Viewing file:  KeyPair.php (12.15 KB) -rw-rw-rw-
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Crypt_RSA allows to do following operations:
* - key pair generation
* - encryption and decryption
* - signing and sign validation
*
* PHP versions 4 and 5
*
* LICENSE: This source file is subject to version 3.0 of the PHP license
* that is available through the world-wide-web at the following URI:
* http://www.php.net/license/3_0.txt. If you did not receive a copy of
* the PHP License and are unable to obtain it through the web, please
* send a note to license@php.net so we can mail you a copy immediately.
*
* @category Encryption
* @package Crypt_RSA
* @author Alexander Valyalkin <valyala@gmail.com>
* @copyright 2005 Alexander Valyalkin
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @version 1.0.0
* @link http://pear.php.net/package/Crypt_RSA
*/
/**
* RSA error handling facilities
*/
require_once 'Crypt/RSA/ErrorHandler.php';
/**
* loader for RSA math wrappers
*/
require_once 'Crypt/RSA/MathLoader.php';
/**
* helper class for single key managing
*/
require_once 'Crypt/RSA/Key.php';
/**
* Crypt_RSA_KeyPair class, derived from Crypt_RSA_ErrorHandler
*
* Provides the following functions:
* - generate($key) - generates new key pair
* - getPublicKey() - returns public key
* - getPrivateKey() - returns private key
* - getKeyLength() - returns bit key length
* - setRandomGenerator($func_name) - sets random generator to $func_name
*
* Example usage:
* // create new 1024-bit key pair
* $key_pair = new Crypt_RSA_KeyPair(1024);
*
* // error check
* if ($key_pair->isError()) {
* echo "error while initializing Crypt_RSA_KeyPair object:\n";
* $erorr = $key_pair->getLastError();
* echo $error->getMessage(), "\n";
* }
*
* // get public key
* $public_key = $key_pair->getPublicKey();
*
* // get private key
* $private_key = $key_pair->getPrivateKey();
*
* // generate new 512-bit key pair
* $key_pair->generate(512);
*
* // error check
* if ($key_pair->isError()) {
* echo "error while generating key pair:\n";
* $erorr = $key_pair->getLastError();
* echo $error->getMessage(), "\n";
* }
*
* // get key pair length
* $length = $key_pair->getKeyLength();
*
* // set random generator to $func_name, where $func_name
* // consists name of random generator function. See comments
* // befor setRandomGenerator() method for details
* $key_pair->setRandomGenerator($func_name);
*
* // error check
* if ($key_pair->isError()) {
* echo "error while changing random generator:\n";
* $erorr = $key_pair->getLastError();
* echo $error->getMessage(), "\n";
* }
*
* // using factory() method instead of constructor (it returns PEAR_Error object on failure)
* $rsa_obj = &Crypt_RSA_KeyPair::factory($key_len);
* if (PEAR::isError($rsa_obj)) {
* echo "error: ", $rsa_obj->getMessage(), "\n";
* }
*
* @category Encryption
* @package Crypt_RSA
* @author Alexander Valyalkin <valyala@gmail.com>
* @copyright 2005 Alexander Valyalkin
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @link http://pear.php.net/package/Crypt_RSA
* @version @package_version@
* @access public
*/
class Crypt_RSA_KeyPair extends Crypt_RSA_ErrorHandler
{
/**
* Reference to math wrapper object, which is used to
* manipulate large integers in RSA algorithm.
*
* @var object of Crypt_RSA_Math_* class
* @access private
*/
var $_math_obj;
/**
* length of each key in the key pair
*
* @var int
* @access private
*/
var $_key_len;
/**
* public key
*
* @var object of Crypt_RSA_KEY class
* @access private
*/
var $_public_key;
/**
* private key
*
* @var object of Crypt_RSA_KEY class
* @access private
*/
var $_private_key;
/**
* name of function, which is used as random generator
*
* @var string
* @access private
*/
var $_random_generator;
/**
* Crypt_RSA_KeyPair constructor.
*
* @param int $key_len bit length of key pair, which will be generated in constructor
* @param string $wrapper_name
* Name of math wrapper, which will be used to
* perform different operations with big integers.
* See contents of Crypt/RSA/Math folder for examples of wrappers.
* Read docs/Crypt_RSA/docs/math_wrappers.txt for details.
*
* @param string $error_handler name of error handler function
*
* @access public
*/
function Crypt_RSA_KeyPair($key_len, $wrapper_name = 'default', $error_handler = '')
{
// set error handler
$this->setErrorHandler($error_handler);
// try to load math wrapper
$obj = &Crypt_RSA_MathLoader::loadWrapper($wrapper_name);
if (PEAR::isError($obj)) {
// error during loading of math wrapper
$this->pushError($obj);
return;
}
$this->_math_obj = &$obj;
// set default random generator
if (!$this->setRandomGenerator()) {
// error in setRandomGenerator() function
return;
}
// generate key pair
if (!$this->generate($key_len)) {
// error during generating key pair
return;
}
}
/**
* Crypt_RSA_KeyPair factory.
