What SFTP server implementations support check-file extension [closed]

I want to synchronise directories on the local host and a remote server via SFTP, using paramiko.sftp_file.SFTPFile.check() in Python to calculate MD5 checksums on the remote server.

According to http://docs.paramiko.org/en/2.1/api/sftp.html and https://stackoverflow.com/questions/30056566/how-to-perform-checksums-during-a-sftp-file-transfer-for-data-integrity, most SFTP server implementations (including OpenSSH, which I'm running by default) do not support the "check-file" extension.

My provider recommends vsftpd (see https://security.appspot.com/vsftpd.html) but its FAQ doesn't mention the "check-file" extension. Can anyone tell me whether vsftpd supports this, or otherwise recommend an SSH/SFTP implementation? I've tried Googling without success for this.

Thanks!

Few servers that I know to support check-file SFTP extension are:

• ProFTPD mod_sftp - open source
• Vandyke VShell - commercial
• Bitvise SSH Server - commercial - free for non-commercial personal use

vsftpd is FTP(S) server, not SFTP server.