c_enc.c revision 55715
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 62void CAST_encrypt(CAST_LONG *data, CAST_KEY *key) 63 { 64 register CAST_LONG l,r,*k,t; 65 66 k= &(key->data[0]); 67 l=data[0]; 68 r=data[1]; 69 70 E_CAST( 0,k,l,r,+,^,-); 71 E_CAST( 1,k,r,l,^,-,+); 72 E_CAST( 2,k,l,r,-,+,^); 73 E_CAST( 3,k,r,l,+,^,-); 74 E_CAST( 4,k,l,r,^,-,+); 75 E_CAST( 5,k,r,l,-,+,^); 76 E_CAST( 6,k,l,r,+,^,-); 77 E_CAST( 7,k,r,l,^,-,+); 78 E_CAST( 8,k,l,r,-,+,^); 79 E_CAST( 9,k,r,l,+,^,-); 80 E_CAST(10,k,l,r,^,-,+); 81 E_CAST(11,k,r,l,-,+,^); 82 if(!key->short_key) 83 { 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 94void CAST_decrypt(CAST_LONG *data, CAST_KEY *key) 95 { 96 register CAST_LONG l,r,*k,t; 97 98 k= &(key->data[0]); 99 l=data[0]; 100 r=data[1]; 101 102 if(!key->short_key) 103 { 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 126void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out, long length, 127 CAST_KEY *ks, unsigned char *iv, int enc) 128 { 129 register CAST_LONG tin0,tin1; 130 register CAST_LONG tout0,tout1,xor0,xor1; 131 register long l=length; 132 CAST_LONG tin[2]; 133 134 if (enc) 135 { 136 n2l(iv,tout0); 137 n2l(iv,tout1); 138 iv-=8; 139 for (l-=8; l>=0; l-=8) 140 { 141 n2l(in,tin0); 142 n2l(in,tin1); 143 tin0^=tout0; 144 tin1^=tout1; 145 tin[0]=tin0; 146 tin[1]=tin1; 147 CAST_encrypt(tin,ks); 148 tout0=tin[0]; 149 tout1=tin[1]; 150 l2n(tout0,out); 151 l2n(tout1,out); 152 } 153 if (l != -8) 154 { 155 n2ln(in,tin0,tin1,l+8); 156 tin0^=tout0; 157 tin1^=tout1; 158 tin[0]=tin0; 159 tin[1]=tin1; 160 CAST_encrypt(tin,ks); 161 tout0=tin[0]; 162 tout1=tin[1]; 163 l2n(tout0,out); 164 l2n(tout1,out); 165 } 166 l2n(tout0,iv); 167 l2n(tout1,iv); 168 } 169 else 170 { 171 n2l(iv,xor0); 172 n2l(iv,xor1); 173 iv-=8; 174 for (l-=8; l>=0; l-=8) 175 { 176 n2l(in,tin0); 177 n2l(in,tin1); 178 tin[0]=tin0; 179 tin[1]=tin1; 180 CAST_decrypt(tin,ks); 181 tout0=tin[0]^xor0; 182 tout1=tin[1]^xor1; 183 l2n(tout0,out); 184 l2n(tout1,out); 185 xor0=tin0; 186 xor1=tin1; 187 } 188 if (l != -8) 189 { 190 n2l(in,tin0); 191 n2l(in,tin1); 192 tin[0]=tin0; 193 tin[1]=tin1; 194 CAST_decrypt(tin,ks); 195 tout0=tin[0]^xor0; 196 tout1=tin[1]^xor1; 197 l2nn(tout0,tout1,out,l+8); 198 xor0=tin0; 199 xor1=tin1; 200 } 201 l2n(xor0,iv); 202 l2n(xor1,iv); 203 } 204 tin0=tin1=tout0=tout1=xor0=xor1=0; 205 tin[0]=tin[1]=0; 206 } 207 208