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
~Entropy()31 Entropy::~Entropy() {
32 if (mRandom >= 0) {
33 close(mRandom);
34 }
35 }
36
open()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
generate_random_data(uint8_t * data,size_t size) const47 bool Entropy::generate_random_data(uint8_t* data, size_t size) const {
48 return (readFully(mRandom, data, size) == size);
49 }
50