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 | } |
324 | |