1 /**
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "encryption_info.h"
20 #include "mem.h"
21 #include "intreadwrite.h"
22
23 #define FF_ENCRYPTION_INFO_EXTRA 24
24
25 // The format of the AVEncryptionInfo side data:
26 // u32be scheme
27 // u32be crypt_byte_block
28 // u32be skip_byte_block
29 // u32be key_id_size
30 // u32be iv_size
31 // u32be subsample_count
32 // u8[key_id_size] key_id
33 // u8[iv_size] iv
34 // {
35 // u32be bytes_of_clear_data
36 // u32be bytes_of_protected_data
37 // }[subsample_count]
38
av_encryption_info_alloc(uint32_t subsample_count,uint32_t key_id_size,uint32_t iv_size)39 AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size)
40 {
41 AVEncryptionInfo *info;
42
43 info = av_mallocz(sizeof(*info));
44 if (!info)
45 return NULL;
46
47 info->key_id = av_mallocz(key_id_size);
48 info->key_id_size = key_id_size;
49 info->iv = av_mallocz(iv_size);
50 info->iv_size = iv_size;
51 info->subsamples = av_calloc(subsample_count, sizeof(*info->subsamples));
52 info->subsample_count = subsample_count;
53
54 // Allow info->subsamples to be NULL if there are no subsamples.
55 if (!info->key_id || !info->iv || (!info->subsamples && subsample_count)) {
56 av_encryption_info_free(info);
57 return NULL;
58 }
59
60 return info;
61 }
62
av_encryption_info_clone(const AVEncryptionInfo * info)63 AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info)
64 {
65 AVEncryptionInfo *ret;
66
67 ret = av_encryption_info_alloc(info->subsample_count, info->key_id_size, info->iv_size);
68 if (!ret)
69 return NULL;
70
71 ret->scheme = info->scheme;
72 ret->crypt_byte_block = info->crypt_byte_block;
73 ret->skip_byte_block = info->skip_byte_block;
74 memcpy(ret->iv, info->iv, info->iv_size);
75 memcpy(ret->key_id, info->key_id, info->key_id_size);
76 memcpy(ret->subsamples, info->subsamples, sizeof(*info->subsamples) * info->subsample_count);
77 return ret;
78 }
79
av_encryption_info_free(AVEncryptionInfo * info)80 void av_encryption_info_free(AVEncryptionInfo *info)
81 {
82 if (info) {
83 av_free(info->key_id);
84 av_free(info->iv);
85 av_free(info->subsamples);
86 av_free(info);
87 }
88 }
89
av_encryption_info_get_side_data(const uint8_t * buffer,size_t size)90 AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t* buffer, size_t size)
91 {
92 AVEncryptionInfo *info;
93 uint64_t key_id_size, iv_size, subsample_count, i;
94
95 if (!buffer || size < FF_ENCRYPTION_INFO_EXTRA)
96 return NULL;
97
98 key_id_size = AV_RB32(buffer + 12);
99 iv_size = AV_RB32(buffer + 16);
100 subsample_count = AV_RB32(buffer + 20);
101
102 if (size < FF_ENCRYPTION_INFO_EXTRA + key_id_size + iv_size + subsample_count * 8)
103 return NULL;
104
105 info = av_encryption_info_alloc(subsample_count, key_id_size, iv_size);
106 if (!info)
107 return NULL;
108
109 info->scheme = AV_RB32(buffer);
110 info->crypt_byte_block = AV_RB32(buffer + 4);
111 info->skip_byte_block = AV_RB32(buffer + 8);
112 memcpy(info->key_id, buffer + 24, key_id_size);
113 memcpy(info->iv, buffer + key_id_size + 24, iv_size);
114
115 buffer += key_id_size + iv_size + 24;
116 for (i = 0; i < subsample_count; i++) {
