From 54f6666996fd8b8b8e44506739b58784e6038309 Mon Sep 17 00:00:00 2001
From: Jacob Trimble <modmaker@google.com>
Date: Tue, 5 Dec 2017 14:52:22 -0800
Subject: [PATCH] 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 <modmaker@google.com>
---
doc/APIchanges | 4 +
libavcodec/avcodec.h | 13 ++
libavutil/Makefile | 2 +
libavutil/encryption_info.c | 295 ++++++++++++++++++++++++++++++++++++++++++++
libavutil/encryption_info.h | 200 ++++++++++++++++++++++++++++++
libavutil/version.h | 2 +-
6 files changed, 515 insertions(+), 1 deletion(-)
create mode 100644 libavutil/encryption_info.c
create mode 100644 libavutil/encryption_info.h
@@ -15,6 +15,10 @@ libavutil: 2017-10-21
API changes, most recent first:
+2018-xx-xx - xxxxxxx - lavu 56.8.100 - encryption_info.h
+ Add AVEncryptionInitInfo and AVEncryptionInfo structures to hold new side-data
+ for encryption info.
+
2018-01-xx - xxxxxxx - lavfi 7.11.101 - avfilter.h
Deprecate avfilter_link_get_channels(). Use av_buffersink_get_channels().
@@ -1341,6 +1341,19 @@ enum AVPacketSideDataType {
*/
AV_PKT_DATA_A53_CC,
+ /**
+ * This side data is encryption initialization data.
+ * The format is not part of ABI, use av_encryption_init_info_* methods to
+ * access.
+ */
+ AV_PKT_DATA_ENCRYPTION_INIT_INFO,
+
+ /**
+ * This side data contains encryption info for how to decrypt the packet.
+ * The format is not part of ABI, use av_encryption_info_* methods to access.
+ */
+ AV_PKT_DATA_ENCRYPTION_INFO,
+
/**
* The number of side data types.
* This is not part of the public API/ABI in the sense that it may
@@ -24,6 +24,7 @@ HEADERS = adler32.h \
dict.h \
display.h \
downmix_info.h \
+ encryption_info.h \
error.h \
eval.h \
fifo.h \
@@ -107,6 +108,7 @@ OBJS = adler32.o \
dict.o \
display.o \
downmix_info.o \
+ encryption_info.o \
error.o \
eval.o \
fifo.o \
new file mode 100644
@@ -0,0 +1,295 @@
+/**
+ * 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
+ */
+
+#include "encryption_info.h"
+#include "mem.h"
+#include "intreadwrite.h"
+
+#define FF_ENCRYPTION_INFO_EXTRA 24
+
+// The format of the AVEncryptionInfo side data:
+// u32be scheme
+// u32be crypt_byte_block
+// u32be skip_byte_block
+// u32be key_id_size
+// u32be iv_size
+// u32be subsample_count
+// u8[key_id_size] key_id
+// u8[iv_size] iv
+// {
+// u32be bytes_of_clear_data
+// u32be bytes_of_protected_data
+// }[subsample_count]
+
+AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size)
+{
+ AVEncryptionInfo *info;
+
+ info = av_mallocz(sizeof(*info));
+ if (!info)
+ return NULL;
+
+ info->key_id = av_mallocz(key_id_size);
+ info->key_id_size = key_id_size;
+ info->iv = av_mallocz(iv_size);
+ info->iv_size = iv_size;
+ info->subsamples = av_mallocz_array(subsample_count, sizeof(*info->subsamples));
+ info->subsample_count = subsample_count;
+
+ // Allow info->subsamples to be NULL if there are no subsamples.
