OK, I'll try to contact VanDyke to see if this is feature of their client or of their server. It may be both. Thanks for hint.
Actually, I have. VanDyke's SecureFX has this capability. I think they permit command line SSH to the destination box and then run MD5. MD5 has to be loaded on the destination box for this to work -- but I have used it.
Have you seen any other FTP/SFTP/SCP client doing this? I cannot imagine how to do it wihout downloading the file back to local machine.
Since this a file transfer program with encryption capabilties, I would REALLY like to see an automated MD5 hash take place on the transferred file after transfer has been completed -- and have the MD5 result show somewhere on the screen. Or at least have this as an option for those who may not need to use it. https://www.fourmilab.ch/md5/ has a freeware/public-domain program that you might be able to incorporate easily into your product.