You can setup custom command for that.

About integrating the function to WinSCP: Only the very recent versions of SFTP protocol support MD5 hashes. There is very few servers supporting that, if any. So it is not worth implementing the function into WinSCP yet.

I often need to know if two versions of a file are identical. Timestamps get changed, and filesize is unreliable as it's often rounded to the nearest 64K (or such) block by compilers/linkers. Only a hash (MD5, SHA, etc.) is positive proof. I want an "MD5" command under Files which would show me the MD5 hash of the file. When moving/copying files which appear to be duplicates, I'd to see the MD5 hashes of the files (perhaps as an option). I would even like a command to calculate the MD5 hashes of a directory and show it as a column in the directory panes. (Under Show Columns, if the MD5 column was enabled, it would automatically calculate and show these, for both local and remote sides).