1 /* $OpenBSD: cipher-3des1.c,v 1.7 2010/10/01 23:05:32 djm Exp $ */ 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" 27 28 #include <sys/types.h> 29 30 #include <openssl/evp.h> 31 32 #include <stdarg.h> 33 #include <string.h> 34 35 #include "xmalloc.h" 36 #include "log.h" 37 38 #include "openbsd-compat/openssl-compat.h" 39 40 /* 41 * This is used by SSH1: 42 * 43 * What kind of triple DES are these 2 routines? 44 * 45 * Why is there a redundant initialization vector? 46 * 47 * If only iv3 was used, then, this would till effect have been 48 * outer-cbc. However, there is also a private iv1 == iv2 which 49 * perhaps makes differential analysis easier. On the other hand, the 50 * private iv1 probably makes the CRC-32 attack ineffective. This is a 51 * result of that there is no longer any known iv1 to use when 52 * choosing the X block. 53 */ 54 struct ssh1_3des_ctx 55 { 56 EVP_CIPHER_CTX k1, k2, k3; 57 }; 58 59 const EVP_CIPHER * evp_ssh1_3des(void); 60 void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int); 61 62 static int 63 ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 64 int enc) 65 { 66 struct ssh1_3des_ctx *c; 67 u_char *k1, *k2, *k3; 68 69 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 70 c = xmalloc(sizeof(*c)); 71 EVP_CIPHER_CTX_set_app_data(ctx, c); 72 } 73 if (key == NULL) 74 return (1); 75 if (enc == -1) 76 enc = ctx->encrypt; 77 k1 = k2 = k3 = (u_char *) key; 78 k2 += 8; 79 if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { 80 if (enc) 81 k3 += 16; 82 else 83 k1 += 16; 84 } 85 EVP_CIPHER_CTX_init(&c->k1); 86 EVP_CIPHER_CTX_init(&c->k2); 87 EVP_CIPHER_CTX_init(&c->k3); 88 #ifdef SSH_OLD_EVP 89 EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); 90 EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); 91 EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); 92 #else 93 if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || 94 EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || 95 EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { 96 memset(c, 0, sizeof(*c)); 97 xfree(c); 98 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 99 return (0); 100 } 101 #endif 102 return (1); 103 } 104 105 static int 106 ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, 107 LIBCRYPTO_EVP_INL_TYPE len) 108 { 109 struct ssh1_3des_ctx *c; 110 111 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 112 error("ssh1_3des_cbc: no context"); 113 return (0); 114 } 115 #ifdef SSH_OLD_EVP 116 EVP_Cipher(&c->k1, dest, (u_char *)src, len); 117 EVP_Cipher(&c->k2, dest, dest, len); 118 EVP_Cipher(&c->k3, dest, dest, len); 119 #else 120 if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || 121 EVP_Cipher(&c->k2, dest, dest, len) == 0 || 122 EVP_Cipher(&c->k3, dest, dest, len) == 0) 123 return (0); 124 #endif 125 return (1); 126 } 127 128 static int 129 ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) 130 { 131 struct ssh1_3des_ctx *c; 132 133 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 134 EVP_CIPHER_CTX_cleanup(&c->k1); 135 EVP_CIPHER_CTX_cleanup(&c->k2); 136 EVP_CIPHER_CTX_cleanup(&c->k3); 137 memset(c, 0, sizeof(*c)); 138 xfree(c); 139 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 140 } 141 return (1); 142 } 143 144 void 145 ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len) 146 { 147 struct ssh1_3des_ctx *c; 148 149 if (len != 24) 150 fatal("%s: bad 3des iv length: %d", __func__, len); 151 if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) 152 fatal("%s: no 3des context", __func__); 153 if (doset) { 154 debug3("%s: Installed 3DES IV", __func__); 155 memcpy(c->k1.iv, iv, 8); 156 memcpy(c->k2.iv, iv + 8, 8); 157 memcpy(c->k3.iv, iv + 16, 8); 158 } else { 159 debug3("%s: Copying 3DES IV", __func__); 160 memcpy(iv, c->k1.iv, 8); 161 memcpy(iv + 8, c->k2.iv, 8); 162 memcpy(iv + 16, c->k3.iv, 8); 163 } 164 } 165 166 const EVP_CIPHER * 167 evp_ssh1_3des(void) 168 { 169 static EVP_CIPHER ssh1_3des; 170 171 memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); 172 ssh1_3des.nid = NID_undef; 173 ssh1_3des.block_size = 8; 174 ssh1_3des.iv_len = 0; 175 ssh1_3des.key_len = 16; 176 ssh1_3des.init = ssh1_3des_init; 177 ssh1_3des.cleanup = ssh1_3des_cleanup; 178 ssh1_3des.do_cipher = ssh1_3des_cbc; 179 #ifndef SSH_OLD_EVP 180 ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; 181 #endif 182 return (&ssh1_3des); 183 } 184
