                                 + "filename*=UTF-8''M%C3%A9di%C3%A1%20%283%29.jfif")))
                 .andExpect(content().string(bitstreamContent));
     }

dspace-server-webapp/src/test/java/org/dspace/app/rest/BitstreamRestControllerIT.java

@@ -8,7 +8,6 @@
 package org.dspace.app.rest;
 
 import static java.util.UUID.randomUUID;
-import static javax.mail.internet.MimeUtility.encodeText;
 import static org.apache.commons.codec.CharEncoding.UTF_8;
 import static org.apache.commons.collections.CollectionUtils.isEmpty;
 import static org.apache.commons.io.IOUtils.toInputStream;
@@ -364,7 +363,11 @@ public void testBitstreamName() throws Exception {
         //2. A public item with a bitstream
 
         String bitstreamContent = "0123456789";
-        String bitstreamName = "ภาษาไทย";
+        String bitstreamName = "ภาษาไทย-com-acentuação.pdf";
+        String expectedAscii = "-com-acentuacao.pdf";
+        String expectedUtf8Encoded =
+        "%E0%B8%A0%E0%B8%B2%E0%B8%A9%E0%B8%B2%E0%B9%84%E0%B8%97%E0%B8%A2-"
+        + "com-acentua%C3%A7%C3%A3o.pdf";
 
         try (InputStream is = IOUtils.toInputStream(bitstreamContent, CharEncoding.UTF_8)) {
 
@@ -388,7 +391,9 @@ public void testBitstreamName() throws Exception {
             //We expect the content disposition to have the encoded bitstream name
             .andExpect(header().string(
                 "Content-Disposition",
-                "attachment;filename=\"" + encodeText(bitstreamName) + "\""
+                String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                              expectedAscii,
+                              expectedUtf8Encoded)
             ));
     }