<?php
/**
 * @package   awf
 * @copyright Copyright (c)2014-2022 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license   GNU GPL version 3 or later
 */

/**
 * A Compatibility library with PHP 5.5's simplified password hashing API.
 *
 * @author Anthony Ferrara <ircmaxell@php.net>
 * @license http://www.opensource.org/licenses/mit-license.html MIT License
 * @copyright 2012 The Authors
 */

namespace {

	if (!defined('PASSWORD_DEFAULT')) {

		define('PASSWORD_BCRYPT', 1);
		define('PASSWORD_DEFAULT', PASSWORD_BCRYPT);

		/**
		 * Hash the password using the specified algorithm
		 *
		 * @param string $password The password to hash
		 * @param int    $algo     The algorithm to use (Defined by PASSWORD_* constants)
		 * @param array  $options  The options for the algorithm to use
		 *
		 * @return string|false The hashed password, or false on error.
		 */
		function password_hash($password, $algo, array $options = array()) {
			if (!function_exists('crypt')) {
				trigger_error("Crypt must be loaded for password_hash to function", E_USER_WARNING);
				return null;
			}
			if (!is_string($password)) {
				trigger_error("password_hash(): Password must be a string", E_USER_WARNING);
				return null;
			}
			if (!is_int($algo)) {
				trigger_error("password_hash() expects parameter 2 to be long, " . gettype($algo) . " given", E_USER_WARNING);
				return null;
			}
			$resultLength = 0;
			switch ($algo) {
				case PASSWORD_BCRYPT:
					// Note that this is a C constant, but not exposed to PHP, so we don't define it here.
					$cost = 10;
					if (isset($options['cost'])) {
						$cost = $options['cost'];
						if ($cost < 4 || $cost > 31) {
							trigger_error(sprintf("password_hash(): Invalid bcrypt cost parameter specified: %d", $cost), E_USER_WARNING);
							return null;
						}
					}
					// The length of salt to generate
					$raw_salt_len = 16;
					// The length required in the final serialization
					$required_salt_len = 22;
					$hash_format = sprintf("$2y$%02d$", $cost);
					// The expected length of the final crypt() output
					$resultLength = 60;
					break;
				default:
					trigger_error(sprintf("password_hash(): Unknown password hashing algorithm: %s", $algo), E_USER_WARNING);
					return null;
			}
			$salt_requires_encoding = false;
			if (isset($options['salt'])) {
				switch (gettype($options['salt'])) {
					case 'NULL':
					case 'boolean':
					case 'integer':
					case 'double':
					case 'string':
						$salt = (string) $options['salt'];
						break;
					case 'object':
						if (method_exists($options['salt'], '__tostring')) {
							$salt = (string) $options['salt'];
							break;
						}
					case 'array':
					case 'resource':
					default:
						trigger_error('password_hash(): Non-string salt parameter supplied', E_USER_WARNING);
						return null;
				}
				if (PasswordCompat\binary\_strlen($salt) < $required_salt_len) {
					trigger_error(sprintf("password_hash(): Provided salt is too short: %d expecting %d", PasswordCompat\binary\_strlen($salt), $required_salt_len), E_USER_WARNING);
					return null;
				} elseif (0 == preg_match('#^[a-zA-Z0-9./]+$#D', $salt)) {
					$salt_requires_encoding = true;
				}
			} else {
				$buffer = '';
				$buffer_valid = false;
				if (function_exists('mcrypt_create_iv') && !defined('PHALANGER')) {
					$buffer = mcrypt_create_iv($raw_salt_len, MCRYPT_DEV_URANDOM);
					if ($buffer) {
						$buffer_valid = true;
					}
				}
				if (!$buffer_valid && function_exists('openssl_random_pseudo_bytes')) {
					$buffer = openssl_random_pseudo_bytes($raw_salt_len);
					if ($buffer) {
						$buffer_valid = true;
					}
				}
				if (!$buffer_valid && @is_readable('/dev/urandom')) {
					$f = fopen('/dev/urandom', 'r');
					$read = PasswordCompat\binary\_strlen($buffer);
					while ($read < $raw_salt_len) {
						$buffer .= fread($f, $raw_salt_len - $read);
						$read = PasswordCompat\binary\_strlen($buffer);
					}
					fclose($f);
					if ($read >= $raw_salt_len) {
						$buffer_valid = true;
					}
				}
				if (!$buffer_valid || PasswordCompat\binary\_strlen($buffer) < $raw_salt_len) {
					$bl = PasswordCompat\binary\_strlen($buffer);
					for ($i = 0; $i < $raw_salt_len; $i++) {
						if ($i < $bl) {
							$buffer[$i] = $buffer[$i] ^ chr(mt_rand(0, 255));
						} else {
							$buffer .= chr(mt_rand(0, 255));
						}
					}
				}
				$salt = $buffer;
				$salt_requires_encoding = true;
			}
			if ($salt_requires_encoding) {
				// encode string with the Base64 variant used by crypt
				$base64_digits =
					'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
				$bcrypt64_digits =
					'./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

