1 /* crypto/aes/aes_ige.c -*- mode:C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
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
15 * distribution.
16 *
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/)"
21 *
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.
26 *
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.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
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 * ====================================================================
49 *
50 */
51
52 #include "cryptlib.h"
53
54 #include <openssl/aes.h>
55 #include "aes_locl.h"
56
57 #define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long))
58 typedef struct {
59 unsigned long data[N_WORDS];
60 } aes_block_t;
61
62 /* XXX: probably some better way to do this */
63 #if defined(__i386__) || defined(__x86_64__)
64 #define UNALIGNED_MEMOPS_ARE_FAST 1
65 #else
66 #define UNALIGNED_MEMOPS_ARE_FAST 0
67 #endif
68
69 #if UNALIGNED_MEMOPS_ARE_FAST
70 #define load_block(d, s) (d) = *(const aes_block_t *)(s)
71 #define store_block(d, s) *(aes_block_t *)(d) = (s)
72 #else
73 #define load_block(d, s) memcpy((d).data, (s), AES_BLOCK_SIZE)
74 #define store_block(d, s) memcpy((d), (s).data, AES_BLOCK_SIZE)
75 #endif
76
77 /* N.B. The IV for this mode is _twice_ the block size */
78
79 void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
80 size_t length, const AES_KEY *key,
81 unsigned char *ivec, const int enc)
82 {
83 size_t n;
84 size_t len = length;
85
86 OPENSSL_assert(in && out && key && ivec);
87 OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
88 OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
89
90 len = length / AES_BLOCK_SIZE;
91
92 if (AES_ENCRYPT == enc)
93 {
94 if (in != out &&
95 (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
96 {
97 aes_block_t *ivp = (aes_block_t *)ivec;
98 aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
99
100 while (len)
101 {
102 aes_block_t *inp = (aes_block_t *)in;
103 aes_block_t *outp = (aes_block_t *)out;
104
105 for(n=0 ; n < N_WORDS; ++n)
106 outp->data[n] = inp->data[n] ^ ivp->data[n];
107 AES_encrypt((unsigned char *)outp->data, (unsigned char *)outp->data, key);
108 for(n=0 ; n < N_WORDS; ++n)
109 outp->data[n] ^= iv2p->data[n];
110 ivp = outp;
111 iv2p = inp;
112 --len;
113 in += AES_BLOCK_SIZE;
114 out += AES_BLOCK_SIZE;
115 }
116 memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
117 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
118 }
119 else
120 {
121 aes_block_t tmp, tmp2;
122 aes_block_t iv;
123 aes_block_t iv2;
124
125 load_block(iv, ivec);
126 load_block(iv2, ivec + AES_BLOCK_SIZE);
127
128 while (len)
129 {
130 load_block(tmp, in);
131 for(n=0 ; n < N_WORDS; ++n)
132 tmp2.data[n] = tmp.data[n] ^ iv.data[n];
133 AES_encrypt((unsigned char *)tmp2.data, (unsigned char *)tmp2.data, key);
134 for(n=0 ; n < N_WORDS; ++n)
135 tmp2.data[n] ^= iv2.data[n];
136 store_block(out, tmp2);
137 iv = tmp2;
138 iv2 = tmp;
139 --len;
140 in += AES_BLOCK_SIZE;
141 out += AES_BLOCK_SIZE;
142 }
143 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
144 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
145 }
146 }
147 else
148 {
149 if (in != out &&
150 (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
151 {
152 aes_block_t *ivp = (aes_block_t *)ivec;
153 aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
154
155 while (len)
156 {
157 aes_block_t tmp;
158 aes_block_t *inp = (aes_block_t *)in;
159 aes_block_t *outp = (aes_block_t *)out;
160
161 for(n=0 ; n < N_WORDS; ++n)
162 tmp.data[n] = inp->data[n] ^ iv2p->data[n];
163 AES_decrypt((unsigned char *)tmp.data, (unsigned char *)outp->data, key);
164 for(n=0 ; n < N_WORDS; ++n)
165 outp->data[n] ^= ivp->data[n];
166 ivp = inp;
167 iv2p = outp;
168 --len;
169 in += AES_BLOCK_SIZE;
170 out += AES_BLOCK_SIZE;
171 }
172 memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
173 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
174 }
175 else
176 {
177 aes_block_t tmp, tmp2;
178 aes_block_t iv;
179 aes_block_t iv2;
180
181 load_block(iv, ivec);
182 load_block(iv2, ivec + AES_BLOCK_SIZE);
183
184 while (len)
185 {
186 load_block(tmp, in);
187 tmp2 = tmp;
188 for(n=0 ; n < N_WORDS; ++n)
189 tmp.data[n] ^= iv2.data[n];
190 AES_decrypt((unsigned char *)tmp.data, (unsigned char *)tmp.data, key);
191 for(n=0 ; n < N_WORDS; ++n)
192 tmp.data[n] ^= iv.data[n];
193 store_block(out, tmp);
194 iv = tmp2;
195 iv2 = tmp;
196 --len;
197 in += AES_BLOCK_SIZE;
198 out += AES_BLOCK_SIZE;
199 }
200 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
201 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
202 }
203 }
204 }
205
206 /*
207 * Note that its effectively impossible to do biIGE in anything other
208 * than a single pass, so no provision is made for chaining.
