Imported Debian version 2.5.0~trusty1.1
[deb_ffmpeg.git] / ffmpeg / libavutil / aes.c
1 /*
2 * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * some optimization ideas from aes128.c by Reimar Doeffinger
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "common.h"
24 #include "aes.h"
25 #include "intreadwrite.h"
26 #include "timer.h"
27
28 typedef union {
29 uint64_t u64[2];
30 uint32_t u32[4];
31 uint8_t u8x4[4][4];
32 uint8_t u8[16];
33 } av_aes_block;
34
35 typedef struct AVAES {
36 // Note: round_key[16] is accessed in the init code, but this only
37 // overwrites state, which does not matter (see also commit ba554c0).
38 av_aes_block round_key[15];
39 av_aes_block state[2];
40 int rounds;
41 } AVAES;
42
43 const int av_aes_size= sizeof(AVAES);
44
45 struct AVAES *av_aes_alloc(void)
46 {
47 return av_mallocz(sizeof(struct AVAES));
48 }
49
50 static const uint8_t rcon[10] = {
51 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
52 };
53
54 static uint8_t sbox[256];
55 static uint8_t inv_sbox[256];
56 #if CONFIG_SMALL
57 static uint32_t enc_multbl[1][256];
58 static uint32_t dec_multbl[1][256];
59 #else
60 static uint32_t enc_multbl[4][256];
61 static uint32_t dec_multbl[4][256];
62 #endif
63
64 #if HAVE_BIGENDIAN
65 # define ROT(x, s) ((x >> s) | (x << (32-s)))
66 #else
67 # define ROT(x, s) ((x << s) | (x >> (32-s)))
68 #endif
69
70 static inline void addkey(av_aes_block *dst, const av_aes_block *src,
71 const av_aes_block *round_key)
72 {
73 dst->u64[0] = src->u64[0] ^ round_key->u64[0];
74 dst->u64[1] = src->u64[1] ^ round_key->u64[1];
75 }
76
77 static inline void addkey_s(av_aes_block *dst, const uint8_t *src,
78 const av_aes_block *round_key)
79 {
80 dst->u64[0] = AV_RN64(src) ^ round_key->u64[0];
81 dst->u64[1] = AV_RN64(src + 8) ^ round_key->u64[1];
82 }
83
84 static inline void addkey_d(uint8_t *dst, const av_aes_block *src,
85 const av_aes_block *round_key)
86 {
87 AV_WN64(dst, src->u64[0] ^ round_key->u64[0]);
88 AV_WN64(dst + 8, src->u64[1] ^ round_key->u64[1]);
89 }
90
91 static void subshift(av_aes_block s0[2], int s, const uint8_t *box)
92 {
93 av_aes_block *s1 = (av_aes_block *) (s0[0].u8 - s);
94 av_aes_block *s3 = (av_aes_block *) (s0[0].u8 + s);
95
96 s0[0].u8[ 0] = box[s0[1].u8[ 0]];
97 s0[0].u8[ 4] = box[s0[1].u8[ 4]];
98 s0[0].u8[ 8] = box[s0[1].u8[ 8]];
99 s0[0].u8[12] = box[s0[1].u8[12]];
100 s1[0].u8[ 3] = box[s1[1].u8[ 7]];
101 s1[0].u8[ 7] = box[s1[1].u8[11]];
102 s1[0].u8[11] = box[s1[1].u8[15]];
103 s1[0].u8[15] = box[s1[1].u8[ 3]];
104 s0[0].u8[ 2] = box[s0[1].u8[10]];
105 s0[0].u8[10] = box[s0[1].u8[ 2]];
106 s0[0].u8[ 6] = box[s0[1].u8[14]];
107 s0[0].u8[14] = box[s0[1].u8[ 6]];
108 s3[0].u8[ 1] = box[s3[1].u8[13]];
109 s3[0].u8[13] = box[s3[1].u8[ 9]];
110 s3[0].u8[ 9] = box[s3[1].u8[ 5]];
111 s3[0].u8[ 5] = box[s3[1].u8[ 1]];
112 }
113
114 static inline int mix_core(uint32_t multbl[][256], int a, int b, int c, int d){
115 #if CONFIG_SMALL
116 return multbl[0][a] ^ ROT(multbl[0][b], 8) ^ ROT(multbl[0][c], 16) ^ ROT(multbl[0][d], 24);
117 #else
