1 files changed, 17 insertions, 1 deletions

diff --git a/ssh.c b/ssh.c
index ee51823cd..4736b5dd0 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.507 2019/09/13 04:27:35 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.508 2019/10/31 21:18:28 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1344,6 +1344,22 @@ main(int ac, char **av)
                 exit(0);
         }
 
+        /* Expand SecurityKeyProvider if it refers to an environment variable */
+        if (options.sk_provider != NULL && *options.sk_provider == '$' &&
+            strlen(options.sk_provider) > 1) {
+                if ((cp = getenv(options.sk_provider + 1)) == NULL) {
+                        debug("Security key provider %s did not resolve; "
+                            "disabling", options.sk_provider);
+                        free(options.sk_provider);
+                        options.sk_provider = NULL;
+                } else {
+                        debug2("resolved SecurityKeyProvider %s => %s",
+                            options.sk_provider, cp);
+                        free(options.sk_provider);
+                        options.sk_provider = xstrdup(cp);
+                }
+        }
+
         if (muxclient_command != 0 && options.control_path == NULL)
                 fatal("No ControlPath specified for \"-O\" command");
         if (options.control_path != NULL) {