1 /*
2  * Copyright (C) 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #define LOG_TAG "clearkey-Session"
17 
18 #include <utils/Log.h>
19 
20 #include "Session.h"
21 
22 #include "AesCtrDecryptor.h"
23 #include "InitDataParser.h"
24 #include "JsonWebKey.h"
25 
26 namespace clearkeydrm {
27 
28 using ::android::Mutex;
29 using ::android::sp;
30 
getKeyRequest(const std::vector<uint8_t> & initData,const std::string & mimeType,CdmKeyType keyType,std::vector<uint8_t> * keyRequest) const31 CdmResponseType Session::getKeyRequest(const std::vector<uint8_t>& initData,
32                                        const std::string& mimeType,
33                                        CdmKeyType keyType,
34                                        std::vector<uint8_t>* keyRequest) const {
35     InitDataParser parser;
36     return parser.parse(initData, mimeType, keyType, keyRequest);
37 }
38 
provideKeyResponse(const std::vector<uint8_t> & response)39 CdmResponseType Session::provideKeyResponse(const std::vector<uint8_t>& response) {
40     std::string responseString(reinterpret_cast<const char*>(response.data()), response.size());
41     KeyMap keys;
42 
43     Mutex::Autolock lock(mMapLock);
44     JsonWebKey parser;
45     if (parser.extractKeysFromJsonWebKeySet(responseString, &keys)) {
46         for (auto& key : keys) {
47             std::string first(key.first.begin(), key.first.end());
48             std::string second(key.second.begin(), key.second.end());
49             mKeyMap.insert(
50                     std::pair<std::vector<uint8_t>, std::vector<uint8_t>>(key.first, key.second));
51         }
52         return clearkeydrm::OK;
53     } else {
54         return clearkeydrm::ERROR_UNKNOWN;
55     }
56 }
57 
decrypt(const KeyId keyId,const Iv iv,const uint8_t * srcPtr,uint8_t * destPtr,const std::vector<int32_t> & clearDataLengths,const std::vector<int32_t> & encryptedDataLengths,size_t * bytesDecryptedOut)58 CdmResponseType Session::decrypt(const KeyId keyId, const Iv iv,
59                                  const uint8_t* srcPtr, uint8_t* destPtr,
60                                  const std::vector<int32_t>& clearDataLengths,
61                                  const std::vector<int32_t>& encryptedDataLengths,
62                                  size_t* bytesDecryptedOut) {
63     Mutex::Autolock lock(mMapLock);
64 
65     if (getMockError() != clearkeydrm::OK) {
66         return getMockError();
67     }
68 
69     std::vector<uint8_t> keyIdVector;
70     keyIdVector.clear();
71     keyIdVector.insert(keyIdVector.end(), keyId, keyId + kBlockSize);
72     std::map<std::vector<uint8_t>, std::vector<uint8_t>>::iterator itr;
73     itr = mKeyMap.find(keyIdVector);
74     if (itr == mKeyMap.end()) {
75         return clearkeydrm::ERROR_NO_LICENSE;
76     }
77 
78     clearkeydrm::AesCtrDecryptor decryptor;
79     auto status = decryptor.decrypt(itr->second /*key*/, iv, srcPtr, destPtr,
80                                     clearDataLengths,
81                                     encryptedDataLengths,
82                                     bytesDecryptedOut);
83     return status;
84 }
85 
86 }  // namespace clearkeydrm
87