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12 * Lesser General Public License for more details.
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19 #include "encryption_info.h"
21 #include "intreadwrite.h"
23 #define FF_ENCRYPTION_INFO_EXTRA 24
25 // The format of the AVEncryptionInfo side data:
27 // u32be crypt_byte_block
28 // u32be skip_byte_block
31 // u32be subsample_count
32 // u8[key_id_size] key_id
35 // u32be bytes_of_clear_data
36 // u32be bytes_of_protected_data
39 AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size)
41 AVEncryptionInfo *info;
43 info = av_mallocz(sizeof(*info));
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_mallocz_array(subsample_count, sizeof(*info->subsamples));
52 info->subsample_count = subsample_count;
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);
63 AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info)
65 AVEncryptionInfo *ret;
67 ret = av_encryption_info_alloc(info->subsample_count, info->key_id_size, info->iv_size);
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);
80 void av_encryption_info_free(AVEncryptionInfo *info)
83 av_free(info->key_id);
85 av_free(info->subsamples);
90 AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t* buffer, size_t size)
92 AVEncryptionInfo *info;
93 uint64_t key_id_size, iv_size, subsample_count, i;
95 if (!buffer || size < FF_ENCRYPTION_INFO_EXTRA)
98 key_id_size = AV_RB32(buffer + 12);
99 iv_size = AV_RB32(buffer + 16);
100 subsample_count = AV_RB32(buffer + 20);
102 if (size < FF_ENCRYPTION_INFO_EXTRA + key_id_size + iv_size + subsample_count * 8)
105 info = av_encryption_info_alloc(subsample_count, key_id_size, iv_size);
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);
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);
125 uint8_t *av_encryption_info_add_side_data(const AVEncryptionInfo *info, size_t *size)
127 uint8_t *buffer, *cur_buffer;
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) {
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);
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);
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);
162 // The format of the AVEncryptionInitInfo side data:
163 // u32be system_id_size
167 // u8[system_id_size] system_id
168 // u8[key_id_size][num_key_id] key_ids
169 // u8[data_size] data
171 #define FF_ENCRYPTION_INIT_INFO_EXTRA 16
173 AVEncryptionInitInfo *av_encryption_init_info_alloc(
174 uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size)
176 AVEncryptionInitInfo *info;
179 info = av_mallocz(sizeof(*info));
183 info->system_id = av_mallocz(system_id_size);
184 info->system_id_size = system_id_size;
185 info->key_ids = key_id_size ? av_mallocz_array(num_key_ids, sizeof(*info->key_ids)) : NULL;
186 info->num_key_ids = num_key_ids;
187 info->key_id_size = key_id_size;
188 info->data = av_mallocz(data_size);
189 info->data_size = data_size;
191 // Allow pointers to be NULL if the size is 0.
192 if ((!info->system_id && system_id_size) || (!info->data && data_size) ||
193 (!info->key_ids && num_key_ids && key_id_size)) {
194 av_encryption_init_info_free(info);
199 for (i = 0; i < num_key_ids; i++) {
200 info->key_ids[i] = av_mallocz(key_id_size);
201 if (!info->key_ids[i]) {
202 av_encryption_init_info_free(info);
211 void av_encryption_init_info_free(AVEncryptionInitInfo *info)
215 for (i = 0; i < info->num_key_ids; i++) {
216 av_free(info->key_ids[i]);
218 av_free(info->system_id);
219 av_free(info->key_ids);
225 AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
226 const uint8_t *side_data, size_t side_data_size)
228 AVEncryptionInitInfo *info;
229 uint64_t system_id_size, num_key_ids, key_id_size, data_size, i;
231 if (!side_data || side_data_size < FF_ENCRYPTION_INIT_INFO_EXTRA)
234 system_id_size = AV_RB32(side_data);
235 num_key_ids = AV_RB32(side_data + 4);
236 key_id_size = AV_RB32(side_data + 8);
237 data_size = AV_RB32(side_data + 12);
239 // UINT32_MAX + UINT32_MAX + UINT32_MAX * UINT32_MAX == UINT64_MAX
240 if (side_data_size - FF_ENCRYPTION_INIT_INFO_EXTRA < system_id_size + data_size + num_key_ids * key_id_size)
243 info = av_encryption_init_info_alloc(system_id_size, num_key_ids, key_id_size, data_size);
247 memcpy(info->system_id, side_data + 16, system_id_size);
248 side_data += system_id_size + 16;
249 for (i = 0; i < num_key_ids; i++) {
250 memcpy(info->key_ids[i], side_data, key_id_size);
251 side_data += key_id_size;
253 memcpy(info->data, side_data, data_size);
258 uint8_t *av_encryption_init_info_add_side_data(const AVEncryptionInitInfo *info, size_t *side_data_size)
260 uint8_t *buffer, *cur_buffer;
261 uint32_t i, max_size;
263 if (UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA < info->system_id_size ||
264 UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA - info->system_id_size < info->data_size) {
268 if (info->num_key_ids) {
269 max_size = UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA - info->system_id_size - info->data_size;
270 if (max_size / info->num_key_ids < info->key_id_size)
274 *side_data_size = FF_ENCRYPTION_INIT_INFO_EXTRA + info->system_id_size +
275 info->data_size + (info->num_key_ids * info->key_id_size);
276 cur_buffer = buffer = av_malloc(*side_data_size);
280 AV_WB32(cur_buffer, info->system_id_size);
281 AV_WB32(cur_buffer + 4, info->num_key_ids);
282 AV_WB32(cur_buffer + 8, info->key_id_size);
283 AV_WB32(cur_buffer + 12, info->data_size);
286 memcpy(cur_buffer, info->system_id, info->system_id_size);
287 cur_buffer += info->system_id_size;
288 for (i = 0; i < info->num_key_ids; i++) {
289 memcpy(cur_buffer, info->key_ids[i], info->key_id_size);
290 cur_buffer += info->key_id_size;
292 memcpy(cur_buffer, info->data, info->data_size);