<?php
#
# Portable PHP password hashing framework.
#
# Version 0.5 / genuine.
# Version 0.5 / ClicShopping:
#   * Added stream_set_read_buffer() when reading from /dev/urandom
#   * Added openssl_random_pseudo_bytes() and random_bytes() to
#     get_random_bytes()
#
# Written by Solar Designer <solar at openwall.com> in 2004-2006 and placed in
# the public domain.  Revised in subsequent years, still public domain.
#
# There's absolutely no warranty.
#
# The homepage URL for this framework is:
#
#	http://www.openwall.com/phpass/
#
# Please be sure to update the Version line if you edit this file in any way.
# It is suggested that you leave the main version number intact, but indicate
# your project name (after the slash) and add your own revision information.
#
# Please do not change the "private" password hashing method implemented in
# here, thereby making your hashes incompatible.  However, if you must, please
# change the hash type identifier (the "$P$") to something different.
#
# Obviously, since this code is in the public domain, the above are not
# requirements (there can be none), but merely suggestions.
#

class PasswordHash
{
  public string $itoa64;
  public mixed $iteration_count_log2;
  public $portable_hashes;
  public string $random_state;

  public function __construct($iteration_count_log2, $portable_hashes)
  {
    $this->itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

    if ($iteration_count_log2 < 4 || $iteration_count_log2 > 31)
      $iteration_count_log2 = 8;
    $this->iteration_count_log2 = $iteration_count_log2;

    $this->portable_hashes = $portable_hashes;

    $this->random_state = microtime();
    if (function_exists('getmypid'))
      $this->random_state .= getmypid();
  }

  public function PasswordHash($iteration_count_log2, $portable_hashes)
  {
    self::__construct($iteration_count_log2, $portable_hashes);
  }

  public function get_random_bytes($count)
  {
    $output = '';

    if (is_callable('random_bytes')) {
      $output = random_bytes($count);
    } elseif (@is_readable('/dev/urandom') && ($fh = @fopen('/dev/urandom', 'rb'))) {
      if (function_exists('stream_set_read_buffer')) {
        stream_set_read_buffer($fh, 0);
      }

      $output = fread($fh, $count);
      fclose($fh);
    }

    if (\strlen($output) < $count) {
      $output = '';
      for ($i = 0; $i < $count; $i += 16) {
        $this->random_state =
          md5(microtime() . $this->random_state);
        $output .= md5($this->random_state, TRUE);
      }
      $output = substr($output, 0, $count);
    }

    return $output;
  }

  public function encode64($input, $count)
  {
    $output = '';
    $i = 0;
    do {
      $value = ord($input[$i++]);
      $output .= $this->itoa64[$value & 0x3f];
      if ($i < $count) {
        $value |= ord($input[$i]) << 8;
      }
      $output .= $this->itoa64[($value >> 6) & 0x3f];
      if ($i++ >= $count) {
        break;
      }
      if ($i < $count) {
        $value |= ord($input[$i]) << 16;
      }
      $output .= $this->itoa64[($value >> 12) & 0x3f];
      if ($i++ >= $count) {
        break;
      }
      $output .= $this->itoa64[($value >> 18) & 0x3f];
    } while ($i < $count);

    return $output;
  }

  public function gensalt_private($input)
  {
    $output = '$P$';
    $output .= $this->itoa64[min($this->iteration_count_log2 +
      ((PHP_VERSION >= '5') ? 5 : 3), 30)];
    $output .= $this->encode64($input, 6);

    return $output;
  }

  public function crypt_private($password, $setting)
  {
    $output = '*0';
    if (substr($setting, 0, 2) === $output)
      $output = '*1';

    $id = substr($setting, 0, 3);
    # We use "$P$", phpBB3 uses "$H$" for the same thing
    if ($id !== '$P$' && $id !== '$H$') {
      return $output;
    }

    $count_log2 = strpos($this->itoa64, $setting[3]);
    if ($count_log2 < 7 || $count_log2 > 30) {
      return $output;
    }

    $count = 1 << $count_log2;

    $salt = substr($setting, 4, 8);
    if (\strlen($salt) !== 8) {
      return $output;
    }

    # We were kind of forced to use MD5 here since it's the only
    # cryptographic primitive that was available in all versions
    # of PHP in use.  To implement our own low-level crypto in PHP
    # would have resulted in much worse performance and
    # consequently in lower iteration counts and hashes that are
    # quicker to crack (by non-PHP code).
    $hash = md5($salt . $password, TRUE);
    do {
      $hash = md5($hash . $password, TRUE);
    } while (--$count);

    $output = substr($setting, 0, 12);
    $output .= $this->encode64($hash, 16);

    return $output;
  }

  public function gensalt_blowfish($input)
  {
    # This one needs to use a different order of characters and a
    # different encoding scheme from the one in encode64() above.
    # We care because the last character in our encoded string will
    # only represent 2 bits.  While two known implementations of
    # bcrypt will happily accept and correct a salt string which
    # has the 4 unused bits set to non-zero, we do not want to take
    # chances and we also do not want to waste an additional byte
    # of entropy.
    $itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

    $output = '$2a$';
    $output .= chr(ord('0') + $this->iteration_count_log2 / 10);
    $output .= chr(ord('0') + $this->iteration_count_log2 % 10);
    $output .= '$';

    $i = 0;
    do {
      $c1 = ord($input[$i++]);
      $output .= $itoa64[$c1 >> 2];
      $c1 = ($c1 & 0x03) << 4;
      if ($i >= 16) {
        $output .= $itoa64[$c1];
        break;
      }

      $c2 = ord($input[$i++]);
      $c1 |= $c2 >> 4;
      $output .= $itoa64[$c1];
      $c1 = ($c2 & 0x0f) << 2;

      $c2 = ord($input[$i++]);
      $c1 |= $c2 >> 6;
      $output .= $itoa64[$c1];
      $output .= $itoa64[$c2 & 0x3f];
    } while (1);

    return $output;
  }

  public function HashPassword($password)
  {
    $random = '';

    if (CRYPT_BLOWFISH === 1 && !$this->portable_hashes) {
      $random = $this->get_random_bytes(16);
      $hash =
        crypt($password, $this->gensalt_blowfish($random));
      if (\strlen($hash) === 60)
        return $hash;
    }

    if (\strlen($random) < 6)
      $random = $this->get_random_bytes(6);
    $hash =
      $this->crypt_private($password,
        $this->gensalt_private($random));
    if (\strlen($hash) === 34)
      return $hash;

    # Returning '*' on error is safe here, but would _not_ be safe
    # in a crypt(3)-like function used _both_ for generating new
    # hashes and for validating passwords against existing hashes.
    return '*';
  }

  public function checkPassword($password, $stored_hash)
  {
    $hash = $this->crypt_private($password, $stored_hash);
    if ($hash[0] === '*')
      $hash = crypt($password, $stored_hash);

    # This is not constant-time.  In order to keep the code simple,
    # for timing safety we currently rely on the salts being
    # unpredictable, which they are at least in the non-fallback
    # cases (that is, when we use /dev/urandom and bcrypt).
    return $hash === $stored_hash;
  }
}