/**
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_ENCRYPTION_INFO_H
#define AVUTIL_ENCRYPTION_INFO_H
#include <stddef.h>
#include <stdint.h>
typedef struct AVSubsampleEncryptionInfo {
/** The number of bytes that are clear. */
unsigned int bytes_of_clear_data;
/**
* The number of bytes that are protected. If using pattern encryption,
* the pattern applies to only the protected bytes; if not using pattern
* encryption, all these bytes are encrypted.
*/
unsigned int bytes_of_protected_data;
} AVSubsampleEncryptionInfo;
/**
* This describes encryption info for a packet. This contains frame-specific
* info for how to decrypt the packet before passing it to the decoder.
*
* The size of this struct is not part of the public ABI.
*/
typedef struct AVEncryptionInfo {
/** The fourcc encryption scheme, in big-endian byte order. */
uint32_t scheme;
/**
* Only used for pattern encryption. This is the number of 16-byte blocks
* that are encrypted.
*/
uint32_t crypt_byte_block;
/**
* Only used for pattern encryption. This is the number of 16-byte blocks
* that are clear.
*/
uint32_t skip_byte_block;
/**
* The ID of the key used to encrypt the packet. This should always be
* 16 bytes long, but may be changed in the future.
*/
uint8_t *key_id;
uint32_t key_id_size;
/**
* The initialization vector. This may have been zero-filled to be the
* correct block size. This should always be 16 bytes long, but may be
* changed in the future.
*/
uint8_t *iv;
uint32_t iv_size;
/**
* An array of subsample encryption info specifying how parts of the sample
* are encrypted. If there are no subsamples, then the whole sample is
* encrypted.
*/
AVSubsampleEncryptionInfo *subsamples;
uint32_t subsample_count;
} AVEncryptionInfo;
/**
* This describes info used to initialize an encryption key system.
*
* The size of this struct is not part of the public ABI.
*/
typedef struct AVEncryptionInitInfo {
/**
* A unique identifier for the key system this is for, can be NULL if it
* is not known. This should always be 16 bytes, but may change in the
* future.
*/
uint8_t* system_id;
uint32_t system_id_size;
/**
* An array of key IDs this initialization data is for. All IDs are the
* same length. Can be NULL if there are no known key IDs.
*/
uint8_t** key_ids;
/** The number of key IDs. */
uint32_t num_key_ids;
/**
* The number of bytes in each key ID. This should always be 16, but may
* change in the future.
*/
uint32_t key_id_size;
/**
* Key-system specific initialization data. This data is copied directly
* from the file and the format depends on the specific key system. This
* can be NULL if there is no initialization data; in that case, there
* will be at least one key ID.
*/
uint8_t* data;
uint32_t data_size;
/**
* An optional pointer to the next initialization info in the list.
*/
struct AVEncryptionInitInfo *next;
} AVEncryptionInitInfo;
/**
* Allocates an AVEncryptionInfo structure and sub-pointers to hold the given
* number of subsamples. This will allocate pointers for the key ID, IV,
* and subsample entries, set the size members, and zero-initialize the rest.
*
* @param subsample_count The number of subsamples.
* @param key_id_size The number of bytes in the key ID, should be 16.
* @param iv_size The number of bytes in the IV, should be 16.
*
* @return The new AVEncryptionInfo structure, or NULL on error.
*/
AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size);
/**
* Allocates an AVEncryptionInfo structure with a copy of the given data.
* @return The new AVEncryptionInfo structure, or NULL on error.
*/
AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info);
/**
* Frees the given encryption info object. This MUST NOT be used to free the
* side-data data pointer, that should use normal side-data methods.
*/
void av_encryption_info_free(AVEncryptionInfo *info);
/**
* Creates a copy of the AVEncryptionInfo that is contained in the given side
* data. The resulting object should be passed to av_encryption_info_free()
* when done.
*
* @return The new AVEncryptionInfo structure, or NULL on error.
*/
AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t *side_data, size_t side_data_size);
/**
* Allocates and initializes side data that holds a copy of the given encryption
* info. The resulting pointer should be either freed using av_free or given
* to av_packet_add_side_data().
*
* @return The new side-data pointer, or NULL.
*/
uint8_t *av_encryption_info_add_side_data(
const AVEncryptionInfo *info, size_t *side_data_size);
/**
* Allocates an AVEncryptionInitInfo structure and sub-pointers to hold the
* given sizes. This will allocate pointers and set all the fields.
*
* @return The new AVEncryptionInitInfo structure, or NULL on error.
*/
AVEncryptionInitInfo *av_encryption_init_info_alloc(
uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size);
/**
* Frees the given encryption init info object. This MUST NOT be used to free
* the side-data data pointer, that should use normal side-data methods.
*/
void av_encryption_init_info_free(AVEncryptionInitInfo* info);
/**
* Creates a copy of the AVEncryptionInitInfo that is contained in the given
* side data. The resulting object should be passed to
* av_encryption_init_info_free() when done.
*
* @return The new AVEncryptionInitInfo structure, or NULL on error.
*/
AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
const uint8_t* side_data, size_t side_data_size);
/**
* Allocates and initializes side data that holds a copy of the given encryption
* init info. The resulting pointer should be either freed using av_free or
* given to av_packet_add_side_data().
*
* @return The new side-data pointer, or NULL.
*/
uint8_t *av_encryption_init_info_add_side_data(
const AVEncryptionInitInfo *info, size_t *side_data_size);
#endif /* AVUTIL_ENCRYPTION_INFO_H */