1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * Copyright (c) 2000 Niels Provos. All rights reserved. 3*0Sstevel@tonic-gate * Copyright (c) 2001 Markus Friedl. All rights reserved. 4*0Sstevel@tonic-gate * 5*0Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without 6*0Sstevel@tonic-gate * modification, are permitted provided that the following conditions 7*0Sstevel@tonic-gate * are met: 8*0Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright 9*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer. 10*0Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright 11*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the 12*0Sstevel@tonic-gate * documentation and/or other materials provided with the distribution. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15*0Sstevel@tonic-gate * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16*0Sstevel@tonic-gate * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17*0Sstevel@tonic-gate * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18*0Sstevel@tonic-gate * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19*0Sstevel@tonic-gate * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20*0Sstevel@tonic-gate * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21*0Sstevel@tonic-gate * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22*0Sstevel@tonic-gate * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23*0Sstevel@tonic-gate * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24*0Sstevel@tonic-gate */ 25*0Sstevel@tonic-gate 26*0Sstevel@tonic-gate #include "includes.h" 27*0Sstevel@tonic-gate RCSID("$OpenBSD: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $"); 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 30*0Sstevel@tonic-gate 31*0Sstevel@tonic-gate #include <openssl/bn.h> 32*0Sstevel@tonic-gate 33*0Sstevel@tonic-gate #include "xmalloc.h" 34*0Sstevel@tonic-gate #include "buffer.h" 35*0Sstevel@tonic-gate #include "bufaux.h" 36*0Sstevel@tonic-gate #include "key.h" 37*0Sstevel@tonic-gate #include "kex.h" 38*0Sstevel@tonic-gate #include "log.h" 39*0Sstevel@tonic-gate #include "packet.h" 40*0Sstevel@tonic-gate #include "dh.h" 41*0Sstevel@tonic-gate #include "ssh2.h" 42*0Sstevel@tonic-gate #include "compat.h" 43*0Sstevel@tonic-gate #include "monitor_wrap.h" 44*0Sstevel@tonic-gate 45*0Sstevel@tonic-gate u_char * 46*0Sstevel@tonic-gate kexgex_hash( 47*0Sstevel@tonic-gate char *client_version_string, 48*0Sstevel@tonic-gate char *server_version_string, 49*0Sstevel@tonic-gate char *ckexinit, int ckexinitlen, 50*0Sstevel@tonic-gate char *skexinit, int skexinitlen, 51*0Sstevel@tonic-gate u_char *serverhostkeyblob, int sbloblen, 52*0Sstevel@tonic-gate int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen, 53*0Sstevel@tonic-gate BIGNUM *client_dh_pub, 54*0Sstevel@tonic-gate BIGNUM *server_dh_pub, 55*0Sstevel@tonic-gate BIGNUM *shared_secret) 56*0Sstevel@tonic-gate { 57*0Sstevel@tonic-gate Buffer b; 58*0Sstevel@tonic-gate static u_char digest[EVP_MAX_MD_SIZE]; 59*0Sstevel@tonic-gate const EVP_MD *evp_md = EVP_sha1(); 60*0Sstevel@tonic-gate EVP_MD_CTX md; 61*0Sstevel@tonic-gate 62*0Sstevel@tonic-gate buffer_init(&b); 63*0Sstevel@tonic-gate buffer_put_cstring(&b, client_version_string); 64*0Sstevel@tonic-gate buffer_put_cstring(&b, server_version_string); 65*0Sstevel@tonic-gate 66*0Sstevel@tonic-gate /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 67*0Sstevel@tonic-gate buffer_put_int(&b, ckexinitlen+1); 68*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT); 69*0Sstevel@tonic-gate buffer_append(&b, ckexinit, ckexinitlen); 70*0Sstevel@tonic-gate buffer_put_int(&b, skexinitlen+1); 71*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT); 72*0Sstevel@tonic-gate buffer_append(&b, skexinit, skexinitlen); 73*0Sstevel@tonic-gate 74*0Sstevel@tonic-gate buffer_put_string(&b, serverhostkeyblob, sbloblen); 75*0Sstevel@tonic-gate if (min == -1 || max == -1) 76*0Sstevel@tonic-gate buffer_put_int(&b, wantbits); 77*0Sstevel@tonic-gate else { 78*0Sstevel@tonic-gate buffer_put_int(&b, min); 79*0Sstevel@tonic-gate buffer_put_int(&b, wantbits); 80*0Sstevel@tonic-gate buffer_put_int(&b, max); 81*0Sstevel@tonic-gate } 82*0Sstevel@tonic-gate buffer_put_bignum2(&b, prime); 83*0Sstevel@tonic-gate buffer_put_bignum2(&b, gen); 84*0Sstevel@tonic-gate buffer_put_bignum2(&b, client_dh_pub); 85*0Sstevel@tonic-gate buffer_put_bignum2(&b, server_dh_pub); 86*0Sstevel@tonic-gate buffer_put_bignum2(&b, shared_secret); 87*0Sstevel@tonic-gate 88*0Sstevel@tonic-gate #ifdef DEBUG_KEXDH 89*0Sstevel@tonic-gate buffer_dump(&b); 90*0Sstevel@tonic-gate #endif 91*0Sstevel@tonic-gate EVP_DigestInit(&md, evp_md); 92*0Sstevel@tonic-gate EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 93*0Sstevel@tonic-gate EVP_DigestFinal(&md, digest, NULL); 94*0Sstevel@tonic-gate 95*0Sstevel@tonic-gate buffer_free(&b); 96*0Sstevel@tonic-gate 97*0Sstevel@tonic-gate #ifdef DEBUG_KEXDH 98*0Sstevel@tonic-gate dump_digest("hash", digest, EVP_MD_size(evp_md)); 99*0Sstevel@tonic-gate #endif 100*0Sstevel@tonic-gate return digest; 101*0Sstevel@tonic-gate } 102