upstream: Add new structure for signature options

This is populated during signature verification with additional fields
that are present in and covered by the signature. At the moment, it is
only used to record security key-specific options, especially the flags
field.

with and ok markus@

OpenBSD-Commit-ID: 338a1f0e04904008836130bedb9ece4faafd4e49

1 files changed, 11 insertions, 3 deletions

diff --git a/monitor.c b/monitor.c
index 1186c1dd5..40ff43ee2 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.201 2019/11/19 22:21:15 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.202 2019/11/25 00:51:37 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1391,6 +1391,7 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
         char *sigalg;
         size_t signaturelen, datalen, bloblen;
         int r, ret, valid_data = 0, encoded_ret;
+        struct sshkey_sig_details *sig_details = NULL;
 
         if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 ||
             (r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 ||
@@ -1430,7 +1431,7 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
                 fatal("%s: bad signature data blob", __func__);
 
         ret = sshkey_verify(key, signature, signaturelen, data, datalen,
-            sigalg, ssh->compat);
+            sigalg, ssh->compat, &sig_details);
         debug3("%s: %s %p signature %s%s%s", __func__, auth_method, key,
             (ret == 0) ? "verified" : "unverified",
             (ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
@@ -1450,8 +1451,15 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
 
         /* encode ret != 0 as positive integer, since we're sending u32 */
         encoded_ret = (ret != 0);
-        if ((r = sshbuf_put_u32(m, encoded_ret)) != 0)
+        if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
+            (r = sshbuf_put_u8(m, sig_details != NULL != 0)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        if (sig_details != NULL) {
+                if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
+                    (r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
+                        fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        }
+        sshkey_sig_details_free(sig_details);
         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
 
         return ret == 0;