New Feature: dynamically replacing files during packaging

DriveBackup/src/main/java/ratismal/drivebackup/UploadThread.java

@@ -257,7 +257,7 @@ void run_internal() {
             backupBackingUp++;
             for (Path folder : set.location.getPaths()) {
                 if (set.create) {
-                    makeBackupFile(folder.toString(), set.formatter, Arrays.asList(set.blacklist));
+                    makeBackupFile(folder.toString(), set.formatter, Arrays.asList(set.blacklist), set.replace);
                 }
             }
         }
@@ -381,11 +381,11 @@ private void pruneLocalBackups() {
      * @param formatter save format configuration
      * @param blackList a configured blacklist (with globs)
      */
-    private void makeBackupFile(String location, LocalDateTimeFormatter formatter, List<String> blackList) {
+    private void makeBackupFile(String location, LocalDateTimeFormatter formatter, List<String> blackList, Map<String, String> replace) {
         logger.info(intl("backup-local-file-start"), "location", location);
         try {
             ServerUtil.setAutoSave(false);
-            fileUtil.makeBackup(location, formatter, blackList);
+            fileUtil.makeBackup(location, formatter, blackList, replace);
         } catch (AbsolutePathException exception) {
             logger.log(intl("backup-failed-absolute-path"));
             return;
@@ -524,7 +524,8 @@ private void makeExternalFileBackup(ExternalFTPSource externalBackup) {
             new PathBackupLocation("external-backups" + "/" + tempFolderName),
             externalBackup.format,
             true,
-            new String[0]
+            new String[0],
+            new HashMap<>()
         );
         backupList.add(backup);
         if (ftpUploader.isErrorWhileUploading()) {
@@ -569,7 +570,8 @@ private void makeExternalDatabaseBackup(ExternalMySQLSource externalBackup) {
             new PathBackupLocation("external-backups" + "/" + tempFolderName),
             externalBackup.format,
             true,
-            new String[0]
+            new String[0],
+            new HashMap<>()
         );
         backupList.add(backup);
         if (mysqlUploader.isErrorWhileUploading()) {

DriveBackup/src/main/java/ratismal/drivebackup/config/configSections/BackupList.java

@@ -12,6 +12,8 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -63,18 +65,21 @@ public String toString() {
         public final LocalDateTimeFormatter formatter;
         public final boolean create;
         public final String[] blacklist;
+        public final Map<String, String> replace;
 
         public BackupListEntry(
             BackupLocation location,
             LocalDateTimeFormatter formatter, 
             boolean create, 
-            String[] blacklist
+            String[] blacklist,
+            Map<String, String> replace
             ) {
 
             this.location = location;
             this.formatter = formatter;
             this.create = create;
             this.blacklist = blacklist;
+            this.replace = replace;
         }
     }
 
@@ -134,7 +139,23 @@ public static BackupList parse(@NotNull FileConfiguration config, Logger logger)
                     logger.log(intl("backup-list-blacklist-invalid"), ENTRY, entryIndex);
                 }
             }
-            list.add(new BackupListEntry(location, formatter, create, blacklist));
+            Map<String, String> replace = new LinkedHashMap<>();
+            if (rawListEntry.containsKey("path") && rawListEntry.containsKey("replace")) {
+                try {
+                    List<Map<String, String>> replaceList = (List<Map<String, String>>) rawListEntry.get("replace");
+                    for (Map<String, String> replaceListEntry : replaceList) {
+                        if (replaceListEntry.containsKey("file") && replaceListEntry.containsKey("with")) {
+                            replace.put(replaceListEntry.get("file"), replaceListEntry.get("with"));
+                        } else {
+                            replace.clear();
+                            throw new IllegalArgumentException();
+                        }
+                    }
+                } catch (IllegalArgumentException | ClassCastException e) {
+                    logger.log(intl("backup-list-replace-invalid"), ENTRY, entryIndex);
+                }
+            }
+            list.add(new BackupListEntry(location, formatter, create, blacklist, replace));
         }
         return new BackupList(list.toArray(new BackupListEntry[0]));
     }

