Crypt Password Storage Scheme

The Crypt Password Storage Scheme provides a mechanism for encoding user passwords like Unix crypt does. Like on most Unix systems, the password may be encrypted using different algorithms, either Unix crypt, md5, sha256 or sha512.

This scheme contains only an implementation for the user password syntax, with a storage scheme name of "CRYPT". Like on most Unixes, the "CRYPT" storage scheme has different algorithms, the default being Unix crypt. Warning: even though Unix crypt is a one-way digest, it is very weak by today's standards. Only the first 8 characters in a password are used, and it only uses the bottom 7 bits of each character. It only supports a 12-bit salt (meaning that there are only 4096 possible ways to encode a given password), so it is vulnerable to dictionary attacks. You should therefore use this algorithm only in cases where an external application expects to retrieve the password and verify it outside of the directory, instead of by performing an LDAP bind.