Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 1 | /* $OpenBSD: cipher-3des1.c,v 1.6 2006/08/03 03:34:42 deraadt Exp $ */ |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2003 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" |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 27 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 28 | #include <sys/types.h> |
| 29 | |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 30 | #include <openssl/evp.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 31 | |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 32 | #include <stdarg.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 33 | #include <string.h> |
| 34 | |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 35 | #include "xmalloc.h" |
| 36 | #include "log.h" |
| 37 | |
Damien Miller | 5c3a558 | 2003-09-23 22:12:38 +1000 | [diff] [blame] | 38 | #if OPENSSL_VERSION_NUMBER < 0x00906000L |
| 39 | #define SSH_OLD_EVP |
| 40 | #endif |
| 41 | |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 42 | /* |
| 43 | * This is used by SSH1: |
| 44 | * |
| 45 | * What kind of triple DES are these 2 routines? |
| 46 | * |
| 47 | * Why is there a redundant initialization vector? |
| 48 | * |
| 49 | * If only iv3 was used, then, this would till effect have been |
| 50 | * outer-cbc. However, there is also a private iv1 == iv2 which |
| 51 | * perhaps makes differential analysis easier. On the other hand, the |
| 52 | * private iv1 probably makes the CRC-32 attack ineffective. This is a |
| 53 | * result of that there is no longer any known iv1 to use when |
| 54 | * choosing the X block. |
| 55 | */ |
| 56 | struct ssh1_3des_ctx |
| 57 | { |
| 58 | EVP_CIPHER_CTX k1, k2, k3; |
| 59 | }; |
| 60 | |
| 61 | const EVP_CIPHER * evp_ssh1_3des(void); |
| 62 | void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int); |
| 63 | |
| 64 | static int |
| 65 | ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, |
| 66 | int enc) |
| 67 | { |
| 68 | struct ssh1_3des_ctx *c; |
| 69 | u_char *k1, *k2, *k3; |
| 70 | |
| 71 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { |
| 72 | c = xmalloc(sizeof(*c)); |
| 73 | EVP_CIPHER_CTX_set_app_data(ctx, c); |
| 74 | } |
| 75 | if (key == NULL) |
| 76 | return (1); |
| 77 | if (enc == -1) |
| 78 | enc = ctx->encrypt; |
| 79 | k1 = k2 = k3 = (u_char *) key; |
| 80 | k2 += 8; |
| 81 | if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { |
| 82 | if (enc) |
| 83 | k3 += 16; |
| 84 | else |
| 85 | k1 += 16; |
| 86 | } |
| 87 | EVP_CIPHER_CTX_init(&c->k1); |
| 88 | EVP_CIPHER_CTX_init(&c->k2); |
| 89 | EVP_CIPHER_CTX_init(&c->k3); |
| 90 | #ifdef SSH_OLD_EVP |
| 91 | EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); |
| 92 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); |
| 93 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); |
| 94 | #else |
| 95 | if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || |
| 96 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || |
| 97 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { |
| 98 | memset(c, 0, sizeof(*c)); |
| 99 | xfree(c); |
| 100 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); |
| 101 | return (0); |
| 102 | } |
| 103 | #endif |
| 104 | return (1); |
| 105 | } |
| 106 | |
| 107 | static int |
| 108 | ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) |
| 109 | { |
| 110 | struct ssh1_3des_ctx *c; |
| 111 | |
| 112 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { |
| 113 | error("ssh1_3des_cbc: no context"); |
| 114 | return (0); |
| 115 | } |
| 116 | #ifdef SSH_OLD_EVP |
| 117 | EVP_Cipher(&c->k1, dest, (u_char *)src, len); |
| 118 | EVP_Cipher(&c->k2, dest, dest, len); |
| 119 | EVP_Cipher(&c->k3, dest, dest, len); |
| 120 | #else |
| 121 | if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || |
| 122 | EVP_Cipher(&c->k2, dest, dest, len) == 0 || |
| 123 | EVP_Cipher(&c->k3, dest, dest, len) == 0) |
| 124 | return (0); |
| 125 | #endif |
| 126 | return (1); |
| 127 | } |
| 128 | |
| 129 | static int |
| 130 | ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) |
| 131 | { |
| 132 | struct ssh1_3des_ctx *c; |
| 133 | |
| 134 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { |
Darren Tucker | a32e19c | 2003-12-31 11:36:00 +1100 | [diff] [blame] | 135 | EVP_CIPHER_CTX_cleanup(&c->k1); |
| 136 | EVP_CIPHER_CTX_cleanup(&c->k2); |
| 137 | EVP_CIPHER_CTX_cleanup(&c->k3); |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 138 | memset(c, 0, sizeof(*c)); |
| 139 | xfree(c); |
| 140 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); |
| 141 | } |
| 142 | return (1); |
| 143 | } |
| 144 | |
| 145 | void |
| 146 | ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len) |
| 147 | { |
| 148 | struct ssh1_3des_ctx *c; |
| 149 | |
| 150 | if (len != 24) |
| 151 | fatal("%s: bad 3des iv length: %d", __func__, len); |
| 152 | if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) |
| 153 | fatal("%s: no 3des context", __func__); |
| 154 | if (doset) { |
| 155 | debug3("%s: Installed 3DES IV", __func__); |
| 156 | memcpy(c->k1.iv, iv, 8); |
| 157 | memcpy(c->k2.iv, iv + 8, 8); |
| 158 | memcpy(c->k3.iv, iv + 16, 8); |
| 159 | } else { |
| 160 | debug3("%s: Copying 3DES IV", __func__); |
| 161 | memcpy(iv, c->k1.iv, 8); |
| 162 | memcpy(iv + 8, c->k2.iv, 8); |
| 163 | memcpy(iv + 16, c->k3.iv, 8); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | const EVP_CIPHER * |
| 168 | evp_ssh1_3des(void) |
| 169 | { |
| 170 | static EVP_CIPHER ssh1_3des; |
| 171 | |
| 172 | memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); |
| 173 | ssh1_3des.nid = NID_undef; |
| 174 | ssh1_3des.block_size = 8; |
| 175 | ssh1_3des.iv_len = 0; |
| 176 | ssh1_3des.key_len = 16; |
| 177 | ssh1_3des.init = ssh1_3des_init; |
| 178 | ssh1_3des.cleanup = ssh1_3des_cleanup; |
| 179 | ssh1_3des.do_cipher = ssh1_3des_cbc; |
| 180 | #ifndef SSH_OLD_EVP |
| 181 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; |
| 182 | #endif |
| 183 | return (&ssh1_3des); |
| 184 | } |