Commit | Line | Data |
---|---|---|
805e021f CE |
1 | /* |
2 | * Copyright (c) 2004 Kungliga Tekniska Högskolan | |
3 | * (Royal Institute of Technology, Stockholm, Sweden). | |
4 | * All rights reserved. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without | |
7 | * modification, are permitted provided that the following conditions | |
8 | * are met: | |
9 | * | |
10 | * 1. Redistributions of source code must retain the above copyright | |
11 | * notice, this list of conditions and the following disclaimer. | |
12 | * | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * | |
17 | * 3. Neither the name of the Institute nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #include <config.h> | |
35 | ||
36 | #include "rc2.h" | |
37 | #include <stdio.h> | |
38 | #include <stdlib.h> | |
39 | #include <string.h> | |
40 | ||
41 | /* | |
42 | * Implemented from Peter Gutmann's "Specification for Ron Rivests Cipher No.2" | |
43 | * rfc2268 and "On the Design and Security of RC2" was also useful. | |
44 | */ | |
45 | ||
46 | static unsigned int Sbox[256] = { | |
47 | 0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, | |
48 | 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d, | |
49 | 0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, | |
50 | 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2, | |
51 | 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, | |
52 | 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32, | |
53 | 0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, | |
54 | 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82, | |
55 | 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, | |
56 | 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc, | |
57 | 0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, | |
58 | 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26, | |
59 | 0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, | |
60 | 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03, | |
61 | 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, | |
62 | 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7, | |
63 | 0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, | |
64 | 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a, | |
65 | 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, | |
66 | 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec, | |
67 | 0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, | |
68 | 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39, | |
69 | 0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, | |
70 | 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31, | |
71 | 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, | |
72 | 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9, | |
73 | 0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, | |
74 | 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9, | |
75 | 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, | |
76 | 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e, | |
77 | 0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, | |
78 | 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad | |
79 | }; | |
80 | ||
81 | void | |
82 | RC2_set_key(RC2_KEY *key, int len, const unsigned char *data, int bits) | |
83 | { | |
84 | unsigned char k[128]; | |
85 | int j, T8, TM; | |
86 | ||
87 | if (len <= 0) | |
88 | abort(); | |
89 | if (len > 128) | |
90 | len = 128; | |
91 | if (bits <= 0 || bits > 1024) | |
92 | bits = 1024; | |
93 | ||
94 | for (j = 0; j < len; j++) | |
95 | k[j] = data[j]; | |
96 | for (; j < 128; j++) | |
97 | k[j] = Sbox[(k[j - len] + k[j - 1]) & 0xff]; | |
98 | ||
99 | T8 = (bits + 7) / 8; | |
100 | j = (8*T8 - bits); | |
101 | TM = 0xff >> j; | |
102 | ||
103 | k[128 - T8] = Sbox[k[128 - T8] & TM]; | |
104 | ||
105 | for (j = 127 - T8; j >= 0; j--) | |
106 | k[j] = Sbox[k[j + 1] ^ k[j + T8]]; | |
107 | ||
108 | for (j = 0; j < 64; j++) | |
109 | key->data[j] = k[(j * 2) + 0] | (k[(j * 2) + 1] << 8); | |
110 | memset(k, 0, sizeof(k)); | |
111 | } | |
112 | ||
113 | #define ROT16L(w,n) ((w<<n)|(w>>(16-n))) | |
114 | #define ROT16R(w,n) ((w>>n)|(w<<(16-n))) | |
115 | ||
116 | void | |
