It actually started as a wrapper around Young's much earlier DES implementation, written as a drop-in replacement for Solaris's DES tools which were unavailable outside the US because of export restrictions.

I know this because I've dealt with a company that distributes files in Solaris-compatible DES format from an unencrypted FTP server and helpfully supplies Young's libdes to interface with it.

Well, at least it isn't EBCDIC...