Line data Source code
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 : #include <roken.h>
36 :
37 : #include "rc2.h"
38 :
39 : /*
40 : * Implemented from Peter Gutmann's "Specification for Ron Rivests Cipher No.2"
41 : * rfc2268 and "On the Design and Security of RC2" was also useful.
42 : */
43 :
44 : static unsigned int Sbox[256] = {
45 : 0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed,
46 : 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d,
47 : 0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e,
48 : 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2,
49 : 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13,
50 : 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32,
51 : 0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b,
52 : 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82,
53 : 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c,
54 : 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
55 : 0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1,
56 : 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26,
57 : 0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57,
58 : 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03,
59 : 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7,
60 : 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7,
61 : 0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7,
62 : 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a,
63 : 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74,
64 : 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
65 : 0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc,
66 : 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39,
67 : 0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a,
68 : 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31,
69 : 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae,
70 : 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9,
71 : 0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c,
72 : 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9,
73 : 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0,
74 : 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
75 : 0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77,
76 : 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad
77 : };
78 :
79 : void
80 0 : RC2_set_key(RC2_KEY *key, int len, const unsigned char *data, int bits)
81 : {
82 0 : unsigned char k[128];
83 0 : int j, T8, TM;
84 :
85 0 : if (len <= 0)
86 0 : abort();
87 0 : if (len > 128)
88 0 : len = 128;
89 0 : if (bits <= 0 || bits > 1024)
90 0 : bits = 1024;
91 :
92 0 : for (j = 0; j < len; j++)
93 0 : k[j] = data[j];
94 0 : for (; j < 128; j++)
95 0 : k[j] = Sbox[(k[j - len] + k[j - 1]) & 0xff];
96 :
97 0 : T8 = (bits + 7) / 8;
98 0 : j = (8*T8 - bits);
99 0 : TM = 0xff >> j;
100 :
101 0 : k[128 - T8] = Sbox[k[128 - T8] & TM];
102 :
103 0 : for (j = 127 - T8; j >= 0; j--)
104 0 : k[j] = Sbox[k[j + 1] ^ k[j + T8]];
105 :
106 0 : for (j = 0; j < 64; j++)
107 0 : key->data[j] = k[(j * 2) + 0] | (k[(j * 2) + 1] << 8);
108 0 : memset_s(k, sizeof(k), 0, sizeof(k));
109 0 : }
110 :
111 : #define ROT16L(w,n) ((w<<n)|(w>>(16-n)))
112 : #define ROT16R(w,n) ((w>>n)|(w<<(16-n)))
113 :
114 : void
115 0 : RC2_encryptc(unsigned char *in, unsigned char *out, const RC2_KEY *key)
116 : {
117 0 : int i, j;
118 0 : int w0, w1, w2, w3;
119 0 : int t0, t1, t2, t3;
120 :
121 0 : w0 = in[0] | (in[1] << 8);
122 0 : w1 = in[2] | (in[3] << 8);
123 0 : w2 = in[4] | (in[5] << 8);
124 0 : w3 = in[6] | (in[7] << 8);
125 :
126 0 : for (i = 0; i < 16; i++) {
