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djm@openbsd.org0a843d92018-12-27 03:25:24 +00001/* $OpenBSD: kexdh.c,v 1.27 2018/12/27 03:25:25 djm Exp $ */
Ben Lindstrom22b19b42001-04-04 17:39:19 +00002/*
3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
Ben Lindstrom22b19b42001-04-04 17:39:19 +000027
Damien Miller72ef7c12015-01-15 02:21:31 +110028#ifdef WITH_OPENSSL
29
Damien Millerd7834352006-08-05 12:39:39 +100030#include <sys/types.h>
31
32#include <signal.h>
33
Damien Miller8e7fb332003-02-24 12:03:03 +110034#include <openssl/evp.h>
Ben Lindstrom22b19b42001-04-04 17:39:19 +000035
Damien Miller48f54b92018-09-13 12:13:50 +100036#include "openbsd-compat/openssl-compat.h"
37
Ben Lindstrom22b19b42001-04-04 17:39:19 +000038#include "ssh2.h"
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000039#include "sshkey.h"
Damien Millerd7834352006-08-05 12:39:39 +100040#include "cipher.h"
Damien Miller8e7fb332003-02-24 12:03:03 +110041#include "kex.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 +000047kex_dh_hash(
djm@openbsd.org0e8eeec2016-05-02 10:26:04 +000048 int hash_alg,
djm@openbsd.org0a843d92018-12-27 03:25:24 +000049 const struct sshbuf *client_version,
50 const struct sshbuf *server_version,
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000051 const u_char *ckexinit, size_t ckexinitlen,
52 const u_char *skexinit, size_t skexinitlen,
53 const u_char *serverhostkeyblob, size_t sbloblen,
54 const BIGNUM *client_dh_pub,
55 const BIGNUM *server_dh_pub,
56 const BIGNUM *shared_secret,
57 u_char *hash, size_t *hashlen)
Ben Lindstrom22b19b42001-04-04 17:39:19 +000058{
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000059 struct sshbuf *b;
60 int r;
Ben Lindstrom22b19b42001-04-04 17:39:19 +000061
djm@openbsd.org0e8eeec2016-05-02 10:26:04 +000062 if (*hashlen < ssh_digest_bytes(hash_alg))
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000063 return SSH_ERR_INVALID_ARGUMENT;
64 if ((b = sshbuf_new()) == NULL)
65 return SSH_ERR_ALLOC_FAIL;
djm@openbsd.org0a843d92018-12-27 03:25:24 +000066 if ((r = sshbuf_put_stringb(b, client_version)) < 0 ||
67 (r = sshbuf_put_stringb(b, server_version)) < 0 ||
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000068 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
69 (r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 ||
70 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
71 (r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 ||
72 (r = sshbuf_put_u32(b, skexinitlen+1)) != 0 ||
73 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
74 (r = sshbuf_put(b, skexinit, skexinitlen)) != 0 ||
75 (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 ||
76 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 ||
77 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 ||
78 (r = sshbuf_put_bignum2(b, shared_secret)) != 0) {
79 sshbuf_free(b);
80 return r;
81 }
Ben Lindstrom22b19b42001-04-04 17:39:19 +000082#ifdef DEBUG_KEX
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000083 sshbuf_dump(b, stderr);
Ben Lindstrom22b19b42001-04-04 17:39:19 +000084#endif
djm@openbsd.org0e8eeec2016-05-02 10:26:04 +000085 if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) {
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000086 sshbuf_free(b);
87 return SSH_ERR_LIBCRYPTO_ERROR;
88 }
89 sshbuf_free(b);
djm@openbsd.org0e8eeec2016-05-02 10:26:04 +000090 *hashlen = ssh_digest_bytes(hash_alg);
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000091#ifdef DEBUG_KEX
92 dump_digest("hash", hash, *hashlen);
93#endif
94 return 0;
Ben Lindstrom22b19b42001-04-04 17:39:19 +000095}
Damien Miller72ef7c12015-01-15 02:21:31 +110096#endif /* WITH_OPENSSL */