DriveBackup/src/main/java/ratismal/drivebackup/util/FileUtil.java

@@ -20,7 +20,9 @@
 import java.nio.file.attribute.BasicFileAttributes;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.TreeMap;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -71,7 +73,7 @@ public TreeMap<Long, File> getLocalBackups(String location, LocalDateTimeFormatt
      * @param blacklistGlobs a list of glob patterns of files/folders to not include in the backup.
      * @throws Exception
      */
-    public void makeBackup(@NotNull String location, LocalDateTimeFormatter formatter, List<String> blacklistGlobs) throws Exception {
+    public void makeBackup(@NotNull String location, LocalDateTimeFormatter formatter, List<String> blacklistGlobs, Map<String, String> replace) throws Exception {
         Config config = ConfigParser.getConfig();
         if (location.charAt(0) == '/') {
             throw new AbsolutePathException("Location cannot start with a slash");
@@ -105,6 +107,41 @@ public void makeBackup(@NotNull String location, LocalDateTimeFormatter formatte
                     "glob-pattern", globPattern);
             }
         }
+        Map<String, String> checkedReplace = new HashMap<>();
+        if (Files.isDirectory(Paths.get(location))) {
+            Map<Path, String> fileListPaths = fileList.getList().stream()
+                .collect(Collectors.toMap(Paths::get, s -> s, (a, b) -> a));
+            replace.forEach((key, value) -> {
+                if (isUnsafeRelativePath(key) || isUnsafeRelativePath(value)) {
+                    logger.info(intl("backup-list-replace-unsafe-path"), "file-path", key + " -> " + value);
+                    return;
+                }
+                File file = new File(location + "/" + key);
+                File with = new File(location + "/" + value);
+                if (!isWithinLocation(location, with)) {
+                    logger.info(intl("local-backup-replace-escapes-location"), "file-path", key + " -> " + value, "location", location);
+                    return;
+                }
+                Path filePath = Paths.get(key);
+                Path withPath = Paths.get(value);
+                String matched = fileListPaths.get(filePath);
+                if (file.isFile() && with.isFile() && matched != null) {
+                    if (isWithinLocation(config.backupStorage.localDirectory, with)) {
+                        fileList.incFilesInBackupFolder();
+                        return;
+                    }
+                    if (checkedReplace.containsKey(matched)) {
+                        logger.info(intl("local-backup-replace-duplicate"), "file-path", matched);
+                        return;
+                    }
+                    checkedReplace.put(matched, withPath.toString());
+                    return;
+                }
+                logger.info(intl("local-backup-replace-skipped"), "file-path", file.getPath(), "with-path", with.getPath());
+            });
+        } else if (!replace.isEmpty()) {
+            logger.info(intl("local-backup-replace-not-folder"), "location", location);
+        }
         int filesInBackupFolder = fileList.getFilesInBackupFolder();
         if (filesInBackupFolder > 0) {
             logger.info(
@@ -116,7 +153,7 @@ public void makeBackup(@NotNull String location, LocalDateTimeFormatter formatte
             String lastFolderName = location.substring(lastSeparatorIndex + 1);
             fileName = fileName.replace(NAME_KEYWORD, lastFolderName);
         }
-        zipIt(location, path.getPath() + "/" + fileName, fileList);
+        zipIt(location, path.getPath() + "/" + fileName, fileList, checkedReplace);
     }
 
