upstream: unshield security key privkey before attempting signature

in agent. spotted by dtucker@

OpenBSD-Commit-ID: fb67d451665385b8a0a55371231c50aac67b91d2

1 files changed, 16 insertions, 4 deletions

diff --git a/ssh-agent.c b/ssh-agent.c
index 702dec17d..b1ebe0783 100644
--- a/ssh-agent.c
+++ b/ssh-agent.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-agent.c,v 1.245 2019/11/15 04:12:32 djm Exp $ */
+/* $OpenBSD: ssh-agent.c,v 1.246 2019/11/15 05:37:27 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -426,7 +426,7 @@ process_sign_request2(SocketEntry *e)
         u_char *signature = NULL;
         size_t dlen, slen = 0;
         u_int compat = 0, flags;
-        int r, ok = -1;
+        int was_shielded, r, r2, ok = -1;
         struct sshbuf *msg;
         struct sshkey *key = NULL;
         struct identity *id;
@@ -449,9 +449,21 @@ process_sign_request2(SocketEntry *e)
                 goto send;
         }
         if (id->sk_provider != NULL) {
-                if ((r = provider_sign(id->sk_provider, id->key, &signature,
+                was_shielded = sshkey_is_shielded(id->key);
+                if ((r = sshkey_unshield_private(id->key)) != 0) {
+                        error("%s: unshield: %s", __func__, ssh_err(r));
+                        goto send;
+                }
+                r = provider_sign(id->sk_provider, id->key, &signature,
                     &slen, data, dlen, agent_decode_alg(key, flags),
-                    compat)) != 0) {
+                    compat);
+                if (was_shielded &&
+                    (r2 = sshkey_shield_private(id->key)) != 0) {
+                        error("%s: shield: %s", __func__, ssh_err(r));
+                        r = r2;
+                        goto send;
+                }
+                if (r != 0) {
                         error("%s: sign: %s", __func__, ssh_err(r));
                         goto send;
                 }