1/* $OpenBSD: kexdh.c,v 1.23 2006/08/03 03:34:42 deraadt Exp $ */ 2/* 3 * Copyright (c) 2001 Markus Friedl. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "includes.h" 27 28#include <sys/types.h> 29 30#include <signal.h> 31 32#ifdef __APPLE_CRYPTO__ 33#include "ossl-evp.h" 34#else 35#include <openssl/evp.h> 36#endif 37 38#include "buffer.h" 39#include "ssh2.h" 40#include "key.h" 41#include "cipher.h" 42#include "kex.h" 43 44void 45kex_dh_hash( 46 char *client_version_string, 47 char *server_version_string, 48 char *ckexinit, int ckexinitlen, 49 char *skexinit, int skexinitlen, 50 u_char *serverhostkeyblob, int sbloblen, 51 BIGNUM *client_dh_pub, 52 BIGNUM *server_dh_pub, 53 BIGNUM *shared_secret, 54 u_char **hash, u_int *hashlen) 55{ 56 Buffer b; 57 static u_char digest[EVP_MAX_MD_SIZE]; 58 const EVP_MD *evp_md = EVP_sha1(); 59 EVP_MD_CTX md; 60 61 buffer_init(&b); 62 buffer_put_cstring(&b, client_version_string); 63 buffer_put_cstring(&b, server_version_string); 64 65 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 66 buffer_put_int(&b, ckexinitlen+1); 67 buffer_put_char(&b, SSH2_MSG_KEXINIT); 68 buffer_append(&b, ckexinit, ckexinitlen); 69 buffer_put_int(&b, skexinitlen+1); 70 buffer_put_char(&b, SSH2_MSG_KEXINIT); 71 buffer_append(&b, skexinit, skexinitlen); 72 73 buffer_put_string(&b, serverhostkeyblob, sbloblen); 74 buffer_put_bignum2(&b, client_dh_pub); 75 buffer_put_bignum2(&b, server_dh_pub); 76 buffer_put_bignum2(&b, shared_secret); 77 78#ifdef DEBUG_KEX 79 buffer_dump(&b); 80#endif 81 EVP_DigestInit(&md, evp_md); 82 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 83 EVP_DigestFinal(&md, digest, NULL); 84 85 buffer_free(&b); 86 87#ifdef DEBUG_KEX 88 dump_digest("hash", digest, EVP_MD_size(evp_md)); 89#endif 90 *hash = digest; 91 *hashlen = EVP_MD_size(evp_md); 92} 93