From db2a7c947ec28b0a04a4e5193c9b0d33de823fbb Mon Sep 17 00:00:00 2001 From: Jacob Trimble Date: Tue, 5 Dec 2017 14:52:22 -0800 Subject: avcodec/avcodec.h: Add encryption info side data. This new side-data will contain info on how a packet is encrypted. This allows the app to handle packet decryption. Signed-off-by: Jacob Trimble Signed-off-by: Michael Niedermayer --- libavutil/encryption_info.h | 200 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 200 insertions(+) create mode 100644 libavutil/encryption_info.h (limited to 'libavutil/encryption_info.h') diff --git a/libavutil/encryption_info.h b/libavutil/encryption_info.h new file mode 100644 index 0000000000..47dc3a35ca --- /dev/null +++ b/libavutil/encryption_info.h @@ -0,0 +1,200 @@ +/** + * 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 +#include + +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. */ + 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; +} 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 key_id_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 */ -- cgit v1.2.3