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 TLOG_TAG "hwrng_fake_srv"
18 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <uapi/err.h>
23 
24 #include <hwcrypto/hwrng_dev.h>
25 #include <trusty_log.h>
26 
27 #pragma message "Compiling FAKE HWRNG provider"
28 
hwrng_dev_init(void)29 int hwrng_dev_init(void) {
30     TLOGE("Init FAKE!!!! HWRNG service provider\n");
31     TLOGE("FAKE HWRNG service provider MUST be replaced with the REAL one\n");
32     return NO_ERROR;
33 }
34 
35 static size_t counter = 1;
36 
37 __attribute__((no_sanitize("unsigned-integer-overflow"))) int
hwrng_dev_get_rng_data(uint8_t * buf,size_t buf_len)38 hwrng_dev_get_rng_data(uint8_t* buf, size_t buf_len) {
39     for (uint8_t* end = buf + buf_len; buf < end; ++buf) {
40         *buf = counter++ & 0xff;
41     }
42     return NO_ERROR;
43 }
44