1 /* crypto/cast/c_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 <openssl/cast.h>
60 #include <cast_lcl.h>
61
62 void CAST_encrypt(CAST_LONG *data, const CAST_KEY *key)
63 {
64 register CAST_LONG l,r,t;
65 register const CAST_LONG *k;
66
67 k= &(key->data[0]);
68 l=data[0];
69 r=data[1];
70
71 E_CAST( 0,k,l,r,+,^,-);
72 E_CAST( 1,k,r,l,^,-,+);
73 E_CAST( 2,k,l,r,-,+,^);
74 E_CAST( 3,k,r,l,+,^,-);
75 E_CAST( 4,k,l,r,^,-,+);
76 E_CAST( 5,k,r,l,-,+,^);
77 E_CAST( 6,k,l,r,+,^,-);
78 E_CAST( 7,k,r,l,^,-,+);
79 E_CAST( 8,k,l,r,-,+,^);
80 E_CAST( 9,k,r,l,+,^,-);
81 E_CAST(10,k,l,r,^,-,+);
82 E_CAST(11,k,r,l,-,+,^);
83 if(!key->short_key)
84 {
85 E_CAST(12,k,l,r,+,^,-);
86 E_CAST(13,k,r,l,^,-,+);
87 E_CAST(14,k,l,r,-,+,^);
88 E_CAST(15,k,r,l,+,^,-);
89 }
90
91 data[1]=l&0xffffffffL;
92 data[0]=r&0xffffffffL;
93 }
94
95 void CAST_decrypt(CAST_LONG *data, const CAST_KEY *key)
96 {
97 register CAST_LONG l,r,t;
98 register const CAST_LONG *k;
99
100 k= &(key->data[0]);
101 l=data[0];
102 r=data[1];
103
104 if(!key->short_key)
105 {
106 E_CAST(15,k,l,r,+,^,-);
107 E_CAST(14,k,r,l,-,+,^);
108 E_CAST(13,k,l,r,^,-,+);
109 E_CAST(12,k,r,l,+,^,-);
110 }
111 E_CAST(11,k,l,r,-,+,^);
112 E_CAST(10,k,r,l,^,-,+);
113 E_CAST( 9,k,l,r,+,^,-);
114 E_CAST( 8,k,r,l,-,+,^);
115 E_CAST( 7,k,l,r,^,-,+);
116 E_CAST( 6,k,r,l,+,^,-);
117 E_CAST( 5,k,l,r,-,+,^);
118 E_CAST( 4,k,r,l,^,-,+);
119 E_CAST( 3,k,l,r,+,^,-);
120 E_CAST( 2,k,r,l,-,+,^);
121 E_CAST( 1,k,l,r,^,-,+);
122 E_CAST( 0,k,r,l,+,^,-);
123
124 data[1]=l&0xffffffffL;
125 data[0]=r&0xffffffffL;
126 }
127
128 void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
129 const CAST_KEY *ks, unsigned char *iv, int enc)
130 {
131 register CAST_LONG tin0,tin1;
132 register CAST_LONG tout0,tout1,xor0,xor1;
133 register long l=length;
134 CAST_LONG tin[2];
135
136 if (enc)
137 {
138 n2l(iv,tout0);
139 n2l(iv,tout1);
140 iv-=8;
141 for (l-=8; l>=0; l-=8)
142 {
143 n2l(in,tin0);
144 n2l(in,tin1);
145 tin0^=tout0;
146 tin1^=tout1;
147 tin[0]=tin0;
148 tin[1]=tin1;
149 CAST_encrypt(tin,ks);
150 tout0=tin[0];
151 tout1=tin[1];
152 l2n(tout0,out);
153 l2n(tout1,out);
154 }
155 if (l != -8)
156 {
157 n2ln(in,tin0,tin1,l+8);
158 tin0^=tout0;
159 tin1^=tout1;
160 tin[0]=tin0;
161 tin[1]=tin1;
162 CAST_encrypt(tin,ks);
163 tout0=tin[0];
164 tout1=tin[1];
165 l2n(tout0,out);
166 l2n(tout1,out);
167 }
168 l2n(tout0,iv);
169 l2n(tout1,iv);
170 }
171 else
172 {
173 n2l(iv,xor0);
174 n2l(iv,xor1);
175 iv-=8;
176 for (l-=8; l>=0; l-=8)
177 {
178 n2l(in,tin0);
179 n2l(in,tin1);
180 tin[0]=tin0;
181 tin[1]=tin1;
182 CAST_decrypt(tin,ks);
183 tout0=tin[0]^xor0;
184 tout1=tin[1]^xor1;
185 l2n(tout0,out);
186 l2n(tout1,out);
187 xor0=tin0;
188 xor1=tin1;
189 }
190 if (l != -8)
191 {
192 n2l(in,tin0);
193 n2l(in,tin1);
194 tin[0]=tin0;
195 tin[1]=tin1;
196 CAST_decrypt(tin,ks);
197 tout0=tin[0]^xor0;
198 tout1=tin[1]^xor1;
199 l2nn(tout0,tout1,out,l+8);
200 xor0=tin0;
201 xor1=tin1;
202 }
203 l2n(xor0,iv);
204 l2n(xor1,iv);
205 }
206 tin0=tin1=tout0=tout1=xor0=xor1=0;
207 tin[0]=tin[1]=0;
208 }