117 info->subsamples[i].bytes_of_clear_data = AV_RB32(buffer);
118 info->subsamples[i].bytes_of_protected_data = AV_RB32(buffer + 4);
119 buffer += 8;
120 }
121
122 return info;
123 }
124
av_encryption_info_add_side_data(const AVEncryptionInfo * info,size_t * size)125 uint8_t *av_encryption_info_add_side_data(const AVEncryptionInfo *info, size_t *size)
126 {
127 uint8_t *buffer, *cur_buffer;
128 uint32_t i;
129
130 if (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA < info->key_id_size ||
131 UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size < info->iv_size ||
132 (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size - info->iv_size) / 8 < info->subsample_count) {
133 return NULL;
134 }
135
136 *size = FF_ENCRYPTION_INFO_EXTRA + info->key_id_size + info->iv_size +
137 (info->subsample_count * 8);
138 cur_buffer = buffer = av_malloc(*size);
139 if (!buffer)
140 return NULL;
141
142 AV_WB32(cur_buffer, info->scheme);
143 AV_WB32(cur_buffer + 4, info->crypt_byte_block);
144 AV_WB32(cur_buffer + 8, info->skip_byte_block);
145 AV_WB32(cur_buffer + 12, info->key_id_size);
146 AV_WB32(cur_buffer + 16, info->iv_size);
147 AV_WB32(cur_buffer + 20, info->subsample_count);
148 cur_buffer += 24;
149 memcpy(cur_buffer, info->key_id, info->key_id_size);
150 cur_buffer += info->key_id_size;
151 memcpy(cur_buffer, info->iv, info->iv_size);
152 cur_buffer += info->iv_size;
153 for (i = 0; i < info->subsample_count; i++) {
154 AV_WB32(cur_buffer, info->subsamples[i].bytes_of_clear_data);
155 AV_WB32(cur_buffer + 4, info->subsamples[i].bytes_of_protected_data);
156 cur_buffer += 8;
157 }
158
159 return buffer;
160 }
161
162 #ifdef OHOS_DRM
av_encryption_info_set_drm_algo(uint32_t algo,AV_DrmCencInfo * cenc_info)163 static void av_encryption_info_set_drm_algo(uint32_t algo, AV_DrmCencInfo *cenc_info)
164 {
165 switch (algo) {
166 case MKBETAG('c','e','n','c'):
167 case MKBETAG('c','e','n','s'):
168 cenc_info->algo = AV_DRM_ALG_CENC_AES_CTR;
169 break;
170 case MKBETAG('c','b','c','1'):
171 case MKBETAG('c','b','c','s'):
172 cenc_info->algo = AV_DRM_ALG_CENC_AES_CBC;
173 break;
174 case MKBETAG('s','m','4','c'):
175 case MKBETAG('s','m','4','s'):
176 cenc_info->algo = AV_DRM_ALG_CENC_SM4_CBC;
177 break;
178 case MKBETAG('s','m','4','t'):
179 case MKBETAG('s','m','4','r'):
180 cenc_info->algo = AV_DRM_ALG_CENC_SM4_CTR;
181 break;
182 default:
183 cenc_info->algo = AV_DRM_ALG_CENC_UNENCRYPTED;
184 break;
185 }
186 return;
187 }
188
av_encryption_info_add_side_data_ex(const AVEncryptionInfo * info,size_t * side_data_size,AV_DrmCencInfo * cenc_info)189 AV_DrmCencInfo *av_encryption_info_add_side_data_ex(const AVEncryptionInfo *info, size_t *side_data_size,
190 AV_DrmCencInfo *cenc_info)
191 {
192 uint32_t i;
193 if ((info == NULL) || (info->key_id_size != AV_DRM_KEY_ID_SIZE) || (info->iv_size > AV_DRM_IV_SIZE) ||
194 (info->iv_size == 0) || (info->subsample_count > AV_DRM_MAX_SUB_SAMPLE_NUM) || (info->key_id == NULL) ||
195 (info->iv == NULL) || (info->subsamples == NULL) || (side_data_size == NULL)) {
196 return NULL;
197 }
198
199 *side_data_size = sizeof(AV_DrmCencInfo);
