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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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 * ====================================================================
51 #include "modes_lcl.h"
61 /* The input and output encrypted as though 128bit cfb mode is being
62 * used. The extra state information to record how much of the
63 * 128bit block we have used is contained in *num;
65 void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
66 size_t len, const void *key,
67 unsigned char ivec[16], int *num,
68 int enc, block128_f block)
73 assert(in && out && key && ivec && num);
78 #if !defined(OPENSSL_SMALL_FOOTPRINT)
79 if (16%sizeof(size_t) == 0) do { /* always true actually */
81 *(out++) = ivec[n] ^= *(in++);
85 #if defined(STRICT_ALIGNMENT)
86 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
90 (*block)(ivec, ivec, key);
91 for (; n<16; n+=sizeof(size_t)) {
93 *(size_t*)(ivec+n) ^= *(size_t*)(in+n);
101 (*block)(ivec, ivec, key);
103 out[n] = ivec[n] ^= in[n];
110 /* the rest would be commonly eliminated by x86* compiler */
114 (*block)(ivec, ivec, key);
116 out[l] = ivec[n] ^= in[l];
122 #if !defined(OPENSSL_SMALL_FOOTPRINT)
123 if (16%sizeof(size_t) == 0) do { /* always true actually */
126 *(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
130 #if defined(STRICT_ALIGNMENT)
131 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
135 (*block)(ivec, ivec, key);
136 for (; n<16; n+=sizeof(size_t)) {
137 size_t t = *(size_t*)(in+n);
138 *(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t;
139 *(size_t*)(ivec+n) = t;
147 (*block)(ivec, ivec, key);
150 out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;
157 /* the rest would be commonly eliminated by x86* compiler */
162 (*block)(ivec, ivec, key);
164 out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
172 /* This expects a single block of size nbits for both in and out. Note that
173 it corrupts any extra bits in the last byte of out */
174 static void cfbr_encrypt_block(const unsigned char *in,unsigned char *out,
175 int nbits,const void *key,
176 unsigned char ivec[16],int enc,
180 unsigned char ovec[16*2 + 1]; /* +1 because we dererefence (but don't use) one byte off the end */
182 if (nbits<=0 || nbits>128) return;
184 /* fill in the first half of the new IV with the current IV */
185 memcpy(ovec,ivec,16);
186 /* construct the new IV */
187 (*block)(ivec,ivec,key);
189 if (enc) /* encrypt the input */
190 for(n=0 ; n < num ; ++n)
191 out[n] = (ovec[16+n] = in[n] ^ ivec[n]);
192 else /* decrypt the input */
193 for(n=0 ; n < num ; ++n)
194 out[n] = (ovec[16+n] = in[n]) ^ ivec[n];
195 /* shift ovec left... */
199 memcpy(ivec,ovec+num,16);
201 for(n=0 ; n < 16 ; ++n)
202 ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);
204 /* it is not necessary to cleanse ovec, since the IV is not secret */
207 /* N.B. This expects the input to be packed, MS bit first */
208 void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,
209 size_t bits, const void *key,
210 unsigned char ivec[16], int *num,
211 int enc, block128_f block)
214 unsigned char c[1],d[1];
216 assert(in && out && key && ivec && num);
219 for(n=0 ; n<bits ; ++n)
221 c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;
222 cfbr_encrypt_block(c,d,1,key,ivec,enc,block);
223 out[n/8]=(out[n/8]&~(1 << (unsigned int)(7-n%8))) |
224 ((d[0]&0x80) >> (unsigned int)(n%8));
228 void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
229 size_t length, const void *key,
230 unsigned char ivec[16], int *num,
231 int enc, block128_f block)
235 assert(in && out && key && ivec && num);
238 for(n=0 ; n<length ; ++n)
239 cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc,block);