blob: 8040a13202fc03bbfe65590d9082f58b3359e82a [file] [log] [blame]
djm@openbsd.orgbb956ea2019-01-23 00:30:41 +00001/* $OpenBSD: kexgex.c,v 1.32 2019/01/23 00:30:41 djm Exp $ */
Ben Lindstrom22b19b42001-04-04 17:39:19 +00002/*
3 * Copyright (c) 2000 Niels Provos. All rights reserved.
4 * Copyright (c) 2001 Markus Friedl. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
Ben Lindstrom22b19b42001-04-04 17:39:19 +000028
Damien Miller72ef7c12015-01-15 02:21:31 +110029#ifdef WITH_OPENSSL
30
Damien Millerd7834352006-08-05 12:39:39 +100031#include <sys/types.h>
32
Damien Miller8e7fb332003-02-24 12:03:03 +110033#include <openssl/evp.h>
Damien Millerd7834352006-08-05 12:39:39 +100034#include <signal.h>
Ben Lindstrom22b19b42001-04-04 17:39:19 +000035
Damien Miller48f54b92018-09-13 12:13:50 +100036#include "openbsd-compat/openssl-compat.h"
37
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000038#include "sshkey.h"
Damien Millerd7834352006-08-05 12:39:39 +100039#include "cipher.h"
Ben Lindstrom22b19b42001-04-04 17:39:19 +000040#include "kex.h"
Ben Lindstrom22b19b42001-04-04 17:39:19 +000041#include "ssh2.h"
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000042#include "ssherr.h"
43#include "sshbuf.h"
Damien Millerb3051d02014-01-10 10:58:53 +110044#include "digest.h"
Ben Lindstrom22b19b42001-04-04 17:39:19 +000045
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000046int
Ben Lindstrom22b19b42001-04-04 17:39:19 +000047kexgex_hash(
Damien Millerb3051d02014-01-10 10:58:53 +110048 int hash_alg,
djm@openbsd.org0a843d92018-12-27 03:25:24 +000049 const struct sshbuf *client_version,
50 const struct sshbuf *server_version,
djm@openbsd.orgbb956ea2019-01-23 00:30:41 +000051 const struct sshbuf *client_kexinit,
52 const struct sshbuf *server_kexinit,
53 const struct sshbuf *server_host_key_blob,
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000054 int min, int wantbits, int max,
55 const BIGNUM *prime,
56 const BIGNUM *gen,
57 const BIGNUM *client_dh_pub,
58 const BIGNUM *server_dh_pub,
djm@openbsd.orgdec5e9d2019-01-21 10:03:37 +000059 const u_char *shared_secret, size_t secretlen,
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000060 u_char *hash, size_t *hashlen)
Ben Lindstrom22b19b42001-04-04 17:39:19 +000061{
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000062 struct sshbuf *b;
63 int r;
Ben Lindstrom22b19b42001-04-04 17:39:19 +000064
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000065 if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1))
66 return SSH_ERR_INVALID_ARGUMENT;
67 if ((b = sshbuf_new()) == NULL)
68 return SSH_ERR_ALLOC_FAIL;
djm@openbsd.org0a843d92018-12-27 03:25:24 +000069 if ((r = sshbuf_put_stringb(b, client_version)) < 0 ||
70 (r = sshbuf_put_stringb(b, server_version)) < 0 ||
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000071 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
djm@openbsd.orgbb956ea2019-01-23 00:30:41 +000072 (r = sshbuf_put_u32(b, sshbuf_len(client_kexinit) + 1)) != 0 ||
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000073 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
djm@openbsd.orgbb956ea2019-01-23 00:30:41 +000074 (r = sshbuf_putb(b, client_kexinit)) != 0 ||
75 (r = sshbuf_put_u32(b, sshbuf_len(server_kexinit) + 1)) != 0 ||
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000076 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
djm@openbsd.orgbb956ea2019-01-23 00:30:41 +000077 (r = sshbuf_putb(b, server_kexinit)) != 0 ||
78 (r = sshbuf_put_stringb(b, server_host_key_blob)) != 0 ||
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000079 (min != -1 && (r = sshbuf_put_u32(b, min)) != 0) ||
80 (r = sshbuf_put_u32(b, wantbits)) != 0 ||
81 (max != -1 && (r = sshbuf_put_u32(b, max)) != 0) ||
82 (r = sshbuf_put_bignum2(b, prime)) != 0 ||
83 (r = sshbuf_put_bignum2(b, gen)) != 0 ||
84 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 ||
85 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 ||
djm@openbsd.orgdec5e9d2019-01-21 10:03:37 +000086 (r = sshbuf_put(b, shared_secret, secretlen)) != 0) {
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000087 sshbuf_free(b);
88 return r;
Ben Lindstrom22b19b42001-04-04 17:39:19 +000089 }
Ben Lindstrom22b19b42001-04-04 17:39:19 +000090#ifdef DEBUG_KEXDH
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000091 sshbuf_dump(b, stderr);
Ben Lindstrom22b19b42001-04-04 17:39:19 +000092#endif
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000093 if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) {
94 sshbuf_free(b);
95 return SSH_ERR_LIBCRYPTO_ERROR;
96 }
97 sshbuf_free(b);
Damien Millerb3051d02014-01-10 10:58:53 +110098 *hashlen = ssh_digest_bytes(hash_alg);
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000099#ifdef DEBUG_KEXDH
100 dump_digest("hash", hash, *hashlen);
101#endif
102 return 0;
Ben Lindstrom22b19b42001-04-04 17:39:19 +0000103}
Damien Miller72ef7c12015-01-15 02:21:31 +1100104#endif /* WITH_OPENSSL */