1 /* $NetBSD: kexgex.c,v 1.2 2009/06/07 22:38:46 christos Exp $ */ 2 /* $OpenBSD: kexgex.c,v 1.27 2006/08/03 03:34:42 deraadt Exp $ */ 3 /* 4 * Copyright (c) 2000 Niels Provos. All rights reserved. 5 * Copyright (c) 2001 Markus Friedl. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 __RCSID("$NetBSD: kexgex.c,v 1.2 2009/06/07 22:38:46 christos Exp $"); 30 #include <sys/types.h> 31 32 #include <openssl/evp.h> 33 #include <signal.h> 34 35 #include "buffer.h" 36 #include "key.h" 37 #include "cipher.h" 38 #include "kex.h" 39 #include "ssh2.h" 40 41 void 42 kexgex_hash( 43 const EVP_MD *evp_md, 44 char *client_version_string, 45 char *server_version_string, 46 char *ckexinit, int ckexinitlen, 47 char *skexinit, int skexinitlen, 48 u_char *serverhostkeyblob, int sbloblen, 49 int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen, 50 BIGNUM *client_dh_pub, 51 BIGNUM *server_dh_pub, 52 BIGNUM *shared_secret, 53 u_char **hash, u_int *hashlen) 54 { 55 Buffer b; 56 static u_char digest[EVP_MAX_MD_SIZE]; 57 EVP_MD_CTX md; 58 59 buffer_init(&b); 60 buffer_put_cstring(&b, client_version_string); 61 buffer_put_cstring(&b, server_version_string); 62 63 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 64 buffer_put_int(&b, ckexinitlen+1); 65 buffer_put_char(&b, SSH2_MSG_KEXINIT); 66 buffer_append(&b, ckexinit, ckexinitlen); 67 buffer_put_int(&b, skexinitlen+1); 68 buffer_put_char(&b, SSH2_MSG_KEXINIT); 69 buffer_append(&b, skexinit, skexinitlen); 70 71 buffer_put_string(&b, serverhostkeyblob, sbloblen); 72 if (min == -1 || max == -1) 73 buffer_put_int(&b, wantbits); 74 else { 75 buffer_put_int(&b, min); 76 buffer_put_int(&b, wantbits); 77 buffer_put_int(&b, max); 78 } 79 buffer_put_bignum2(&b, prime); 80 buffer_put_bignum2(&b, gen); 81 buffer_put_bignum2(&b, client_dh_pub); 82 buffer_put_bignum2(&b, server_dh_pub); 83 buffer_put_bignum2(&b, shared_secret); 84 85 #ifdef DEBUG_KEXDH 86 buffer_dump(&b); 87 #endif 88 89 EVP_DigestInit(&md, evp_md); 90 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 91 EVP_DigestFinal(&md, digest, NULL); 92 93 buffer_free(&b); 94 *hash = digest; 95 *hashlen = EVP_MD_size(evp_md); 96 #ifdef DEBUG_KEXDH 97 dump_digest("hash", digest, *hashlen); 98 #endif 99 } 100