upstream: refuse to add verify-required (PINful) FIDO keys to

ssh-agent until the agent supports them properly

OpenBSD-Commit-ID: 125bd55a8df32c87c3ec33c6ebe437673a3d037e

1 files changed, 16 insertions, 7 deletions

diff --git a/ssh-add.c b/ssh-add.c
index 931197474..936dc2128 100644
--- a/ssh-add.c
+++ b/ssh-add.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-add.c,v 1.156 2020/06/26 05:04:07 djm Exp $ */
+/* $OpenBSD: ssh-add.c,v 1.157 2020/08/31 04:33:17 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -67,6 +67,7 @@
 #include "ssherr.h"
 #include "digest.h"
 #include "ssh-sk.h"
+#include "sk-api.h"
 
 /* argv0 */
 extern char *__progname;
@@ -348,12 +349,20 @@ add_file(int agent_fd, const char *filename, int key_only, int qflag,
                 ssh_free_identitylist(idlist);
         }
 
-        if (!sshkey_is_sk(private))
-                skprovider = NULL; /* Don't send constraint for other keys */
-        else if (skprovider == NULL) {
-                fprintf(stderr, "Cannot load authenticator-hosted key %s "
-                    "without provider\n", filename);
-                goto out;
+        if (sshkey_is_sk(private)) {
+                if (skprovider == NULL) {
+                        fprintf(stderr, "Cannot load FIDO key %s "
+                            "without provider\n", filename);
+                        goto out;
+                }
+                if ((private->sk_flags & SSH_SK_USER_VERIFICATION_REQD) != 0) {
+                        fprintf(stderr, "FIDO verify-required key %s is not "
+                            "currently supported by ssh-agent\n", filename);
+                        goto out;
+                }
+        } else {
+                /* Don't send provider constraint for other keys */
+                skprovider = NULL;
         }
 
         if ((r = ssh_add_identity_constrained(agent_fd, private, comment,