1 /*
2 * Copyright (C) 2014 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
17 //#define LOG_NDEBUG 0
18 #define LOG_TAG "ClearKeySession"
19 #include <utils/Log.h>
20
21 #include <media/stagefright/MediaErrors.h>
22 #include <utils/String8.h>
23
24 #include "Session.h"
25
26 #include "AesCtrDecryptor.h"
27 #include "InitDataParser.h"
28 #include "JsonWebKey.h"
29
30 namespace clearkeydrm {
31
32 using android::Mutex;
33 using android::String8;
34 using android::Vector;
35 using android::status_t;
36
getKeyRequest(const Vector<uint8_t> & initData,const String8 & mimeType,Vector<uint8_t> * keyRequest) const37 status_t Session::getKeyRequest(
38 const Vector<uint8_t>& initData,
39 const String8& mimeType,
40 Vector<uint8_t>* keyRequest) const {
41 InitDataParser parser;
42 return parser.parse(initData, mimeType, keyRequest);
43 }
44
provideKeyResponse(const Vector<uint8_t> & response)45 status_t Session::provideKeyResponse(const Vector<uint8_t>& response) {
46 String8 responseString(
47 reinterpret_cast<const char*>(response.array()), response.size());
48 KeyMap keys;
49
50 Mutex::Autolock lock(mMapLock);
51 JsonWebKey parser;
52 if (parser.extractKeysFromJsonWebKeySet(responseString, &keys)) {
53 for (size_t i = 0; i < keys.size(); ++i) {
54 const KeyMap::key_type& keyId = keys.keyAt(i);
55 const KeyMap::value_type& key = keys.valueAt(i);
56 mKeyMap.add(keyId, key);
57 }
58 return android::OK;
59 } else {
60 return android::ERROR_DRM_UNKNOWN;
61 }
62 }
63
decrypt(const KeyId keyId,const Iv iv,const void * source,void * destination,const SubSample * subSamples,size_t numSubSamples,size_t * bytesDecryptedOut)64 status_t Session::decrypt(
65 const KeyId keyId, const Iv iv, const void* source,
66 void* destination, const SubSample* subSamples,
67 size_t numSubSamples, size_t* bytesDecryptedOut) {
68 Mutex::Autolock lock(mMapLock);
69
70 Vector<uint8_t> keyIdVector;
71 keyIdVector.appendArray(keyId, kBlockSize);
72 if (mKeyMap.indexOfKey(keyIdVector) < 0) {
73 return android::ERROR_DRM_NO_LICENSE;
74 }
75
76 const Vector<uint8_t>& key = mKeyMap.valueFor(keyIdVector);
77 AesCtrDecryptor decryptor;
78 return decryptor.decrypt(
79 key, iv,
80 reinterpret_cast<const uint8_t*>(source),
81 reinterpret_cast<uint8_t*>(destination), subSamples,
82 numSubSamples, bytesDecryptedOut);
83 }
84
85 } // namespace clearkeydrm
86