PhpassPasswordHash.php

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<?php
 
declare(strict_types=1);
 
/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */
 
namespace ‪TYPO3\CMS\Core\Crypto\PasswordHashing;
 
use ‪TYPO3\CMS\Core\Crypto\Random;
use ‪TYPO3\CMS\Core\Utility\GeneralUtility;
 
class ‪PhpassPasswordHash implements ‪PasswordHashInterface
{
    protected const ‪PREFIX = '$P$';
 
    protected ‪$options = [
        'hash_count' => 14,
    ];
 
    public function ‪__construct(array ‪$options = [])
    {
        $newOptions = ‪$this->options;
        if (isset(‪$options['hash_count'])) {
            if ((int)‪$options['hash_count'] < 7 || (int)‪$options['hash_count'] > 24) {
                throw new \InvalidArgumentException(
                    'hash_count must not be lower than 7 or bigger than 24',
                    1533940454
                );
            }
            $newOptions['hash_count'] = (int)‪$options['hash_count'];
        }
        $this->options = $newOptions;
    }
 
    public function ‪checkPassword(string $plainPW, string $saltedHashPW): bool
    {
        $hash = $this->‪cryptPassword($plainPW, $saltedHashPW);
        return $hash && hash_equals($hash, $saltedHashPW);
    }
 
    public function ‪isAvailable(): bool
    {
        return true;
    }
 
    public function ‪getHashedPassword(string $password): ?string
    {
        $saltedPW = null;
        if (!empty($password)) {
            $salt = $this->‪getGeneratedSalt();
            $saltedPW = $this->‪cryptPassword($password, $this->‪applySettingsToSalt($salt));
        }
        return $saltedPW;
    }
 
    public function ‪isHashUpdateNeeded(string $passString): bool
    {
        // Check whether this was an updated password.
        if (strncmp($passString, '$P$', 3) || strlen($passString) != 34) {
            return true;
        }
        // Check whether the iteration count used differs from the standard number.
        return $this->‪getCountLog2($passString) < $this->options['hash_count'];
    }
 
    public function ‪isValidSaltedPW(string $saltedPW): bool
    {
        $isValid = !strncmp(self::PREFIX, $saltedPW, strlen(self::PREFIX));
        if ($isValid) {
            $isValid = $this->‪isValidSalt($saltedPW);
        }
        return $isValid;
    }
 
    protected function ‪applySettingsToSalt(string $salt): string
    {
        $saltWithSettings = $salt;
        $reqLenBase64 = $this->‪getLengthBase64FromBytes(6);
        // Salt without setting
        if (strlen($salt) == $reqLenBase64) {
            // We encode the final log2 iteration count in base 64.
            $itoa64 = $this->‪getItoa64();
            $saltWithSettings = self::PREFIX . $itoa64[$this->options['hash_count']];
            $saltWithSettings .= $salt;
        }
        return $saltWithSettings;
    }
 
    protected function ‪cryptPassword(string $password, string $setting)
    {
        $saltedPW = null;
        $reqLenBase64 = $this->‪getLengthBase64FromBytes(6);
        // Retrieving settings with salt
        $setting = substr($setting, 0, strlen(self::PREFIX) + 1 + $reqLenBase64);
        $count_log2 = $this->‪getCountLog2($setting);
        // Hashes may be imported from elsewhere, so we allow != HASH_COUNT
        if ($count_log2 >= 7 && $count_log2 <= 24) {
            $salt = substr($setting, strlen(self::PREFIX) + 1, $reqLenBase64);
            // We must use md5() or sha1() here since they are the only cryptographic
            // primitives always available in PHP 5. To implement our own low-level
            // cryptographic function in PHP would result in much worse performance and
            // consequently in lower iteration counts and hashes that are quicker to crack
            // (by non-PHP code).
            $count = 1 << $count_log2;
            $hash = md5($salt . $password, true);
            do {
                $hash = md5($hash . $password, true);
            } while (--$count);
            $saltedPW = $setting . $this->‪base64Encode($hash, 16);
            // base64Encode() of a 16 byte MD5 will always be 22 characters.
            return strlen($saltedPW) == 34 ? $saltedPW : false;
        }
        return $saltedPW;
    }
 
    protected function ‪getCountLog2(string $setting): int
    {
        return strpos($this->‪getItoa64(), $setting[strlen(self::PREFIX)]);
    }
 
    protected function ‪getGeneratedSalt(): string
    {
        $randomBytes = GeneralUtility::makeInstance(Random::class)->generateRandomBytes(6);
        return $this->‪base64Encode($randomBytes, 6);
    }
 
    protected function ‪getItoa64(): string
    {
        return './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    }
 
    protected function ‪isValidSalt(string $salt): bool
    {
        $isValid = ($skip = false);
        $reqLenBase64 = $this->‪getLengthBase64FromBytes(6);
        if (strlen($salt) >= $reqLenBase64) {
            // Salt with prefixed setting
            if (!strncmp('$', $salt, 1)) {
                if (!strncmp(self::PREFIX, $salt, strlen(self::PREFIX))) {
                    $isValid = true;
                    $salt = substr($salt, (int)strrpos($salt, '$') + 2);
                } else {
                    $skip = true;
                }
            }
            // Checking base64 characters
            if (!$skip && strlen($salt) >= $reqLenBase64) {
                if (preg_match('/^[' . preg_quote($this->‪getItoa64(), '/') . ']{' . $reqLenBase64 . ',' . $reqLenBase64 . '}$/', substr($salt, 0, $reqLenBase64))) {
                    $isValid = true;
                }
            }
        }
        return $isValid;
    }
 
    protected function ‪base64Encode(string $input, int $count): string
    {
        ‪$output = '';
        $i = 0;
        $itoa64 = $this->‪getItoa64();
        do {
            $value = ord($input[$i++]);
            ‪$output .= $itoa64[$value & 63];
            if ($i < $count) {
                $value |= ord($input[$i]) << 8;
            }
            ‪$output .= $itoa64[$value >> 6 & 63];
            if ($i++ >= $count) {
                break;
            }
            if ($i < $count) {
                $value |= ord($input[$i]) << 16;
            }
            ‪$output .= $itoa64[$value >> 12 & 63];
            if ($i++ >= $count) {
                break;
            }
            ‪$output .= $itoa64[$value >> 18 & 63];
        } while ($i < $count);
        return ‪$output;
    }
 
    protected function ‪getLengthBase64FromBytes(int $byteLength): int
    {
        // Calculates bytes in bits in base64
        return (int)ceil($byteLength * 8 / 6);
    }
}