class-phpass.php

<?php
/**
 * Portable PHP password hashing framework.
 *
 * @package phpass
 * @since 2.5.0
 * @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 2.5.0
 */
class PasswordHash {

	/**
	 * Itoa64.
	 *
	 * @var mixed
	 * @access public
	 */
	var $itoa64;

	/**
	 * Iteration Count Log 2.
	 *
	 * @var mixed
	 * @access public
	 */
	var $iteration_count_log2;

	/**
	 * Protable Hashes.
	 *
	 * @var mixed
	 * @access public
	 */
	var $portable_hashes;

	/**
	 * Random State.
	 *
	 * @var mixed
	 * @access public
	 */
	var $random_state;

	/**
	 * PHP5 constructor.
	 *
	 * @access public
	 * @param mixed $iteration_count_log2 Iteration Count Log2.
	 * @param mixed $portable_hashes Portable Hashes.
	 * @return void
	 */
	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() . uniqid( rand(), true ); // Removed getmypid() for compatibility reasons.
	}

	/**
	 * PHP4 constructor.
	 */

	/**
	 * Password Hash.
	 *
	 * @access public
	 * @param mixed $iteration_count_log2 Iteration Count Log2.
	 * @param mixed $portable_hashes Portable Hashes.
	 */
	public function PasswordHash( $iteration_count_log2, $portable_hashes ) {
		self::__construct( $iteration_count_log2, $portable_hashes );
	}

	/**
	 * Generate Random Bytes.
	 *
	 * @access public
	 * @param mixed $count Count.
	 */
	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;
	}

	/**
	 * Encode64.
	 *
	 * @access public
	 * @param mixed $input Input.
	 * @param mixed $count Count.
	 */
	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;
	}

	/**
	 * Generate Salt Private.
	 *
	 * @access public
	 * @param mixed $input Input.
	 */
	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;
	}

	/**
	 * Crypt Private.
	 *
	 * @access public
	 * @param mixed $password Password.
	 * @param mixed $setting Setting.
	 */
	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$" for the same thing.
		if ( '$P$' != $id && '$H$' != $id ) {
			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;
	}

	/**
	 * Generate Salt Extended.
	 *
	 * @access public
	 * @param mixed $input Input.
	 */
	public 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;
	}

	/**
	 * Generate Salt Blowfish.
	 *
	 * @access public
	 * @param mixed $input Input.
	 */
	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;
	}

	/**
	 * Hash Password.
	 *
	 * @access public
	 * @param mixed $password Password.
	 */
	public function HashPassword( $password ) {
		if ( strlen( $password ) > 4096 ) {
			return '*';
		}

		$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 '*';
	}

	/**
	 * Check Password.
	 *
	 * @access public
	 * @param mixed $password Password.
	 * @param mixed $stored_hash Stored Hash.
	 */
	public function CheckPassword( $password, $stored_hash ) {
		if ( strlen( $password ) > 4096 ) {
			return false;
		}

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

		return $hash === $stored_hash;
	}
}