Crypto.cpp revision 5beac28a34e557251bd4bbd77a6d9303a69d4319 
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//#define LOG_NDEBUG 0
18#define LOG_TAG "Crypto"
19#include <utils/Log.h>
20#include <dirent.h>
21#include <dlfcn.h>
22
23#include "Crypto.h"
24
25#include <media/hardware/CryptoAPI.h>
26#include <media/stagefright/foundation/ADebug.h>
27#include <media/stagefright/foundation/AString.h>
28#include <media/stagefright/foundation/hexdump.h>
29#include <media/stagefright/MediaErrors.h>
30
31namespace android {
32
33KeyedVector<Vector<uint8_t>, String8> Crypto::mUUIDToLibraryPathMap;
34KeyedVector<String8, wp<SharedLibrary> > Crypto::mLibraryPathToOpenLibraryMap;
35Mutex Crypto::mMapLock;
36
37static bool operator<(const Vector<uint8_t> &lhs, const Vector<uint8_t> &rhs) {
38    if (lhs.size() < rhs.size()) {
39        return true;
40    } else if (lhs.size() > rhs.size()) {
41        return false;
42    }
43
44    return memcmp((void *)lhs.array(), (void *)rhs.array(), rhs.size()) < 0;
45}
46
47Crypto::Crypto()
48    : mInitCheck(NO_INIT),
49      mFactory(NULL),
50      mPlugin(NULL) {
51}
52
53Crypto::~Crypto() {
54    delete mPlugin;
55    mPlugin = NULL;
56    closeFactory();
57}
58
59void Crypto::closeFactory() {
60    delete mFactory;
61    mFactory = NULL;
62    mLibrary.clear();
63}
64
65status_t Crypto::initCheck() const {
66    return mInitCheck;
67}
68
69/*
70 * Search the plugins directory for a plugin that supports the scheme
71 * specified by uuid
72 *
73 * If found:
74 *    mLibrary holds a strong pointer to the dlopen'd library
75 *    mFactory is set to the library's factory method
76 *    mInitCheck is set to OK
77 *
78 * If not found:
79 *    mLibrary is cleared and mFactory are set to NULL
80 *    mInitCheck is set to an error (!OK)
81 */
82void Crypto::findFactoryForScheme(const uint8_t uuid[16]) {
83
84    closeFactory();
85
86    // lock static maps
87    Mutex::Autolock autoLock(mMapLock);
88
89    // first check cache
90    Vector<uint8_t> uuidVector;
91    uuidVector.appendArray(uuid, sizeof(uuid));
92    ssize_t index = mUUIDToLibraryPathMap.indexOfKey(uuidVector);
93    if (index >= 0) {
94        if (loadLibraryForScheme(mUUIDToLibraryPathMap[index], uuid)) {
95            mInitCheck = OK;
96            return;
97        } else {
98            ALOGE("Failed to load from cached library path!");
99            mInitCheck = ERROR_UNSUPPORTED;
100            return;
101        }
102    }
103
104    // no luck, have to search
105    String8 dirPath("/vendor/lib/mediadrm");
106    String8 pluginPath;
107
108    DIR* pDir = opendir(dirPath.string());
109    if (pDir) {
110        struct dirent* pEntry;
111        while ((pEntry = readdir(pDir))) {
112
113            pluginPath = dirPath + "/" + pEntry->d_name;
114
115            if (pluginPath.getPathExtension() == ".so") {
116
117                if (loadLibraryForScheme(pluginPath, uuid)) {
118                    mUUIDToLibraryPathMap.add(uuidVector, pluginPath);
119                    mInitCheck = OK;
120                    closedir(pDir);
121                    return;
122                }
123            }
124        }
125
126        closedir(pDir);
127    }
128
129    // try the legacy libdrmdecrypt.so
130    pluginPath = "libdrmdecrypt.so";
131    if (loadLibraryForScheme(pluginPath, uuid)) {
132        mUUIDToLibraryPathMap.add(uuidVector, pluginPath);
