FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavutil/encryption_info.c
Date: 2026-04-19 20:43:40
Exec Total Coverage
Lines: 160 184 87.0%
Functions: 9 9 100.0%
Branches: 56 96 58.3%
Line Branch Exec Source
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 <string.h>
20
21 #include "encryption_info.h"
22 #include "mem.h"
23 #include "intreadwrite.h"
24
25 #define FF_ENCRYPTION_INFO_EXTRA 24
26
27 // The format of the AVEncryptionInfo side data:
28 // u32be scheme
29 // u32be crypt_byte_block
30 // u32be skip_byte_block
31 // u32be key_id_size
32 // u32be iv_size
33 // u32be subsample_count
34 // u8[key_id_size] key_id
35 // u8[iv_size] iv
36 // {
37 // u32be bytes_of_clear_data
38 // u32be bytes_of_protected_data
39 // }[subsample_count]
40
41 153 AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size)
42 {
43 AVEncryptionInfo *info;
44
45 153 info = av_mallocz(sizeof(*info));
46
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 153 if (!info)
47 ✗ return NULL;
48
49 153 info->key_id = av_mallocz(key_id_size);
50 153 info->key_id_size = key_id_size;
51 153 info->iv = av_mallocz(iv_size);
52 153 info->iv_size = iv_size;
53 153 info->subsamples = av_calloc(subsample_count, sizeof(*info->subsamples));
54 153 info->subsample_count = subsample_count;
55
56 // Allow info->subsamples to be NULL if there are no subsamples.
57
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 153 if (!info->key_id || !info->iv || (!info->subsamples && subsample_count)) {
58 ✗ av_encryption_info_free(info);
59 ✗ return NULL;
60 }
61
62 153 return info;
63 }
64
65 145 AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info)
66 {
67 AVEncryptionInfo *ret;
68
69 145 ret = av_encryption_info_alloc(info->subsample_count, info->key_id_size, info->iv_size);
70
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 145 if (!ret)
71 ✗ return NULL;
72
73 145 ret->scheme = info->scheme;
74 145 ret->crypt_byte_block = info->crypt_byte_block;
75 145 ret->skip_byte_block = info->skip_byte_block;
76 145 memcpy(ret->iv, info->iv, info->iv_size);
77 145 memcpy(ret->key_id, info->key_id, info->key_id_size);
78 145 memcpy(ret->subsamples, info->subsamples, sizeof(*info->subsamples) * info->subsample_count);
79 145 return ret;
80 }
81
82 831 void av_encryption_info_free(AVEncryptionInfo *info)
83 {
84
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 831 if (info) {
85 153 av_free(info->key_id);
86 153 av_free(info->iv);
87 153 av_free(info->subsamples);
88 153 av_free(info);
89 }
90 831 }
91
92 1 AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t* buffer, size_t size)
93 {
94 AVEncryptionInfo *info;
95 uint64_t key_id_size, iv_size, subsample_count, i;
96
97
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 1 if (!buffer || size < FF_ENCRYPTION_INFO_EXTRA)
98 ✗ return NULL;
99
100 1 key_id_size = AV_RB32(buffer + 12);
101 1 iv_size = AV_RB32(buffer + 16);
102 1 subsample_count = AV_RB32(buffer + 20);
103
104
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 1 if (size < FF_ENCRYPTION_INFO_EXTRA + key_id_size + iv_size + subsample_count * 8)
105 ✗ return NULL;
106
107 1 info = av_encryption_info_alloc(subsample_count, key_id_size, iv_size);
108
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 1 if (!info)
109 ✗ return NULL;
110
111 1 info->scheme = AV_RB32(buffer);
112 1 info->crypt_byte_block = AV_RB32(buffer + 4);
113 1 info->skip_byte_block = AV_RB32(buffer + 8);
114 1 memcpy(info->key_id, buffer + 24, key_id_size);
115 1 memcpy(info->iv, buffer + key_id_size + 24, iv_size);
116
117 1 buffer += key_id_size + iv_size + 24;
118
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 5 for (i = 0; i < subsample_count; i++) {
119 4 info->subsamples[i].bytes_of_clear_data = AV_RB32(buffer);
120 4 info->subsamples[i].bytes_of_protected_data = AV_RB32(buffer + 4);
121 4 buffer += 8;
122 }
123
124 1 return info;
125 }
126
127 1 uint8_t *av_encryption_info_add_side_data(const AVEncryptionInfo *info, size_t *size)
128 {
129 uint8_t *buffer, *cur_buffer;
130 uint32_t i;
131
132
