upstream: factor out kex_verify_hostkey() - again, duplicated

almost exactly across client and server for several KEX methods.

from markus@ ok djm@

OpenBSD-Commit-ID: 4e4a16d949dadde002a0aacf6d280a684e20829c

1 files changed, 2 insertions, 14 deletions

diff --git a/kexgexc.c b/kexgexc.c
index 600d91acc..ac42127af 100644
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexc.c,v 1.32 2019/01/21 10:03:37 djm Exp $ */
+/* $OpenBSD: kexgexc.c,v 1.33 2019/01/21 10:07:22 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -153,26 +153,14 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
         int r;
 
         debug("got SSH2_MSG_KEX_DH_GEX_REPLY");
-        if (kex->verify_host_key == NULL) {
-                r = SSH_ERR_INVALID_ARGUMENT;
-                goto out;
-        }
         /* key, cert */
         if ((r = sshpkt_get_string(ssh, &server_host_key_blob,
             &sbloblen)) != 0 ||
             (r = sshkey_from_blob(server_host_key_blob, sbloblen,
             &server_host_key)) != 0)
                 goto out;
-        if (server_host_key->type != kex->hostkey_type ||
-            (kex->hostkey_type == KEY_ECDSA &&
-            server_host_key->ecdsa_nid != kex->hostkey_nid)) {
-                r = SSH_ERR_KEY_TYPE_MISMATCH;
+        if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)
                 goto out;
-        }
-        if (kex->verify_host_key(server_host_key, ssh) == -1) {
-                r = SSH_ERR_SIGNATURE_INVALID;
-                goto out;
-        }
         /* DH parameter f, server public DH key, signed H */
         if ((r = sshpkt_get_bignum2(ssh, &dh_server_pub)) != 0 ||
             (r = sshpkt_get_string(ssh, &signature, &slen)) != 0 ||