Perl

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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $success = 0;

my $fortuna = Chilkat2::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->AddEntropy('01020304', 'hex');
$success = $fortuna->AddEntropy('hello world', 'ascii');

# Generate some random data:
my $strRandHex = $fortuna->GenRandom(16, 'hex');
my $strRandBase64 = $fortuna->GenRandom(22, 'base64');
my $strRandBase58 = $fortuna->GenRandom(32, 'base58');

print 'hex random bytes: ', $strRandHex, "\n";
print 'base64 random bytes: ', $strRandBase64, "\n";
print 'base58 random bytes: ', $strRandBase58, "\n";

# Try it again with a different object to verify that the same results are obtained:
my $fortuna2 = Chilkat2::Prng->new;

$success = $fortuna2->AddEntropy('01020304', 'hex');
$success = $fortuna2->AddEntropy('hello world', 'ascii');

$strRandHex = $fortuna2->GenRandom(16, 'hex');
$strRandBase64 = $fortuna2->GenRandom(22, 'base64');
$strRandBase58 = $fortuna2->GenRandom(32, 'base58');

print 'hex random bytes: ', $strRandHex, "\n";
print 'base64 random bytes: ', $strRandBase64, "\n";
print 'base58 random bytes: ', $strRandBase58, "\n";