133        mInitCheck = OK;
134        return;
135    }
136
137    ALOGE("Failed to find crypto plugin");
138    mInitCheck = ERROR_UNSUPPORTED;
139}
140
141bool Crypto::loadLibraryForScheme(const String8 &path, const uint8_t uuid[16]) {
142
143    // get strong pointer to open shared library
144    ssize_t index = mLibraryPathToOpenLibraryMap.indexOfKey(path);
145    if (index >= 0) {
146        mLibrary = mLibraryPathToOpenLibraryMap[index].promote();
147    } else {
148        index = mLibraryPathToOpenLibraryMap.add(path, NULL);
149    }
150
151    if (!mLibrary.get()) {
152        mLibrary = new SharedLibrary(path);
153        if (!*mLibrary) {
154            return false;
155        }
156
157        mLibraryPathToOpenLibraryMap.replaceValueAt(index, mLibrary);
158    }
159
160    typedef CryptoFactory *(*CreateCryptoFactoryFunc)();
161
162    CreateCryptoFactoryFunc createCryptoFactory =
163        (CreateCryptoFactoryFunc)mLibrary->lookup("createCryptoFactory");
164
165    if (createCryptoFactory == NULL ||
166        (mFactory = createCryptoFactory()) == NULL ||
167        !mFactory->isCryptoSchemeSupported(uuid)) {
168        closeFactory();
169        return false;
170    }
171    return true;
172}
173
174bool Crypto::isCryptoSchemeSupported(const uint8_t uuid[16]) {
175    Mutex::Autolock autoLock(mLock);
176
177    if (mFactory && mFactory->isCryptoSchemeSupported(uuid)) {
178        return true;
179    }
180
181    findFactoryForScheme(uuid);
182    return (mInitCheck == OK);
183}
184
185status_t Crypto::createPlugin(
186        const uint8_t uuid[16], const void *data, size_t size) {
187    Mutex::Autolock autoLock(mLock);
188
189    if (mPlugin != NULL) {
190        return -EINVAL;
191    }
192
193    if (!mFactory || !mFactory->isCryptoSchemeSupported(uuid)) {
194        findFactoryForScheme(uuid);
195    }
196
197    if (mInitCheck != OK) {
198        return mInitCheck;
199    }
200
201    return mFactory->createPlugin(uuid, data, size, &mPlugin);
202}
203
204status_t Crypto::destroyPlugin() {
205    Mutex::Autolock autoLock(mLock);
206
207    if (mInitCheck != OK) {
208        return mInitCheck;
209    }
210
211    if (mPlugin == NULL) {
212        return -EINVAL;
213    }
214
215    delete mPlugin;
216    mPlugin = NULL;
217
218    return OK;
219}
220
221bool Crypto::requiresSecureDecoderComponent(const char *mime) const {
222    Mutex::Autolock autoLock(mLock);
223
224    if (mInitCheck != OK) {
225        return mInitCheck;
226    }
227
228    if (mPlugin == NULL) {
229        return -EINVAL;
230    }
231
232    return mPlugin->requiresSecureDecoderComponent(mime);
233}
234
235ssize_t Crypto::decrypt(
236        bool secure,
237        const uint8_t key[16],
238        const uint8_t iv[16],
239        CryptoPlugin::Mode mode,
240        const void *srcPtr,
241        const CryptoPlugin::SubSample *subSamples, size_t numSubSamples,
242        void *dstPtr,
243        AString *errorDetailMsg) {
244    Mutex::Autolock autoLock(mLock);
245
246    if (mInitCheck != OK) {
247        return mInitCheck;
248    }
249
250    if (mPlugin == NULL) {
251        return -EINVAL;
252    }
253
254    return mPlugin->decrypt(
255            secure, key, iv, mode, srcPtr, subSamples, numSubSamples, dstPtr,
256            errorDetailMsg);
257}
258
259}  // namespace android
260