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rc2_cbc.c
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1 /* crypto/rc2/rc2_cbc.c */
2 /* Copyright (C) 1995-1998 Eric Young ([email protected])
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young ([email protected]).
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 ([email protected]).
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 ([email protected])"
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 ([email protected])"
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/rc2.h>
60 #include "rc2_locl.h"
61 
62 void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
63  RC2_KEY *ks, unsigned char *iv, int encrypt)
64  {
65  register unsigned long tin0,tin1;
66  register unsigned long tout0,tout1,xor0,xor1;
67  register long l=length;
68  unsigned long tin[2];
69 
70  if (encrypt)
71  {
72  c2l(iv,tout0);
73  c2l(iv,tout1);
74  iv-=8;
75  for (l-=8; l>=0; l-=8)
76  {
77  c2l(in,tin0);
78  c2l(in,tin1);
79  tin0^=tout0;
80  tin1^=tout1;
81  tin[0]=tin0;
82  tin[1]=tin1;
83  RC2_encrypt(tin,ks);
84  tout0=tin[0]; l2c(tout0,out);
85  tout1=tin[1]; l2c(tout1,out);
86  }
87  if (l != -8)
88  {
89  c2ln(in,tin0,tin1,l+8);
90  tin0^=tout0;
91  tin1^=tout1;
92  tin[0]=tin0;
93  tin[1]=tin1;
94  RC2_encrypt(tin,ks);
95  tout0=tin[0]; l2c(tout0,out);
96  tout1=tin[1]; l2c(tout1,out);
97  }
98  l2c(tout0,iv);
99  l2c(tout1,iv);
100  }
101  else
102  {
103  c2l(iv,xor0);
104  c2l(iv,xor1);
105  iv-=8;
106  for (l-=8; l>=0; l-=8)
107  {
108  c2l(in,tin0); tin[0]=tin0;
109  c2l(in,tin1); tin[1]=tin1;
110  RC2_decrypt(tin,ks);
111  tout0=tin[0]^xor0;
112  tout1=tin[1]^xor1;
113  l2c(tout0,out);
114  l2c(tout1,out);
115  xor0=tin0;
116  xor1=tin1;
117  }
118  if (l != -8)
119  {
120  c2l(in,tin0); tin[0]=tin0;
121  c2l(in,tin1); tin[1]=tin1;
122  RC2_decrypt(tin,ks);
123  tout0=tin[0]^xor0;
124  tout1=tin[1]^xor1;
125  l2cn(tout0,tout1,out,l+8);
126  xor0=tin0;
127  xor1=tin1;
128  }
129  l2c(xor0,iv);
130  l2c(xor1,iv);
131  }
132  tin0=tin1=tout0=tout1=xor0=xor1=0;
133  tin[0]=tin[1]=0;
134  }
135 
136 void RC2_encrypt(unsigned long *d, RC2_KEY *key)
137  {
138  int i,n;
139  register RC2_INT *p0,*p1;
140  register RC2_INT x0,x1,x2,x3,t;
141  unsigned long l;
142 
143  l=d[0];
144  x0=(RC2_INT)l&0xffff;
145  x1=(RC2_INT)(l>>16L);
146  l=d[1];
147  x2=(RC2_INT)l&0xffff;
148  x3=(RC2_INT)(l>>16L);
149 
150  n=3;
151  i=5;
152 
153  p0=p1= &(key->data[0]);
154  for (;;)
155  {
156  t=(x0+(x1& ~x3)+(x2&x3)+ *(p0++))&0xffff;
157  x0=(t<<1)|(t>>15);
158  t=(x1+(x2& ~x0)+(x3&x0)+ *(p0++))&0xffff;
159  x1=(t<<2)|(t>>14);
160  t=(x2+(x3& ~x1)+(x0&x1)+ *(p0++))&0xffff;
161  x2=(t<<3)|(t>>13);
162  t=(x3+(x0& ~x2)+(x1&x2)+ *(p0++))&0xffff;
163  x3=(t<<5)|(t>>11);
164 
165  if (--i == 0)
166  {
167  if (--n == 0) break;
168  i=(n == 2)?6:5;
169 
170  x0+=p1[x3&0x3f];
171  x1+=p1[x0&0x3f];
172  x2+=p1[x1&0x3f];
173  x3+=p1[x2&0x3f];
174  }
175  }
176 
177  d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
178  d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
179  }
180 
181 void RC2_decrypt(unsigned long *d, RC2_KEY *key)
182  {
183  int i,n;
184  register RC2_INT *p0,*p1;
185  register RC2_INT x0,x1,x2,x3,t;
186  unsigned long l;
187 
188  l=d[0];
189  x0=(RC2_INT)l&0xffff;
190  x1=(RC2_INT)(l>>16L);
191  l=d[1];
192  x2=(RC2_INT)l&0xffff;
193  x3=(RC2_INT)(l>>16L);
194 
195  n=3;
196  i=5;
197 
198  p0= &(key->data[63]);
199  p1= &(key->data[0]);
200  for (;;)
201  {
202  t=((x3<<11)|(x3>>5))&0xffff;
203  x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff;
204  t=((x2<<13)|(x2>>3))&0xffff;
205  x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff;
206  t=((x1<<14)|(x1>>2))&0xffff;
207  x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff;
208  t=((x0<<15)|(x0>>1))&0xffff;
209  x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff;
210 
211  if (--i == 0)
212  {
213  if (--n == 0) break;
214  i=(n == 2)?6:5;
215 
216  x3=(x3-p1[x2&0x3f])&0xffff;
217  x2=(x2-p1[x1&0x3f])&0xffff;
218  x1=(x1-p1[x0&0x3f])&0xffff;
219  x0=(x0-p1[x3&0x3f])&0xffff;
220  }
221  }
222 
223  d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
224  d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
225  }
226 
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