1 // Copyright (C) 2018-2019, Cloudflare, Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright notice,
9 // this list of conditions and the following disclaimer.
10 //
11 // * Redistributions in binary form must reproduce the above copyright
12 // notice, this list of conditions and the following disclaimer in the
13 // documentation and/or other materials provided with the distribution.
14 //
15 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
16 // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 // THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
19 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
24 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
rand_bytes(buf: &mut [u8])27 pub fn rand_bytes(buf: &mut [u8]) {
28 unsafe {
29 RAND_bytes(buf.as_mut_ptr(), buf.len());
30 }
31 }
32
rand_u8() -> u833 pub fn rand_u8() -> u8 {
34 let mut buf = [0; 1];
35
36 rand_bytes(&mut buf);
37
38 buf[0]
39 }
40
rand_u64() -> u6441 pub fn rand_u64() -> u64 {
42 let mut buf = [0; 8];
43
44 rand_bytes(&mut buf);
45
46 u64::from_ne_bytes(buf)
47 }
48
rand_u64_uniform(max: u64) -> u6449 pub fn rand_u64_uniform(max: u64) -> u64 {
50 let chunk_size = u64::max_value() / max;
51 let end_of_last_chunk = chunk_size * max;
52
53 let mut r = rand_u64();
54
55 while r >= end_of_last_chunk {
56 r = rand_u64();
57 }
58
59 r / chunk_size
60 }
61
62 extern {
RAND_bytes(buf: *mut u8, len: libc::size_t) -> libc::c_int63 fn RAND_bytes(buf: *mut u8, len: libc::size_t) -> libc::c_int;
64 }
65