math_uvrandom.lua

local uv = require 'uv'
local bit = require 'bit'

-- Generates cryptographically secure integers in the range [min, max).
function math.uvrandom(min, max)
	assert(min, 'expected lower bound')
	assert(max, 'expected upper bound')
	assert(max > min, 'expected max > min')
	local range = max - min
	
	local log256range = math.ceil(math.log(range, 256)) -- number of bytes required to store range

	local bytes = uv.random(log256range * 2) -- get double the bytes required so we can distribute evenly with modulo
	local random = 0

	for i = 1, #bytes do
		random = bit.lshift(random, 8) + bytes:byte(i, i)
	end
	
	return random % range + min
end