117 | RC2_encryptc(unsigned char *in, unsigned char *out, const RC2_KEY *key) | |
118 | { | |
119 | int i, j; | |
120 | int w0, w1, w2, w3; | |
121 | int t0, t1, t2, t3; | |
122 | ||
123 | w0 = in[0] | (in[1] << 8); | |
124 | w1 = in[2] | (in[3] << 8); | |
125 | w2 = in[4] | (in[5] << 8); | |
126 | w3 = in[6] | (in[7] << 8); | |
127 | ||
128 | for (i = 0; i < 16; i++) { | |
129 | j = i * 4; | |
130 | t0 = (w0 + (w1 & ~w3) + (w2 & w3) + key->data[j + 0]) & 0xffff; | |
131 | w0 = ROT16L(t0, 1); | |
132 | t1 = (w1 + (w2 & ~w0) + (w3 & w0) + key->data[j + 1]) & 0xffff; | |
133 | w1 = ROT16L(t1, 2); | |
134 | t2 = (w2 + (w3 & ~w1) + (w0 & w1) + key->data[j + 2]) & 0xffff; | |
135 | w2 = ROT16L(t2, 3); | |
136 | t3 = (w3 + (w0 & ~w2) + (w1 & w2) + key->data[j + 3]) & 0xffff; | |
137 | w3 = ROT16L(t3, 5); | |
138 | if(i == 4 || i == 10) { | |
139 | w0 += key->data[w3 & 63]; | |
140 | w1 += key->data[w0 & 63]; | |
141 | w2 += key->data[w1 & 63]; | |
142 | w3 += key->data[w2 & 63]; | |
143 | } | |
144 | } | |
145 | ||
146 | out[0] = w0 & 0xff; | |
147 | out[1] = (w0 >> 8) & 0xff; | |
148 | out[2] = w1 & 0xff; | |
149 | out[3] = (w1 >> 8) & 0xff; | |
150 | out[4] = w2 & 0xff; | |
151 | out[5] = (w2 >> 8) & 0xff; | |
152 | out[6] = w3 & 0xff; | |
153 | out[7] = (w3 >> 8) & 0xff; | |
154 | } | |
155 | ||
156 | void | |
157 | RC2_decryptc(unsigned char *in, unsigned char *out, const RC2_KEY *key) | |
158 | { | |
159 | int i, j; | |
160 | int w0, w1, w2, w3; | |
161 | int t0, t1, t2, t3; | |
162 | ||
163 | w0 = in[0] | (in[1] << 8); | |
164 | w1 = in[2] | (in[3] << 8); | |
165 | w2 = in[4] | (in[5] << 8); | |
166 | w3 = in[6] | (in[7] << 8); | |
167 | ||
168 | for (i = 15; i >= 0; i--) { | |
169 | j = i * 4; | |
170 | ||
171 | if(i == 4 || i == 10) { | |
172 | w3 = (w3 - key->data[w2 & 63]) & 0xffff; | |
173 | w2 = (w2 - key->data[w1 & 63]) & 0xffff; | |
174 | w1 = (w1 - key->data[w0 & 63]) & 0xffff; | |
175 | w0 = (w0 - key->data[w3 & 63]) & 0xffff; | |
176 | } | |
177 | ||
178 | t3 = ROT16R(w3, 5); | |
179 | w3 = (t3 - (w0 & ~w2) - (w1 & w2) - key->data[j + 3]) & 0xffff; | |
180 | t2 = ROT16R(w2, 3); | |
181 | w2 = (t2 - (w3 & ~w1) - (w0 & w1) - key->data[j + 2]) & 0xffff; | |
182 | t1 = ROT16R(w1, 2); | |
183 | w1 = (t1 - (w2 & ~w0) - (w3 & w0) - key->data[j + 1]) & 0xffff; | |
184 | t0 = ROT16R(w0, 1); | |
185 | w0 = (t0 - (w1 & ~w3) - (w2 & w3) - key->data[j + 0]) & 0xffff; | |
186 | ||
187 | } | |
188 | out[0] = w0 & 0xff; | |
189 | out[1] = (w0 >> 8) & 0xff; | |
190 | out[2] = w1 & 0xff; | |
191 | out[3] = (w1 >> 8) & 0xff; | |
192 | out[4] = w2 & 0xff; | |
193 | out[5] = (w2 >> 8) & 0xff; | |
194 | out[6] = w3 & 0xff; | |
195 | out[7] = (w3 >> 8) & 0xff; | |
196 | } | |
197 | ||
198 | void | |
199 | RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long size, | |
200 | RC2_KEY *key, unsigned char *iv, int forward_encrypt) | |
201 | { | |
202 | unsigned char tmp[RC2_BLOCK_SIZE]; | |
203 | int i; | |
204 | ||
205 | if (forward_encrypt) { | |
206 | while (size >= RC2_BLOCK_SIZE) { | |
207 | for (i = 0; i < RC2_BLOCK_SIZE; i++) | |
208 | tmp[i] = in[i] ^ iv[i]; | |
209 | RC2_encryptc(tmp, out, key); | |
210 | memcpy(iv, out, RC2_BLOCK_SIZE); | |
211 | size -= RC2_BLOCK_SIZE; | |
212 | in += RC2_BLOCK_SIZE; | |
213 | out += RC2_BLOCK_SIZE; | |
214 | } | |
215 | if (size) { | |
216 | for (i = 0; i < size; i++) | |
217 | tmp[i] = in[i] ^ iv[i]; | |
218 | for (i = size; i < RC2_BLOCK_SIZE; i++) | |
219 | tmp[i] = iv[i]; | |
220 | RC2_encryptc(tmp, out, key); | |
221 | memcpy(iv, out, RC2_BLOCK_SIZE); | |
222 | } | |
223 | } else { | |
224 | while (size >= RC2_BLOCK_SIZE) { | |
225 | memcpy(tmp, in, RC2_BLOCK_SIZE); | |
226 | RC2_decryptc(tmp, out, key); | |
227 | for (i = 0; i < RC2_BLOCK_SIZE; i++) | |
228 | out[i] ^= iv[i]; | |
229 | memcpy(iv, tmp, RC2_BLOCK_SIZE); | |
230 | size -= RC2_BLOCK_SIZE; | |
231 | in += RC2_BLOCK_SIZE; | |
232 | out += RC2_BLOCK_SIZE; | |
233 | } | |
234 | if (size) { | |
235 | memcpy(tmp, in, RC2_BLOCK_SIZE); | |
236 | RC2_decryptc(tmp, out, key); | |
237 | for (i = 0; i < size; i++) | |
238 | out[i] ^= iv[i]; | |
239 | memcpy(iv, tmp, RC2_BLOCK_SIZE); | |
240 | } | |
241 | } | |
242 | } |