1 /* crypto/rc2/rc2_cbc.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 "rc2.h" 60 #include "rc2_locl.h" 61 62 void RC2_cbc_encrypt(in, out, length, ks, iv, encrypt) 63 unsigned char *in; 64 unsigned char *out; 65 long length; 66 RC2_KEY *ks; 67 unsigned char *iv; 68 int encrypt; 69 { 70 register unsigned long tin0,tin1; 71 register unsigned long tout0,tout1,xor0,xor1; 72 register long l=length; 73 unsigned long tin[2]; 74 75 if (encrypt) 76 { 77 c2l(iv,tout0); 78 c2l(iv,tout1); 79 iv-=8; 80 for (l-=8; l>=0; l-=8) 81 { 82 c2l(in,tin0); 83 c2l(in,tin1); 84 tin0^=tout0; 85 tin1^=tout1; 86 tin[0]=tin0; 87 tin[1]=tin1; 88 RC2_encrypt(tin,ks); 89 tout0=tin[0]; l2c(tout0,out); 90 tout1=tin[1]; l2c(tout1,out); 91 } 92 if (l != -8) 93 { 94 c2ln(in,tin0,tin1,l+8); 95 tin0^=tout0; 96 tin1^=tout1; 97 tin[0]=tin0; 98 tin[1]=tin1; 99 RC2_encrypt(tin,ks); 100 tout0=tin[0]; l2c(tout0,out); 101 tout1=tin[1]; l2c(tout1,out); 102 } 103 l2c(tout0,iv); 104 l2c(tout1,iv); 105 } 106 else 107 { 108 c2l(iv,xor0); 109 c2l(iv,xor1); 110 iv-=8; 111 for (l-=8; l>=0; l-=8) 112 { 113 c2l(in,tin0); tin[0]=tin0; 114 c2l(in,tin1); tin[1]=tin1; 115 RC2_decrypt(tin,ks); 116 tout0=tin[0]^xor0; 117 tout1=tin[1]^xor1; 118 l2c(tout0,out); 119 l2c(tout1,out); 120 xor0=tin0; 121 xor1=tin1; 122 } 123 if (l != -8) 124 { 125 c2l(in,tin0); tin[0]=tin0; 126 c2l(in,tin1); tin[1]=tin1; 127 RC2_decrypt(tin,ks); 128 tout0=tin[0]^xor0; 129 tout1=tin[1]^xor1; 130 l2cn(tout0,tout1,out,l+8); 131 xor0=tin0; 132 xor1=tin1; 133 } 134 l2c(xor0,iv); 135 l2c(xor1,iv); 136 } 137 tin0=tin1=tout0=tout1=xor0=xor1=0; 138 tin[0]=tin[1]=0; 139 } 140 141 void RC2_encrypt(d,key) 142 unsigned long *d; 143 RC2_KEY *key; 144 { 145 int i,n; 146 register RC2_INT *p0,*p1; 147 register RC2_INT x0,x1,x2,x3,t; 148 unsigned long l; 149 150 l=d[0]; 151 x0=(RC2_INT)l&0xffff; 152 x1=(RC2_INT)(l>>16L); 153 l=d[1]; 154 x2=(RC2_INT)l&0xffff; 155 x3=(RC2_INT)(l>>16L); 156 157 n=3; 158 i=5; 159 160 p0=p1= &(key->data[0]); 161 for (;;) 162 { 163 t=(x0+(x1& ~x3)+(x2&x3)+ *(p0++))&0xffff; 164 x0=(t<<1)|(t>>15); 165 t=(x1+(x2& ~x0)+(x3&x0)+ *(p0++))&0xffff; 166 x1=(t<<2)|(t>>14); 167 t=(x2+(x3& ~x1)+(x0&x1)+ *(p0++))&0xffff; 168 x2=(t<<3)|(t>>13); 169 t=(x3+(x0& ~x2)+(x1&x2)+ *(p0++))&0xffff; 170 x3=(t<<5)|(t>>11); 171 172 if (--i == 0) 173 { 174 if (--n == 0) break; 175 i=(n == 2)?6:5; 176 177 x0+=p1[x3&0x3f]; 178 x1+=p1[x0&0x3f]; 179 x2+=p1[x1&0x3f]; 180 x3+=p1[x2&0x3f]; 181 } 182 } 183 184 d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L); 185 d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L); 186 } 187 188 void RC2_decrypt(d,key) 189 unsigned long *d; 190 RC2_KEY *key; 191 { 192 int i,n; 193 register RC2_INT *p0,*p1; 194 register RC2_INT x0,x1,x2,x3,t; 195 unsigned long l; 196 197 l=d[0]; 198 x0=(RC2_INT)l&0xffff; 199 x1=(RC2_INT)(l>>16L); 200 l=d[1]; 201 x2=(RC2_INT)l&0xffff; 202 x3=(RC2_INT)(l>>16L); 203 204 n=3; 205 i=5; 206 207 p0= &(key->data[63]); 208 p1= &(key->data[0]); 209 for (;;) 210 { 211 t=((x3<<11)|(x3>>5))&0xffff; 212 x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff; 213 t=((x2<<13)|(x2>>3))&0xffff; 214 x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff; 215 t=((x1<<14)|(x1>>2))&0xffff; 216 x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff; 217 t=((x0<<15)|(x0>>1))&0xffff; 218 x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff; 219 220 if (--i == 0) 221 { 222 if (--n == 0) break; 223 i=(n == 2)?6:5; 224 225 x3=(x3-p1[x2&0x3f])&0xffff; 226 x2=(x2-p1[x1&0x3f])&0xffff; 227 x1=(x1-p1[x0&0x3f])&0xffff; 228 x0=(x0-p1[x3&0x3f])&0xffff; 229 } 230 } 231 232 d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L); 233 d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L); 234 } 235 236