22e89f04418c9d6df71513068cb79d3ca8dc2fbc
[openssl.git] / crypto / rc2 / rc2_cbc.c
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