This allows the SSH_AUTH_SOCK environment variable to work inside of
su and agent forwarding to succeed.
Fixes#12467
Signed-off-by: Percy Wegmann <percy@tailscale.com>
Checking in the incubator as this used to do fails because
the getenforce command is not on the PATH.
Updates #12442
Signed-off-by: Percy Wegmann <percy@tailscale.com>
This allows pam authentication to run for ssh sessions, triggering
automation like pam_mkhomedir.
Updates #11854
Signed-off-by: Percy Wegmann <percy@tailscale.com>