Add RSA key based authentication for SFTP

[kslychan]

mc asks me for user's password on a SSH server whenever I connect to it via SFTP, even though the client's public RSA key is authorized for that user account on the server and I can connect to it via openssh-client without giving password.

Test case:

1. on machine "foo", install mc, openssh-client
2. on machine "foo", use ssh-keygen to generate a pair of RSA keys
3. on machine "bar", install openssh-server
4. on machine "bar", add the contents of machine A's ~/.ssh/id_rsa.pub to the ~/.ssh/authorized_keys file
5. verify that you can connect from foo to bar without being asked for password: ssh bar (or: ssh differentusername@bar)
6. if 5., then run mc, connect via SFTP, enter hostname
7. you're asked for password

Consider using key-based SSH authentication.

[hut]

vote for that feature as well. Tried different options in ~/.ssh/config for passwordless sftp loging, but nothing worked out.
Host sftp.host

User sftp_user
HostbasedAuthentication? yes
IdentitiesOnly? yes
KbdInteractiveAuthentication? no
PasswordAuthentication? no
ChallengeResponseAuthentication? no
PasswordAuthentication? no
RSAAuthentication yes
PubkeyAuthentication? yes
IdentityFile? /home/user/sftp_key.key

sftp sftp.host connects flawlessly, while mc asks for password. But, mc can parse ~/.ssh/config maybe not completely (it suggests passworf for user specified in the config file)

[jsamyth]

With FISH failing/broken, and actually being removed by some distros (opensuse), SFTP is more important than ever.
We don't want to leave our servers open to script kiddies to try password after password and would rather allow public key authentication FIRST, which is far more secure.

[steevithak]

I need this feature too because I frequently deal with Amazon EC2 servers and key-based ssh/sftp is the only easy way to connect. I'd like to be able to use MC to do that.

[and]

this bug maybe resolved by #3581
Can someone re-check this case?

[kslychan]

mc 4.8.15 - works OK. Let's close. Thanks! :)