upstream: pass most arguments to the KEX hash functions as sshbuf

rather than pointer+length; ok markus@

OpenBSD-Commit-ID: ef0c89c52ccc89817a13a5205725148a28492bf7

1 files changed, 17 insertions, 12 deletions

diff --git a/kexgexc.c b/kexgexc.c
index ac42127af..1c65b8a18 100644
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexc.c,v 1.33 2019/01/21 10:07:22 djm Exp $ */
+/* $OpenBSD: kexgexc.c,v 1.34 2019/01/23 00:30:41 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -146,20 +146,24 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
         BIGNUM *dh_server_pub = NULL;
         const BIGNUM *pub_key, *dh_p, *dh_g;
         struct sshbuf *shared_secret = NULL;
+        struct sshbuf *tmp = NULL, *server_host_key_blob = NULL;
         struct sshkey *server_host_key = NULL;
-        u_char *signature = NULL, *server_host_key_blob = NULL;
+        u_char *signature = NULL;
         u_char hash[SSH_DIGEST_MAX_LENGTH];
-        size_t slen, sbloblen, hashlen;
+        size_t slen, hashlen;
         int r;
 
         debug("got SSH2_MSG_KEX_DH_GEX_REPLY");
         /* 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)
+        if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
                 goto out;
-        if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)
+        /* sshkey_fromb() consumes its buffer, so make a copy */
+        if ((tmp = sshbuf_fromb(server_host_key_blob)) == NULL) {
+                r = SSH_ERR_ALLOC_FAIL;
+                goto out;
+        }
+        if ((r = sshkey_fromb(tmp, &server_host_key)) != 0 ||
+            (r = kex_verify_host_key(ssh, server_host_key)) != 0)
                 goto out;
         /* DH parameter f, server public DH key, signed H */
         if ((r = sshpkt_get_bignum2(ssh, &dh_server_pub)) != 0 ||
@@ -183,9 +187,9 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
             kex->hash_alg,
             kex->client_version,
             kex->server_version,
-            sshbuf_ptr(kex->my), sshbuf_len(kex->my),
-            sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
-            server_host_key_blob, sbloblen,
+            kex->my,
+            kex->peer,
+            server_host_key_blob,
             kex->min, kex->nbits, kex->max,
             dh_p, dh_g,
             pub_key,
@@ -207,7 +211,8 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
         BN_clear_free(dh_server_pub);
         sshbuf_free(shared_secret);
         sshkey_free(server_host_key);
-        free(server_host_key_blob);
+        sshbuf_free(tmp);
+        sshbuf_free(server_host_key_blob);
         free(signature);
         return r;
 }