11305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood/* $OpenBSD: kexdh.c,v 1.23 2006/08/03 03:34:42 deraadt Exp $ */ 21305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood/* 31305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * Copyright (c) 2001 Markus Friedl. All rights reserved. 41305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * 51305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * Redistribution and use in source and binary forms, with or without 61305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * modification, are permitted provided that the following conditions 71305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * are met: 81305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * 1. Redistributions of source code must retain the above copyright 91305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * notice, this list of conditions and the following disclaimer. 101305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * 2. Redistributions in binary form must reproduce the above copyright 111305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * notice, this list of conditions and the following disclaimer in the 121305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * documentation and/or other materials provided with the distribution. 131305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * 141305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 151305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 161305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 171305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 181305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 191305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 201305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 211305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 221305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 231305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 241305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood */ 251305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 261305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "includes.h" 271305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 281305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include <sys/types.h> 291305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 301305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include <signal.h> 311305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 321305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include <openssl/evp.h> 331305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 341305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "buffer.h" 351305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "ssh2.h" 361305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "key.h" 371305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "cipher.h" 381305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#include "kex.h" 391305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 401305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwoodvoid 411305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwoodkex_dh_hash( 421305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood char *client_version_string, 431305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood char *server_version_string, 441305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood char *ckexinit, int ckexinitlen, 451305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood char *skexinit, int skexinitlen, 461305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood u_char *serverhostkeyblob, int sbloblen, 471305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood BIGNUM *client_dh_pub, 481305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood BIGNUM *server_dh_pub, 491305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood BIGNUM *shared_secret, 501305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood u_char **hash, u_int *hashlen) 511305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood{ 521305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood Buffer b; 531305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood static u_char digest[EVP_MAX_MD_SIZE]; 541305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood const EVP_MD *evp_md = EVP_sha1(); 551305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood EVP_MD_CTX md; 561305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 571305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_init(&b); 581305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_cstring(&b, client_version_string); 591305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_cstring(&b, server_version_string); 601305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 611305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 621305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_int(&b, ckexinitlen+1); 631305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_char(&b, SSH2_MSG_KEXINIT); 641305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_append(&b, ckexinit, ckexinitlen); 651305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_int(&b, skexinitlen+1); 661305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_char(&b, SSH2_MSG_KEXINIT); 671305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_append(&b, skexinit, skexinitlen); 681305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 691305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_string(&b, serverhostkeyblob, sbloblen); 701305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_bignum2(&b, client_dh_pub); 711305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_bignum2(&b, server_dh_pub); 721305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_put_bignum2(&b, shared_secret); 731305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 741305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#ifdef DEBUG_KEX 751305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_dump(&b); 761305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#endif 771305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood EVP_DigestInit(&md, evp_md); 781305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 791305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood EVP_DigestFinal(&md, digest, NULL); 801305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 811305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood buffer_free(&b); 821305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood 831305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#ifdef DEBUG_KEX 841305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood dump_digest("hash", digest, EVP_MD_size(evp_md)); 851305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood#endif 861305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood *hash = digest; 871305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood *hashlen = EVP_MD_size(evp_md); 881305e95ba6ff9fa202d0818caf10405df4b0f648Mike Lockwood} 89