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/*
* Copyright 2015, Mozilla Foundation and contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __ClearKeyDecryptionManager_h__
#define __ClearKeyDecryptionManager_h__
// This include is required in order for content_decryption_module to work
// on Unix systems.
#include <stddef.h>
#include <map>
#include "content_decryption_module.h"
#include "ClearKeyUtils.h"
#include "RefCounted.h"
class ClearKeyDecryptor;
class CryptoMetaData {
public:
CryptoMetaData() = default;
explicit CryptoMetaData(const cdm::InputBuffer_2* aInputBuffer) {
Init(aInputBuffer);
}
void Init(const cdm::InputBuffer_2* aInputBuffer) {
if (!aInputBuffer) {
assert(!IsValid());
return;
}
mEncryptionScheme = aInputBuffer->encryption_scheme;
Assign(mKeyId, aInputBuffer->key_id, aInputBuffer->key_id_size);
Assign(mIV, aInputBuffer->iv, aInputBuffer->iv_size);
mCryptByteBlock = aInputBuffer->pattern.crypt_byte_block;
mSkipByteBlock = aInputBuffer->pattern.skip_byte_block;
for (uint32_t i = 0; i < aInputBuffer->num_subsamples; ++i) {
const cdm::SubsampleEntry& subsample = aInputBuffer->subsamples[i];
mClearBytes.push_back(subsample.clear_bytes);
mCipherBytes.push_back(subsample.cipher_bytes);
}
}
bool IsValid() const {
return !mKeyId.empty() && !mIV.empty() && !mCipherBytes.empty() &&
!mClearBytes.empty();
}
size_t NumSubsamples() const {
assert(mClearBytes.size() == mCipherBytes.size());
return mClearBytes.size();
}
cdm::EncryptionScheme mEncryptionScheme;
std::vector<uint8_t> mKeyId;
std::vector<uint8_t> mIV;
uint32_t mCryptByteBlock;
uint32_t mSkipByteBlock;
std::vector<uint32_t> mClearBytes;
std::vector<uint32_t> mCipherBytes;
};
class ClearKeyDecryptionManager : public RefCounted {
private:
ClearKeyDecryptionManager();
~ClearKeyDecryptionManager();
static ClearKeyDecryptionManager* sInstance;
public:
static ClearKeyDecryptionManager* Get();
bool HasSeenKeyId(const KeyId& aKeyId) const;
bool HasKeyForKeyId(const KeyId& aKeyId) const;
const Key& GetDecryptionKey(const KeyId& aKeyId);
// Create a decryptor for the given KeyId if one does not already exist.
void InitKey(KeyId aKeyId, Key aKey);
void ExpectKeyId(KeyId aKeyId);
void ReleaseKeyId(KeyId aKeyId);
// Decrypts buffer *in place*.
cdm::Status Decrypt(uint8_t* aBuffer, uint32_t aBufferSize,
const CryptoMetaData& aMetadata);
cdm::Status Decrypt(std::vector<uint8_t>& aBuffer,
const CryptoMetaData& aMetadata);
private:
bool IsExpectingKeyForKeyId(const KeyId& aKeyId) const;
std::map<KeyId, ClearKeyDecryptor*> mDecryptors;
};
#endif // __ClearKeyDecryptionManager_h__
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