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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp')
-rw-r--r-- | media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp b/media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp new file mode 100644 index 0000000000..532ee738ea --- /dev/null +++ b/media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp @@ -0,0 +1,289 @@ +/* + * 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. + */ + +#include "ClearKeyDecryptionManager.h" + +#include <assert.h> +#include <string.h> + +#include <vector> +#include <algorithm> + +#include "mozilla/CheckedInt.h" +#include "mozilla/Span.h" +#include "psshparser/PsshParser.h" + +using namespace cdm; + +bool AllZero(const std::vector<uint32_t>& aBytes) { + return all_of(aBytes.begin(), aBytes.end(), + [](uint32_t b) { return b == 0; }); +} + +class ClearKeyDecryptor : public RefCounted { + public: + ClearKeyDecryptor(); + + void InitKey(const Key& aKey); + bool HasKey() const { return !mKey.empty(); } + + Status Decrypt(uint8_t* aBuffer, uint32_t aBufferSize, + const CryptoMetaData& aMetadata); + + const Key& DecryptionKey() const { return mKey; } + + private: + ~ClearKeyDecryptor(); + + Key mKey; +}; + +/* static */ +ClearKeyDecryptionManager* ClearKeyDecryptionManager::sInstance = nullptr; + +/* static */ +ClearKeyDecryptionManager* ClearKeyDecryptionManager::Get() { + if (!sInstance) { + sInstance = new ClearKeyDecryptionManager(); + } + return sInstance; +} + +ClearKeyDecryptionManager::ClearKeyDecryptionManager() { + CK_LOGD("ClearKeyDecryptionManager::ClearKeyDecryptionManager"); +} + +ClearKeyDecryptionManager::~ClearKeyDecryptionManager() { + CK_LOGD("ClearKeyDecryptionManager::~ClearKeyDecryptionManager"); + + sInstance = nullptr; + + for (auto it = mDecryptors.begin(); it != mDecryptors.end(); it++) { + it->second->Release(); + } + mDecryptors.clear(); +} + +bool ClearKeyDecryptionManager::HasSeenKeyId(const KeyId& aKeyId) const { + CK_LOGD("ClearKeyDecryptionManager::SeenKeyId %s", + mDecryptors.find(aKeyId) != mDecryptors.end() ? "t" : "f"); + return mDecryptors.find(aKeyId) != mDecryptors.end(); +} + +bool ClearKeyDecryptionManager::IsExpectingKeyForKeyId( + const KeyId& aKeyId) const { + CK_LOGARRAY("ClearKeyDecryptionManager::IsExpectingKeyForId ", aKeyId.data(), + aKeyId.size()); + const auto& decryptor = mDecryptors.find(aKeyId); + return decryptor != mDecryptors.end() && !decryptor->second->HasKey(); +} + +bool ClearKeyDecryptionManager::HasKeyForKeyId(const KeyId& aKeyId) const { + CK_LOGD("ClearKeyDecryptionManager::HasKeyForKeyId"); + const auto& decryptor = mDecryptors.find(aKeyId); + return decryptor != mDecryptors.end() && decryptor->second->HasKey(); +} + +const Key& ClearKeyDecryptionManager::GetDecryptionKey(const KeyId& aKeyId) { + assert(HasKeyForKeyId(aKeyId)); + return mDecryptors[aKeyId]->DecryptionKey(); +} + +void ClearKeyDecryptionManager::InitKey(KeyId aKeyId, Key aKey) { + CK_LOGD("ClearKeyDecryptionManager::InitKey ", aKeyId.data(), aKeyId.size()); + if (IsExpectingKeyForKeyId(aKeyId)) { + CK_LOGARRAY("Initialized Key ", aKeyId.data(), aKeyId.size()); + mDecryptors[aKeyId]->InitKey(aKey); + } else { + CK_LOGARRAY("Failed to initialize key ", aKeyId.data(), aKeyId.size()); + } +} + +void ClearKeyDecryptionManager::ExpectKeyId(KeyId aKeyId) { + CK_LOGD("ClearKeyDecryptionManager::ExpectKeyId ", aKeyId.data(), + aKeyId.size()); + if (!HasSeenKeyId(aKeyId)) { + mDecryptors[aKeyId] = new ClearKeyDecryptor(); + } + mDecryptors[aKeyId]->AddRef(); +} + +void ClearKeyDecryptionManager::ReleaseKeyId(KeyId aKeyId) { + CK_LOGD("ClearKeyDecryptionManager::ReleaseKeyId"); + assert(HasSeenKeyId(aKeyId)); + + ClearKeyDecryptor* decryptor = mDecryptors[aKeyId]; + if (!decryptor->Release()) { + mDecryptors.erase(aKeyId); + } +} + +Status ClearKeyDecryptionManager::Decrypt(std::vector<uint8_t>& aBuffer, + const CryptoMetaData& aMetadata) { + return Decrypt(&aBuffer[0], aBuffer.size(), aMetadata); +} + +Status ClearKeyDecryptionManager::Decrypt(uint8_t* aBuffer, + uint32_t aBufferSize, + const CryptoMetaData& aMetadata) { + CK_LOGD("ClearKeyDecryptionManager::Decrypt"); + if (!HasKeyForKeyId(aMetadata.mKeyId)) { + CK_LOGARRAY("Unable to find decryptor for keyId: ", aMetadata.mKeyId.data(), + aMetadata.mKeyId.size()); + return Status::kNoKey; + } + + CK_LOGARRAY("Found decryptor for keyId: ", aMetadata.mKeyId.data(), + aMetadata.mKeyId.size()); + return mDecryptors[aMetadata.mKeyId]->Decrypt(aBuffer, aBufferSize, + aMetadata); +} + +ClearKeyDecryptor::ClearKeyDecryptor() { CK_LOGD("ClearKeyDecryptor