Start ssh-agent as a user unit

This has some advantages:

* You get ssh-agent regardless of how you logged in. Previously it was
  only started for X11 sessions.

* All sessions of a user share the same agent. So if you added a key
  on tty1, it will also be available on tty2.

* Systemd will restart ssh-agent if it dies.

* $SSH_AUTH_SOCK now points to the /run/user/<uid> directory, which is
  more secure than /tmp.

For bonus points, we should patch ssh-agent to support socket-based
activation...

1 files changed, 0 insertions, 11 deletions

diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index 2deff602982b..3bf18bd58c84 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -51,17 +51,6 @@ let
 
       ''}
 
-      ${optionalString cfg.startOpenSSHAgent ''
-        if test -z "$SSH_AUTH_SOCK"; then
-            # Restart this script as a child of the SSH agent.  (It is
-            # also possible to start the agent as a child that prints
-            # the required environment variabled on stdout, but in
-            # that mode ssh-agent is not terminated when we log out.)
-            export SSH_ASKPASS=${pkgs.x11_ssh_askpass}/libexec/x11-ssh-askpass
-            exec ${pkgs.openssh}/bin/ssh-agent "$0" "$sessionType"
-        fi
-      ''}
-
       ${optionalString cfg.startGnuPGAgent ''
         if test -z "$SSH_AUTH_SOCK"; then
             # Restart this script as a child of the GnuPG agent.