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 1 if (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA < info->key_id_size ||
133
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 1 UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size < info->iv_size ||
134
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 1 (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size - info->iv_size) / 8 < info->subsample_count) {
135 ✗ return NULL;
136 }
137
138 1 *size = FF_ENCRYPTION_INFO_EXTRA + info->key_id_size + info->iv_size +
139 1 (info->subsample_count * 8);
140 1 cur_buffer = buffer = av_malloc(*size);
141
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 1 if (!buffer)
142 ✗ return NULL;
143
144 1 AV_WB32(cur_buffer, info->scheme);
145 1 AV_WB32(cur_buffer + 4, info->crypt_byte_block);
146 1 AV_WB32(cur_buffer + 8, info->skip_byte_block);
147 1 AV_WB32(cur_buffer + 12, info->key_id_size);
148 1 AV_WB32(cur_buffer + 16, info->iv_size);
149 1 AV_WB32(cur_buffer + 20, info->subsample_count);
150 1 cur_buffer += 24;
151 1 memcpy(cur_buffer, info->key_id, info->key_id_size);
152 1 cur_buffer += info->key_id_size;
153 1 memcpy(cur_buffer, info->iv, info->iv_size);
154 1 cur_buffer += info->iv_size;
155
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 5 for (i = 0; i < info->subsample_count; i++) {
156 4 AV_WB32(cur_buffer, info->subsamples[i].bytes_of_clear_data);
157 4 AV_WB32(cur_buffer + 4, info->subsamples[i].bytes_of_protected_data);
158 4 cur_buffer += 8;
159 }
160
161 1 return buffer;
162 }
163
164 // The format of the AVEncryptionInitInfo side data:
165 // u32be init_info_count
166 // {
167 // u32be system_id_size
168 // u32be num_key_ids
169 // u32be key_id_size
170 // u32be data_size
171 // u8[system_id_size] system_id
172 // u8[key_id_size][num_key_id] key_ids
173 // u8[data_size] data
174 // }[init_info_count]
175
176 #define FF_ENCRYPTION_INIT_INFO_EXTRA 16
177
178 9 AVEncryptionInitInfo *av_encryption_init_info_alloc(
179 uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size)
180 {
181 AVEncryptionInitInfo *info;
182 uint32_t i;
183
184 9 info = av_mallocz(sizeof(*info));
185
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 9 if (!info)
186 ✗ return NULL;
187
188 9 info->system_id = av_mallocz(system_id_size);
189 9 info->system_id_size = system_id_size;
190
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 9 info->key_ids = key_id_size ? av_calloc(num_key_ids, sizeof(*info->key_ids)) : NULL;
191 9 info->num_key_ids = num_key_ids;
192 9 info->key_id_size = key_id_size;
193 9 info->data = av_mallocz(data_size);
194 9 info->data_size = data_size;
195
196 // Allow pointers to be NULL if the size is 0.
197
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 9 if ((!info->system_id && system_id_size) || (!info->data && data_size) ||
198
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 9 (!info->key_ids && num_key_ids && key_id_size)) {
199 ✗ av_encryption_init_info_free(info);
200 ✗ return NULL;
201 }
202
203
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 9 if (key_id_size) {
204
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 19 for (i = 0; i < num_key_ids; i++) {
205 10 info->key_ids[i] = av_mallocz(key_id_size);
206
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 10 if (!info->key_ids[i]) {
207 ✗ av_encryption_init_info_free(info);
208 ✗ return NULL;
209 }
210 }
211 }
212
213 9 return info;
214 }
215
216 16 void av_encryption_init_info_free(AVEncryptionInitInfo *info)
217 {
218 uint32_t i;
219
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 16 if (info) {
220
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 23 for (i = 0; i < info->num_key_ids; i++) {
221 14 av_free(info->key_ids[i]);
222 }
223 9 av_encryption_init_info_free(info->next);
224 9 av_free(info->system_id);
225 9 av_free(info->key_ids);
226 9 av_free(info->data);
227 9 av_free(info);
228 }
229 16 }
230
231 2 AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
232 const uint8_t *side_data, size_t side_data_size)
233 {
234 // |ret| tracks the front of the list, |info| tracks the back.
