1 /* 2 * Copyright (C) 2016 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 #ifndef ANDROID_VOLD_KEYUTIL_H 18 #define ANDROID_VOLD_KEYUTIL_H 19 20 #include "KeyBuffer.h" 21 #include "KeyStorage.h" 22 23 #include <fscrypt/fscrypt.h> 24 25 #include <memory> 26 #include <string> 27 28 namespace android { 29 namespace vold { 30 31 // Description of how to generate a key when needed. 32 struct KeyGeneration { 33 size_t keysize; 34 bool allow_gen; 35 bool use_hw_wrapped_key; 36 }; 37 38 // Generate a key as specified in KeyGeneration 39 bool generateStorageKey(const KeyGeneration& gen, KeyBuffer* key); 40 41 // Returns a key with allow_gen false so generateStorageKey returns false; 42 // this is used to indicate to retrieveOrGenerateKey that a key should not 43 // be generated. 44 const KeyGeneration neverGen(); 45 46 // Install a file-based encryption key to the kernel, for use by encrypted files 47 // on the specified filesystem using the specified encryption policy version. 48 // 49 // Returns %true on success, %false on failure. On success also sets *policy 50 // to the EncryptionPolicy used to refer to this key. 51 bool installKey(const std::string& mountpoint, const android::fscrypt::EncryptionOptions& options, 52 const KeyBuffer& key, android::fscrypt::EncryptionPolicy* policy); 53 54 // Evict a file-based encryption key from the kernel. 55 bool evictKey(const std::string& mountpoint, const android::fscrypt::EncryptionPolicy& policy); 56 57 // Retrieves the key from the named directory, or generates it if it doesn't 58 // exist. 59 bool retrieveOrGenerateKey(const std::string& key_path, const std::string& tmp_path, 60 const KeyAuthentication& key_authentication, const KeyGeneration& gen, 61 KeyBuffer* key); 62 63 } // namespace vold 64 } // namespace android 65 66 #endif 67