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, 18 insertions, 3 deletions

diff --git a/ssh-ecdsa-sk.c b/ssh-ecdsa-sk.c
index f33fac714..b2f31ae2d 100644
--- a/ssh-ecdsa-sk.c
+++ b/ssh-ecdsa-sk.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ecdsa-sk.c,v 1.3 2019/11/25 00:38:17 djm Exp $ */
+/* $OpenBSD: ssh-ecdsa-sk.c,v 1.4 2019/11/25 00:51:37 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -53,7 +53,8 @@
 int
 ssh_ecdsa_sk_verify(const struct sshkey *key,
     const u_char *signature, size_t signaturelen,
-    const u_char *data, size_t datalen, u_int compat)
+    const u_char *data, size_t datalen, u_int compat,
+    struct sshkey_sig_details **detailsp)
 {
         ECDSA_SIG *sig = NULL;
         BIGNUM *sig_r = NULL, *sig_s = NULL;
@@ -63,10 +64,13 @@ ssh_ecdsa_sk_verify(const struct sshkey *key,
         int ret = SSH_ERR_INTERNAL_ERROR;
         struct sshbuf *b = NULL, *sigbuf = NULL, *original_signed = NULL;
         char *ktype = NULL;
+        struct sshkey_sig_details *details = NULL;
 #ifdef DEBUG_SK
         char *tmp = NULL;
 #endif
 
+        if (detailsp != NULL)
+                *detailsp = NULL;
         if (key == NULL || key->ecdsa == NULL ||
             sshkey_type_plain(key->type) != KEY_ECDSA_SK ||
             signature == NULL || signaturelen == 0)
@@ -149,6 +153,12 @@ ssh_ecdsa_sk_verify(const struct sshkey *key,
         if ((ret = ssh_digest_buffer(SSH_DIGEST_SHA256, original_signed,
             sighash, sizeof(sighash))) != 0)
                 goto out;
+        if ((details = calloc(1, sizeof(*details))) == NULL) {
+                ret = SSH_ERR_ALLOC_FAIL;
+                goto out;
+        }
+        details->sk_counter = sig_counter;
+        details->sk_flags = sig_flags;
 #ifdef DEBUG_SK
         fprintf(stderr, "%s: signed buf:\n", __func__);
         sshbuf_dump(original_signed, stderr);
@@ -168,13 +178,18 @@ ssh_ecdsa_sk_verify(const struct sshkey *key,
                 ret = SSH_ERR_LIBCRYPTO_ERROR;
                 goto out;
         }
-
+        /* success */
+        if (detailsp != NULL) {
+                *detailsp = details;
+                details = NULL;
+        }
  out:
         explicit_bzero(&sig_flags, sizeof(sig_flags));
         explicit_bzero(&sig_counter, sizeof(sig_counter));
         explicit_bzero(msghash, sizeof(msghash));
         explicit_bzero(sighash, sizeof(msghash));
         explicit_bzero(apphash, sizeof(apphash));
+        sshkey_sig_details_free(details);
         sshbuf_free(original_signed);
         sshbuf_free(sigbuf);
         sshbuf_free(b);