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 #pragma once
25 
26 #include <compiler.h>
27 #include <sys/types.h>
28 
29 __BEGIN_CDECLS;
30 
31 /**
32  * rand_get_size() - Get Random Integer
33  *
34  * @max:  inclusive upper bound for the random integer
35  *
36  * Return: a pseudorandom integer in the range 0 to max inclusive
37  *         (i.e., the mathematical range [0, max]).
38  */
39 size_t rand_get_size(size_t max);
40 
41 /**
42  * rand_get_bytes() - Get Random Bytes
43  *
44  * @buf:  points to bytes array that will contain random bytes
45  * @len:  number of random bytes
46  *
47  * Return: 0 if buf is filled up with len random bytes,
48  *         non-zero otherwise.
49  */
50 int rand_get_bytes(uint8_t* buf, size_t len);
51 
52 /**
53  * add_entropy() - Add entropy to CSPRNG
54  *
55  * @buf:  points to data from entropy source
56  * @len:  number of bytes from entropy source
57  *
58  * Return: 0 if new entropy is added to CSPRNG,
59  *         non-zero otherwise.
60  */
61 int rand_add_entropy(const uint8_t* buf, size_t len);
62 
63 __END_CDECLS;
64