Greetings Crypto Sub!
I am dealing with a kind of cryptolocker situation... Not \_that\_ bad, but kinda bad.
Data that is encrypted out of my reach: \~8 years of Signal Desktop data (including family photos and much else).
How it went beyond reach: In late 2024, Signal Desktop started encrypting its data encryption key using DPAPI. Then, in early 2025, my laptop died. While I have a full file system backup (thank you backblaze!), the old SSD is damaged and dead (I currently have it in an M.2->USB enclosure, imaging apps like Macrium and Acronis fail to image it, repairs like fdisk are not able to fully repair the volume).
IOW: The old Windows OS is not bootable. (If it were, I would be able to use [this tool ](https://github.com/bepaald/signalbackup-tools/blob/master/desktopdatabase/getkeyfromencrypted_win.cc)to decrypt the Signal crypto key)
The crypto path is:
(a) Signal Data Encryption key -> (b) Itself encrypted via DPAPI under OldPC -> (c) WinUser1
The puzzle I am trying to solve is (b)
I have dug around the DPAPI world.. My specific context is: OldPC was Win11 but WinUser1 is an "old style" Windows user \[e.g. not a [microsoft.com](http://microsoft.com) account\] \_and\_ I know the Windows Password for that user \[as that user was yours truly\].
Ideally, there would be an offline DPAPI tool or cracker. I can give it (b) and the Windows Password for (c). I can also provide the raw registry files or other files from the old Windows OS (or potentially extract values from those files).
Is there a possible path forward?