euantorano/sysrandom.nim

A Nim library to generate random numbers and random ranges of bytes using the system's PRNG.

sysrandom.nim

A simple library to generate random data, using the system's PRNG.

The following sources of randomness are used depending on platform:

• On OpenBSD, arc4random(3) is used.
• On Windows, RtlGenRandom() is used.
• On recent (>=3.17) versions of the Linux kernel, getrandom(2) is used.
• On all other posix systems, /dev/urandom is used.

Installation

sysrandom can be installed using Nimble:

nimble install sysrandom

Or add the following to your .nimble file:

# Dependencies

requires "sysrandom >= 1.1.0"

API Documentation

Usage

import sysrandom

## Make sure to close the `/dev/urandom` file on posix or close the DLL handle on Windows after you're finished generating random data
defer: closeRandom()

## Fill a buffer with x random bytes
var buffer = newSeq[byte](20)
getRandomBytes(addr buffer[0], len(buffer))

## Create an array of 10 random bytes (`array[10, byte]`)
let randomBytes = getRandomBytes(10)
echo "Generating 10 random bytes: ", repr(randomBytes)

## Get a random unsigned 32 bit integer (`uint32`) in the range 0..0xffffffff
let randomUint32 = getRandom()
echo "Random integer: ", randomUint32

## Generate a random string based upon a 32 byte array of random values, base 64 encoded
let randomString = getRandomString(32)
echo "Random string: ", randomString