1 /* $OpenBSD: kexdh.c,v 1.25 2015/01/19 20:16:15 markus 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 "includes.h" 27 28 #ifdef WITH_OPENSSL 29 30 #include <sys/types.h> 31 32 #include <signal.h> 33 34 #include <openssl/evp.h> 35 36 #include "ssh2.h" 37 #include "sshkey.h" 38 #include "cipher.h" 39 #include "kex.h" 40 #include "ssherr.h" 41 #include "sshbuf.h" 42 #include "digest.h" 43 44 int 45 kex_dh_hash( 46 const char *client_version_string, 47 const char *server_version_string, 48 const u_char *ckexinit, size_t ckexinitlen, 49 const u_char *skexinit, size_t skexinitlen, 50 const u_char *serverhostkeyblob, size_t sbloblen, 51 const BIGNUM *client_dh_pub, 52 const BIGNUM *server_dh_pub, 53 const BIGNUM *shared_secret, 54 u_char *hash, size_t *hashlen) 55 { 56 struct sshbuf *b; 57 int r; 58 59 if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1)) 60 return SSH_ERR_INVALID_ARGUMENT; 61 if ((b = sshbuf_new()) == NULL) 62 return SSH_ERR_ALLOC_FAIL; 63 if ((r = sshbuf_put_cstring(b, client_version_string)) != 0 || 64 (r = sshbuf_put_cstring(b, server_version_string)) != 0 || 65 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 66 (r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 || 67 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 68 (r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 || 69 (r = sshbuf_put_u32(b, skexinitlen+1)) != 0 || 70 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 71 (r = sshbuf_put(b, skexinit, skexinitlen)) != 0 || 72 (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 || 73 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 || 74 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 || 75 (r = sshbuf_put_bignum2(b, shared_secret)) != 0) { 76 sshbuf_free(b); 77 return r; 78 } 79 #ifdef DEBUG_KEX 80 sshbuf_dump(b, stderr); 81 #endif 82 if (ssh_digest_buffer(SSH_DIGEST_SHA1, b, hash, *hashlen) != 0) { 83 sshbuf_free(b); 84 return SSH_ERR_LIBCRYPTO_ERROR; 85 } 86 sshbuf_free(b); 87 *hashlen = ssh_digest_bytes(SSH_DIGEST_SHA1); 88 #ifdef DEBUG_KEX 89 dump_digest("hash", hash, *hashlen); 90 #endif 91 return 0; 92 } 93 #endif /* WITH_OPENSSL */ 94