Using Public-Key Authentication with the SOCKS Proxy
When transparent tunneling is used with public-key authentication to the
Secure Shell servers, there is no facility for asking the passphrases of the
private keys form the user. You must either use a private key without a
passphrase, or to be more secure, use the ssh-socks-proxy-ctl
tool to
give passphrases to private keys and load the keys in cache before the
keys are actually needed.
As the default SSHSP
user cannot log in to the USS side, you have to
use another (UID 0) user for creating and listing the keys.