upstream: Allow testing signature syntax and validity without verifying

that a signature came from a trusted signer. To discourage accidental or
unintentional use, this is invoked by the deliberately ugly option name
"check-novalidate"

from Sebastian Kinne

OpenBSD-Commit-ID: cea42c36ab7d6b70890e2d8635c1b5b943adcc0b

1 files changed, 23 insertions, 7 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 570f31795..0dfad08c4 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.349 2019/09/06 07:53:40 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.350 2019/09/16 03:23:02 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2666,8 +2666,9 @@ verify(const char *signature, const char *sig_namespace, const char *principal,
                 }
         }
 
-        if ((r = sshsig_check_allowed_keys(allowed_keys, sign_key,
-            principal, sig_namespace)) != 0) {
+        if (allowed_keys != NULL &&
+            (r = sshsig_check_allowed_keys(allowed_keys, sign_key,
+                                           principal, sig_namespace)) != 0) {
                 debug3("sshsig_check_allowed_keys failed: %s", ssh_err(r));
                 goto done;
         }
@@ -2681,9 +2682,15 @@ done:
                                 fatal("%s: sshkey_fingerprint failed",
                                     __func__);
                         }
-                        printf("Good \"%s\" signature for %s with %s key %s\n",
-                            sig_namespace, principal,
-                            sshkey_type(sign_key), fp);
+                        if (principal == NULL) {
+                                printf("Good \"%s\" signature with %s key %s\n",
+                                       sig_namespace, sshkey_type(sign_key), fp);
+
+                        } else {
+                                printf("Good \"%s\" signature for %s with %s key %s\n",
+                                       sig_namespace, principal,
+                                       sshkey_type(sign_key), fp);
+                        }
                 } else {
                         printf("Could not verify signature.\n");
                 }
@@ -2735,7 +2742,8 @@ usage(void)
             "       ssh-keygen -Q -f krl_file file ...\n"
             "       ssh-keygen -Y sign -f sign_key -n namespace\n"
             "       ssh-keygen -Y verify -I signer_identity -s signature_file\n"
-            "                  -n namespace -f allowed_keys [-r revoked_keys]\n");
+            "                  -n namespace -f allowed_keys [-r revoked_keys]\n"
+            "       ssh-keygen -Y check-novalidate -s signature_file -n namespace\n");
         exit(1);
 }
 
@@ -3034,6 +3042,14 @@ main(int argc, char **argv)
                                 exit(1);
                         }
                         return sign(identity_file, cert_principals, argc, argv);
+                } else if (strncmp(sign_op, "check-novalidate", 16) == 0) {
+                        if (ca_key_path == NULL) {
+                                error("Too few arguments for check-novalidate: "
+                                      "missing signature file");
+                                exit(1);
+                        }
+                        return verify(ca_key_path, cert_principals,
+                                      NULL, NULL, NULL);
                 } else if (strncmp(sign_op, "verify", 6) == 0) {
                         if (ca_key_path == NULL) {
                                 error("Too few arguments for verify: "