Validate and generate Hmailserver passwords using PHP

Hmail_Pass

<?php

/**
 * A poor implementation of Hmailserver's HashCreator.h in PHP
 * 
 * Blowfish(ETBlowFish) and "plaintext"(ETNone) not currently supported.
 * 
 * This matches with accountpwencryption field on DB. Hmail_Pass class uses different constants for types, like original source.
 * From \hmailserver\source\Server\Common\Util\Crypt.h
 *       ETNone = 0,
         ETBlowFish = 1,
         ETMD5 = 2,
         ETSHA256 = 3
 *
 * @author Hazar
 */

class Hmail_Pass {

	// From hmailserver\source\Server\Common\Util\Hashing\HashCreator.h
	const SALT_LENGTH = 6;
	const SHA1 = 1;
	const SHA256 = 2;
	const MD5 = 3;
	const hex = 1;
	const base64 = 2;

	public function GenerateHash($string, $salt = NULL, $output = self::hex) {

		if (!$salt || empty($salt) || strlen($salt) != self::SALT_LENGTH) {
			$salt = substr(md5(rand()), 0, self::SALT_LENGTH);
		}

		return $salt . self::GetHash($salt . $string, self::SHA256, $output);
	}

	public function ValidateHash($password, $originalHash, $useSalt = true, $hashType = self::SHA256) {
		if ($useSalt) {
			$salt = self::GetSalt($originalHash);
			$hash = self::GetHash($salt . $password, $hashType);

			return ($originalHash == ($salt . $hash));
		} else {
			$hash = self::GetHash($password, $hashType);
			
			return ($originalHash == $hash);
		}
	}

	private function GetSalt($string) {
		return substr($string, 0, self::SALT_LENGTH);
	}

	private function GetHash($string, $encoding = self::SHA256, $output = self::hex) {
		$raw = ($output == self::base64) ? true : false;

		switch ($encoding) {
			case self::SHA1:
				$hash = hash('sha1', $string, $raw);
				break;

			case self::SHA256:
				$hash = hash('sha256', $string, $raw);
				break;

			case self::MD5:
				$hash = hash('md5', $string, $raw);
				break;
		}

		return ($raw) ? base64_encode($hash) : $hash;
	}

}