We have developed a module which offers support for the XCRC, XSHA, XSHA1 and XSHA256 commands. You can find more details at: http://www.smartftp.com/oss/proftpd/
mod_digest for ProFTPD
The mod_digest is an add-on module for ProFTPD which offers several hash functions which can be used to verify the file integrity. The module implements the following features XCRC, XMD5, XSHA1 and XSHA256.