1 /* ====================================================================
2 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
30 * 6. Redistributions of any form whatsoever must retain the following
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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)
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45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
51 #include <openssl/crypto.h>
52 #include "modes_lcl.h"
56 * The input and output encrypted as though 128bit cfb mode is being used.
57 * The extra state information to record how much of the 128bit block we have
58 * used is contained in *num;
60 void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
61 size_t len, const void *key,
62 unsigned char ivec[16], int *num,
63 int enc, block128_f block)
71 #if !defined(OPENSSL_SMALL_FOOTPRINT)
72 if (16 % sizeof(size_t) == 0) { /* always true actually */
75 *(out++) = ivec[n] ^= *(in++);
79 # if defined(STRICT_ALIGNMENT)
80 if (((size_t)in | (size_t)out | (size_t)ivec) %
85 (*block) (ivec, ivec, key);
86 for (; n < 16; n += sizeof(size_t)) {
87 *(size_t *)(out + n) =
88 *(size_t *)(ivec + n) ^= *(size_t *)(in + n);
96 (*block) (ivec, ivec, key);
98 out[n] = ivec[n] ^= in[n];
106 /* the rest would be commonly eliminated by x86* compiler */
110 (*block) (ivec, ivec, key);
112 out[l] = ivec[n] ^= in[l];
118 #if !defined(OPENSSL_SMALL_FOOTPRINT)
119 if (16 % sizeof(size_t) == 0) { /* always true actually */
123 *(out++) = ivec[n] ^ (c = *(in++));
128 # if defined(STRICT_ALIGNMENT)
129 if (((size_t)in | (size_t)out | (size_t)ivec) %
134 (*block) (ivec, ivec, key);
135 for (; n < 16; n += sizeof(size_t)) {
136 size_t t = *(size_t *)(in + n);
137 *(size_t *)(out + n) = *(size_t *)(ivec + n) ^ t;
138 *(size_t *)(ivec + n) = t;
146 (*block) (ivec, ivec, key);
149 out[n] = ivec[n] ^ (c = in[n]);
158 /* the rest would be commonly eliminated by x86* compiler */
163 (*block) (ivec, ivec, key);
165 out[l] = ivec[n] ^ (c = in[l]);
175 * This expects a single block of size nbits for both in and out. Note that
176 * it corrupts any extra bits in the last byte of out
178 static void cfbr_encrypt_block(const unsigned char *in, unsigned char *out,
179 int nbits, const void *key,
180 unsigned char ivec[16], int enc,
184 unsigned char ovec[16 * 2 + 1]; /* +1 because we dereference (but don't
185 * use) one byte off the end */
187 if (nbits <= 0 || nbits > 128)
190 /* fill in the first half of the new IV with the current IV */
191 memcpy(ovec, ivec, 16);
192 /* construct the new IV */
193 (*block) (ivec, ivec, key);
194 num = (nbits + 7) / 8;
195 if (enc) /* encrypt the input */
196 for (n = 0; n < num; ++n)
197 out[n] = (ovec[16 + n] = in[n] ^ ivec[n]);
198 else /* decrypt the input */
199 for (n = 0; n < num; ++n)
200 out[n] = (ovec[16 + n] = in[n]) ^ ivec[n];
201 /* shift ovec left... */
205 memcpy(ivec, ovec + num, 16);
207 for (n = 0; n < 16; ++n)
208 ivec[n] = ovec[n + num] << rem | ovec[n + num + 1] >> (8 - rem);
210 /* it is not necessary to cleanse ovec, since the IV is not secret */
213 /* N.B. This expects the input to be packed, MS bit first */
214 void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,
215 size_t bits, const void *key,
216 unsigned char ivec[16], int *num,
217 int enc, block128_f block)
220 unsigned char c[1], d[1];
222 for (n = 0; n < bits; ++n) {
223 c[0] = (in[n / 8] & (1 << (7 - n % 8))) ? 0x80 : 0;
224 cfbr_encrypt_block(c, d, 1, key, ivec, enc, block);
225 out[n / 8] = (out[n / 8] & ~(1 << (unsigned int)(7 - n % 8))) |
226 ((d[0] & 0x80) >> (unsigned int)(n % 8));
230 void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
231 size_t length, const void *key,
232 unsigned char ivec[16], int *num,
233 int enc, block128_f block)
237 for (n = 0; n < length; ++n)
238 cfbr_encrypt_block(&in[n], &out[n], 8, key, ivec, enc, block);