What is the probability what restic had an unexpected breaking change?

Getting Help
1

Hello. I’m a newbie here and need some advice from experienced and long-term users. I’ll do my best to explain the situation concisely.

  1. In April 2022 I created a backup using restic 0.12.1 or 0.13.0 (Sorry, I do not remember exact version unfortunately)
  2. To create a password I used my password manager and stored that password there (I checked the time of password generation really close to the time of key creation)
  3. I can’t swear that this is what happened, because it happened too long ago. But I do remember that after the backup was finished, I checked the contents to make sure I could restore it.
  4. Moved away
  5. Right now, I finally managed to assemble storage and decided to restore my backup using restic 0.16.5
  6. On any operation when I provide my password from password manager (both via prompt and password file) I got “wrong password or key not found”.

So I want to ask, what is the odds of

  1. I somehow forgot what I used password not from the password manager
  2. Some breaking change in restic which prevents the new version from accessing the master key using my password

I do not insist that there is a problem with the software. I am ready to accept the fact that I butchered my backup. But if there is a chance to recover, I’m prepared to invest more time int this.

2

The easiest way to try is to simply download an old version of restic from Github and check whether it can open the repository.

The only things that has changed since 0.12.0 in regards to password parsing is Incorrect File Encoding Used When Adding Keys - Previously Added UTF-16 Key Files Cannot Be Used to Access the Repository · Issue #4850 · restic/restic · GitHub . But in that case the key would never work for creating a backup.

We would definitely have learned about such an issue. But I don’t recall any such complaints. So most likely you’re using the wrong password.

2 Likes
3

Obligatory check for leading or trailing spaces when copying and pasting your password, perhaps? Compare your l’s and 1’s, 0’s and O’s? Etc.

Make sure there’s actually a file inside the “keys” folder of the repo, as well.

If your password manager has a “history” feature - check past passwords. Could be you accidentally generated a new one at some point.

4

Thank you. This is exactly my thoughts. I just did not want to give up on hope )))

5

Thank you for the suggestion. I was able to find the history of the password generator. However, it appears I did not update the generated password or generate a new one outside of that record. So, there is still hope I used one of my common passwords.

6

This is my plan for tomorrow (right now, the repository is copying from an external drive into an array). In 2022 I installed restic via Nix, so my plan to check history and get revision of nixpkgs and rebuild it from that revision.

7

Here’s a long shot… if you’re on Linux / Mac, you might search your terminal history for “RESTIC_PASSWORD”

1 Like
8

I identified the version I used back in 2022. Thanks to Nix, I successfully built it. But as we thought, this case is not about the restic version, but about a butchered password. I do not know what happened in those days. Most likely, I used the RESTIC_PASSWORD variable, and I checked most possible cases for mangling variable values (like ? and ! symbols), but without success. Maybe when the backup was completed, I validated it using the same Shell session, and it explains why validation passed.

So, I guess the only thing left for me is to wait for a breakthrough in quantum computing. When will all the asymmetric cryptography become obsolete?

9

Any chance you’ve got a different, old backup, where you could sift through terminal history? Only idea I’ve got haha