Unable to restore files on mac os

Im backing up some files to a S3 bucket using encryption on my mac.

Backing the files up, seems to work perfectly. But restoring them fails with the error message:

[Error-Duplicati.Library.Main.Operation.RestoreHandler-PatchingFailed]: Failed to patch with remote file: “duplicati-b087a4a545a1d44238d44fb795252e6b7.dblock.zip.aes”, message: Failed to decrypt data (invalid passphrase?): Invalid password or corrupted data

Curiously enough, when i import the backup configuration on windows 10 (including the passphrase), recreate the database and then restore the files I backed up from my mac to the s3 bucket, I can restore them successfully without getting any error messages.

This seems to suggest, that this has nothing to do with the passphrase, such that the restoration fails for other reasons.

Does anyone have a clue about this? First, i thought, this might be related to the file/directory access restrictions which came along with Catalina. But duplicati does create a file in the target location. It is just corrupted and useless.

Since im using the same key to decrypt the backups from my windows 10 machine, which i use to encrypt it in the mac, I can certainly exclude, that I’m not using the right passphrase as the error message indicates. If I use the restore-dialogue from the backup task, I assume, that it uses the same key I associated with that task.

Having to rely on a different OS to restore my files is not really a viable options. Storing my files unencrypted on S3 is neither.

I tried again with the current canary (.36)

I get 1 Warning:
2019-12-12 07:54:05 +01 - [Warning-Duplicati.Library.Main.Operation.RestoreHandler-NoFilesRestored]: Restore completed without errors but no files were restored

and 1 Error:
2019-12-12 07:54:05 +01 - [Error-Duplicati.Library.Main.Operation.RestoreHandler-PatchingFailed]: Failed to patch with remote file: “duplicati-b087a4a545a1d44238d44fb795252e6b7.dblock.zip.aes”, message: Failed to decrypt data (invalid passphrase?): Invalid password or corrupted data

Not sure what else I can look into for further troubleshooting.

Any help is appreciated!

Hello, I agree with your reasoning that the passphrase must be correct as it works on your Win10 machine. I only have limited experience with macOS and no access to Mac hardware, so I can’t troubleshoot or speculate as to the root cause.

Hopefully someone else will come along soon to assist you.

Do you have some other S3 downloader? If not, Duplicati has one, but it’s not very user friendly.

The idea is to get the file some other way and see what some other decrypter tool can do with it.

Duplicati includes SharpAESCrypt, which would be the closest to its use. You can see help here.

Here is a more user-friendly GUI tool if you wish to start there. Its error message will be different.

There are other harder ways to pick this apart, e.g. one can check file hash against expectations. Generally though, I’d have thought the hash would be checked before decrypting, but I’m unsure. Decryption has a cryptographic integrity check, which is what’s complaining for you — somehow.

Note test restores on the original system should use –no-local-blocks=true to prevent shortcuts… Seeing your test error try to “patch with remote file” means it didn’t optimize for that particular file, however after getting this issue fixed, it’s best practice in the future when trying to verify restores.

Your test on Windows working is odd. I’m unsure why, so will try some other tests. I have no Mac.