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v/vlib/crypto/rand/rand_solaris.v
2020-03-21 09:48:02 +01:00

46 lines
1.1 KiB
V

// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module rand
import math
#include <sys/random.h>
fn C.getrandom(p byteptr, n size_t, flags u32) int
const (
read_batch_size = 256
)
pub fn read(bytes_needed int) ?[]byte {
mut buffer := &byte(0)
unsafe {
buffer = malloc(bytes_needed)
}
mut bytes_read := 0
// getrandom syscall wont block if requesting <= 256 bytes
if bytes_needed > read_batch_size {
no_batches := int(math.floor(f64(bytes_needed/read_batch_size)))
for i:=0; i<no_batches; i++ {
if v_getrandom(read_batch_size, buffer+bytes_read) == -1 {
return read_error
}
bytes_read += read_batch_size
}
}
if v_getrandom(bytes_needed-bytes_read, buffer+bytes_read) == -1 {
return read_error
}
return c_array_to_bytes_tmp(bytes_needed, buffer)
}
fn v_getrandom(bytes_needed int, buffer voidptr) int {
if bytes_needed > read_batch_size {
panic('getrandom() dont request more than $read_batch_size bytes at once.')
}
return C.getrandom(buffer, bytes_needed, 0)
}