1 /* $OpenBSD: kexgex.c,v 1.32 2019/01/23 00:30:41 djm Exp $ */ 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" 28 29 #ifdef WITH_OPENSSL 30 31 #include <sys/types.h> 32 33 #include <openssl/evp.h> 34 #include <signal.h> 35 36 #include "openbsd-compat/openssl-compat.h" 37 38 #include "sshkey.h" 39 #include "cipher.h" 40 #include "kex.h" 41 #include "ssh2.h" 42 #include "ssherr.h" 43 #include "sshbuf.h" 44 #include "digest.h" 45 46 int 47 kexgex_hash( 48 int hash_alg, 49 const struct sshbuf *client_version, 50 const struct sshbuf *server_version, 51 const struct sshbuf *client_kexinit, 52 const struct sshbuf *server_kexinit, 53 const struct sshbuf *server_host_key_blob, 54 int min, int wantbits, int max, 55 const BIGNUM *prime, 56 const BIGNUM *gen, 57 const BIGNUM *client_dh_pub, 58 const BIGNUM *server_dh_pub, 59 const u_char *shared_secret, size_t secretlen, 60 u_char *hash, size_t *hashlen) 61 { 62 struct sshbuf *b; 63 int r; 64 65 if (*hashlen < ssh_digest_bytes(SSH_DIGEST_SHA1)) 66 return SSH_ERR_INVALID_ARGUMENT; 67 if ((b = sshbuf_new()) == NULL) 68 return SSH_ERR_ALLOC_FAIL; 69 if ((r = sshbuf_put_stringb(b, client_version)) < 0 || 70 (r = sshbuf_put_stringb(b, server_version)) < 0 || 71 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */ 72 (r = sshbuf_put_u32(b, sshbuf_len(client_kexinit) + 1)) != 0 || 73 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 74 (r = sshbuf_putb(b, client_kexinit)) != 0 || 75 (r = sshbuf_put_u32(b, sshbuf_len(server_kexinit) + 1)) != 0 || 76 (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 || 77 (r = sshbuf_putb(b, server_kexinit)) != 0 || 78 (r = sshbuf_put_stringb(b, server_host_key_blob)) != 0 || 79 (min != -1 && (r = sshbuf_put_u32(b, min)) != 0) || 80 (r = sshbuf_put_u32(b, wantbits)) != 0 || 81 (max != -1 && (r = sshbuf_put_u32(b, max)) != 0) || 82 (r = sshbuf_put_bignum2(b, prime)) != 0 || 83 (r = sshbuf_put_bignum2(b, gen)) != 0 || 84 (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 || 85 (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 || 86 (r = sshbuf_put(b, shared_secret, secretlen)) != 0) { 87 sshbuf_free(b); 88 return r; 89 } 90 #ifdef DEBUG_KEXDH 91 sshbuf_dump(b, stderr); 92 #endif 93 if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) { 94 sshbuf_free(b); 95 return SSH_ERR_LIBCRYPTO_ERROR; 96 } 97 sshbuf_free(b); 98 *hashlen = ssh_digest_bytes(hash_alg); 99 #ifdef DEBUG_KEXDH 100 dump_digest("hash", hash, *hashlen); 101 #endif 102 return 0; 103 } 104 #endif /* WITH_OPENSSL */ 105