1/* $NetBSD: kexgex.c,v 1.7 2019/04/20 17:16:40 christos Exp $ */ 2/* $OpenBSD: kexgex.c,v 1.32 2019/01/23 00:30:41 djm 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 1.7 2019/04/20 17:16:40 christos Exp $"); 30#include <sys/types.h> 31 32#include <openssl/evp.h> 33#include <signal.h> 34 35#include "sshkey.h" 36#include "cipher.h" 37#include "kex.h" 38#include "ssh2.h" 39#include "ssherr.h" 40#include "sshbuf.h" 41#include "digest.h" 42 43int 44kexgex_hash( 45 int hash_alg, 46 const struct sshbuf *client_version, 47 const struct sshbuf *server_version, 48 const struct sshbuf *client_kexinit, 49 const struct sshbuf *server_kexinit, 50 const struct sshbuf *server_host_key_blob, 51 int min, int wantbits, int max, 52 const BIGNUM *prime, 53 const BIGNUM *gen, 54 const BIGNUM *client_dh_pub, 55 const BIGNUM *server_dh_pub, 56 const u_char *shared_secret, size_t secretlen, 57 u_char *hash, size_t *hashlen) 58{ 59 struct sshbuf *b; 60 int r; 61 62 if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1)) 63 return SSH_ERR_INVALID_ARGUMENT; 64 if ((b = sshbuf_new()) == NULL) 65 return SSH_ERR_ALLOC_FAIL; 66 if ((r = sshbuf_put_stringb(b, client_version)) < 0 || 67 (r = sshbuf_put_stringb(b, server_version)) < 0 || 68 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 69 (r = sshbuf_put_u32(b, sshbuf_len(client_kexinit) + 1)) != 0 || 70 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 71 (r = sshbuf_putb(b, client_kexinit)) != 0 || 72 (r = sshbuf_put_u32(b, sshbuf_len(server_kexinit) + 1)) != 0 || 73 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 74 (r = sshbuf_putb(b, server_kexinit)) != 0 || 75 (r = sshbuf_put_stringb(b, server_host_key_blob)) != 0 || 76 (min != -1 && (r = sshbuf_put_u32(b, min)) != 0) || 77 (r = sshbuf_put_u32(b, wantbits)) != 0 || 78 (max != -1 && (r = sshbuf_put_u32(b, max)) != 0) || 79 (r = sshbuf_put_bignum2(b, prime)) != 0 || 80 (r = sshbuf_put_bignum2(b, gen)) != 0 || 81 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 || 82 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 || 83 (r = sshbuf_put(b, shared_secret, secretlen)) != 0) { 84 sshbuf_free(b); 85 return r; 86 } 87#ifdef DEBUG_KEXDH 88 sshbuf_dump(b, stderr); 89#endif 90 if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) { 91 sshbuf_free(b); 92 return SSH_ERR_LIBCRYPTO_ERROR; 93 } 94 sshbuf_free(b); 95 *hashlen = ssh_digest_bytes(hash_alg); 96#ifdef DEBUG_KEXDH 97 dump_digest("hash", hash, *hashlen); 98#endif 99 return 0; 100} 101