     /**
@@ -176,7 +213,7 @@ public void pruneLocalBackups(String location, LocalDateTimeFormatter formatter)
      * @param outputFilePath the path of the folder to put it in
      * @param fileList file to include in the zip
      */
-    private void zipIt(String inputFolderPath, String outputFilePath, BackupFileList fileList) throws Exception {
+    private void zipIt(String inputFolderPath, String outputFilePath, BackupFileList fileList, Map<String, String> replace) throws Exception {
         byte[] buffer = new byte[1024];
         FileOutputStream fileOutputStream;
         ZipOutputStream zipOutputStream = null;
@@ -190,7 +227,7 @@ private void zipIt(String inputFolderPath, String outputFilePath, BackupFileList
             zipOutputStream.setLevel(ConfigParser.getConfig().backupStorage.zipCompression);
             for (String file : fileList.getList()) {
                 ZipEntry entry = new ZipEntry(formattedInputFolderPath + "/" + file);
-                String filePath = inputFolderPath + "/" + file;
+                String filePath = inputFolderPath + "/" + replace.getOrDefault(file, file);
                 BasicFileAttributes fileAttributes = null;
                 try {
                     fileAttributes = Files.readAttributes(Paths.get(filePath), BasicFileAttributes.class);
@@ -325,6 +362,31 @@ private static String escapeBackupLocation(@NotNull String location) {
         return location.replace("../", "");
     }
 
+    private static boolean isUnsafeRelativePath(@NotNull String path) {
+        if (path.isEmpty()) return true;
+        Path p = Paths.get(path);
+        if (p.isAbsolute()) return true;
+        for (Path seg : p) {
+            if (seg.toString().equals("..")) return true;
+        }
+        return false;
+    }
+
+    /**
+     * Whether the target file's real (symlink-resolved) path is still contained within location.
+     * Guards against a symlink inside location pointing outside of it, which a purely
+     * string-based check like {@link #isUnsafeRelativePath} cannot detect.
+     */
+    private static boolean isWithinLocation(String location, File target) {
+        try {
+            Path root = new File(location).getCanonicalFile().toPath();
+            Path real = target.getCanonicalFile().toPath();
+            return real.startsWith(root);
+        } catch (IOException e) {
+            return false;
+        }
+    }
+
     /**
      * Finds all folders that match a glob
      * @param glob the glob to search

DriveBackup/src/main/resources/intl.yml

@@ -17,6 +17,8 @@ backup-failed-absolute-path: |-
 backup-file-upload-complete: 'Upload(s) for file "<file-name>" complete'
 backup-file-upload-start: 'Starting upload(s) for file "<file-name>"'
 backup-forced: "Forcing a backup"
+backup-list-replace-invalid: "Replace invalid in backup entry <entry>, leaving blank"
+backup-list-replace-unsafe-path: 'Skipping unsafe replace path "<file-path>", it must be a relative path without ".."'
 backup-list-blacklist-invalid: "Blacklist invalid in backup entry <entry>, leaving blank"
 backup-list-format-invalid: "Format invalid, skipping backup list entry <entry>"
 backup-list-glob-invalid: "Glob invalid, skipping backup list entry <entry>"
@@ -198,6 +200,10 @@ local-backup-limit-reached: "There are <backup-count> file(s) which exceeds the
 local-backup-no-limit: "Local backup limit is set to 0, skipping pruning"
 local-backup-pruning-complete: 'Local backup pruning complete for "<location>"'
 local-backup-pruning-start: 'Pruning local backups for "<location>"'
+local-backup-replace-duplicate: 'Multiple replace entries target "<file-path>" in the backup, using the first one'
+local-backup-replace-escapes-location: 'Skipping replace of "<file-path>", it resolves outside of location "<location>" (possibly via a symlink)'
+local-backup-replace-not-folder: 'Ignoring replace for "<location>", it must be a folder to use replace'
+local-backup-replace-skipped: 'Skipping replace of "<file-path>" with "<with-path>", make sure both files exist and "<file-path>" is not blacklisted'
 local-keep-count-invalid: "Inputted local keep count invalid, using default"
 local-save-directory-not-relative: "Local save directory is not relative, making relative to server directory"
 location-empty: "Location <location> is empty, skipping"