README

A PHP library for generating random strings using Crockford Base32 encoding alphabet.

Features

• Generates cryptographically secure random strings using PHP 8.3+'s Random\Randomizer
• Uses Crockford Base32 alphabet: 0123456789ABCDEFGHJKMNPQRSTVWXYZ
• Excludes ambiguous characters (I, L, O, U) for better readability
• Type-safe with strict typing enabled
• Comprehensive error handling
• Optional brick/math dependency for large unique pools (> 1.15 quintillion codes)

Requirements

• PHP 8.3 or higher
• Random\Randomizer extension (included in PHP 8.3+)

Optional Dependencies

• brick/math (^0.8 || ^0.9 || ^0.10 || ^0.11 || ^0.12) - Required only for UniqueCrockfordPool with lengths > 12. For most use cases (pool lengths 1-12, which support up to 1.15 quintillion unique codes), native PHP integers are sufficient.

Installation

composer require checkthiscloud/crockford-random

Usage

Basic Random String Generation

<?php
use CheckThisCloud\CrockfordRandom\CrockfordRandom;

// Generate a random string of specified length
$randomString = CrockfordRandom::generate(10);
echo $randomString; // Example: "4G2KPQRST3"

// Generate empty string
$empty = CrockfordRandom::generate(0);
echo $empty; // ""

// Generate longer strings
$longString = CrockfordRandom::generate(32);
echo $longString; // Example: "8N2KPQRST34G2KPQRST34G2KPQRST3W"

Unique Code Pool (Experimental)

The UniqueCrockfordPool class generates unique Crockford Base32 codes of a fixed length, ensuring no duplicates within a pool instance:

<?php
use CheckThisCloud\CrockfordRandom\UniqueCrockfordPool;

// Create a pool for 6-character codes (capacity: 1,073,741,824 unique codes)
$pool = new UniqueCrockfordPool(6);

// Get the next unique code
$code1 = $pool->next();  // Example: "A3F2K9"
$code2 = $pool->next();  // Example: "7Y4MXP" (guaranteed different from code1)

// Reserve multiple codes at once
$codes = $pool->reserve(100);  // Returns array of 100 unique codes

// Check pool status
echo $pool->issuedCount();  // 102 (2 + 100)
echo $pool->capacityInt();  // 1073741824
echo $pool->remaining();    // 1073741722

// Check if a code was issued
$pool->hasIssued($code1);  // true
$pool->hasIssued('ZZZZZZ');  // false

// Reset the pool (useful for testing)
$pool->reset();
echo $pool->issuedCount();  // 0

Pool Capacity Limits

The pool capacity is 32^length:

• Length 1-12: Supported without brick/math (up to 1.15 quintillion codes at length 12)
• Length 13+: Requires brick/math library

# Install brick/math for large pools (optional)
composer require brick/math

If you try to create a pool with length > 12 without brick/math, you'll get a clear error message:

// Without brick/math installed
$pool = new UniqueCrockfordPool(13);
// Throws: InvalidLength: "Length 13 requires brick/math library. 
//         Install it with: composer require brick/math. 
//         For lengths up to 12, brick/math is not required."

Error Handling

The library throws ValueError for invalid input:

try {
    CrockfordRandom::generate(-1);
} catch (ValueError $e) {
    echo $e->getMessage(); // "Length must be positive"
}

Testing

Run the tests with PHPUnit:

composer test
# or
./vendor/bin/phpunit

Character Set

The library uses the Crockford Base32 alphabet which excludes ambiguous characters:

• Included: 0123456789ABCDEFGHJKMNPQRSTVWXYZ
• Excluded: I, L, O, U (to avoid confusion with 1, 1, 0, V)

License

MIT License