crypto/external/bsd/openssh/dist/cipher-3des1.c

   1 /*      $NetBSD: cipher-3des1.c,v 1.2 2009/06/07 22:38:46 christos Exp $        */
   2 /* $OpenBSD: cipher-3des1.c,v 1.6 2006/08/03 03:34:42 deraadt Exp $ */
   3 /*
   4  * Copyright (c) 2003 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 __RCSID("$NetBSD: cipher-3des1.c,v 1.2 2009/06/07 22:38:46 christos Exp $");
  29 #include <sys/types.h>
  30
  31 #include <openssl/evp.h>
  32
  33 #include <string.h>
  34
  35 #include "xmalloc.h"
  36 #include "log.h"
  37
  38 /*
  39  * This is used by SSH1:
  40  *
  41  * What kind of triple DES are these 2 routines?
  42  *
  43  * Why is there a redundant initialization vector?
  44  *
  45  * If only iv3 was used, then, this would till effect have been
  46  * outer-cbc. However, there is also a private iv1 == iv2 which
  47  * perhaps makes differential analysis easier. On the other hand, the
  48  * private iv1 probably makes the CRC-32 attack ineffective. This is a
  49  * result of that there is no longer any known iv1 to use when
  50  * choosing the X block.
  51  */
  52 struct ssh1_3des_ctx
  53 {
  54         EVP_CIPHER_CTX  k1, k2, k3;
  55 };
  56
  57 const EVP_CIPHER * evp_ssh1_3des(void);
  58 void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
  59
  60 static int
  61 ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
  62     int enc)
  63 {
  64         struct ssh1_3des_ctx *c;
  65         u_char *k1, *k2, *k3;
  66
  67         if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
  68                 c = xmalloc(sizeof(*c));
  69                 EVP_CIPHER_CTX_set_app_data(ctx, c);
  70         }
  71         if (key == NULL)
  72                 return (1);
  73         if (enc == -1)
  74                 enc = ctx->encrypt;
  75         k1 = k2 = k3 = (u_char *) key;
  76         k2 += 8;
  77         if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
  78                 if (enc)
  79                         k3 += 16;
  80                 else
  81                         k1 += 16;
  82         }
  83         EVP_CIPHER_CTX_init(&c->k1);
  84         EVP_CIPHER_CTX_init(&c->k2);
  85         EVP_CIPHER_CTX_init(&c->k3);
  86         if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
  87             EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
  88             EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
  89                 memset(c, 0, sizeof(*c));
  90                 xfree(c);
  91                 EVP_CIPHER_CTX_set_app_data(ctx, NULL);
  92                 return (0);
  93         }
  94         return (1);
  95 }
  96
  97 static int
  98 ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, size_t len)
  99 {
 100         struct ssh1_3des_ctx *c;
 101
 102         if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
 103                 error("ssh1_3des_cbc: no context");
 104                 return (0);
 105         }
 106         if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
 107             EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
 108             EVP_Cipher(&c->k3, dest, dest, len) == 0)
 109                 return (0);
 110         return (1);
 111 }
 112
 113 static int
 114 ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
 115 {
 116         struct ssh1_3des_ctx *c;
 117
 118         if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
 119                 EVP_CIPHER_CTX_cleanup(&c->k1);
 120                 EVP_CIPHER_CTX_cleanup(&c->k2);
 121                 EVP_CIPHER_CTX_cleanup(&c->k3);
 122                 memset(c, 0, sizeof(*c));
 123                 xfree(c);
 124                 EVP_CIPHER_CTX_set_app_data(ctx, NULL);
 125         }
 126         return (1);
 127 }
 128
 129 void
 130 ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len)
 131 {
 132         struct ssh1_3des_ctx *c;
 133
 134         if (len != 24)
 135                 fatal("%s: bad 3des iv length: %d", __func__, len);
 136         if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
 137                 fatal("%s: no 3des context", __func__);
 138         if (doset) {
 139                 debug3("%s: Installed 3DES IV", __func__);
 140                 memcpy(c->k1.iv, iv, 8);
 141                 memcpy(c->k2.iv, iv + 8, 8);
 142                 memcpy(c->k3.iv, iv + 16, 8);
 143         } else {
 144                 debug3("%s: Copying 3DES IV", __func__);
 145                 memcpy(iv, c->k1.iv, 8);
 146                 memcpy(iv + 8, c->k2.iv, 8);
 147                 memcpy(iv + 16, c->k3.iv, 8);
 148         }
 149 }
 150
 151 const EVP_CIPHER *
 152 evp_ssh1_3des(void)
 153 {
 154         static EVP_CIPHER ssh1_3des;
 155
 156         memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
 157         ssh1_3des.nid = NID_undef;
 158         ssh1_3des.block_size = 8;
 159         ssh1_3des.iv_len = 0;
 160         ssh1_3des.key_len = 16;
 161         ssh1_3des.init = ssh1_3des_init;
 162         ssh1_3des.cleanup = ssh1_3des_cleanup;
 163         ssh1_3des.do_cipher = ssh1_3des_cbc;
 164         ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
 165         return (&ssh1_3des);
 166 }