encryption_info.h (7056B)
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 #ifndef AVUTIL_ENCRYPTION_INFO_H 20 #define AVUTIL_ENCRYPTION_INFO_H 21 22 #include <stddef.h> 23 #include <stdint.h> 24 25 typedef struct AVSubsampleEncryptionInfo { 26 /** The number of bytes that are clear. */ 27 unsigned int bytes_of_clear_data; 28 29 /** 30 * The number of bytes that are protected. If using pattern encryption, 31 * the pattern applies to only the protected bytes; if not using pattern 32 * encryption, all these bytes are encrypted. 33 */ 34 unsigned int bytes_of_protected_data; 35 } AVSubsampleEncryptionInfo; 36 37 /** 38 * This describes encryption info for a packet. This contains frame-specific 39 * info for how to decrypt the packet before passing it to the decoder. 40 * 41 * The size of this struct is not part of the public ABI. 42 */ 43 typedef struct AVEncryptionInfo { 44 /** The fourcc encryption scheme, in big-endian byte order. */ 45 uint32_t scheme; 46 47 /** 48 * Only used for pattern encryption. This is the number of 16-byte blocks 49 * that are encrypted. 50 */ 51 uint32_t crypt_byte_block; 52 53 /** 54 * Only used for pattern encryption. This is the number of 16-byte blocks 55 * that are clear. 56 */ 57 uint32_t skip_byte_block; 58 59 /** 60 * The ID of the key used to encrypt the packet. This should always be 61 * 16 bytes long, but may be changed in the future. 62 */ 63 uint8_t *key_id; 64 uint32_t key_id_size; 65 66 /** 67 * The initialization vector. This may have been zero-filled to be the 68 * correct block size. This should always be 16 bytes long, but may be 69 * changed in the future. 70 */ 71 uint8_t *iv; 72 uint32_t iv_size; 73 74 /** 75 * An array of subsample encryption info specifying how parts of the sample 76 * are encrypted. If there are no subsamples, then the whole sample is 77 * encrypted. 78 */ 79 AVSubsampleEncryptionInfo *subsamples; 80 uint32_t subsample_count; 81 } AVEncryptionInfo; 82 83 /** 84 * This describes info used to initialize an encryption key system. 85 * 86 * The size of this struct is not part of the public ABI. 87 */ 88 typedef struct AVEncryptionInitInfo { 89 /** 90 * A unique identifier for the key system this is for, can be NULL if it 91 * is not known. This should always be 16 bytes, but may change in the 92 * future. 93 */ 94 uint8_t* system_id; 95 uint32_t system_id_size; 96 97 /** 98 * An array of key IDs this initialization data is for. All IDs are the 99 * same length. Can be NULL if there are no known key IDs. 100 */ 101 uint8_t** key_ids; 102 /** The number of key IDs. */ 103 uint32_t num_key_ids; 104 /** 105 * The number of bytes in each key ID. This should always be 16, but may 106 * change in the future. 107 */ 108 uint32_t key_id_size; 109 110 /** 111 * Key-system specific initialization data. This data is copied directly 112 * from the file and the format depends on the specific key system. This 113 * can be NULL if there is no initialization data; in that case, there 114 * will be at least one key ID. 115 */ 116 uint8_t* data; 117 uint32_t data_size; 118 119 /** 120 * An optional pointer to the next initialization info in the list. 121 */ 122 struct AVEncryptionInitInfo *next; 123 } AVEncryptionInitInfo; 124 125 /** 126 * Allocates an AVEncryptionInfo structure and sub-pointers to hold the given 127 * number of subsamples. This will allocate pointers for the key ID, IV, 128 * and subsample entries, set the size members, and zero-initialize the rest. 129 * 130 * @param subsample_count The number of subsamples. 131 * @param key_id_size The number of bytes in the key ID, should be 16. 132 * @param iv_size The number of bytes in the IV, should be 16. 133 * 134 * @return The new AVEncryptionInfo structure, or NULL on error. 135 */ 136 AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size); 137 138 /** 139 * Allocates an AVEncryptionInfo structure with a copy of the given data. 140 * @return The new AVEncryptionInfo structure, or NULL on error. 141 */ 142 AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info); 143 144 /** 145 * Frees the given encryption info object. This MUST NOT be used to free the 146 * side-data data pointer, that should use normal side-data methods. 147 */ 148 void av_encryption_info_free(AVEncryptionInfo *info); 149 150 /** 151 * Creates a copy of the AVEncryptionInfo that is contained in the given side 152 * data. The resulting object should be passed to av_encryption_info_free() 153 * when done. 154 * 155 * @return The new AVEncryptionInfo structure, or NULL on error. 156 */ 157 AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t *side_data, size_t side_data_size); 158 159 /** 160 * Allocates and initializes side data that holds a copy of the given encryption 161 * info. The resulting pointer should be either freed using av_free or given 162 * to av_packet_add_side_data(). 163 * 164 * @return The new side-data pointer, or NULL. 165 */ 166 uint8_t *av_encryption_info_add_side_data( 167 const AVEncryptionInfo *info, size_t *side_data_size); 168 169 170 /** 171 * Allocates an AVEncryptionInitInfo structure and sub-pointers to hold the 172 * given sizes. This will allocate pointers and set all the fields. 173 * 174 * @return The new AVEncryptionInitInfo structure, or NULL on error. 175 */ 176 AVEncryptionInitInfo *av_encryption_init_info_alloc( 177 uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size); 178 179 /** 180 * Frees the given encryption init info object. This MUST NOT be used to free 181 * the side-data data pointer, that should use normal side-data methods. 182 */ 183 void av_encryption_init_info_free(AVEncryptionInitInfo* info); 184 185 /** 186 * Creates a copy of the AVEncryptionInitInfo that is contained in the given 187 * side data. The resulting object should be passed to 188 * av_encryption_init_info_free() when done. 189 * 190 * @return The new AVEncryptionInitInfo structure, or NULL on error. 191 */ 192 AVEncryptionInitInfo *av_encryption_init_info_get_side_data( 193 const uint8_t* side_data, size_t side_data_size); 194 195 /** 196 * Allocates and initializes side data that holds a copy of the given encryption 197 * init info. The resulting pointer should be either freed using av_free or 198 * given to av_packet_add_side_data(). 199 * 200 * @return The new side-data pointer, or NULL. 201 */ 202 uint8_t *av_encryption_init_info_add_side_data( 203 const AVEncryptionInitInfo *info, size_t *side_data_size); 204 205 #endif /* AVUTIL_ENCRYPTION_INFO_H */