ctor"); } + +ClearKeyDecryptor::~ClearKeyDecryptor() { + if (HasKey()) { + CK_LOGARRAY("ClearKeyDecryptor dtor; key = ", mKey.data(), mKey.size()); + } else { + CK_LOGD("ClearKeyDecryptor dtor"); + } +} + +void ClearKeyDecryptor::InitKey(const Key& aKey) { mKey = aKey; } + +Status ClearKeyDecryptor::Decrypt(uint8_t* aBuffer, uint32_t aBufferSize, + const CryptoMetaData& aMetadata) { + CK_LOGD("ClearKeyDecryptor::Decrypt"); + // If the sample is split up into multiple encrypted subsamples, we need to + // stitch them into one continuous buffer for decryption. + std::vector<uint8_t> tmp(aBufferSize); + static_assert(sizeof(uintptr_t) == sizeof(uint8_t*), + "We need uintptr_t to be exactly the same size as a pointer"); + + // Decrypt CBCS case: + if (aMetadata.mEncryptionScheme == EncryptionScheme::kCbcs) { + mozilla::CheckedInt<uintptr_t> data = reinterpret_cast<uintptr_t>(aBuffer); + if (!data.isValid()) { + return Status::kDecryptError; + } + const uintptr_t endBuffer = + reinterpret_cast<uintptr_t>(aBuffer + aBufferSize); + + if (aMetadata.NumSubsamples() == 0) { + if (data.value() > endBuffer) { + return Status::kDecryptError; + } + mozilla::Span<uint8_t> encryptedSpan = + mozilla::Span(reinterpret_cast<uint8_t*>(data.value()), aBufferSize); + if (!ClearKeyUtils::DecryptCbcs(mKey, aMetadata.mIV, encryptedSpan, + aMetadata.mCryptByteBlock, + aMetadata.mSkipByteBlock)) { + return Status::kDecryptError; + } + return Status::kSuccess; + } + + for (size_t i = 0; i < aMetadata.NumSubsamples(); i++) { + data += aMetadata.mClearBytes[i]; + if (!data.isValid() || data.value() > endBuffer) { + return Status::kDecryptError; + } + mozilla::CheckedInt<uintptr_t> dataAfterCipher = + data + aMetadata.mCipherBytes[i]; + if (!dataAfterCipher.isValid() || dataAfterCipher.value() > endBuffer) { + // Trying to read past the end of the buffer! + return Status::kDecryptError; + } + mozilla::Span<uint8_t> encryptedSpan = mozilla::Span( + reinterpret_cast<uint8_t*>(data.value()), aMetadata.mCipherBytes[i]); + if (!ClearKeyUtils::DecryptCbcs(mKey, aMetadata.mIV, encryptedSpan, + aMetadata.mCryptByteBlock, + aMetadata.mSkipByteBlock)) { + return Status::kDecryptError; + } + data += aMetadata.mCipherBytes[i]; + if (!data.isValid()) { + return Status::kDecryptError; + } + return Status::kSuccess; + } + } + + // Decrypt CENC case: + if (aMetadata.NumSubsamples()) { + // Take all encrypted parts of subsamples and stitch them into one + // continuous encrypted buffer. + mozilla::CheckedInt<uintptr_t> data = reinterpret_cast<uintptr_t>(aBuffer); + const uintptr_t endBuffer = + reinterpret_cast<uintptr_t>(aBuffer + aBufferSize); + uint8_t* iter = &tmp[0]; + for (size_t i = 0; i < aMetadata.NumSubsamples(); i++) { + data += aMetadata.mClearBytes[i]; + if (!data.isValid() || data.value() > endBuffer) { + // Trying to read past the end of the buffer! + return Status::kDecryptError; + } + const uint32_t& cipherBytes = aMetadata.mCipherBytes[i]; + mozilla::CheckedInt<uintptr_t> dataAfterCipher = data + cipherBytes; + if (!dataAfterCipher.isValid() || dataAfterCipher.value() > endBuffer) { + // Trying to read past the end of the buffer! + return Status::kDecryptError; + } + + memcpy(iter, reinterpret_cast<uint8_t*>(data.value()), cipherBytes); + + data = dataAfterCipher; + iter += cipherBytes; + } + + tmp.resize((size_t)(iter - &tmp[0])); + } else { + memcpy(&tmp[0], aBuffer, aBufferSize); + } + + // It is possible that we could be passed an unencrypted sample, if all + // encrypted sample lengths are zero, and in this case, a zero length + // IV is allowed. + assert(aMetadata.mIV.size() == 8 || aMetadata.mIV.size() == 16 || + (aMetadata.mIV.empty() && AllZero(aMetadata.mCipherBytes))); + + std::vector<uint8_t> iv(aMetadata.mIV); + iv.insert(iv.end(), CENC_KEY_LEN - aMetadata.mIV.size(), 0); + + if (!ClearKeyUtils::DecryptAES(mKey, tmp, iv)) { + return Status::kDecryptError; + } + + if (aMetadata.NumSubsamples()) { + // Take the decrypted buffer, split up into subsamples, and insert those + // subsamples back into their original position in the original buffer. + uint8_t* data = aBuffer; + uint8_t* iter = &tmp[0]; + for (size_t i = 0; i < aMetadata.NumSubsamples(); i++) { + data += aMetadata.mClearBytes[i]; + uint32_t cipherBytes = aMetadata.mCipherBytes[i]; + + memcpy(data, iter, cipherBytes); + + data += cipherBytes; + iter += cipherBytes; + } + } else { + memcpy(aBuffer, &tmp[0], aBufferSize); + } + + return Status::kSuccess; +} |