1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * Copyright (c) 2001 Markus Friedl. All rights reserved.
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without
5*0Sstevel@tonic-gate * modification, are permitted provided that the following conditions
6*0Sstevel@tonic-gate * are met:
7*0Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright
8*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer.
9*0Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright
10*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the
11*0Sstevel@tonic-gate * documentation and/or other materials provided with the distribution.
12*0Sstevel@tonic-gate *
13*0Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14*0Sstevel@tonic-gate * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15*0Sstevel@tonic-gate * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16*0Sstevel@tonic-gate * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17*0Sstevel@tonic-gate * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18*0Sstevel@tonic-gate * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19*0Sstevel@tonic-gate * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20*0Sstevel@tonic-gate * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21*0Sstevel@tonic-gate * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22*0Sstevel@tonic-gate * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23*0Sstevel@tonic-gate */
24*0Sstevel@tonic-gate
25*0Sstevel@tonic-gate #include "includes.h"
26*0Sstevel@tonic-gate RCSID("$OpenBSD: kexdh.c,v 1.18 2002/03/18 17:50:31 provos Exp $");
27*0Sstevel@tonic-gate
28*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI"
29*0Sstevel@tonic-gate
30*0Sstevel@tonic-gate #include <openssl/crypto.h>
31*0Sstevel@tonic-gate #include <openssl/bn.h>
32*0Sstevel@tonic-gate
33*0Sstevel@tonic-gate #include "xmalloc.h"
34*0Sstevel@tonic-gate #include "buffer.h"
35*0Sstevel@tonic-gate #include "bufaux.h"
36*0Sstevel@tonic-gate #include "key.h"
37*0Sstevel@tonic-gate #include "kex.h"
38*0Sstevel@tonic-gate #include "log.h"
39*0Sstevel@tonic-gate #include "packet.h"
40*0Sstevel@tonic-gate #include "dh.h"
41*0Sstevel@tonic-gate #include "ssh2.h"
42*0Sstevel@tonic-gate
43*0Sstevel@tonic-gate u_char *
kex_dh_hash(char * client_version_string,char * server_version_string,char * ckexinit,int ckexinitlen,char * skexinit,int skexinitlen,u_char * serverhostkeyblob,int sbloblen,BIGNUM * client_dh_pub,BIGNUM * server_dh_pub,BIGNUM * shared_secret)44*0Sstevel@tonic-gate kex_dh_hash(
45*0Sstevel@tonic-gate char *client_version_string,
46*0Sstevel@tonic-gate char *server_version_string,
47*0Sstevel@tonic-gate char *ckexinit, int ckexinitlen,
48*0Sstevel@tonic-gate char *skexinit, int skexinitlen,
49*0Sstevel@tonic-gate u_char *serverhostkeyblob, int sbloblen,
50*0Sstevel@tonic-gate BIGNUM *client_dh_pub,
51*0Sstevel@tonic-gate BIGNUM *server_dh_pub,
52*0Sstevel@tonic-gate BIGNUM *shared_secret)
53*0Sstevel@tonic-gate {
54*0Sstevel@tonic-gate Buffer b;
55*0Sstevel@tonic-gate static u_char digest[EVP_MAX_MD_SIZE];
56*0Sstevel@tonic-gate const EVP_MD *evp_md = EVP_sha1();
57*0Sstevel@tonic-gate EVP_MD_CTX md;
58*0Sstevel@tonic-gate
59*0Sstevel@tonic-gate buffer_init(&b);
60*0Sstevel@tonic-gate buffer_put_cstring(&b, client_version_string);
61*0Sstevel@tonic-gate buffer_put_cstring(&b, server_version_string);
62*0Sstevel@tonic-gate
63*0Sstevel@tonic-gate /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
64*0Sstevel@tonic-gate buffer_put_int(&b, ckexinitlen+1);
65*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT);
66*0Sstevel@tonic-gate buffer_append(&b, ckexinit, ckexinitlen);
67*0Sstevel@tonic-gate buffer_put_int(&b, skexinitlen+1);
68*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT);
69*0Sstevel@tonic-gate buffer_append(&b, skexinit, skexinitlen);
70*0Sstevel@tonic-gate
71*0Sstevel@tonic-gate buffer_put_string(&b, serverhostkeyblob, sbloblen);
72*0Sstevel@tonic-gate buffer_put_bignum2(&b, client_dh_pub);
73*0Sstevel@tonic-gate buffer_put_bignum2(&b, server_dh_pub);
74*0Sstevel@tonic-gate buffer_put_bignum2(&b, shared_secret);
75*0Sstevel@tonic-gate
76*0Sstevel@tonic-gate #ifdef DEBUG_KEX
77*0Sstevel@tonic-gate buffer_dump(&b);
78*0Sstevel@tonic-gate #endif
79*0Sstevel@tonic-gate EVP_DigestInit(&md, evp_md);
80*0Sstevel@tonic-gate EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
81*0Sstevel@tonic-gate EVP_DigestFinal(&md, digest, NULL);
82*0Sstevel@tonic-gate
83*0Sstevel@tonic-gate buffer_free(&b);
84*0Sstevel@tonic-gate
85*0Sstevel@tonic-gate #ifdef DEBUG_KEX
86*0Sstevel@tonic-gate dump_digest("hash", digest, EVP_MD_size(evp_md));
87*0Sstevel@tonic-gate #endif
88*0Sstevel@tonic-gate return digest;
89*0Sstevel@tonic-gate }
90