200 cenc_info = av_mallocz(*side_data_size);
201 if (!cenc_info)
202 return NULL;
203
204 av_encryption_info_set_drm_algo(info->scheme, cenc_info);
205 cenc_info->key_id_len = info->key_id_size;
206 memcpy(cenc_info->key_id, info->key_id, info->key_id_size);
207 cenc_info->iv_len = info->iv_size;
208 memcpy(cenc_info->iv, info->iv, info->iv_size);
209 cenc_info->mode = AV_DRM_CENC_INFO_KEY_IV_SUBSAMPLES_SET;
210 cenc_info->encrypt_blocks = info->crypt_byte_block;
211 cenc_info->skip_blocks = info->skip_byte_block;
212 cenc_info->first_encrypt_offset = 0;
213 cenc_info->sub_sample_num = info->subsample_count;
214
215 for (i = 0; i < cenc_info->sub_sample_num; i++) {
216 cenc_info->sub_samples[i].clear_header_len = info->subsamples[i].bytes_of_clear_data;
217 cenc_info->sub_samples[i].pay_load_len = info->subsamples[i].bytes_of_protected_data;
218 }
219 return cenc_info;
220 }
221 #endif
222
223 // The format of the AVEncryptionInitInfo side data:
224 // u32be init_info_count
225 // {
226 // u32be system_id_size
227 // u32be num_key_ids
228 // u32be key_id_size
229 // u32be data_size
230 // u8[system_id_size] system_id
231 // u8[key_id_size][num_key_id] key_ids
232 // u8[data_size] data
233 // }[init_info_count]
234
235 #define FF_ENCRYPTION_INIT_INFO_EXTRA 16
236
av_encryption_init_info_alloc(uint32_t system_id_size,uint32_t num_key_ids,uint32_t key_id_size,uint32_t data_size)237 AVEncryptionInitInfo *av_encryption_init_info_alloc(
238 uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size)
239 {
240 AVEncryptionInitInfo *info;
241 uint32_t i;
242
243 info = av_mallocz(sizeof(*info));
244 if (!info)
245 return NULL;
246
247 info->system_id = av_mallocz(system_id_size);
248 info->system_id_size = system_id_size;
249 info->key_ids = key_id_size ? av_calloc(num_key_ids, sizeof(*info->key_ids)) : NULL;
250 info->num_key_ids = num_key_ids;
251 info->key_id_size = key_id_size;
252 info->data = av_mallocz(data_size);
253 info->data_size = data_size;
254
255 // Allow pointers to be NULL if the size is 0.
256 if ((!info->system_id && system_id_size) || (!info->data && data_size) ||
257 (!info->key_ids && num_key_ids && key_id_size)) {
258 av_encryption_init_info_free(info);
259 return NULL;
260 }
261
262 if (key_id_size) {
263 for (i = 0; i < num_key_ids; i++) {
264 info->key_ids[i] = av_mallocz(key_id_size);
265 if (!info->key_ids[i]) {
266 av_encryption_init_info_free(info);
267 return NULL;
268 }
269 }
270 }
271
272 return info;
273 }
274
av_encryption_init_info_free(AVEncryptionInitInfo * info)275 void av_encryption_init_info_free(AVEncryptionInitInfo *info)
276 {
277 uint32_t i;
278 if (info) {
279 for (i = 0; i < info->num_key_ids; i++) {
280 av_free(info->key_ids[i]);
281 }
282 av_encryption_init_info_free(info->next);
283 av_free(info->system_id);
284 av_free(info->key_ids);
285 av_free(info->data);
286 av_free(info);
287 }
288 }
289
av_encryption_init_info_get_side_data(const uint8_t * side_data,size_t side_data_size)290 AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
291 const uint8_t *side_data, size_t side_data_size)
292 {
293 // |ret| tracks the front of the list, |info| tracks the back.
