I’m working on a project in which there is a need to encrypt passwords in format that is compatible with the crypt(3) function from the GNU C Library. I looked around a bit and found a couple of alternatives, but none that implemented the SHA-512 and SHA-256 variants which are now commonplace on Linux systems.

Lacking any better alternatives, I produced my own Crypt4j module which provides a crypt(3) compatible implementation in Java, by using the open-source C implementations as a reference.

Crypt4j is open source, and uses the ASL 2.0 license. If you use it in your own project, I’d like to hear about it.