1 /* crypto/aes/aes_cfb.c -*- mode:C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
31 * 6. Redistributions of any form whatsoever must retain the following
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
51 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
52 * All rights reserved.
54 * This package is an SSL implementation written
55 * by Eric Young (eay@cryptsoft.com).
56 * The implementation was written so as to conform with Netscapes SSL.
58 * This library is free for commercial and non-commercial use as long as
59 * the following conditions are aheared to. The following conditions
60 * apply to all code found in this distribution, be it the RC4, RSA,
61 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
62 * included with this distribution is covered by the same copyright terms
63 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
65 * Copyright remains Eric Young's, and as such any Copyright notices in
66 * the code are not to be removed.
67 * If this package is used in a product, Eric Young should be given attribution
68 * as the author of the parts of the library used.
69 * This can be in the form of a textual message at program startup or
70 * in documentation (online or textual) provided with the package.
72 * Redistribution and use in source and binary forms, with or without
73 * modification, are permitted provided that the following conditions
75 * 1. Redistributions of source code must retain the copyright
76 * notice, this list of conditions and the following disclaimer.
77 * 2. Redistributions in binary form must reproduce the above copyright
78 * notice, this list of conditions and the following disclaimer in the
79 * documentation and/or other materials provided with the distribution.
80 * 3. All advertising materials mentioning features or use of this software
81 * must display the following acknowledgement:
82 * "This product includes cryptographic software written by
83 * Eric Young (eay@cryptsoft.com)"
84 * The word 'cryptographic' can be left out if the rouines from the library
85 * being used are not cryptographic related :-).
86 * 4. If you include any Windows specific code (or a derivative thereof) from
87 * the apps directory (application code) you must include an acknowledgement:
88 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
90 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
91 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
92 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
93 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
94 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
95 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
96 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
97 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
98 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
99 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
102 * The licence and distribution terms for any publically available version or
103 * derivative of this code cannot be changed. i.e. this code cannot simply be
104 * copied and put under another distribution licence
105 * [including the GNU Public Licence.]
115 #include <openssl/aes.h>
116 #include "aes_locl.h"
119 #define STRICT_ALIGNMENT
120 #if defined(__i386) || defined(__i386__) || \
121 defined(__x86_64) || defined(__x86_64__) || \
122 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64)
123 # undef STRICT_ALIGNMENT
126 /* The input and output encrypted as though 128bit cfb mode is being
127 * used. The extra state information to record how much of the
128 * 128bit block we have used is contained in *num;
131 void AES_cfb128_encrypt(const unsigned char *in, unsigned char *out,
132 unsigned long length, const AES_KEY *key,
133 unsigned char *ivec, int *num, const int enc) {
138 assert(in && out && key && ivec && num);
142 #if !defined(OPENSSL_SMALL_FOOTPRINT)
143 if (AES_BLOCK_SIZE%sizeof(size_t) == 0) { /* always true actually */
147 *(out++) = ivec[n] ^= *(in++);
149 if(!(n = (n + 1) % AES_BLOCK_SIZE))
153 #if defined(STRICT_ALIGNMENT)
154 if (((size_t)in|(size_t)out)%sizeof(size_t) != 0)
157 while ((l + AES_BLOCK_SIZE) <= length) {
159 AES_encrypt(ivec, ivec, key);
160 for (i=0;i<AES_BLOCK_SIZE;i+=sizeof(size_t)) {
161 *(size_t*)(out+l+i) =
162 *(size_t*)(ivec+i) ^= *(size_t*)(in+l+i);
168 AES_encrypt(ivec, ivec, key);
169 do { out[l] = ivec[n] ^= in[l];
171 } while (l < length);
177 *(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
179 if(!(n = (n + 1) % AES_BLOCK_SIZE))
183 #if defined(STRICT_ALIGNMENT)
184 if (((size_t)in|(size_t)out)%sizeof(size_t) != 0)
187 while (l + AES_BLOCK_SIZE <= length) {
189 AES_encrypt(ivec, ivec, key);
190 for (i=0;i<AES_BLOCK_SIZE;i+=sizeof(size_t)) {
191 size_t t = *(size_t*)(in+l+i);
192 *(size_t*)(out+l+i) = *(size_t*)(ivec+i) ^ t;
193 *(size_t*)(ivec+i) = t;
199 AES_encrypt(ivec, ivec, key);
200 do { unsigned char c;
201 out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
203 } while (l < length);
211 /* this code would be commonly eliminated by x86* compiler */
213 #if defined(STRICT_ALIGNMENT) && !defined(OPENSSL_SMALL_FOOTPRINT)
218 AES_encrypt(ivec, ivec, key);
220 out[l] = ivec[n] ^= in[l];
222 n = (n+1) % AES_BLOCK_SIZE;
225 #if defined(STRICT_ALIGNMENT) && !defined(OPENSSL_SMALL_FOOTPRINT)
231 AES_encrypt(ivec, ivec, key);
233 out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
235 n = (n+1) % AES_BLOCK_SIZE;
242 /* This expects a single block of size nbits for both in and out. Note that
243 it corrupts any extra bits in the last byte of out */
244 void AES_cfbr_encrypt_block(const unsigned char *in,unsigned char *out,
245 const int nbits,const AES_KEY *key,
246 unsigned char *ivec,const int enc)
249 unsigned char ovec[AES_BLOCK_SIZE*2];
251 if (nbits<=0 || nbits>128) return;
253 /* fill in the first half of the new IV with the current IV */
254 memcpy(ovec,ivec,AES_BLOCK_SIZE);
255 /* construct the new IV */
256 AES_encrypt(ivec,ivec,key);
258 if (enc) /* encrypt the input */
259 for(n=0 ; n < num ; ++n)
260 out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n] ^ ivec[n]);
261 else /* decrypt the input */
262 for(n=0 ; n < num ; ++n)
263 out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n]) ^ ivec[n];
264 /* shift ovec left... */
268 memcpy(ivec,ovec+num,AES_BLOCK_SIZE);
270 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
271 ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);
273 /* it is not necessary to cleanse ovec, since the IV is not secret */
276 /* N.B. This expects the input to be packed, MS bit first */
277 void AES_cfb1_encrypt(const unsigned char *in, unsigned char *out,
278 const unsigned long length, const AES_KEY *key,
279 unsigned char *ivec, int *num, const int enc)
282 unsigned char c[1],d[1];
284 assert(in && out && key && ivec && num);
287 memset(out,0,(length+7)/8);
288 for(n=0 ; n < length ; ++n)
290 c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;
291 AES_cfbr_encrypt_block(c,d,1,key,ivec,enc);
292 out[n/8]=(out[n/8]&~(1 << (7-n%8)))|((d[0]&0x80) >> (n%8));
296 void AES_cfb8_encrypt(const unsigned char *in, unsigned char *out,
297 const unsigned long length, const AES_KEY *key,
298 unsigned char *ivec, int *num, const int enc)
302 assert(in && out && key && ivec && num);
305 for(n=0 ; n < length ; ++n)
306 AES_cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc);