rc5_enc.c revision 296465 
1/* crypto/rc5/rc5_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 <stdio.h>
60#include <openssl/rc5.h>
61#include "rc5_locl.h"
62
63void RC5_32_cbc_encrypt(const unsigned char *in, unsigned char *out,
64                        long length, RC5_32_KEY *ks, unsigned char *iv,
65                        int encrypt)
66{
67    register unsigned long tin0, tin1;
68    register unsigned long tout0, tout1, xor0, xor1;
69    register long l = length;
70    unsigned long tin[2];
71
72    if (encrypt) {
73        c2l(iv, tout0);
74        c2l(iv, tout1);
75        iv -= 8;
76        for (l -= 8; l >= 0; l -= 8) {
77            c2l(in, tin0);
78            c2l(in, tin1);
79            tin0 ^= tout0;
80            tin1 ^= tout1;
81            tin[0] = tin0;
82            tin[1] = tin1;
83            RC5_32_encrypt(tin, ks);
84            tout0 = tin[0];
85            l2c(tout0, out);
86            tout1 = tin[1];
87            l2c(tout1, out);
88        }
89        if (l != -8) {
90            c2ln(in, tin0, tin1, l + 8);
91            tin0 ^= tout0;
92            tin1 ^= tout1;
93            tin[0] = tin0;
94            tin[1] = tin1;
95            RC5_32_encrypt(tin, ks);
96            tout0 = tin[0];
97            l2c(tout0, out);
98            tout1 = tin[1];
99            l2c(tout1, out);
100        }
101        l2c(tout0, iv);
102        l2c(tout1, iv);
103    } else {
104        c2l(iv, xor0);
105        c2l(iv, xor1);
106        iv -= 8;
107        for (l -= 8; l >= 0; l -= 8) {
108            c2l(in, tin0);
109            tin[0] = tin0;
110            c2l(in, tin1);
111            tin[1] = tin1;
112            RC5_32_decrypt(tin, ks);
113            tout0 = tin[0] ^ xor0;
114            tout1 = tin[1] ^ xor1;
115            l2c(tout0, out);
116            l2c(tout1, out);
117            xor0 = tin0;
118            xor1 = tin1;
119        }
120        if (l != -8) {
121            c2l(in, tin0);
122            tin[0] = tin0;
123            c2l(in, tin1);
124            tin[1] = tin1;
125            RC5_32_decrypt(tin, ks);
126            tout0 = tin[0] ^ xor0;
127            tout1 = tin[1] ^ xor1;
128            l2cn(tout0, tout1, out, l + 8);
129            xor0 = tin0;
130            xor1 = tin1;
131        }
132        l2c(xor0, iv);
133        l2c(xor1, iv);
134    }
135    tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
136    tin[0] = tin[1] = 0;
137}
138
139void RC5_32_encrypt(unsigned long *d, RC5_32_KEY *key)
140{
141    RC5_32_INT a, b, *s;
142
143    s = key->data;
144
145    a = d[0] + s[0];
146    b = d[1] + s[1];
147    E_RC5_32(a, b, s, 2);
148    E_RC5_32(a, b, s, 4);
149    E_RC5_32(a, b, s, 6);
150    E_RC5_32(a, b, s, 8);
151    E_RC5_32(a, b, s, 10);
152    E_RC5_32(a, b, s, 12);
153    E_RC5_32(a, b, s, 14);
154    E_RC5_32(a, b, s, 16);
155    if (key->rounds == 12) {
156        E_RC5_32(a, b, s, 18);
157        E_RC5_32(a, b, s, 20);
158        E_RC5_32(a, b, s, 22);
159        E_RC5_32(a, b, s, 24);
160    } else if (key->rounds == 16) {
161        /* Do a full expansion to avoid a jump */
162        E_RC5_32(a, b, s, 18);
163        E_RC5_32(a, b, s, 20);
164        E_RC5_32(a, b, s, 22);
165        E_RC5_32(a, b, s, 24);
166        E_RC5_32(a, b, s, 26);
167        E_RC5_32(a, b, s, 28);
168        E_RC5_32(a, b, s, 30);
169        E_RC5_32(a, b, s, 32);
170    }
171    d[0] = a;
172    d[1] = b;
173}
174
175void RC5_32_decrypt(unsigned long *d, RC5_32_KEY *key)
176{
177    RC5_32_INT a, b, *s;
178
179    s = key->data;
180
181    a = d[0];
182    b = d[1];
183    if (key->rounds == 16) {
184        D_RC5_32(a, b, s, 32);
185        D_RC5_32(a, b, s, 30);
186        D_RC5_32(a, b, s, 28);
187        D_RC5_32(a, b, s, 26);
188        /* Do a full expansion to avoid a jump */
189        D_RC5_32(a, b, s, 24);
190        D_RC5_32(a, b, s, 22);
191        D_RC5_32(a, b, s, 20);
192        D_RC5_32(a, b, s, 18);
193    } else if (key->rounds == 12) {
194        D_RC5_32(a, b, s, 24);
195        D_RC5_32(a, b, s, 22);
196        D_RC5_32(a, b, s, 20);
197        D_RC5_32(a, b, s, 18);
198    }
199    D_RC5_32(a, b, s, 16);
200    D_RC5_32(a, b, s, 14);
201    D_RC5_32(a, b, s, 12);
202    D_RC5_32(a, b, s, 10);
203    D_RC5_32(a, b, s, 8);
204    D_RC5_32(a, b, s, 6);
205    D_RC5_32(a, b, s, 4);
206    D_RC5_32(a, b, s, 2);
207    d[0] = a - s[0];
208    d[1] = b - s[1];
209}
210