[openssh.git] / kexdh.c

/*
 * Copyright (c) 2001 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

#include <openssl/evp.h>

#include "buffer.h"
#include "bufaux.h"
#include "ssh2.h"
#include "kex.h"

void
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,
    u_char **hash, u_int *hashlen)
{
	Buffer b;
	static u_char digest[EVP_MAX_MD_SIZE];
	const EVP_MD *evp_md = EVP_sha1();
	EVP_MD_CTX md;

	buffer_init(&b);
	buffer_put_cstring(&b, client_version_string);
	buffer_put_cstring(&b, server_version_string);

	/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
	buffer_put_int(&b, ckexinitlen+1);
	buffer_put_char(&b, SSH2_MSG_KEXINIT);
	buffer_append(&b, ckexinit, ckexinitlen);
	buffer_put_int(&b, skexinitlen+1);
	buffer_put_char(&b, SSH2_MSG_KEXINIT);
	buffer_append(&b, skexinit, skexinitlen);

	buffer_put_string(&b, serverhostkeyblob, sbloblen);
	buffer_put_bignum2(&b, client_dh_pub);
	buffer_put_bignum2(&b, server_dh_pub);
	buffer_put_bignum2(&b, shared_secret);

#ifdef DEBUG_KEX
	buffer_dump(&b);
#endif
	EVP_DigestInit(&md, evp_md);
	EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
	EVP_DigestFinal(&md, digest, NULL);

	buffer_free(&b);

#ifdef DEBUG_KEX
	dump_digest("hash", digest, EVP_MD_size(evp_md));
#endif
	*hash = digest;
	*hashlen = EVP_MD_size(evp_md);
}
Commit	Line	Data
0bc35151	1	/*
	2	* Copyright (c) 2001 Markus Friedl. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	15	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	16	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	17	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	18	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	19	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	20	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	21	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	22	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	23	*/
	24
	25	#include "includes.h"
0bc35151	26
98a58eda	27	#include <openssl/evp.h>
0bc35151	28
0bc35151	29	#include "buffer.h"
0bc35151	30	#include "bufaux.h"
0bc35151	31	#include "ssh2.h"
98a58eda	32	#include "kex.h"
0bc35151	33
47e5dc72	34	void
0bc35151	35	kex_dh_hash(
	36	char *client_version_string,
	37	char *server_version_string,
	38	char *ckexinit, int ckexinitlen,
	39	char *skexinit, int skexinitlen,
cf54363d	40	u_char *serverhostkeyblob, int sbloblen,
0bc35151	41	BIGNUM *client_dh_pub,
0bc35151	42	BIGNUM *server_dh_pub,
47e5dc72	43	BIGNUM *shared_secret,
47e5dc72	44	u_char *hash, u_int hashlen)
0bc35151	45	{
	46	Buffer b;
	47	static u_char digest[EVP_MAX_MD_SIZE];
714954dc	48	const EVP_MD *evp_md = EVP_sha1();
0bc35151	49	EVP_MD_CTX md;
	50
	51	buffer_init(&b);
449c5ba5	52	buffer_put_cstring(&b, client_version_string);
449c5ba5	53	buffer_put_cstring(&b, server_version_string);
0bc35151	54
	55	/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
	56	buffer_put_int(&b, ckexinitlen+1);
	57	buffer_put_char(&b, SSH2_MSG_KEXINIT);
	58	buffer_append(&b, ckexinit, ckexinitlen);
	59	buffer_put_int(&b, skexinitlen+1);
	60	buffer_put_char(&b, SSH2_MSG_KEXINIT);
	61	buffer_append(&b, skexinit, skexinitlen);
	62
	63	buffer_put_string(&b, serverhostkeyblob, sbloblen);
	64	buffer_put_bignum2(&b, client_dh_pub);
	65	buffer_put_bignum2(&b, server_dh_pub);
	66	buffer_put_bignum2(&b, shared_secret);
	67
	68	#ifdef DEBUG_KEX
	69	buffer_dump(&b);
	70	#endif
	71	EVP_DigestInit(&md, evp_md);
	72	EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
	73	EVP_DigestFinal(&md, digest, NULL);
	74
	75	buffer_free(&b);
	76
	77	#ifdef DEBUG_KEX
a209a158	78	dump_digest("hash", digest, EVP_MD_size(evp_md));
0bc35151	79	#endif
47e5dc72	80	*hash = digest;
47e5dc72	81	*hashlen = EVP_MD_size(evp_md);
0bc35151	82	}