209 */
210
211 /* N.B. The IV for this mode is _four times_ the block size */
212
213 void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out,
214 size_t length, const AES_KEY *key,
215 const AES_KEY *key2, const unsigned char *ivec,
216 const int enc)
217 {
218 size_t n;
219 size_t len = length;
220 unsigned char tmp[AES_BLOCK_SIZE];
221 unsigned char tmp2[AES_BLOCK_SIZE];
222 unsigned char tmp3[AES_BLOCK_SIZE];
223 unsigned char prev[AES_BLOCK_SIZE];
224 const unsigned char *iv;
225 const unsigned char *iv2;
226
227 OPENSSL_assert(in && out && key && ivec);
228 OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
229 OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
230
231 if (AES_ENCRYPT == enc)
232 {
233 /* XXX: Do a separate case for when in != out (strictly should
234 check for overlap, too) */
235
236 /* First the forward pass */
237 iv = ivec;
238 iv2 = ivec + AES_BLOCK_SIZE;
239 while (len >= AES_BLOCK_SIZE)
240 {
241 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
242 out[n] = in[n] ^ iv[n];
243 AES_encrypt(out, out, key);
244 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
245 out[n] ^= iv2[n];
246 iv = out;
247 memcpy(prev, in, AES_BLOCK_SIZE);
248 iv2 = prev;
249 len -= AES_BLOCK_SIZE;
250 in += AES_BLOCK_SIZE;
251 out += AES_BLOCK_SIZE;
252 }
253
254 /* And now backwards */
255 iv = ivec + AES_BLOCK_SIZE*2;
256 iv2 = ivec + AES_BLOCK_SIZE*3;
257 len = length;
258 while(len >= AES_BLOCK_SIZE)
259 {
260 out -= AES_BLOCK_SIZE;
261 /* XXX: reduce copies by alternating between buffers */
262 memcpy(tmp, out, AES_BLOCK_SIZE);
263 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
264 out[n] ^= iv[n];
265 /* hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE); */
266 AES_encrypt(out, out, key);
267 /* hexdump(stdout,"enc", out, AES_BLOCK_SIZE); */
268 /* hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE); */
269 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
270 out[n] ^= iv2[n];
271 /* hexdump(stdout,"out", out, AES_BLOCK_SIZE); */
272 iv = out;
273 memcpy(prev, tmp, AES_BLOCK_SIZE);
274 iv2 = prev;
275 len -= AES_BLOCK_SIZE;
276 }
277 }
278 else
279 {
280 /* First backwards */
281 iv = ivec + AES_BLOCK_SIZE*2;
282 iv2 = ivec + AES_BLOCK_SIZE*3;
283 in += length;
284 out += length;
285 while (len >= AES_BLOCK_SIZE)
286 {
287 in -= AES_BLOCK_SIZE;
288 out -= AES_BLOCK_SIZE;
289 memcpy(tmp, in, AES_BLOCK_SIZE);
290 memcpy(tmp2, in, AES_BLOCK_SIZE);
291 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
292 tmp[n] ^= iv2[n];
293 AES_decrypt(tmp, out, key);
294 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
295 out[n] ^= iv[n];
296 memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
297 iv = tmp3;
298 iv2 = out;
299 len -= AES_BLOCK_SIZE;
300 }
301
302 /* And now forwards */
303 iv = ivec;
304 iv2 = ivec + AES_BLOCK_SIZE;
305 len = length;
306 while (len >= AES_BLOCK_SIZE)
307 {
308 memcpy(tmp, out, AES_BLOCK_SIZE);
309 memcpy(tmp2, out, AES_BLOCK_SIZE);
310 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
311 tmp[n] ^= iv2[n];
312 AES_decrypt(tmp, out, key);
313 for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
314 out[n] ^= iv[n];
315 memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
316 iv = tmp3;
317 iv2 = out;
318 len -= AES_BLOCK_SIZE;
319 in += AES_BLOCK_SIZE;
320 out += AES_BLOCK_SIZE;
321 }
322 }
323 }