PHP - Method generates a random password

generatePassword.php

	/**
	 * Method generates a password
	 * @param int $length length of password
	 * @param int $strength 
	 * 0 - Password with random case-sensitive characters and digits (standard set of 64 characters
	 * 1 - Password will be generated of a extended set of 88 characters
	 * @return string the generated password
	 */
	public function generatePassword($length=8, $strength=1) {
		$password = '';
		//standard set of 64 characters
		$chars = '!#%+23456789:=?@ABCDEFGHJKLMNPRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
		if ($stength) {
		  // extended set of 88 characters
			$chars = '!"#$%&()*+,-./23456789:;<=>?@ABCDEFGHJKLMNOPRSTUVWXYZ[\]^_abcdefghijkmnopqrstuvwxyz{|}~'."'";
			//password length at least 12 characters
			$length = ($length <= 12) ? 12 : $length;
		}
		$max = strlen($chars) - 1;
		for ($i = 0; $i < $length; $i++) {
			$password .= $chars[mt_rand(0, $max)];
		}
		return $password;
	}