From 67ddd0ba38cff9b6483ae511557df6421f38c146 Mon Sep 17 00:00:00 2001
From: alperozturk <alper_ozturk@proton.me>
Date: Fri, 22 Mar 2024 10:05:31 +0100
Subject: [PATCH] Fix decryption

Signed-off-by: alperozturk <alper_ozturk@proton.me>
---
 .../operations/DownloadFileOperation.java     |  8 +---
 .../android/utils/EncryptionUtils.java        | 37 ++++++++++---------
 2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/app/src/main/java/com/owncloud/android/operations/DownloadFileOperation.java b/app/src/main/java/com/owncloud/android/operations/DownloadFileOperation.java
index fc286dfd4a..def606f504 100644
--- a/app/src/main/java/com/owncloud/android/operations/DownloadFileOperation.java
+++ b/app/src/main/java/com/owncloud/android/operations/DownloadFileOperation.java
@@ -267,18 +267,14 @@ public class DownloadFileOperation extends RemoteOperation {
 
                 try {
                     Cipher cipher = EncryptionUtils.getCipher(Cipher.DECRYPT_MODE, key, iv);
-                    tmpFile = EncryptionUtils.decryptFile(tmpFile, authenticationTagString, cipher, new ArbitraryDataProviderImpl(operationContext), user);
+                    EncryptionUtils.decryptFile(cipher, tmpFile, newFile, authenticationTagString, new ArbitraryDataProviderImpl(operationContext), user);
                 } catch (Exception e) {
                     return new RemoteOperationResult(e);
                 }
             }
 
             if (downloadType == DownloadType.DOWNLOAD) {
-                moved = tmpFile.renameTo(newFile);
-                newFile.setLastModified(file.getModificationTimestamp());
-                if (!moved) {
-                    result = new RemoteOperationResult(RemoteOperationResult.ResultCode.LOCAL_STORAGE_NOT_MOVED);
-                }
+
             } else if (downloadType == DownloadType.EXPORT) {
                 new FileExportUtils().exportFile(file.getFileName(),
                                                  file.getMimeType(),
diff --git a/app/src/main/java/com/owncloud/android/utils/EncryptionUtils.java b/app/src/main/java/com/owncloud/android/utils/EncryptionUtils.java
index 8a03cd7b3e..a47073458f 100644
--- a/app/src/main/java/com/owncloud/android/utils/EncryptionUtils.java
+++ b/app/src/main/java/com/owncloud/android/utils/EncryptionUtils.java
@@ -568,6 +568,7 @@ public final class EncryptionUtils {
         File encryptedFile = new File(file.getAbsolutePath() + ".enc");
         encryptFileWithGivenCipher(file, encryptedFile, cipher);
         String authenticationTagString = getAuthenticationTag(cipher);
+        Log_OC.d("", "KAVGAM!!: " + authenticationTagString);
         return new EncryptedFile(encryptedFile, authenticationTagString);
     }
 
@@ -600,33 +601,35 @@ public final class EncryptionUtils {
         inputStream.close();
     }
 
-    public static File decryptFile(File encryptedFile,
+    public static void decryptFile(Cipher cipher,
+                                   File encryptedFile,
+                                   File decryptedFile,
                                    String authenticationTag,
-                                   Cipher cipher,
                                    ArbitraryDataProvider arbitraryDataProvider,
-                                   User user) throws InvalidParameterSpecException {
-        File decryptedFile = new File(encryptedFile.getAbsolutePath().replace(".enc", "_decrypted"));
+                                   User user) throws IOException,
+        BadPaddingException, IllegalBlockSizeException, InvalidParameterSpecException {
 
-        try (FileInputStream inputStream = new FileInputStream(encryptedFile);
-             FileOutputStream fileOutputStream = new FileOutputStream(decryptedFile);
-             CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher)) {
-
-            byte[] buffer = new byte[4096];
-            int bytesRead;
-
-            while ((bytesRead = cipherInputStream.read(buffer)) != -1) {
-                fileOutputStream.write(buffer, 0, bytesRead);
+        FileInputStream inputStream = new FileInputStream(encryptedFile);
+        FileOutputStream outputStream = new FileOutputStream(decryptedFile);
+        byte[] buffer = new byte[4096];
+        int bytesRead;
+        while ((bytesRead = inputStream.read(buffer)) != -1) {
+            byte[] output = cipher.update(buffer, 0, bytesRead);
+            if (output != null) {
+                outputStream.write(output);
             }
-        } catch (Exception e) {
-            Log_OC.d(TAG, "Error caught at decryptFile(): " + e.getLocalizedMessage());
         }
+        byte[] output = cipher.doFinal();
+        if (output != null) {
+            outputStream.write(output);
+        }
+        inputStream.close();
+        outputStream.close();
 
         if (!getAuthenticationTag(cipher).equals(authenticationTag)) {
             reportE2eError(arbitraryDataProvider, user);
             throw new SecurityException("Tag not correct");
         }
-
-        return decryptedFile;
     }
 
     // FIXME Decryption is broken