118 return multbl[0][a] ^ multbl[1][b] ^ multbl[2][c] ^ multbl[3][d];
119 #endif
120 }
121
122 static inline void mix(av_aes_block state[2], uint32_t multbl[][256], int s1, int s3){
123 uint8_t (*src)[4] = state[1].u8x4;
124 state[0].u32[0] = mix_core(multbl, src[0][0], src[s1 ][1], src[2][2], src[s3 ][3]);
125 state[0].u32[1] = mix_core(multbl, src[1][0], src[s3-1][1], src[3][2], src[s1-1][3]);
126 state[0].u32[2] = mix_core(multbl, src[2][0], src[s3 ][1], src[0][2], src[s1 ][3]);
127 state[0].u32[3] = mix_core(multbl, src[3][0], src[s1-1][1], src[1][2], src[s3-1][3]);
128 }
129
130 static inline void crypt(AVAES *a, int s, const uint8_t *sbox,
131 uint32_t multbl[][256])
132 {
133 int r;
134
135 for (r = a->rounds - 1; r > 0; r--) {
136 mix(a->state, multbl, 3 - s, 1 + s);
137 addkey(&a->state[1], &a->state[0], &a->round_key[r]);
138 }
139
140 subshift(&a->state[0], s, sbox);
141 }
142
143 void av_aes_crypt(AVAES *a, uint8_t *dst, const uint8_t *src,
144 int count, uint8_t *iv, int decrypt)
145 {
146 while (count--) {
147 addkey_s(&a->state[1], src, &a->round_key[a->rounds]);
148 if (decrypt) {
149 crypt(a, 0, inv_sbox, dec_multbl);
150 if (iv) {
151 addkey_s(&a->state[0], iv, &a->state[0]);
152 memcpy(iv, src, 16);
153 }
154 addkey_d(dst, &a->state[0], &a->round_key[0]);
155 } else {
156 if (iv)
157 addkey_s(&a->state[1], iv, &a->state[1]);
158 crypt(a, 2, sbox, enc_multbl);
159 addkey_d(dst, &a->state[0], &a->round_key[0]);
160 if (iv)
161 memcpy(iv, dst, 16);
162 }
163 src += 16;
164 dst += 16;
165 }
166 }
167
168 static void init_multbl2(uint32_t tbl[][256], const int c[4],
169 const uint8_t *log8, const uint8_t *alog8,
170 const uint8_t *sbox)
171 {
172 int i;
173
174 for (i = 0; i < 256; i++) {
175 int x = sbox[i];
176 if (x) {
177 int k, l, m, n;
178 x = log8[x];
179 k = alog8[x + log8[c[0]]];
180 l = alog8[x + log8[c[1]]];
181 m = alog8[x + log8[c[2]]];
182 n = alog8[x + log8[c[3]]];
183 tbl[0][i] = AV_NE(MKBETAG(k,l,m,n), MKTAG(k,l,m,n));
184 #if !CONFIG_SMALL
185 tbl[1][i] = ROT(tbl[0][i], 8);
186 tbl[2][i] = ROT(tbl[0][i], 16);
187 tbl[3][i] = ROT(tbl[0][i], 24);
188 #endif
189 }
190 }
191 }
192
193 // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
194 int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
195 {
196 int i, j, t, rconpointer = 0;
197 uint8_t tk[8][4];
198 int KC = key_bits >> 5;
199 int rounds = KC + 6;
200 uint8_t log8[256];
201 uint8_t alog8[512];
202
203 if (!enc_multbl[FF_ARRAY_ELEMS(enc_multbl)-1][FF_ARRAY_ELEMS(enc_multbl[0])-1]) {
204 j = 1;
205 for (i = 0; i < 255; i++) {
206 alog8[i] = alog8[i + 255] = j;
207 log8[j] = i;
208 j ^= j + j;
209 if (j > 255)
210 j ^= 0x11B;
211 }
212 for (i = 0; i < 256; i++) {
213 j = i ? alog8[255 - log8[i]] : 0;
214 j ^= (j << 1) ^ (j << 2) ^ (j << 3) ^ (j << 4);
215 j = (j ^ (j >> 8) ^ 99) & 255;
216 inv_sbox[j] = i;
217 sbox[i] = j;
218 }
219 init_multbl2(dec_multbl, (const int[4]) { 0xe, 0x9, 0xd, 0xb },
220 log8, alog8, inv_sbox);
221 init_multbl2(enc_multbl, (const int[4]) { 0x2, 0x1, 0x1, 0x3 },
