CryptoAPI.h revision 383190e475d7bdbe90359dbb99721041773a8646 
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 <utils/Errors.h>
18
19#ifndef CRYPTO_API_H_
20
21#define CRYPTO_API_H_
22
23namespace android {
24
25struct AString;
26struct CryptoPlugin;
27
28struct CryptoFactory {
29    CryptoFactory() {}
30    virtual ~CryptoFactory() {}
31
32    virtual bool isCryptoSchemeSupported(const uint8_t uuid[16]) const = 0;
33
34    virtual status_t createPlugin(
35            const uint8_t uuid[16], const void *data, size_t size,
36            CryptoPlugin **plugin) = 0;
37
38private:
39    CryptoFactory(const CryptoFactory &);
40    CryptoFactory &operator=(const CryptoFactory &);
41};
42
43struct CryptoPlugin {
44    enum Mode {
45        kMode_Unencrypted = 0,
46        kMode_AES_CTR     = 1,
47
48        // Neither key nor iv are being used in this mode.
49        // Each subsample is encrypted w/ an iv of all zeroes.
50        kMode_AES_WV      = 2,  // FIX constant
51    };
52
53    struct SubSample {
54        size_t mNumBytesOfClearData;
55        size_t mNumBytesOfEncryptedData;
56    };
57
58    CryptoPlugin() {}
59    virtual ~CryptoPlugin() {}
60
61    // If this method returns false, a non-secure decoder will be used to
62    // decode the data after decryption. The decrypt API below will have
63    // to support insecure decryption of the data (secure = false) for
64    // media data of the given mime type.
65    virtual bool requiresSecureDecoderComponent(const char *mime) const = 0;
66
67    // If the error returned falls into the range
68    // ERROR_DRM_VENDOR_MIN..ERROR_DRM_VENDOR_MAX, errorDetailMsg should be
69    // filled in with an appropriate string.
70    // At the java level these special errors will then trigger a
71    // MediaCodec.CryptoException that gives clients access to both
72    // the error code and the errorDetailMsg.
73    virtual status_t decrypt(
74            bool secure,
75            const uint8_t key[16],
76            const uint8_t iv[16],
77            Mode mode,
78            const void *srcPtr,
79            const SubSample *subSamples, size_t numSubSamples,
80            void *dstPtr,
81            AString *errorDetailMsg) = 0;
82
83private:
84    CryptoPlugin(const CryptoPlugin &);
85    CryptoPlugin &operator=(const CryptoPlugin &);
86};
87
88}  // namespace android
89
90extern "C" {
91    extern android::CryptoFactory *createCryptoFactory();
92}
93
94#endif  // CRYPTO_API_H_
95