PhpMt

A Rust implementation of PHP's MT19937-based random number generator.

This implementation is bit-for-bit compatible with PHP 7.1+ for:

• mt_srand(seed)
• mt_rand()
• mt_rand(min, max)

Notes:

• In PHP 7.1+, rand() is an alias of mt_rand().
• In PHP 7.1+, srand(seed) is an alias of mt_srand(seed).
• This implementation matches the Zend Engine MT19937 algorithm.

Implementation details:

• 624-element MT19937 state array
• Exact Zend tempering constants
• mt_rand() returns 31-bit output (next_u32() >> 1)
• mt_rand(min, max) uses integer rejection sampling (no float scaling)

This crate is intended for deterministic cross-language compatibility and reproducible test vectors.

Not cryptographically secure.

php_mt

Bit-for-bit compatible implementation of PHP 7.1+ MT19937 (mt_rand) in Rust.

This crate reproduces the exact output of:

• mt_srand(seed)
• mt_rand()
• mt_rand(min, max)

for PHP 7.1 and newer.

It is intended for deterministic cross-language compatibility and reproducible test vectors — not for cryptographic use.

Features

• Exact Zend Engine MT19937 constants
• 624-element state array
• 31-bit output for mt_rand() (matches PHP)
• Integer rejection sampling for mt_rand(min, max)
• No floating point scaling
• No external dependencies
• Fully deterministic

Example

use php_mt::PhpMt;

let mut rng = PhpMt::new(1234);

assert_eq!(rng.mt_rand(), 411284887);
assert_eq!(rng.mt_rand_range(0, 100), 20);