Bad Signature: Decrypting files

Nextcloud version: 13.0.2
Operating system and version: 16.04.1-Ubuntu
Apache or nginx version : Apache/2.4.18
PHP version: 7.0.28

The issue you are facing:
I had a problem with few files, dunno how it came to it but the error said Bad Signature. I already planned to decrypt my data and know it seems like all of my files are rip. I think I have all the stuff I need to decrypt the data but don’t know how.

I’m gettin OCP\Encryption\Exceptions\GenericEncryptionException: Bad Signature and

Uncaught Error: Access to undeclared static property: OC\Files\Filesystem::$normalizedPathCache in /var/www/cloud/public_html/lib/private/Files/Filesystem.php:796 Stack trace: #0 /var/www/cloud/public_html/lib/private/Files/View.php(2057): OC\Files\Filesystem::normalizePath('/zInvalid/files...') #1 /var/www/cloud/public_html/lib/private/Files/View.php(1182): OC\Files\View->unlockFile('/ts3server', 1) #2 [internal function]: OC\Files\View->OC\Files\{closure}() #3 /var/www/cloud/public_html/3rdparty/icewind/streams/src/CallbackWrapper.php(109): call_user_func(Object(Closure)) #4 [internal function]: Icewind\Streams\CallbackWrapper->stream_close() #5 {main} thrown at /var/www/cloud/public_html/lib/private/Files/Filesystem.php#796

Is this the first time you’ve seen this error? (Y/N): Y

Hope you can help me, really need that data back.

The signature uses data from your database. So typically, you get this error, when you restore files with a database which is different to the time when the file was encrypted.

Here is a hint from the developer, how you can disable the signature verification (someone could have altered your file, but still better than to lose your data):

I think the files are already rip, first I ran the command decrypt-all without entering the masterkeys password. This took a while but didn’t decrypt then I read somewhere there’s a bug.Now always when I try the command decrypt-all it takes seconds and not even all files are displayed. Does this mean the files aren’t in the database anymore or sth. like that?

same issue with me, similar config… is there a fix ?

Have been able to recovery your files? If not: We’ve written a tool that allows you to decrypt individual files if you still have your Nextcloud data directory and configuration file. It supports master key encrypted files, user key encrypted files (you additionally need the user passwords) and recovery key encrypted files (you additionally need the recovery password): decrypt-file.php