1 /* $OpenBSD: kexdh.c,v 1.24 2014/01/09 23:20:00 djm 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 <sys/types.h> 27 28 #include <signal.h> 29 30 #include <openssl/evp.h> 31 32 #include "buffer.h" 33 #include "ssh2.h" 34 #include "key.h" 35 #include "cipher.h" 36 #include "kex.h" 37 #include "digest.h" 38 #include "log.h" 39 40 void 41 kex_dh_hash( 42 char *client_version_string, 43 char *server_version_string, 44 char *ckexinit, int ckexinitlen, 45 char *skexinit, int skexinitlen, 46 u_char *serverhostkeyblob, int sbloblen, 47 BIGNUM *client_dh_pub, 48 BIGNUM *server_dh_pub, 49 BIGNUM *shared_secret, 50 u_char **hash, u_int *hashlen) 51 { 52 Buffer b; 53 static u_char digest[SSH_DIGEST_MAX_LENGTH]; 54 55 buffer_init(&b); 56 buffer_put_cstring(&b, client_version_string); 57 buffer_put_cstring(&b, server_version_string); 58 59 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 60 buffer_put_int(&b, ckexinitlen+1); 61 buffer_put_char(&b, SSH2_MSG_KEXINIT); 62 buffer_append(&b, ckexinit, ckexinitlen); 63 buffer_put_int(&b, skexinitlen+1); 64 buffer_put_char(&b, SSH2_MSG_KEXINIT); 65 buffer_append(&b, skexinit, skexinitlen); 66 67 buffer_put_string(&b, serverhostkeyblob, sbloblen); 68 buffer_put_bignum2(&b, client_dh_pub); 69 buffer_put_bignum2(&b, server_dh_pub); 70 buffer_put_bignum2(&b, shared_secret); 71 72 #ifdef DEBUG_KEX 73 buffer_dump(&b); 74 #endif 75 if (ssh_digest_buffer(SSH_DIGEST_SHA1, &b, digest, sizeof(digest)) != 0) 76 fatal("%s: ssh_digest_buffer failed", __func__); 77 78 buffer_free(&b); 79 80 #ifdef DEBUG_KEX 81 dump_digest("hash", digest, ssh_digest_bytes(SSH_DIGEST_SHA1)); 82 #endif 83 *hash = digest; 84 *hashlen = ssh_digest_bytes(SSH_DIGEST_SHA1); 85 } 86