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 #define LOG_TAG "keystore" 18 19 #include "entropy.h" 20 21 #include <errno.h> 22 #include <fcntl.h> 23 #include <stdio.h> 24 #include <string.h> 25 #include <unistd.h> 26 27 #include <cutils/log.h> 28 29 #include "keystore_utils.h" 30 31 Entropy::~Entropy() { 32 if (mRandom >= 0) { 33 close(mRandom); 34 } 35 } 36 37 bool Entropy::open() { 38 const char* randomDevice = "/dev/urandom"; 39 mRandom = TEMP_FAILURE_RETRY(::open(randomDevice, O_RDONLY)); 40 if (mRandom < 0) { 41 ALOGE("open: %s: %s", randomDevice, strerror(errno)); 42 return false; 43 } 44 return true; 45 } 46 47 bool Entropy::generate_random_data(uint8_t* data, size_t size) const { 48 return (readFully(mRandom, data, size) == size); 49 } 50