222 log8, alog8, sbox);
223 }
224
225 if (key_bits != 128 && key_bits != 192 && key_bits != 256)
226 return -1;
227
228 a->rounds = rounds;
229
230 memcpy(tk, key, KC * 4);
231 memcpy(a->round_key[0].u8, key, KC * 4);
232
233 for (t = KC * 4; t < (rounds + 1) * 16; t += KC * 4) {
234 for (i = 0; i < 4; i++)
235 tk[0][i] ^= sbox[tk[KC - 1][(i + 1) & 3]];
236 tk[0][0] ^= rcon[rconpointer++];
237
238 for (j = 1; j < KC; j++) {
239 if (KC != 8 || j != KC >> 1)
240 for (i = 0; i < 4; i++)
241 tk[j][i] ^= tk[j - 1][i];
242 else
243 for (i = 0; i < 4; i++)
244 tk[j][i] ^= sbox[tk[j - 1][i]];
245 }
246
247 memcpy(a->round_key[0].u8 + t, tk, KC * 4);
248 }
249
250 if (decrypt) {
251 for (i = 1; i < rounds; i++) {
252 av_aes_block tmp[3];
253 tmp[2] = a->round_key[i];
254 subshift(&tmp[1], 0, sbox);
255 mix(tmp, dec_multbl, 1, 3);
256 a->round_key[i] = tmp[0];
257 }
258 } else {
259 for (i = 0; i < (rounds + 1) >> 1; i++) {
260 FFSWAP(av_aes_block, a->round_key[i], a->round_key[rounds-i]);
261 }
262 }
263
264 return 0;
265 }
266
267 #ifdef TEST
268 // LCOV_EXCL_START
269 #include <string.h>
270 #include "lfg.h"
271 #include "log.h"
272
273 int main(int argc, char **argv)
274 {
275 int i, j;
276 AVAES b;
277 uint8_t rkey[2][16] = {
278 { 0 },
279 { 0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3,
280 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59 }
281 };
282 uint8_t pt[16], rpt[2][16]= {
283 { 0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad,
284 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3 },
285 { 0 }
286 };
287 uint8_t rct[2][16]= {
288 { 0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7,
289 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf },
290 { 0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0,
291 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65 }
292 };
293 uint8_t temp[16];
294 int err = 0;
295
296 av_log_set_level(AV_LOG_DEBUG);
297
298 for (i = 0; i < 2; i++) {
299 av_aes_init(&b, rkey[i], 128, 1);
300 av_aes_crypt(&b, temp, rct[i], 1, NULL, 1);
301 for (j = 0; j < 16; j++) {
302 if (rpt[i][j] != temp[j]) {
303 av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n",
304 j, rpt[i][j], temp[j]);
305 err = 1;
306 }
307 }
308 }
309
310 if (argc > 1 && !strcmp(argv[1], "-t")) {
311 AVAES ae, ad;
312 AVLFG prng;
313
314 av_aes_init(&ae, "PI=3.141592654..", 128, 0);
315 av_aes_init(&ad, "PI=3.141592654..", 128, 1);
316 av_lfg_init(&prng, 1);
317
318 for (i = 0; i < 10000; i++) {
319 for (j = 0; j < 16; j++) {
320 pt[j] = av_lfg_get(&prng);
321 }
322 {
323 START_TIMER;
324 av_aes_crypt(&ae, temp, pt, 1, NULL, 0);
325 if (!(i & (i - 1)))
326 av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n",
327 temp[0], temp[5], temp[10], temp[15]);
328 av_aes_crypt(&ad, temp, temp, 1, NULL, 1);
329 STOP_TIMER("aes");
330 }
331 for (j = 0; j < 16; j++) {
332 if (pt[j] != temp[j]) {
333 av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n",
334 i, j, pt[j], temp[j]);
335 }
336 }
337 }
338 }
339 return err;
340 }
341 // LCOV_EXCL_STOP
342 #endif