1 /*
2 * Copyright (c) 2020 Google Inc. All rights reserved
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 #include <assert.h>
25 #include <lib/rand/rand.h>
26 #include <platform/random.h>
27 #include <rand.h>
28 #include <stdint.h>
29 #include <sys/types.h>
30
rand_get_size(size_t max)31 size_t rand_get_size(size_t max) {
32 size_t rand_size;
33 rand_get_bytes((uint8_t*)(&rand_size), sizeof(rand_size));
34 if (max == SIZE_MAX) {
35 return rand_size;
36 }
37 size_t retry = SIZE_MAX / (max + 1) * (max + 1);
38 while (rand_size >= retry) {
39 rand_get_bytes((uint8_t*)(&rand_size), sizeof(rand_size));
40 }
41 return rand_size % (max + 1);
42 }
43
rand_get_bytes(uint8_t * buf,size_t len)44 int rand_get_bytes(uint8_t* buf, size_t len) {
45 DEBUG_ASSERT(buf);
46 platform_random_get_bytes(buf, len);
47 return 0;
48 }
49