jiliangzhifu/protected/class/PasswordHash.php

<?php

#
# Portable PHP password hashing framework.
#
# Version 0.3 / genuine.
#
# 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 {

    var $itoa64;
    var $iteration_count_log2;
    var $portable_hashes;
    var $random_state;

    function PasswordHash($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();
    }

    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;
    }

}

?>