kexdh.c revision 181110
1170809Sdelphij/* $OpenBSD: kexdh.c,v 1.23 2006/08/03 03:34:42 deraadt Exp $ */ 2170809Sdelphij/* 3171801Sdelphij * Copyright (c) 2001 Markus Friedl. All rights reserved. 4170809Sdelphij * 5171801Sdelphij * Redistribution and use in source and binary forms, with or without 6170809Sdelphij * modification, are permitted provided that the following conditions 7170809Sdelphij * are met: 8170809Sdelphij * 1. Redistributions of source code must retain the above copyright 9170809Sdelphij * notice, this list of conditions and the following disclaimer. 10170809Sdelphij * 2. Redistributions in binary form must reproduce the above copyright 11170809Sdelphij * notice, this list of conditions and the following disclaimer in the 12170809Sdelphij * documentation and/or other materials provided with the distribution. 13170809Sdelphij * 14170809Sdelphij * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15170809Sdelphij * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16170809Sdelphij * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17170809Sdelphij * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18170809Sdelphij * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19170809Sdelphij * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20170809Sdelphij * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21170809Sdelphij * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22170809Sdelphij * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23170809Sdelphij * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24170809Sdelphij */ 25170809Sdelphij 26170809Sdelphij#include "includes.h" 27170809Sdelphij 28170809Sdelphij#include <sys/types.h> 29170809Sdelphij 30170809Sdelphij#include <signal.h> 31170809Sdelphij 32170809Sdelphij#include <openssl/evp.h> 33170809Sdelphij 34170809Sdelphij#include "buffer.h" 35170809Sdelphij#include "ssh2.h" 36170809Sdelphij#include "key.h" 37170809Sdelphij#include "cipher.h" 38170809Sdelphij#include "kex.h" 39170809Sdelphij 40170809Sdelphijvoid 41170809Sdelphijkex_dh_hash( 42170809Sdelphij char *client_version_string, 43170809Sdelphij char *server_version_string, 44170809Sdelphij char *ckexinit, int ckexinitlen, 45170809Sdelphij char *skexinit, int skexinitlen, 46170809Sdelphij u_char *serverhostkeyblob, int sbloblen, 47170809Sdelphij BIGNUM *client_dh_pub, 48170809Sdelphij BIGNUM *server_dh_pub, 49170809Sdelphij BIGNUM *shared_secret, 50170809Sdelphij u_char **hash, u_int *hashlen) 51170809Sdelphij{ 52170809Sdelphij Buffer b; 53170809Sdelphij static u_char digest[EVP_MAX_MD_SIZE]; 54170809Sdelphij const EVP_MD *evp_md = EVP_sha1(); 55170809Sdelphij EVP_MD_CTX md; 56170809Sdelphij 57170809Sdelphij buffer_init(&b); 58170809Sdelphij buffer_put_cstring(&b, client_version_string); 59170809Sdelphij buffer_put_cstring(&b, server_version_string); 60170809Sdelphij 61170809Sdelphij /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 62170809Sdelphij buffer_put_int(&b, ckexinitlen+1); 63170809Sdelphij buffer_put_char(&b, SSH2_MSG_KEXINIT); 64170809Sdelphij buffer_append(&b, ckexinit, ckexinitlen); 65170809Sdelphij buffer_put_int(&b, skexinitlen+1); 66170809Sdelphij buffer_put_char(&b, SSH2_MSG_KEXINIT); 67170809Sdelphij buffer_append(&b, skexinit, skexinitlen); 68170809Sdelphij 69170809Sdelphij buffer_put_string(&b, serverhostkeyblob, sbloblen); 70170809Sdelphij buffer_put_bignum2(&b, client_dh_pub); 71170809Sdelphij buffer_put_bignum2(&b, server_dh_pub); 72170809Sdelphij buffer_put_bignum2(&b, shared_secret); 73170809Sdelphij 74170809Sdelphij#ifdef DEBUG_KEX 75170809Sdelphij buffer_dump(&b); 76170809Sdelphij#endif 77170809Sdelphij EVP_DigestInit(&md, evp_md); 78170809Sdelphij EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 79 EVP_DigestFinal(&md, digest, NULL); 80 81 buffer_free(&b); 82 83#ifdef DEBUG_KEX 84 dump_digest("hash", digest, EVP_MD_size(evp_md)); 85#endif 86 *hash = digest; 87 *hashlen = EVP_MD_size(evp_md); 88} 89