1/* $OpenBSD: kexgex.c,v 1.27 2006/08/03 03:34:42 deraadt Exp $ */ 2/* 3 * Copyright (c) 2000 Niels Provos. All rights reserved. 4 * Copyright (c) 2001 Markus Friedl. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include "includes.h" 28 29#include <sys/types.h> 30 31#ifdef __APPLE_CRYPTO__ 32#include "ossl-evp.h" 33#else 34#include <openssl/evp.h> 35#endif 36 37#include <signal.h> 38 39#include "buffer.h" 40#include "key.h" 41#include "cipher.h" 42#include "kex.h" 43#include "ssh2.h" 44 45void 46kexgex_hash( 47 const EVP_MD *evp_md, 48 char *client_version_string, 49 char *server_version_string, 50 char *ckexinit, int ckexinitlen, 51 char *skexinit, int skexinitlen, 52 u_char *serverhostkeyblob, int sbloblen, 53 int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen, 54 BIGNUM *client_dh_pub, 55 BIGNUM *server_dh_pub, 56 BIGNUM *shared_secret, 57 u_char **hash, u_int *hashlen) 58{ 59 Buffer b; 60 static u_char digest[EVP_MAX_MD_SIZE]; 61 EVP_MD_CTX md; 62 63 buffer_init(&b); 64 buffer_put_cstring(&b, client_version_string); 65 buffer_put_cstring(&b, server_version_string); 66 67 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 68 buffer_put_int(&b, ckexinitlen+1); 69 buffer_put_char(&b, SSH2_MSG_KEXINIT); 70 buffer_append(&b, ckexinit, ckexinitlen); 71 buffer_put_int(&b, skexinitlen+1); 72 buffer_put_char(&b, SSH2_MSG_KEXINIT); 73 buffer_append(&b, skexinit, skexinitlen); 74 75 buffer_put_string(&b, serverhostkeyblob, sbloblen); 76 if (min == -1 || max == -1) 77 buffer_put_int(&b, wantbits); 78 else { 79 buffer_put_int(&b, min); 80 buffer_put_int(&b, wantbits); 81 buffer_put_int(&b, max); 82 } 83 buffer_put_bignum2(&b, prime); 84 buffer_put_bignum2(&b, gen); 85 buffer_put_bignum2(&b, client_dh_pub); 86 buffer_put_bignum2(&b, server_dh_pub); 87 buffer_put_bignum2(&b, shared_secret); 88 89#ifdef DEBUG_KEXDH 90 buffer_dump(&b); 91#endif 92 93 EVP_DigestInit(&md, evp_md); 94 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 95 EVP_DigestFinal(&md, digest, NULL); 96 97 buffer_free(&b); 98 *hash = digest; 99 *hashlen = EVP_MD_size(evp_md); 100#ifdef DEBUG_KEXDH 101 dump_digest("hash", digest, *hashlen); 102#endif 103} 104