cryptlib  3.4.1
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Properties Macros
rc2cbc.c
Go to the documentation of this file.
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 #if defined( INC_ALL )
60  #include "osconfig.h"
61  #include "rc2.h"
62  #include "rc2locl.h"
63 #else
64  #include "crypt/osconfig.h"
65  #include "crypt/rc2.h"
66  #include "crypt/rc2locl.h"
67 #endif /* Compiler-specific includes */
68 
69 void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
70  RC2_KEY *ks, unsigned char *iv, int encrypt)
71  {
72  register unsigned long tin0,tin1;
73  register unsigned long tout0,tout1,xor0,xor1;
74  register long l=length;
75  unsigned long tin[2];
76 
77  if (encrypt)
78  {
79  c2l(iv,tout0);
80  c2l(iv,tout1);
81  iv-=8;
82  for (l-=8; l>=0; l-=8)
83  {
84  c2l(in,tin0);
85  c2l(in,tin1);
86  tin0^=tout0;
87  tin1^=tout1;
88  tin[0]=tin0;
89  tin[1]=tin1;
90  RC2_encrypt(tin,ks);
91  tout0=tin[0]; l2c(tout0,out);
92  tout1=tin[1]; l2c(tout1,out);
93  }
94  if (l != -8)
95  {
96  c2ln(in,tin0,tin1,l+8);
97  tin0^=tout0;
98  tin1^=tout1;
99  tin[0]=tin0;
100  tin[1]=tin1;
101  RC2_encrypt(tin,ks);
102  tout0=tin[0]; l2c(tout0,out);
103  tout1=tin[1]; l2c(tout1,out);
104  }
105  l2c(tout0,iv);
106  l2c(tout1,iv);
107  }
108  else
109  {
110  c2l(iv,xor0);
111  c2l(iv,xor1);
112  iv-=8;
113  for (l-=8; l>=0; l-=8)
114  {
115  c2l(in,tin0); tin[0]=tin0;
116  c2l(in,tin1); tin[1]=tin1;
117  RC2_decrypt(tin,ks);
118  tout0=tin[0]^xor0;
119  tout1=tin[1]^xor1;
120  l2c(tout0,out);
121  l2c(tout1,out);
122  xor0=tin0;
123  xor1=tin1;
124  }
125  if (l != -8)
126  {
127  c2l(in,tin0); tin[0]=tin0;
128  c2l(in,tin1); tin[1]=tin1;
129  RC2_decrypt(tin,ks);
130  tout0=tin[0]^xor0;
131  tout1=tin[1]^xor1;
132  l2cn(tout0,tout1,out,l+8);
133  xor0=tin0;
134  xor1=tin1;
135  }
136  l2c(xor0,iv);
137  l2c(xor1,iv);
138  }
139  tin0=tin1=tout0=tout1=xor0=xor1=0;
140  tin[0]=tin[1]=0;
141  }
142 
143 void RC2_encrypt(unsigned long *d, 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(unsigned long *d, RC2_KEY *key)
189  {
190  int i,n;
191  register RC2_INT *p0,*p1;
192  register RC2_INT x0,x1,x2,x3,t;
193  unsigned long l;
194 
195  l=d[0];
196  x0=(RC2_INT)l&0xffff;
197  x1=(RC2_INT)(l>>16L);
198  l=d[1];
199  x2=(RC2_INT)l&0xffff;
200  x3=(RC2_INT)(l>>16L);
201 
202  n=3;
203  i=5;
204 
205  p0= &(key->data[63]);
206  p1= &(key->data[0]);
207  for (;;)
208  {
209  t=((x3<<11)|(x3>>5))&0xffff;
210  x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff;
211  t=((x2<<13)|(x2>>3))&0xffff;
212  x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff;
213  t=((x1<<14)|(x1>>2))&0xffff;
214  x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff;
215  t=((x0<<15)|(x0>>1))&0xffff;
216  x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff;
217 
218  if (--i == 0)
219  {
220  if (--n == 0) break;
221  i=(n == 2)?6:5;
222 
223  x3=(x3-p1[x2&0x3f])&0xffff;
224  x2=(x2-p1[x1&0x3f])&0xffff;
225  x1=(x1-p1[x0&0x3f])&0xffff;
226  x0=(x0-p1[x3&0x3f])&0xffff;
227  }
228  }
229 
230  d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
231  d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
232  }
233 
Generated on Thu Jan 10 2013 10:00:45 for cryptlib by   doxygen 1.8.2