294 AVEncryptionInitInfo *ret = NULL, *info, *temp_info;
295 uint64_t system_id_size, num_key_ids, key_id_size, data_size, i, j;
296 uint64_t init_info_count;
297
298 if (!side_data || side_data_size < 4)
299 return NULL;
300
301 init_info_count = AV_RB32(side_data);
302 side_data += 4;
303 side_data_size -= 4;
304 for (i = 0; i < init_info_count; i++) {
305 if (side_data_size < FF_ENCRYPTION_INIT_INFO_EXTRA) {
306 av_encryption_init_info_free(ret);
307 return NULL;
308 }
309
310 system_id_size = AV_RB32(side_data);
311 num_key_ids = AV_RB32(side_data + 4);
312 key_id_size = AV_RB32(side_data + 8);
313 data_size = AV_RB32(side_data + 12);
314
315 // UINT32_MAX + UINT32_MAX + UINT32_MAX * UINT32_MAX == UINT64_MAX
316 if (side_data_size - FF_ENCRYPTION_INIT_INFO_EXTRA < system_id_size + data_size + num_key_ids * key_id_size) {
317 av_encryption_init_info_free(ret);
318 return NULL;
319 }
320 side_data += FF_ENCRYPTION_INIT_INFO_EXTRA;
321 side_data_size -= FF_ENCRYPTION_INIT_INFO_EXTRA;
322
323 temp_info = av_encryption_init_info_alloc(system_id_size, num_key_ids, key_id_size, data_size);
324 if (!temp_info) {
325 av_encryption_init_info_free(ret);
326 return NULL;
327 }
328 if (i == 0) {
329 info = ret = temp_info;
330 } else {
331 info->next = temp_info;
332 info = temp_info;
333 }
334
335 memcpy(info->system_id, side_data, system_id_size);
336 side_data += system_id_size;
337 side_data_size -= system_id_size;
338 for (j = 0; j < num_key_ids; j++) {
339 memcpy(info->key_ids[j], side_data, key_id_size);
340 side_data += key_id_size;
341 side_data_size -= key_id_size;
342 }
343 memcpy(info->data, side_data, data_size);
344 side_data += data_size;
345 side_data_size -= data_size;
346 }
347
348 return ret;
349 }
350
av_encryption_init_info_add_side_data(const AVEncryptionInitInfo * info,size_t * side_data_size)351 uint8_t *av_encryption_init_info_add_side_data(const AVEncryptionInitInfo *info, size_t *side_data_size)
352 {
353 const AVEncryptionInitInfo *cur_info;
354 uint8_t *buffer, *cur_buffer;
355 uint32_t i, init_info_count;
356 uint64_t temp_side_data_size;
357
358 temp_side_data_size = 4;
359 init_info_count = 0;
360 for (cur_info = info; cur_info; cur_info = cur_info->next) {
361 temp_side_data_size += (uint64_t)FF_ENCRYPTION_INIT_INFO_EXTRA + cur_info->system_id_size + cur_info->data_size;
362 if (init_info_count == UINT32_MAX || temp_side_data_size > UINT32_MAX) {
363 return NULL;
364 }
365 init_info_count++;
366
367 if (cur_info->num_key_ids) {
368 temp_side_data_size += (uint64_t)cur_info->num_key_ids * cur_info->key_id_size;
369 if (temp_side_data_size > UINT32_MAX) {
370 return NULL;
371 }
372 }
373 }
374 *side_data_size = temp_side_data_size;
375
376 cur_buffer = buffer = av_malloc(*side_data_size);
377 if (!buffer)
378 return NULL;
379
380 AV_WB32(cur_buffer, init_info_count);
381 cur_buffer += 4;
382 for (cur_info = info; cur_info; cur_info = cur_info->next) {
383 AV_WB32(cur_buffer, cur_info->system_id_size);
384 AV_WB32(cur_buffer + 4, cur_info->num_key_ids);
385 AV_WB32(cur_buffer + 8, cur_info->key_id_size);
386 AV_WB32(cur_buffer + 12, cur_info->data_size);
387 cur_buffer += 16;
388
389 memcpy(cur_buffer, cur_info->system_id, cur_info->system_id_size);
390 cur_buffer += cur_info->system_id_size;
391 for (i = 0; i < cur_info->num_key_ids; i++) {
392 memcpy(cur_buffer, cur_info->key_ids[i], cur_info->key_id_size);
393 cur_buffer += cur_info->key_id_size;
394 }
395 if (cur_info->data_size > 0) {
396 memcpy(cur_buffer, cur_info->data, cur_info->data_size);
397 cur_buffer += cur_info->data_size;
398 }
399 }
400
401 return buffer;
402 }
403