127 0 : j = i * 4;
128 0 : t0 = (w0 + (w1 & ~w3) + (w2 & w3) + key->data[j + 0]) & 0xffff;
129 0 : w0 = ROT16L(t0, 1);
130 0 : t1 = (w1 + (w2 & ~w0) + (w3 & w0) + key->data[j + 1]) & 0xffff;
131 0 : w1 = ROT16L(t1, 2);
132 0 : t2 = (w2 + (w3 & ~w1) + (w0 & w1) + key->data[j + 2]) & 0xffff;
133 0 : w2 = ROT16L(t2, 3);
134 0 : t3 = (w3 + (w0 & ~w2) + (w1 & w2) + key->data[j + 3]) & 0xffff;
135 0 : w3 = ROT16L(t3, 5);
136 0 : if(i == 4 || i == 10) {
137 0 : w0 += key->data[w3 & 63];
138 0 : w1 += key->data[w0 & 63];
139 0 : w2 += key->data[w1 & 63];
140 0 : w3 += key->data[w2 & 63];
141 : }
142 : }
143 :
144 0 : out[0] = w0 & 0xff;
145 0 : out[1] = (w0 >> 8) & 0xff;
146 0 : out[2] = w1 & 0xff;
147 0 : out[3] = (w1 >> 8) & 0xff;
148 0 : out[4] = w2 & 0xff;
149 0 : out[5] = (w2 >> 8) & 0xff;
150 0 : out[6] = w3 & 0xff;
151 0 : out[7] = (w3 >> 8) & 0xff;
152 0 : }
153 :
154 : void
155 0 : RC2_decryptc(unsigned char *in, unsigned char *out, const RC2_KEY *key)
156 : {
157 0 : int i, j;
158 0 : int w0, w1, w2, w3;
159 0 : int t0, t1, t2, t3;
160 :
161 0 : w0 = in[0] | (in[1] << 8);
162 0 : w1 = in[2] | (in[3] << 8);
163 0 : w2 = in[4] | (in[5] << 8);
164 0 : w3 = in[6] | (in[7] << 8);
165 :
166 0 : for (i = 15; i >= 0; i--) {
167 0 : j = i * 4;
168 :
169 0 : if(i == 4 || i == 10) {
170 0 : w3 = (w3 - key->data[w2 & 63]) & 0xffff;
171 0 : w2 = (w2 - key->data[w1 & 63]) & 0xffff;
172 0 : w1 = (w1 - key->data[w0 & 63]) & 0xffff;
173 0 : w0 = (w0 - key->data[w3 & 63]) & 0xffff;
174 : }
175 :
176 0 : t3 = ROT16R(w3, 5);
177 0 : w3 = (t3 - (w0 & ~w2) - (w1 & w2) - key->data[j + 3]) & 0xffff;
178 0 : t2 = ROT16R(w2, 3);
179 0 : w2 = (t2 - (w3 & ~w1) - (w0 & w1) - key->data[j + 2]) & 0xffff;
180 0 : t1 = ROT16R(w1, 2);
181 0 : w1 = (t1 - (w2 & ~w0) - (w3 & w0) - key->data[j + 1]) & 0xffff;
182 0 : t0 = ROT16R(w0, 1);
183 0 : w0 = (t0 - (w1 & ~w3) - (w2 & w3) - key->data[j + 0]) & 0xffff;
184 :
185 : }
186 0 : out[0] = w0 & 0xff;
187 0 : out[1] = (w0 >> 8) & 0xff;
188 0 : out[2] = w1 & 0xff;
189 0 : out[3] = (w1 >> 8) & 0xff;
190 0 : out[4] = w2 & 0xff;
191 0 : out[5] = (w2 >> 8) & 0xff;
192 0 : out[6] = w3 & 0xff;
193 0 : out[7] = (w3 >> 8) & 0xff;
194 0 : }
195 :
196 : void
197 0 : RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long size,
198 : RC2_KEY *key, unsigned char *iv, int forward_encrypt)
199 : {
200 0 : unsigned char tmp[RC2_BLOCK_SIZE];
201 0 : int i;
202 :
203 0 : if (forward_encrypt) {
204 0 : while (size >= RC2_BLOCK_SIZE) {
205 0 : for (i = 0; i < RC2_BLOCK_SIZE; i++)
206 0 : tmp[i] = in[i] ^ iv[i];
207 0 : RC2_encryptc(tmp, out, key);
208 0 : memcpy(iv, out, RC2_BLOCK_SIZE);
209 0 : size -= RC2_BLOCK_SIZE;
210 0 : in += RC2_BLOCK_SIZE;
211 0 : out += RC2_BLOCK_SIZE;
212 : }
213 0 : if (size) {
214 0 : for (i = 0; i < size; i++)
215 0 : tmp[i] = in[i] ^ iv[i];
216 0 : for (i = size; i < RC2_BLOCK_SIZE; i++)
217 0 : tmp[i] = iv[i];
218 0 : RC2_encryptc(tmp, out, key);
219 0 : memcpy(iv, out, RC2_BLOCK_SIZE);
220 : }
221 : } else {
222 0 : while (size >= RC2_BLOCK_SIZE) {
223 0 : memcpy(tmp, in, RC2_BLOCK_SIZE);
224 0 : RC2_decryptc(tmp, out, key);
225 0 : for (i = 0; i < RC2_BLOCK_SIZE; i++)
226 0 : out[i] ^= iv[i];
227 0 : memcpy(iv, tmp, RC2_BLOCK_SIZE);
228 0 : size -= RC2_BLOCK_SIZE;
229 0 : in += RC2_BLOCK_SIZE;
230 0 : out += RC2_BLOCK_SIZE;
231 : }
232 0 : if (size) {
233 0 : memcpy(tmp, in, RC2_BLOCK_SIZE);
234 0 : RC2_decryptc(tmp, out, key);
235 0 : for (i = 0; i < size; i++)
236 0 : out[i] ^= iv[i];
237 0 : memcpy(iv, tmp, RC2_BLOCK_SIZE);
238 : }
239 : }
240 0 : }
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