Lua

Generating Repeatable Random Data for Testing/Debugging

See more PRNG Examples

Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging. Lua

local chilkat = require("chilkat")

-- This example assumes the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local success = false

local fortuna = chilkat.Prng.new()

-- Normally an application would seed the PRNG with entropy from
-- some real random source.  However, sometimes we want the same
-- random sequence of bytes for testing and debugging purposes.
-- This a reason why GetEntropy and AddEntropy are two different methods.
-- An application could omit the call to GetEntropy, and instead pass
-- non-random data to AddEntropy. For example:

-- Seed the PRNG with non-entropy, so we get a repeatable sequence.
-- Note: AddEntropy can be called any number of times.
success = fortuna:add_entropy("01020304", "hex")
success = fortuna:add_entropy("hello world", "ascii")

-- Generate some random data:
local strRandHex = fortuna:gen_random(16, "hex")
local strRandBase64 = fortuna:gen_random(22, "base64")
local strRandBase58 = fortuna:gen_random(32, "base58")

print("hex random bytes: " .. strRandHex)
print("base64 random bytes: " .. strRandBase64)
print("base58 random bytes: " .. strRandBase58)

-- Try it again with a different object to verify that the same results are obtained:
local fortuna2 = chilkat.Prng.new()

success = fortuna2:add_entropy("01020304", "hex")
success = fortuna2:add_entropy("hello world", "ascii")

strRandHex = fortuna2:gen_random(16, "hex")
strRandBase64 = fortuna2:gen_random(22, "base64")
strRandBase58 = fortuna2:gen_random(32, "base58")

print("hex random bytes: " .. strRandHex)
print("base64 random bytes: " .. strRandBase64)
print("base58 random bytes: " .. strRandBase58)