Damien Miller | 57c3011 | 2006-03-26 14:24:48 +1100 | [diff] [blame] | 1 | /* $OpenBSD: kexgex.c,v 1.26 2006/03/25 13:17:02 djm Exp $ */ |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2000 Niels Provos. All rights reserved. |
| 4 | * Copyright (c) 2001 Markus Friedl. All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 17 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 18 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 19 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 20 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 21 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 22 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 24 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include "includes.h" |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 28 | |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 29 | #include <openssl/evp.h> |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 30 | |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 31 | #include "buffer.h" |
| 32 | #include "bufaux.h" |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 33 | #include "kex.h" |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 34 | #include "ssh2.h" |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 35 | |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 36 | void |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 37 | kexgex_hash( |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 38 | const EVP_MD *evp_md, |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 39 | char *client_version_string, |
| 40 | char *server_version_string, |
| 41 | char *ckexinit, int ckexinitlen, |
| 42 | char *skexinit, int skexinitlen, |
Ben Lindstrom | 9e0ddd4 | 2001-09-18 05:41:19 +0000 | [diff] [blame] | 43 | u_char *serverhostkeyblob, int sbloblen, |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 44 | int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen, |
| 45 | BIGNUM *client_dh_pub, |
| 46 | BIGNUM *server_dh_pub, |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 47 | BIGNUM *shared_secret, |
| 48 | u_char **hash, u_int *hashlen) |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 49 | { |
| 50 | Buffer b; |
| 51 | static u_char digest[EVP_MAX_MD_SIZE]; |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 52 | EVP_MD_CTX md; |
| 53 | |
| 54 | buffer_init(&b); |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 55 | buffer_put_cstring(&b, client_version_string); |
| 56 | buffer_put_cstring(&b, server_version_string); |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 57 | |
| 58 | /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ |
| 59 | buffer_put_int(&b, ckexinitlen+1); |
| 60 | buffer_put_char(&b, SSH2_MSG_KEXINIT); |
| 61 | buffer_append(&b, ckexinit, ckexinitlen); |
| 62 | buffer_put_int(&b, skexinitlen+1); |
| 63 | buffer_put_char(&b, SSH2_MSG_KEXINIT); |
| 64 | buffer_append(&b, skexinit, skexinitlen); |
| 65 | |
| 66 | buffer_put_string(&b, serverhostkeyblob, sbloblen); |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 67 | if (min == -1 || max == -1) |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 68 | buffer_put_int(&b, wantbits); |
| 69 | else { |
| 70 | buffer_put_int(&b, min); |
| 71 | buffer_put_int(&b, wantbits); |
| 72 | buffer_put_int(&b, max); |
| 73 | } |
| 74 | buffer_put_bignum2(&b, prime); |
| 75 | buffer_put_bignum2(&b, gen); |
| 76 | buffer_put_bignum2(&b, client_dh_pub); |
| 77 | buffer_put_bignum2(&b, server_dh_pub); |
| 78 | buffer_put_bignum2(&b, shared_secret); |
| 79 | |
| 80 | #ifdef DEBUG_KEXDH |
| 81 | buffer_dump(&b); |
| 82 | #endif |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 83 | |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 84 | EVP_DigestInit(&md, evp_md); |
| 85 | EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
| 86 | EVP_DigestFinal(&md, digest, NULL); |
| 87 | |
| 88 | buffer_free(&b); |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 89 | *hash = digest; |
| 90 | *hashlen = EVP_MD_size(evp_md); |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 91 | #ifdef DEBUG_KEXDH |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 92 | dump_digest("hash", digest, *hashlen); |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 93 | #endif |
Ben Lindstrom | 22b19b4 | 2001-04-04 17:39:19 +0000 | [diff] [blame] | 94 | } |