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PHP Extension

Generating Repeatable Random Data for Testing/Debugging

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

Chilkat PHP Extension Downloads

PHP Extension
<?php

include("chilkat.php");

$success = false;

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

$success = false;

$fortuna = new CkPrng();

// 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:
$strRandHex = $fortuna->genRandom(16,'hex');
$strRandBase64 = $fortuna->genRandom(22,'base64');
$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:
$fortuna2 = new CkPrng();

$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";

?>