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/*
* Copyright (C) 2018 The Android Open Source Project
*
* 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.
*/
//#define LOG_NDEBUG 0
#define LOG_TAG "hidl_ClearKeyCryptoPlugin"
#include <utils/Log.h>
#include "CryptoPlugin.h"
#include "SessionLibrary.h"
#include "TypeConvert.h"
#include <hidlmemory/mapping.h>
namespace android {
namespace hardware {
namespace drm {
namespace V1_1 {
namespace clearkey {
using ::android::hardware::drm::V1_0::BufferType;
Return<void> CryptoPlugin::setSharedBufferBase(
const hidl_memory& base, uint32_t bufferId) {
sp<IMemory> hidlMemory = mapMemory(base);
ALOGE_IF(hidlMemory == nullptr, "mapMemory returns nullptr");
// allow mapMemory to return nullptr
mSharedBufferMap[bufferId] = hidlMemory;
return Void();
}
// Returns negative values for error code and positive values for the size of
// decrypted data. In theory, the output size can be larger than the input
// size, but in practice this will never happen for AES-CTR.
Return<void> CryptoPlugin::decrypt(
bool secure,
const hidl_array<uint8_t, KEY_ID_SIZE>& keyId,
const hidl_array<uint8_t, KEY_IV_SIZE>& iv,
Mode mode,
const Pattern& pattern,
const hidl_vec<SubSample>& subSamples,
const SharedBuffer& source,
uint64_t offset,
const DestinationBuffer& destination,
decrypt_cb _hidl_cb) {
UNUSED(pattern);
if (secure) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"Secure decryption is not supported with ClearKey.");
return Void();
}
if (mSharedBufferMap.find(source.bufferId) == mSharedBufferMap.end()) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"source decrypt buffer base not set");
return Void();
}
if (destination.type == BufferType::SHARED_MEMORY) {
const SharedBuffer& dest = destination.nonsecureMemory;
if (mSharedBufferMap.find(dest.bufferId) == mSharedBufferMap.end()) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"destination decrypt buffer base not set");
return Void();
}
} else {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"destination type not supported");
return Void();
}
sp<IMemory> sourceBase = mSharedBufferMap[source.bufferId];
if (sourceBase == nullptr) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "source is a nullptr");
return Void();
}
if (source.offset + offset + source.size > sourceBase->getSize()) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size");
return Void();
}
uint8_t *base = static_cast<uint8_t *>
(static_cast<void *>(sourceBase->getPointer()));
uint8_t* srcPtr = static_cast<uint8_t *>(base + source.offset + offset);
void* destPtr = NULL;
// destination.type == BufferType::SHARED_MEMORY
const SharedBuffer& destBuffer = destination.nonsecureMemory;
sp<IMemory> destBase = mSharedBufferMap[destBuffer.bufferId];
if (destBase == nullptr) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "destination is a nullptr");
return Void();
}
if (destBuffer.offset + destBuffer.size > destBase->getSize()) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size");
return Void();
}
destPtr = static_cast<void *>(base + destination.nonsecureMemory.offset);
// Calculate the output buffer size and determine if any subsamples are
// encrypted.
size_t destSize = 0;
bool haveEncryptedSubsamples = false;
for (size_t i = 0; i < subSamples.size(); i++) {
const SubSample &subSample = subSamples[i];
if (__builtin_add_overflow(destSize, subSample.numBytesOfClearData, &destSize)) {
_hidl_cb(Status::BAD_VALUE, 0, "subsample clear size overflow");
return Void();
}
if (__builtin_add_overflow(destSize, subSample.numBytesOfEncryptedData, &destSize)) {
_hidl_cb(Status::BAD_VALUE, 0, "subsample encrypted size overflow");
return Void();
}
if (subSample.numBytesOfEncryptedData > 0) {
haveEncryptedSubsamples = true;
}
}
if (destSize > destBuffer.size) {
_hidl_cb(Status::BAD_VALUE, 0, "subsample sum too large");
return Void();
}
if (mode == Mode::UNENCRYPTED) {
if (haveEncryptedSubsamples) {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"Encrypted subsamples found in allegedly unencrypted data.");
return Void();
}
size_t offset = 0;
for (size_t i = 0; i < subSamples.size(); ++i) {
const SubSample& subSample = subSamples[i];
if (subSample.numBytesOfClearData != 0) {
memcpy(reinterpret_cast<uint8_t*>(destPtr) + offset,
reinterpret_cast<const uint8_t*>(srcPtr) + offset,
subSample.numBytesOfClearData);
offset += subSample.numBytesOfClearData;
}
}
_hidl_cb(Status::OK, static_cast<ssize_t>(offset), "");
return Void();
} else if (mode == Mode::AES_CTR) {
size_t bytesDecrypted;
Status res = mSession->decrypt(keyId.data(), iv.data(), srcPtr,
static_cast<uint8_t*>(destPtr), toVector(subSamples), &bytesDecrypted);
if (res == Status::OK) {
_hidl_cb(Status::OK, static_cast<ssize_t>(bytesDecrypted), "");
return Void();
} else {
_hidl_cb(Status::ERROR_DRM_DECRYPT, static_cast<ssize_t>(res),
"Decryption Error");
return Void();
}
} else {
_hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0,
"Selected encryption mode is not supported by the ClearKey DRM Plugin.");
return Void();
}
}
Return<Status> CryptoPlugin::setMediaDrmSession(
const hidl_vec<uint8_t>& sessionId) {
if (!sessionId.size()) {
mSession = nullptr;
} else {
mSession = SessionLibrary::get()->findSession(sessionId);
if (!mSession.get()) {
return Status::ERROR_DRM_SESSION_NOT_OPENED;
}
}
return Status::OK;
}
} // namespace clearkey
} // namespace V1_1
} // namespace drm
} // namespace hardware
} // namespace android
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