1 /*
2 * SPDX-FileCopyrightText: 2018-2022 Espressif Systems (Shanghai) CO LTD
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <sys/random.h>
8 #include <sys/param.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <string.h>
12 #include "esp_random.h"
13 #include "esp_log.h"
14
15 static const char *TAG = "RANDOM";
16
getrandom(void * buf,size_t buflen,unsigned int flags)17 ssize_t getrandom(void *buf, size_t buflen, unsigned int flags)
18 {
19 // Flags are ignored because:
20 // - esp_random is non-blocking so it works for both blocking and non-blocking calls,
21 // - don't have opportunity so set som other source of entropy.
22
23 ESP_LOGD(TAG, "getrandom(buf=0x%x, buflen=%d, flags=%u)", (int) buf, buflen, flags);
24
25 if (buf == NULL) {
26 errno = EFAULT;
27 ESP_LOGD(TAG, "getrandom returns -1 (EFAULT)");
28 return -1;
29 }
30
31 esp_fill_random(buf, buflen);
32
33 ESP_LOGD(TAG, "getrandom returns %d", buflen);
34 return buflen;
35 }
36
