crypto/cast/c_enc.c

   1 /* crypto/cast/c_enc.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <openssl/cast.h>
  60 #include "cast_lcl.h"
  61
  62 void CAST_encrypt(CAST_LONG *data, const CAST_KEY *key)
  63 {
  64     register CAST_LONG l, r, t;
  65     const register CAST_LONG *k;
  66
  67     k = &(key->data[0]);
  68     l = data[0];
  69     r = data[1];
  70
  71     E_CAST(0, k, l, r, +, ^, -);
  72     E_CAST(1, k, r, l, ^, -, +);
  73     E_CAST(2, k, l, r, -, +, ^);
  74     E_CAST(3, k, r, l, +, ^, -);
  75     E_CAST(4, k, l, r, ^, -, +);
  76     E_CAST(5, k, r, l, -, +, ^);
  77     E_CAST(6, k, l, r, +, ^, -);
  78     E_CAST(7, k, r, l, ^, -, +);
  79     E_CAST(8, k, l, r, -, +, ^);
  80     E_CAST(9, k, r, l, +, ^, -);
  81     E_CAST(10, k, l, r, ^, -, +);
  82     E_CAST(11, k, r, l, -, +, ^);
  83     if (!key->short_key) {
  84         E_CAST(12, k, l, r, +, ^, -);
  85         E_CAST(13, k, r, l, ^, -, +);
  86         E_CAST(14, k, l, r, -, +, ^);
  87         E_CAST(15, k, r, l, +, ^, -);
  88     }
  89
  90     data[1] = l & 0xffffffffL;
  91     data[0] = r & 0xffffffffL;
  92 }
  93
  94 void CAST_decrypt(CAST_LONG *data, const CAST_KEY *key)
  95 {
  96     register CAST_LONG l, r, t;
  97     const register CAST_LONG *k;
  98
  99     k = &(key->data[0]);
 100     l = data[0];
 101     r = data[1];
 102
 103     if (!key->short_key) {
 104         E_CAST(15, k, l, r, +, ^, -);
 105         E_CAST(14, k, r, l, -, +, ^);
 106         E_CAST(13, k, l, r, ^, -, +);
 107         E_CAST(12, k, r, l, +, ^, -);
 108     }
 109     E_CAST(11, k, l, r, -, +, ^);
 110     E_CAST(10, k, r, l, ^, -, +);
 111     E_CAST(9, k, l, r, +, ^, -);
 112     E_CAST(8, k, r, l, -, +, ^);
 113     E_CAST(7, k, l, r, ^, -, +);
 114     E_CAST(6, k, r, l, +, ^, -);
 115     E_CAST(5, k, l, r, -, +, ^);
 116     E_CAST(4, k, r, l, ^, -, +);
 117     E_CAST(3, k, l, r, +, ^, -);
 118     E_CAST(2, k, r, l, -, +, ^);
 119     E_CAST(1, k, l, r, ^, -, +);
 120     E_CAST(0, k, r, l, +, ^, -);
 121
 122     data[1] = l & 0xffffffffL;
 123     data[0] = r & 0xffffffffL;
 124 }
 125
 126 void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out,
 127                       long length, const CAST_KEY *ks, unsigned char *iv,
 128                       int enc)
 129 {
 130     register CAST_LONG tin0, tin1;
 131     register CAST_LONG tout0, tout1, xor0, xor1;
 132     register long l = length;
 133     CAST_LONG tin[2];
 134
 135     if (enc) {
 136         n2l(iv, tout0);
 137         n2l(iv, tout1);
 138         iv -= 8;
 139         for (l -= 8; l >= 0; l -= 8) {
 140             n2l(in, tin0);
 141             n2l(in, tin1);
 142             tin0 ^= tout0;
 143             tin1 ^= tout1;
 144             tin[0] = tin0;
 145             tin[1] = tin1;
 146             CAST_encrypt(tin, ks);
 147             tout0 = tin[0];
 148             tout1 = tin[1];
 149             l2n(tout0, out);
 150             l2n(tout1, out);
 151         }
 152         if (l != -8) {
 153             n2ln(in, tin0, tin1, l + 8);
 154             tin0 ^= tout0;
 155             tin1 ^= tout1;
 156             tin[0] = tin0;
 157             tin[1] = tin1;
 158             CAST_encrypt(tin, ks);
 159             tout0 = tin[0];
 160             tout1 = tin[1];
 161             l2n(tout0, out);
 162             l2n(tout1, out);
 163         }
 164         l2n(tout0, iv);
 165         l2n(tout1, iv);
 166     } else {
 167         n2l(iv, xor0);
 168         n2l(iv, xor1);
 169         iv -= 8;
 170         for (l -= 8; l >= 0; l -= 8) {
 171             n2l(in, tin0);
 172             n2l(in, tin1);
 173             tin[0] = tin0;
 174             tin[1] = tin1;
 175             CAST_decrypt(tin, ks);
 176             tout0 = tin[0] ^ xor0;
 177             tout1 = tin[1] ^ xor1;
 178             l2n(tout0, out);
 179             l2n(tout1, out);
 180             xor0 = tin0;
 181             xor1 = tin1;
 182         }
 183         if (l != -8) {
 184             n2l(in, tin0);
 185             n2l(in, tin1);
 186             tin[0] = tin0;
 187             tin[1] = tin1;
 188             CAST_decrypt(tin, ks);
 189             tout0 = tin[0] ^ xor0;
 190             tout1 = tin[1] ^ xor1;
 191             l2nn(tout0, tout1, out, l + 8);
 192             xor0 = tin0;
 193             xor1 = tin1;
 194         }
 195         l2n(xor0, iv);
 196         l2n(xor1, iv);
 197     }
 198     tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
 199     tin[0] = tin[1] = 0;
 200 }