235 2 AVEncryptionInitInfo *ret = NULL, *info, *temp_info;
236 uint64_t system_id_size, num_key_ids, key_id_size, data_size, i, j;
237 uint64_t init_info_count;
238
239
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 2 if (!side_data || side_data_size < 4)
240 ✗ return NULL;
241
242 2 init_info_count = AV_RB32(side_data);
243 2 side_data += 4;
244 2 side_data_size -= 4;
245
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 5 for (i = 0; i < init_info_count; i++) {
246
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 3 if (side_data_size < FF_ENCRYPTION_INIT_INFO_EXTRA) {
247 ✗ av_encryption_init_info_free(ret);
248 ✗ return NULL;
249 }
250
251 3 system_id_size = AV_RB32(side_data);
252 3 num_key_ids = AV_RB32(side_data + 4);
253 3 key_id_size = AV_RB32(side_data + 8);
254 3 data_size = AV_RB32(side_data + 12);
255
256 // UINT32_MAX + UINT32_MAX + UINT32_MAX * UINT32_MAX == UINT64_MAX
257
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 3 if (side_data_size - FF_ENCRYPTION_INIT_INFO_EXTRA < system_id_size + data_size + num_key_ids * key_id_size) {
258 ✗ av_encryption_init_info_free(ret);
259 ✗ return NULL;
260 }
261 3 side_data += FF_ENCRYPTION_INIT_INFO_EXTRA;
262 3 side_data_size -= FF_ENCRYPTION_INIT_INFO_EXTRA;
263
264 3 temp_info = av_encryption_init_info_alloc(system_id_size, num_key_ids, key_id_size, data_size);
265
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 3 if (!temp_info) {
266 ✗ av_encryption_init_info_free(ret);
267 ✗ return NULL;
268 }
269
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 3 if (i == 0) {
270 2 info = ret = temp_info;
271 } else {
272 1 info->next = temp_info;
273 1 info = temp_info;
274 }
275
276 3 memcpy(info->system_id, side_data, system_id_size);
277 3 side_data += system_id_size;
278 3 side_data_size -= system_id_size;
279
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 9 for (j = 0; j < num_key_ids; j++) {
280 6 memcpy(info->key_ids[j], side_data, key_id_size);
281 6 side_data += key_id_size;
282 6 side_data_size -= key_id_size;
283 }
284 3 memcpy(info->data, side_data, data_size);
285 3 side_data += data_size;
286 3 side_data_size -= data_size;
287 }
288
289 2 return ret;
290 }
291
292 6 uint8_t *av_encryption_init_info_add_side_data(const AVEncryptionInitInfo *info, size_t *side_data_size)
293 {
294 const AVEncryptionInitInfo *cur_info;
295 uint8_t *buffer, *cur_buffer;
296 uint32_t i, init_info_count;
297 uint64_t temp_side_data_size;
298
299 6 temp_side_data_size = 4;
300 6 init_info_count = 0;
301
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 13 for (cur_info = info; cur_info; cur_info = cur_info->next) {
302 7 temp_side_data_size += (uint64_t)FF_ENCRYPTION_INIT_INFO_EXTRA + cur_info->system_id_size + cur_info->data_size;
303
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 7 if (init_info_count == UINT32_MAX || temp_side_data_size > UINT32_MAX) {
304 ✗ return NULL;
305 }
306 7 init_info_count++;
307
308
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 7 if (cur_info->num_key_ids) {
309 7 temp_side_data_size += (uint64_t)cur_info->num_key_ids * cur_info->key_id_size;
310
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 7 if (temp_side_data_size > UINT32_MAX) {
311 ✗ return NULL;
312 }
313 }
314 }
315 6 *side_data_size = temp_side_data_size;
316
317 6 cur_buffer = buffer = av_malloc(*side_data_size);
318
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 6 if (!buffer)
319 ✗ return NULL;
320
321 6 AV_WB32(cur_buffer, init_info_count);
322 6 cur_buffer += 4;
323
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 13 for (cur_info = info; cur_info; cur_info = cur_info->next) {
324 7 AV_WB32(cur_buffer, cur_info->system_id_size);
325 7 AV_WB32(cur_buffer + 4, cur_info->num_key_ids);
326 7 AV_WB32(cur_buffer + 8, cur_info->key_id_size);
327 7 AV_WB32(cur_buffer + 12, cur_info->data_size);
328 7 cur_buffer += 16;
329
330 7 memcpy(cur_buffer, cur_info->system_id, cur_info->system_id_size);
331 7 cur_buffer += cur_info->system_id_size;
332
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 17 for (i = 0; i < cur_info->num_key_ids; i++) {
333 10 memcpy(cur_buffer, cur_info->key_ids[i], cur_info->key_id_size);
334 10 cur_buffer += cur_info->key_id_size;
335 }
336
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 7 if (cur_info->data_size > 0) {
337 3 memcpy(cur_buffer, cur_info->data, cur_info->data_size);
338 3 cur_buffer += cur_info->data_size;
339 }
340 }
341
342 6 return buffer;
343 }
344