upstream: Allow ssh_config IdentityAgent directive to accept

environment variable names as well as explicit paths. ok dtucker@

OpenBSD-Commit-ID: 2f0996e103876c53d8c9dd51dcce9889d700767b

1 files changed, 21 insertions, 3 deletions

diff --git a/ssh.c b/ssh.c
index 849fae355..0777c31e4 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.493 2018/09/21 03:11:36 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.494 2018/10/03 06:38:35 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1453,9 +1453,27 @@ main(int ac, char **av)
                             "r", options.user,
                             "u", pw->pw_name,
                             (char *)NULL);
-                        setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
-                        free(cp);
                         free(p);
+                        /*
+                         * If identity_agent represents an environment variable
+                         * then recheck that it is valid (since processing with
+                         * percent_expand() may have changed it) and substitute
+                         * its value.
+                         */
+                        if (cp[0] == '$') {
+                                if (!valid_env_name(cp + 1)) {
+                                        fatal("Invalid IdentityAgent "
+                                            "environment variable name %s", cp);
+                                }
+                                if ((p = getenv(cp + 1)) == NULL)
+                                        unsetenv(SSH_AUTHSOCKET_ENV_NAME);
+                                else
+                                        setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1);
+                        } else {
+                                /* identity_agent specifies a path directly */
+                                setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
+                        }
+                        free(cp);
                 }
         }