1 /* ====================================================================
2 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
14 * distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 * software must display the following acknowledgment:
18 * "This product includes software developed by the OpenSSL Project
19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 * endorse or promote products derived from this software without
23 * prior written permission. For written permission, please contact
24 * openssl-core@openssl.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 * nor may "OpenSSL" appear in their names without prior written
28 * permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 * acknowledgment:
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ==================================================================== */
48
49 #include <openssl/type_check.h>
50
51 #include <assert.h>
52 #include <string.h>
53
54 #include "internal.h"
55
56
57 OPENSSL_COMPILE_ASSERT((16 % sizeof(size_t)) == 0, bad_size_t_size);
58
CRYPTO_cfb128_encrypt(const uint8_t * in,uint8_t * out,size_t len,const void * key,uint8_t ivec[16],int * num,int enc,block128_f block)59 void CRYPTO_cfb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
60 const void *key, uint8_t ivec[16], int *num, int enc,
61 block128_f block) {
62 unsigned int n;
63 size_t l = 0;
64
65 assert(in && out && key && ivec && num);
66
67 n = *num;
68
69 if (enc) {
70 while (n && len) {
71 *(out++) = ivec[n] ^= *(in++);
72 --len;
73 n = (n + 1) % 16;
74 }
75 #if STRICT_ALIGNMENT
76 if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
77 while (l < len) {
78 if (n == 0) {
79 (*block)(ivec, ivec, key);
80 }
81 out[l] = ivec[n] ^= in[l];
82 ++l;
83 n = (n + 1) % 16;
84 }
85 *num = n;
86 return;
87 }
88 #endif
89 while (len >= 16) {
90 (*block)(ivec, ivec, key);
91 for (; n < 16; n += sizeof(size_t)) {
92 *(size_t *)(out + n) = *(size_t *)(ivec + n) ^= *(size_t *)(in + n);
93 }
94 len -= 16;
95 out += 16;
96 in += 16;
97 n = 0;
98 }
99 if (len) {
100 (*block)(ivec, ivec, key);
101 while (len--) {
102 out[n] = ivec[n] ^= in[n];
103 ++n;
104 }
105 }
106 *num = n;
107 return;
108 } else {
109 while (n && len) {
110 uint8_t c;
111 *(out++) = ivec[n] ^ (c = *(in++));
112 ivec[n] = c;
113 --len;
114 n = (n + 1) % 16;
115 }
116 if (STRICT_ALIGNMENT && ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
117 while (l < len) {
118 unsigned char c;
119 if (n == 0) {
120 (*block)(ivec, ivec, key);
121 }
122 out[l] = ivec[n] ^ (c = in[l]);
123 ivec[n] = c;
124 ++l;
125 n = (n + 1) % 16;
126 }
127 *num = n;
128 return;
129 }
130 while (len >= 16) {
131 (*block)(ivec, ivec, key);
132 for (; n < 16; n += sizeof(size_t)) {
133 size_t t = *(size_t *)(in + n);
134 *(size_t *)(out + n) = *(size_t *)(ivec + n) ^ t;
135 *(size_t *)(ivec + n) = t;
136 }
137 len -= 16;
138 out += 16;
139 in += 16;
140 n = 0;
141 }
142 if (len) {
143 (*block)(ivec, ivec, key);
144 while (len--) {
145 uint8_t c;
146 out[n] = ivec[n] ^ (c = in[n]);
147 ivec[n] = c;
148 ++n;
149 }
150 }
151 *num = n;
152 return;
153 }
154 }
155
156
157 /* This expects a single block of size nbits for both in and out. Note that
158 it corrupts any extra bits in the last byte of out */
cfbr_encrypt_block(const uint8_t * in,uint8_t * out,unsigned nbits,const void * key,uint8_t ivec[16],int enc,block128_f block)159 static void cfbr_encrypt_block(const uint8_t *in, uint8_t *out, unsigned nbits,
160 const void *key, uint8_t ivec[16], int enc,
161 block128_f block) {
162 int n, rem, num;
163 uint8_t ovec[16 * 2 + 1]; /* +1 because we dererefence (but don't use) one
164 byte off the end */
165
166 if (nbits <= 0 || nbits > 128) {
167 return;
168 }
169
170 /* fill in the first half of the new IV with the current IV */
171 memcpy(ovec, ivec, 16);
172 /* construct the new IV */
173 (*block)(ivec, ivec, key);
174 num = (nbits + 7) / 8;
175 if (enc) {
176 /* encrypt the input */
177 for (n = 0; n < num; ++n) {
178 out[n] = (ovec[16 + n] = in[n] ^ ivec[n]);
179 }
180 } else {
181 /* decrypt the input */
182 for (n = 0; n < num; ++n) {
183 out[n] = (ovec[16 + n] = in[n]) ^ ivec[n];
184 }
185 }
186 /* shift ovec left... */
187 rem = nbits % 8;
188 num = nbits / 8;
189 if (rem == 0) {
190 memcpy(ivec, ovec + num, 16);
191 } else {
192 for (n = 0; n < 16; ++n) {
193 ivec[n] = ovec[n + num] << rem | ovec[n + num + 1] >> (8 - rem);
194 }
195 }
196
197 /* it is not necessary to cleanse ovec, since the IV is not secret */
198 }
199
200 /* N.B. This expects the input to be packed, MS bit first */
CRYPTO_cfb128_1_encrypt(const uint8_t * in,uint8_t * out,size_t bits,const void * key,uint8_t ivec[16],int * num,int enc,block128_f block)201 void CRYPTO_cfb128_1_encrypt(const uint8_t *in, uint8_t *out, size_t bits,
202 const void *key, uint8_t ivec[16], int *num,
203 int enc, block128_f block) {
204 size_t n;
205 uint8_t c[1], d[1];
206
207 assert(in && out && key && ivec && num);
208 assert(*num == 0);
209
210 for (n = 0; n < bits; ++n) {
211 c[0] = (in[n / 8] & (1 << (7 - n % 8))) ? 0x80 : 0;
212 cfbr_encrypt_block(c, d, 1, key, ivec, enc, block);
213 out[n / 8] = (out[n / 8] & ~(1 << (unsigned int)(7 - n % 8))) |
214 ((d[0] & 0x80) >> (unsigned int)(n % 8));
215 }
216 }
217
CRYPTO_cfb128_8_encrypt(const unsigned char * in,unsigned char * out,size_t length,const void * key,unsigned char ivec[16],int * num,int enc,block128_f block)218 void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
219 size_t length, const void *key,
220 unsigned char ivec[16], int *num, int enc,
221 block128_f block) {
222 size_t n;
223
224 assert(in && out && key && ivec && num);
225 assert(*num == 0);
226
227 for (n = 0; n < length; ++n) {
228 cfbr_encrypt_block(&in[n], &out[n], 8, key, ivec, enc, block);
229 }
230 }
231
232