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/* $OpenBSD: kexgex.c,v 1.30 2018/12/27 03:25:25 djm Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
* 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"
#ifdef WITH_OPENSSL
#include <sys/types.h>
#include <openssl/evp.h>
#include <signal.h>
#include "openbsd-compat/openssl-compat.h"
#include "sshkey.h"
#include "cipher.h"
#include "kex.h"
#include "ssh2.h"
#include "ssherr.h"
#include "sshbuf.h"
#include "digest.h"
int
kexgex_hash(
int hash_alg,
const struct sshbuf *client_version,
const struct sshbuf *server_version,
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)
{
struct sshbuf *b;
int r;
if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1))
return SSH_ERR_INVALID_ARGUMENT;
if ((b = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_stringb(b, client_version)) < 0 ||
(r = sshbuf_put_stringb(b, server_version)) < 0 ||
/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
(r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 ||
(r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
(r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 ||
(r = sshbuf_put_u32(b, skexinitlen+1)) != 0 ||
(r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
(r = sshbuf_put(b, skexinit, skexinitlen)) != 0 ||
(r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 ||
(min != -1 && (r = sshbuf_put_u32(b, min)) != 0) ||
(r = sshbuf_put_u32(b, wantbits)) != 0 ||
(max != -1 && (r = sshbuf_put_u32(b, max)) != 0) ||
(r = sshbuf_put_bignum2(b, prime)) != 0 ||
(r = sshbuf_put_bignum2(b, gen)) != 0 ||
(r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 ||
(r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 ||
(r = sshbuf_put_bignum2(b, shared_secret)) != 0) {
sshbuf_free(b);
return r;
}
#ifdef DEBUG_KEXDH
sshbuf_dump(b, stderr);
#endif
if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) {
sshbuf_free(b);
return SSH_ERR_LIBCRYPTO_ERROR;
}
sshbuf_free(b);
*hashlen = ssh_digest_bytes(hash_alg);
#ifdef DEBUG_KEXDH
dump_digest("hash", hash, *hashlen);
#endif
return 0;
}
#endif /* WITH_OPENSSL */