+ if (!info->key_id || !info->iv || (!info->subsamples && subsample_count)) {
+ av_encryption_info_free(info);
+ return NULL;
+ }
+
+ return info;
+}
+
+AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info)
+{
+ AVEncryptionInfo *ret;
+
+ ret = av_encryption_info_alloc(info->subsample_count, info->key_id_size, info->iv_size);
+ if (!ret)
+ return NULL;
+
+ ret->scheme = info->scheme;
+ ret->crypt_byte_block = info->crypt_byte_block;
+ ret->skip_byte_block = info->skip_byte_block;
+ memcpy(ret->iv, info->iv, info->iv_size);
+ memcpy(ret->key_id, info->key_id, info->key_id_size);
+ memcpy(ret->subsamples, info->subsamples, sizeof(*info->subsamples) * info->subsample_count);
+ return ret;
+}
+
+void av_encryption_info_free(AVEncryptionInfo *info)
+{
+ if (info) {
+ av_free(info->key_id);
+ av_free(info->iv);
+ av_free(info->subsamples);
+ av_free(info);
+ }
+}
+
+AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t* buffer, size_t size)
+{
+ AVEncryptionInfo *info;
+ uint64_t key_id_size, iv_size, subsample_count, i;
+
+ if (!buffer || size < FF_ENCRYPTION_INFO_EXTRA)
+ return NULL;
+
+ key_id_size = AV_RB32(buffer + 12);
+ iv_size = AV_RB32(buffer + 16);
+ subsample_count = AV_RB32(buffer + 20);
+
+ if (size < FF_ENCRYPTION_INFO_EXTRA + key_id_size + iv_size + subsample_count * 8)
+ return NULL;
+
+ info = av_encryption_info_alloc(subsample_count, key_id_size, iv_size);
+ if (!info)
+ return NULL;
+
+ info->scheme = AV_RB32(buffer);
+ info->crypt_byte_block = AV_RB32(buffer + 4);
+ info->skip_byte_block = AV_RB32(buffer + 8);
+ memcpy(info->key_id, buffer + 24, key_id_size);
+ memcpy(info->iv, buffer + key_id_size + 24, iv_size);
+
+ buffer += key_id_size + iv_size + 24;
+ for (i = 0; i < subsample_count; i++) {
+ info->subsamples[i].bytes_of_clear_data = AV_RB32(buffer);
+ info->subsamples[i].bytes_of_protected_data = AV_RB32(buffer + 4);
+ buffer += 8;
+ }
+
+ return info;
+}
+
+uint8_t *av_encryption_info_add_side_data(const AVEncryptionInfo *info, size_t *size)
+{
+ uint8_t *buffer, *cur_buffer;
+ uint32_t i;
+
+ if (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA < info->key_id_size ||
+ UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size < info->iv_size ||
+ (UINT32_MAX - FF_ENCRYPTION_INFO_EXTRA - info->key_id_size - info->iv_size) / 8 < info->subsample_count) {
+ return NULL;
+ }
+
+ *size = FF_ENCRYPTION_INFO_EXTRA + info->key_id_size + info->iv_size +
+ (info->subsample_count * 8);
+ cur_buffer = buffer = av_malloc(*size);
+ if (!buffer)
+ return NULL;
+
+ AV_WB32(cur_buffer, info->scheme);
+ AV_WB32(cur_buffer + 4, info->crypt_byte_block);
+ AV_WB32(cur_buffer + 8, info->skip_byte_block);
+ AV_WB32(cur_buffer + 12, info->key_id_size);
+ AV_WB32(cur_buffer + 16, info->iv_size);
+ AV_WB32(cur_buffer + 20, info->subsample_count);
+ cur_buffer += 24;
+ memcpy(cur_buffer, info->key_id, info->key_id_size);
+ cur_buffer += info->key_id_size;
+ memcpy(cur_buffer, info->iv, info->iv_size);
+ cur_buffer += info->iv_size;
+ for (i = 0; i < info->subsample_count; i++) {
+ AV_WB32(cur_buffer, info->subsamples[i].bytes_of_clear_data);
+ AV_WB32(cur_buffer + 4, info->subsamples[i].bytes_of_protected_data);
+ cur_buffer += 8;
+ }
+
+ return buffer;
+}
+
+// The format of the AVEncryptionInitInfo side data:
+// u32be system_id_size
+// u32be num_key_ids
+// u32be key_id_size
+// u32be data_size
+// u8[system_id_size] system_id
+// u8[key_id_size][num_key_id] key_ids
+// u8[data_size] data
+
+#define FF_ENCRYPTION_INIT_INFO_EXTRA 16
+
+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)
+{
+ AVEncryptionInitInfo *info;
+ uint32_t i;
+
+ info = av_mallocz(sizeof(*info));
+ if (!info)
+ return NULL;
+
+ info->system_id = av_mallocz(system_id_size);
+ info->system_id_size = system_id_size;
+ info->key_ids = key_id_size ? av_mallocz_array(num_key_ids, sizeof(*info->key_ids)) : NULL;
+ info->num_key_ids = num_key_ids;
+ info->key_id_size = key_id_size;
+ info->data = av_mallocz(data_size);
+ info->data_size = data_size;
+
+ // Allow pointers to be NULL if the size is 0.
