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 */
50
51 #include "modes.h"
52 #include <string.h>
53
54 #ifndef MODES_DEBUG
55 # ifndef NDEBUG
56 # define NDEBUG
57 # endif
58 #endif
59 #include <assert.h>
60
61 #define STRICT_ALIGNMENT
62 #if defined(__i386) || defined(__i386__) || \
63 defined(__x86_64) || defined(__x86_64__) || \
64 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
65 defined(__s390__) || defined(__s390x__)
66 # undef STRICT_ALIGNMENT
67 #endif
68
69 /* The input and output encrypted as though 128bit cfb mode is being
70 * used. The extra state information to record how much of the
71 * 128bit block we have used is contained in *num;
72 */
CRYPTO_cfb128_encrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],int * num,int enc,block128_f block)73 void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
74 size_t len, const void *key,
75 unsigned char ivec[16], int *num,
76 int enc, block128_f block)
77 {
78 unsigned int n;
79 size_t l = 0;
80
81 assert(in && out && key && ivec && num);
82
83 n = *num;
84
85 if (enc) {
86 #if !defined(OPENSSL_SMALL_FOOTPRINT)
87 if (16%sizeof(size_t) == 0) do { /* always true actually */
88 while (n && len) {
89 *(out++) = ivec[n] ^= *(in++);
90 --len;
91 n = (n+1) % 16;
92 }
93 #if defined(STRICT_ALIGNMENT)
94 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
95 break;
96 #endif
97 while (len>=16) {
98 (*block)(ivec, ivec, key);
99 for (; n<16; n+=sizeof(size_t)) {
100 *(size_t*)(out+n) =
101 *(size_t*)(ivec+n) ^= *(size_t*)(in+n);
102 }
103 len -= 16;
104 out += 16;
105 in += 16;
106 n = 0;
107 }
108 if (len) {
109 (*block)(ivec, ivec, key);
110 while (len--) {
111 out[n] = ivec[n] ^= in[n];
112 ++n;
113 }
114 }
115 *num = n;
116 return;
117 } while (0);
118 /* the rest would be commonly eliminated by x86* compiler */
119 #endif
120 while (l<len) {
121 if (n == 0) {
122 (*block)(ivec, ivec, key);
123 }
124 out[l] = ivec[n] ^= in[l];
125 ++l;
126 n = (n+1) % 16;
127 }
128 *num = n;
129 } else {
130 #if !defined(OPENSSL_SMALL_FOOTPRINT)
131 if (16%sizeof(size_t) == 0) do { /* always true actually */
132 while (n && len) {
133 unsigned char c;
134 *(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
135 --len;
136 n = (n+1) % 16;
137 }
138 #if defined(STRICT_ALIGNMENT)
139 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
140 break;
141 #endif
142 while (len>=16) {
143 (*block)(ivec, ivec, key);
144 for (; n<16; n+=sizeof(size_t)) {
145 size_t t = *(size_t*)(in+n);
146 *(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t;
147 *(size_t*)(ivec+n) = t;
148 }
149 len -= 16;
150 out += 16;
151 in += 16;
152 n = 0;
153 }
154 if (len) {
155 (*block)(ivec, ivec, key);
156 while (len--) {
157 unsigned char c;
158 out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;
159 ++n;
160 }
161 }
162 *num = n;
163 return;
164 } while (0);
165 /* the rest would be commonly eliminated by x86* compiler */
166 #endif
167 while (l<len) {
168 unsigned char c;
169 if (n == 0) {
170 (*block)(ivec, ivec, key);
171 }
172 out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
173 ++l;
174 n = (n+1) % 16;
175 }
176 *num=n;
177 }
178 }
179
180 /* This expects a single block of size nbits for both in and out. Note that
181 it corrupts any extra bits in the last byte of out */
cfbr_encrypt_block(const unsigned char * in,unsigned char * out,int nbits,const void * key,unsigned char ivec[16],int enc,block128_f block)182 static void cfbr_encrypt_block(const unsigned char *in,unsigned char *out,
183 int nbits,const void *key,
184 unsigned char ivec[16],int enc,
185 block128_f block)
186 {
187 int n,rem,num;
188 unsigned char ovec[16*2 + 1]; /* +1 because we dererefence (but don't use) one byte off the end */
189
190 if (nbits<=0 || nbits>128) return;
191
192 /* fill in the first half of the new IV with the current IV */
193 memcpy(ovec,ivec,16);
194 /* construct the new IV */
195 (*block)(ivec,ivec,key);
196 num = (nbits+7)/8;
197 if (enc) /* encrypt the input */
198 for(n=0 ; n < num ; ++n)
199 out[n] = (ovec[16+n] = in[n] ^ ivec[n]);
200 else /* decrypt the input */
201 for(n=0 ; n < num ; ++n)
202 out[n] = (ovec[16+n] = in[n]) ^ ivec[n];
203 /* shift ovec left... */
204 rem = nbits%8;
205 num = nbits/8;
206 if(rem==0)
207 memcpy(ivec,ovec+num,16);
208 else
209 for(n=0 ; n < 16 ; ++n)
210 ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);
211
212 /* it is not necessary to cleanse ovec, since the IV is not secret */
213 }
214
215 /* N.B. This expects the input to be packed, MS bit first */
CRYPTO_cfb128_1_encrypt(const unsigned char * in,unsigned char * out,size_t bits,const void * key,unsigned char ivec[16],int * num,int enc,block128_f block)216 void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,
217 size_t bits, const void *key,
218 unsigned char ivec[16], int *num,
219 int enc, block128_f block)
220 {
221 size_t n;
222 unsigned char c[1],d[1];
223
224 assert(in && out && key && ivec && num);
225 assert(*num == 0);
226
227 for(n=0 ; n<bits ; ++n)
228 {
229 c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;
230 cfbr_encrypt_block(c,d,1,key,ivec,enc,block);
231 out[n/8]=(out[n/8]&~(1 << (unsigned int)(7-n%8))) |
232 ((d[0]&0x80) >> (unsigned int)(n%8));
233 }
234 }
235
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)236 void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
237 size_t length, const void *key,
238 unsigned char ivec[16], int *num,
239 int enc, block128_f block)
240 {
241 size_t n;
242
243 assert(in && out && key && ivec && num);
244 assert(*num == 0);
245
246 for(n=0 ; n<length ; ++n)
247 cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc,block);
248 }
249
250