1 /* $OpenBSD: kexgex.c,v 1.29 2015/01/19 20:16:15 markus Exp $ */
2 /*
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"
28
29 #ifdef WITH_OPENSSL
30
31 #include <sys/types.h>
32
33 #include <openssl/evp.h>
34 #include <signal.h>
35
36 #include "sshkey.h"
37 #include "cipher.h"
38 #include "kex.h"
39 #include "ssh2.h"
40 #include "ssherr.h"
41 #include "sshbuf.h"
42 #include "digest.h"
43
44 int
kexgex_hash(int hash_alg,const char * client_version_string,const char * server_version_string,const u_char * ckexinit,size_t ckexinitlen,const u_char * skexinit,size_t skexinitlen,const u_char * serverhostkeyblob,size_t sbloblen,int min,int wantbits,int max,const BIGNUM * prime,const BIGNUM * gen,const BIGNUM * client_dh_pub,const BIGNUM * server_dh_pub,const BIGNUM * shared_secret,u_char * hash,size_t * hashlen)45 kexgex_hash(
46 int hash_alg,
47 const char *client_version_string,
48 const char *server_version_string,
49 const u_char *ckexinit, size_t ckexinitlen,
50 const u_char *skexinit, size_t skexinitlen,
51 const u_char *serverhostkeyblob, size_t sbloblen,
52 int min, int wantbits, int max,
53 const BIGNUM *prime,
54 const BIGNUM *gen,
55 const BIGNUM *client_dh_pub,
56 const BIGNUM *server_dh_pub,
57 const BIGNUM *shared_secret,
58 u_char *hash, size_t *hashlen)
59 {
60 struct sshbuf *b;
61 int r;
62
63 if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1))
64 return SSH_ERR_INVALID_ARGUMENT;
65 if ((b = sshbuf_new()) == NULL)
66 return SSH_ERR_ALLOC_FAIL;
67 if ((r = sshbuf_put_cstring(b, client_version_string)) != 0 ||
68 (r = sshbuf_put_cstring(b, server_version_string)) != 0 ||
69 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
70 (r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 ||
71 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
72 (r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 ||
73 (r = sshbuf_put_u32(b, skexinitlen+1)) != 0 ||
74 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
75 (r = sshbuf_put(b, skexinit, skexinitlen)) != 0 ||
76 (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 ||
77 (min != -1 && (r = sshbuf_put_u32(b, min)) != 0) ||
78 (r = sshbuf_put_u32(b, wantbits)) != 0 ||
79 (max != -1 && (r = sshbuf_put_u32(b, max)) != 0) ||
80 (r = sshbuf_put_bignum2(b, prime)) != 0 ||
81 (r = sshbuf_put_bignum2(b, gen)) != 0 ||
82 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 ||
83 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 ||
84 (r = sshbuf_put_bignum2(b, shared_secret)) != 0) {
85 sshbuf_free(b);
86 return r;
87 }
88 #ifdef DEBUG_KEXDH
89 sshbuf_dump(b, stderr);
90 #endif
91 if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) {
92 sshbuf_free(b);
93 return SSH_ERR_LIBCRYPTO_ERROR;
94 }
95 sshbuf_free(b);
96 *hashlen = ssh_digest_bytes(hash_alg);
97 #ifdef DEBUG_KEXDH
98 dump_digest("hash", hash, *hashlen);
99 #endif
100 return 0;
101 }
102 #endif /* WITH_OPENSSL */
103