class-phpass.php

<?php
/**
 * Portable PHP password hashing framework.
 * @package phpass
 * @since 2.5
 * @version 0.3 / WordPress
 * @link http://www.openwall.com/phpass/
 */

#
# 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.
#
# 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.
#

/**
 * Portable PHP password hashing framework.
 *
 * @package phpass
 * @version 0.3 / WordPress
 * @link http://www.openwall.com/phpass/
 * @since 2.5
 */
class WPPasswordHash{
  var $itoa64;
  var $iteration_count_log2;
  var $portable_hashes;
  var $random_state;

  function WPPasswordHash($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() . uniqid(rand(), TRUE); // removed getmypid() for compatibility reasons
  }

  function get_random_bytes($count)
  {
    $output = '';
    if ( @is_readable('/dev/urandom') &&
        ($fh = @fopen('/dev/urandom', 'rb'))) {
      $output = fread($fh, $count);
      fclose($fh);
    }

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

    return $output;
  }

  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;
  }

  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;
  }

  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're kind of forced to use MD5 here since it's the only
    # cryptographic primitive available in all versions of PHP
    # currently in use.  To implement our own low-level crypto
    # 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).
    if (PHP_VERSION >= '5') {
      $hash = md5($salt . $password, TRUE);
      do {
        $hash = md5($hash . $password, TRUE);
      } while (--$count);
    } else {
      $hash = pack('H*', md5($salt . $password));
      do {
        $hash = pack('H*', md5($hash . $password));
      } while (--$count);
    }

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

    return $output;
  }

  function gensalt_extended($input)
  {
    $count_log2 = min($this->iteration_count_log2 + 8, 24);
    # This should be odd to not reveal weak DES keys, and the
    # maximum valid value is (2**24 - 1) which is odd anyway.
    $count = (1 << $count_log2) - 1;

    $output = '_';
    $output .= $this->itoa64[$count & 0x3f];
    $output .= $this->itoa64[($count >> 6) & 0x3f];
    $output .= $this->itoa64[($count >> 12) & 0x3f];
    $output .= $this->itoa64[($count >> 18) & 0x3f];

    $output .= $this->encode64($input, 3);

    return $output;
  }

  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;
  }

  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 (CRYPT_EXT_DES == 1 && !$this->portable_hashes) {
      if (strlen($random) < 3)
        $random = $this->get_random_bytes(3);
      $hash =
          crypt($password, $this->gensalt_extended($random));
      if (strlen($hash) == 20)
        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 '*';
  }

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

    return $hash == $stored_hash;
  }
}

?>