[ftpext] draft-bryan-ftp-hash

[Anthony Bryan <[e-mail]>]

It's nice to see this new list for FTP extension discussion!

We're working on an FTP HASH command:

  The File Transfer Protocol [RFC0959] does not offer any method to
   verify the integrity of a transferred file, nor can two files be
   compared against each other without actually transferring them first.
   Cryptographic hashes are a possible solution to this problem.  In the
   past, several attempts have been made to add commands to obtain
   checksums and hashes, however none have been formally specified,
   leading to non-interoperability and confusion.  To solve these
   issues, this document specifies a new FTP command to be used by
   clients to request cryptographic hashes of files.  HTTP has a similar
   feature named Instance Digests [RFC3230] which allows a client to
   request the cryptographic hash of a file.

We have a couple issues we'd like to discuss:

Should HASH support partial file hashes, similar to the Content-MD5
HTTP Header? (Some of the non-standard hash commands allow this).

Should the server response include the algorithm? i.e.  "S> 213
SHA-256 xxxxxxxxxxxxxxx"

-- 
(( Anthony Bryan ... Metalink [ http://www.metalinker.org ]
  )) Easier, More Reliable, Self Healing Downloads