1 /* 2 * Copyright (C) 2012 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 #include <media/stagefright/MediaErrors.h> 18 #include <utils/Errors.h> 19 #include <utils/Vector.h> 20 21 #ifndef CRYPTO_API_H_ 22 23 #define CRYPTO_API_H_ 24 25 namespace android { 26 27 struct AString; 28 struct CryptoPlugin; 29 30 struct CryptoFactory { CryptoFactoryCryptoFactory31 CryptoFactory() {} ~CryptoFactoryCryptoFactory32 virtual ~CryptoFactory() {} 33 34 virtual bool isCryptoSchemeSupported(const uint8_t uuid[16]) const = 0; 35 36 virtual status_t createPlugin( 37 const uint8_t uuid[16], const void *data, size_t size, 38 CryptoPlugin **plugin) = 0; 39 40 private: 41 CryptoFactory(const CryptoFactory &); 42 CryptoFactory &operator=(const CryptoFactory &); 43 }; 44 45 struct CryptoPlugin { 46 enum Mode { 47 kMode_Unencrypted = 0, 48 kMode_AES_CTR = 1, 49 kMode_AES_WV = 2, 50 kMode_AES_CBC = 3, 51 }; 52 53 struct SubSample { 54 uint32_t mNumBytesOfClearData; 55 uint32_t mNumBytesOfEncryptedData; 56 }; 57 58 struct Pattern { 59 // Number of blocks to be encrypted in the pattern. If zero, pattern 60 // encryption is inoperative. 61 uint32_t mEncryptBlocks; 62 63 // Number of blocks to be skipped (left clear) in the pattern. If zero, 64 // pattern encryption is inoperative. 65 uint32_t mSkipBlocks; 66 }; 67 CryptoPluginCryptoPlugin68 CryptoPlugin() {} ~CryptoPluginCryptoPlugin69 virtual ~CryptoPlugin() {} 70 71 // If this method returns false, a non-secure decoder will be used to 72 // decode the data after decryption. The decrypt API below will have 73 // to support insecure decryption of the data (secure = false) for 74 // media data of the given mime type. 75 virtual bool requiresSecureDecoderComponent(const char *mime) const = 0; 76 77 // To implement resolution constraints, the crypto plugin needs to know 78 // the resolution of the video being decrypted. The media player should 79 // call this method when the resolution is determined and any time it 80 // is subsequently changed. 81 notifyResolutionCryptoPlugin82 virtual void notifyResolution(uint32_t /* width */, uint32_t /* height */) {} 83 84 // A MediaDrm session may be associated with a MediaCrypto session. The 85 // associated MediaDrm session is used to load decryption keys 86 // into the crypto/drm plugin. The keys are then referenced by key-id 87 // in the 'key' parameter to the decrypt() method. 88 // Should return NO_ERROR on success, ERROR_DRM_SESSION_NOT_OPENED if 89 // the session is not opened and a code from MediaErrors.h otherwise. setMediaDrmSessionCryptoPlugin90 virtual status_t setMediaDrmSession(const Vector<uint8_t> & /*sessionId */) { 91 return ERROR_UNSUPPORTED; 92 } 93 94 // If the error returned falls into the range 95 // ERROR_DRM_VENDOR_MIN..ERROR_DRM_VENDOR_MAX, errorDetailMsg should be 96 // filled in with an appropriate string. 97 // At the java level these special errors will then trigger a 98 // MediaCodec.CryptoException that gives clients access to both 99 // the error code and the errorDetailMsg. 100 // Returns a non-negative result to indicate the number of bytes written 101 // to the dstPtr, or a negative result to indicate an error. 102 virtual ssize_t decrypt( 103 bool secure, 104 const uint8_t key[16], 105 const uint8_t iv[16], 106 Mode mode, 107 const Pattern &pattern, 108 const void *srcPtr, 109 const SubSample *subSamples, size_t numSubSamples, 110 void *dstPtr, 111 AString *errorDetailMsg) = 0; 112 113 private: 114 CryptoPlugin(const CryptoPlugin &); 115 CryptoPlugin &operator=(const CryptoPlugin &); 116 }; 117 118 } // namespace android 119 120 extern "C" { 121 extern android::CryptoFactory *createCryptoFactory(); 122 } 123 124 #endif // CRYPTO_API_H_ 125