				$base64_string = base64_encode($salt);
				$salt = strtr(rtrim($base64_string, '='), $base64_digits, $bcrypt64_digits);
			}
			$salt = PasswordCompat\binary\_substr($salt, 0, $required_salt_len);

			$hash = $hash_format . $salt;

			$ret = crypt($password, $hash);

			if (!is_string($ret) || PasswordCompat\binary\_strlen($ret) != $resultLength) {
				return false;
			}

			return $ret;
		}

		/**
		 * Get information about the password hash. Returns an array of the information
		 * that was used to generate the password hash.
		 *
		 * array(
		 *    'algo' => 1,
		 *    'algoName' => 'bcrypt',
		 *    'options' => array(
		 *        'cost' => 10,
		 *    ),
		 * )
		 *
		 * @param string $hash The password hash to extract info from
		 *
		 * @return array The array of information about the hash.
		 */
		function password_get_info($hash) {
			$return = array(
				'algo' => 0,
				'algoName' => 'unknown',
				'options' => array(),
			);
			if (PasswordCompat\binary\_substr($hash, 0, 4) == '$2y$' && PasswordCompat\binary\_strlen($hash) == 60) {
				$return['algo'] = PASSWORD_BCRYPT;
				$return['algoName'] = 'bcrypt';
				list($cost) = sscanf($hash, "$2y$%d$");
				$return['options']['cost'] = $cost;
			}
			return $return;
		}

		/**
		 * Determine if the password hash needs to be rehashed according to the options provided
		 *
		 * If the answer is true, after validating the password using password_verify, rehash it.
		 *
		 * @param string $hash    The hash to test
		 * @param int    $algo    The algorithm used for new password hashes
		 * @param array  $options The options array passed to password_hash
		 *
		 * @return boolean True if the password needs to be rehashed.
		 */
		function password_needs_rehash($hash, $algo, array $options = array()) {
			$info = password_get_info($hash);
			if ($info['algo'] != $algo) {
				return true;
			}
			switch ($algo) {
				case PASSWORD_BCRYPT:
					$cost = isset($options['cost']) ? $options['cost'] : 10;
					if ($cost != $info['options']['cost']) {
						return true;
					}
					break;
			}
			return false;
		}

		/**
		 * Verify a password against a hash using a timing attack resistant approach
		 *
		 * @param string $password The password to verify
		 * @param string $hash     The hash to verify against
		 *
		 * @return boolean If the password matches the hash
		 */
		function password_verify($password, $hash) {
			if (!function_exists('crypt')) {
				trigger_error("Crypt must be loaded for password_verify to function", E_USER_WARNING);
				return false;
			}
			$ret = crypt($password, $hash);
			if (!is_string($ret) || PasswordCompat\binary\_strlen($ret) != PasswordCompat\binary\_strlen($hash) || PasswordCompat\binary\_strlen($ret) <= 13) {
				return false;
			}

			$status = 0;
			for ($i = 0; $i < PasswordCompat\binary\_strlen($ret); $i++) {
				$status |= (ord($ret[$i]) ^ ord($hash[$i]));
			}

			return $status === 0;
		}
	}

}

namespace PasswordCompat\binary {
	if (!function_exists('PasswordCompat\\binary\\_strlen'))
	{
		/**
		 * Count the number of bytes in a string
		 *
		 * We cannot simply use strlen() for this, because it might be overwritten by the mbstring extension.
		 * In this case, strlen() will count the number of *characters* based on the internal encoding. A
		 * sequence of bytes might be regarded as a single multibyte character.
		 *
		 * @param string $binary_string The input string
		 *
		 * @internal
		 * @return int The number of bytes
		 */
		function _strlen($binary_string) {
			if (function_exists('mb_strlen')) {
				return mb_strlen($binary_string, '8bit');
			}
			return strlen($binary_string);
		}
	}

	if (!function_exists('PasswordCompat\\binary\\_substr'))
	{
		/**
		 * Get a substring based on byte limits
		 *
		 * @see _strlen()
		 *
		 * @param string $binary_string The input string
		 * @param int    $start
		 * @param int    $length
		 *
		 * @internal
		 * @return string The substring
		 */
		function _substr($binary_string, $start, $length) {
			if (function_exists('mb_substr')) {
				return mb_substr($binary_string, $start, $length, '8bit');
			}
			return substr($binary_string, $start, $length);
		}
	}
}