+ if ((!info->system_id && system_id_size) || (!info->data && data_size) ||
+ (!info->key_ids && num_key_ids && key_id_size)) {
+ av_encryption_init_info_free(info);
+ return NULL;
+ }
+
+ if (key_id_size) {
+ for (i = 0; i < num_key_ids; i++) {
+ info->key_ids[i] = av_mallocz(key_id_size);
+ if (!info->key_ids[i]) {
+ av_encryption_init_info_free(info);
+ return NULL;
+ }
+ }
+ }
+
+ return info;
+}
+
+void av_encryption_init_info_free(AVEncryptionInitInfo *info)
+{
+ uint32_t i;
+ if (info) {
+ for (i = 0; i < info->num_key_ids; i++) {
+ av_free(info->key_ids[i]);
+ }
+ av_free(info->system_id);
+ av_free(info->key_ids);
+ av_free(info->data);
+ av_free(info);
+ }
+}
+
+AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
+ const uint8_t *side_data, size_t side_data_size)
+{
+ AVEncryptionInitInfo *info;
+ uint64_t system_id_size, num_key_ids, key_id_size, data_size, i;
+
+ if (!side_data || side_data_size < FF_ENCRYPTION_INIT_INFO_EXTRA)
+ return NULL;
+
+ system_id_size = AV_RB32(side_data);
+ num_key_ids = AV_RB32(side_data + 4);
+ key_id_size = AV_RB32(side_data + 8);
+ data_size = AV_RB32(side_data + 12);
+
+ // UINT32_MAX + UINT32_MAX + UINT32_MAX * UINT32_MAX == UINT64_MAX
+ if (side_data_size - FF_ENCRYPTION_INIT_INFO_EXTRA < system_id_size + data_size + num_key_ids * key_id_size)
+ return NULL;
+
+ info = av_encryption_init_info_alloc(system_id_size, num_key_ids, key_id_size, data_size);
+ if (!info)
+ return NULL;
+
+ memcpy(info->system_id, side_data + 16, system_id_size);
+ side_data += system_id_size + 16;
+ for (i = 0; i < num_key_ids; i++) {
+ memcpy(info->key_ids[i], side_data, key_id_size);
+ side_data += key_id_size;
+ }
+ memcpy(info->data, side_data, data_size);
+
+ return info;
+}
+
+uint8_t *av_encryption_init_info_add_side_data(const AVEncryptionInitInfo *info, size_t *side_data_size)
+{
+ uint8_t *buffer, *cur_buffer;
+ uint32_t i, max_size;
+
+ if (UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA < info->system_id_size ||
+ UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA - info->system_id_size < info->data_size) {
+ return NULL;
+ }
+
+ if (info->num_key_ids) {
+ max_size = UINT32_MAX - FF_ENCRYPTION_INIT_INFO_EXTRA - info->system_id_size - info->data_size;
+ if (max_size / info->num_key_ids < info->key_id_size)
+ return NULL;
+ }
+
+ *side_data_size = FF_ENCRYPTION_INIT_INFO_EXTRA + info->system_id_size +
+ info->data_size + (info->num_key_ids * info->key_id_size);
+ cur_buffer = buffer = av_malloc(*side_data_size);
+ if (!buffer)
+ return NULL;
+
+ AV_WB32(cur_buffer, info->system_id_size);
+ AV_WB32(cur_buffer + 4, info->num_key_ids);
+ AV_WB32(cur_buffer + 8, info->key_id_size);
+ AV_WB32(cur_buffer + 12, info->data_size);
+ cur_buffer += 16;
+
+ memcpy(cur_buffer, info->system_id, info->system_id_size);
+ cur_buffer += info->system_id_size;
+ for (i = 0; i < info->num_key_ids; i++) {
+ memcpy(cur_buffer, info->key_ids[i], info->key_id_size);
+ cur_buffer += info->key_id_size;
+ }
+ memcpy(cur_buffer, info->data, info->data_size);
+
+ return buffer;
+}
new file mode 100644
@@ -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 <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. */
+ 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 */
@@ -79,7 +79,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 56
-#define LIBAVUTIL_VERSION_MINOR 7
+#define LIBAVUTIL_VERSION_MINOR 8
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
--
2.16.0.rc0.223.g4a4ac83678-goog