Does SFTP support TLS 1.2? I am using Chilkat_9_5_0.SFtp in Powerbuilder.
SFTP is the Secure File Transfer over SSH.
FTPS is the FTP protocol using TLS for the secure communications channel.
The SSH protocol creates a secure communications channel for a TCP connection.
Likewise, SSL and TLS are also protocols for creating a secure communications channel for a TCP connection.
If you want a secure communications channel, TLS and SSH are both choices.
Given that understanding, I hope one can see that it makes no sense to ask "Does SSH support TLS 1.2?"
PS> Tunneling is a separate question. Given that both SSH and TLS provide secure communications channels to send and receive a byte stream, that byte stream could potentially be anything -- even a protocol such as TLS or SSH. Thus with Chilkat it's even possible to tunnel TLS within SSH, or even SSH within SSH (which is what happens for multi-hop SSH).