This is a CLI tool that tries to use multiple passphrases from a given wordlist to decrypt an encrypted private key that has a DEK header.
In some encrypted private keys you can see a special header that indicates the encryption algorithm, like so:
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,FD9831D6BE43C1FA
If a private key starts with a similar header it's likely supported by this tool.
Usage of ./x509bf:
-c uint level of concurrency, number of cores is the default (default 8)
-k string path to the encrypted PEM file
-l string path to the wordlist to try, e.g. /usr/share/wordlists/rockyou.txt
-v verbose logging (slower)
This tool is supposed to be used for research purposes only and must be NOT used for illegal actions.