*
* @param int $key_len bit length of key pair, which will be generated in constructor
* @param string $wrapper_name
* Name of math wrapper, which will be used to
* perform different operations with big integers.
* See contents of Crypt/RSA/Math folder for examples of wrappers.
* Read docs/Crypt_RSA/docs/math_wrappers.txt for details.
*
* @return object new Crypt_RSA_KeyPair object on success or PEAR_Error object on failure
* @access public
*/
function &factory($key_len, $wrapper_name = 'default')
{
$obj = &new Crypt_RSA_KeyPair($key_len, $wrapper_name);
if ($obj->isError()) {
// error during creating a new object. Retrurn PEAR_Error object
return $obj->getLastError();
}
// object created successfully. Return it
return $obj;
}
/**
* Generates new Crypt_RSA key pair with length $key_len.
* If $key_len is missed, use an old key length from $this->_key_len
*
* @param int $key_len bit length of key pair, which will be generated
* @return bool true on success or false on error
* @access public
*/
function generate($key_len = null)
{
if (is_null($key_len)) {
// use an old key length
$key_len = $this->_key_len;
if (is_null($key_len)) {
$obj = PEAR::raiseError('missing key_len parameter', CRYPT_RSA_ERROR_MISSING_KEY_LEN);
$this->pushError($obj);
return false;
}
}
// align $key_len to 8 bits
if ($key_len & 7) {
$key_len += 8 - ($key_len % 8);
}
// store key length in the _key_len property
$this->_key_len = $key_len;
// generate two primes p and q
$p_len = (int) ($key_len / 2) + 1;
$q_len = $key_len - $p_len;
$p = $this->_math_obj->getRand($p_len, $this->_random_generator, true);
$p = $this->_math_obj->nextPrime($p);
do {
do {
$q = $this->_math_obj->getRand($q_len, $this->_random_generator, true);
$tmp_len = $this->_math_obj->bitLen($this->_math_obj->mul($p, $q));
if ($tmp_len < $key_len) $q_len++;
elseif ($tmp_len > $key_len) $q_len--;
} while ($tmp_len != $key_len);
$q = $this->_math_obj->nextPrime($q);
$tmp = $this->_math_obj->mul($p, $q);
} while ($this->_math_obj->bitLen($tmp) != $key_len);
// $n - is shared modulus
$n = $this->_math_obj->mul($p, $q);
// generate public ($e) and private ($d) keys
$pq = $this->_math_obj->mul($this->_math_obj->dec($p), $this->_math_obj->dec($q));
do {
$e = $this->_math_obj->getRand($q_len, $this->_random_generator);
if ($this->_math_obj->isZero($e) || $this->_math_obj->isZero($this->_math_obj->dec($e))) {
// exponent cannot be equal to 0 or 1
continue;
}
if ($this->_math_obj->isZero($this->_math_obj->dec($this->_math_obj->gcd($e, $pq)))) {
// exponent is found
break;
}
} while (true);
$d = $this->_math_obj->invmod($e, $pq);
$modulus = $this->_math_obj->int2bin($n);
$public_exp = $this->_math_obj->int2bin($e);
$private_exp = $this->_math_obj->int2bin($d);
// try to create public key object
$obj = &new Crypt_RSA_Key(
$modulus,
$public_exp,
'public',
$this->_math_obj->getWrapperName(),
$this->_error_handler
);
if ($obj->isError()) {
// error during creating public object
$this->pushError($obj->getLastError());
return false;
}
$this->_public_key = &$obj;
// try to create private key object
$obj = &new Crypt_RSA_Key(
$modulus,
$private_exp,
'private',
$this->_math_obj->getWrapperName(),
$this->_error_handler
);
if ($obj->isError()) {
// error during creating private key object
$this->pushError($obj->getLastError());
return false;
}
$this->_private_key = &$obj;
return true; // key pair successfully generated
}
/**
* Returns public key from the pair
*
* @return object public key object of class Crypt_RSA_Key
* @access public
*/
function getPublicKey()
{
return $this->_public_key;
}
/**
* Returns private key from the pair
*
* @return object private key object of class Crypt_RSA_Key
* @access public
*/
function getPrivateKey()
{
return $this->_private_key;
}
/**
* Sets name of random generator function for key generation.
* If parameter is skipped, then sets to default random generator.
*
* Random generator function must return integer with at least 8 lower
* significant bits, which will be used as random values.
*
* @param string $random_generator name of random generator function
* @return bool true on success or false on error
* @access public
*/
function setRandomGenerator($random_generator = null)
{
static $default_random_generator = null;
if (is_string($random_generator)) {
// set user's random generator
if (!function_exists($random_generator)) {
$obj = PEAR::raiseError("can't find random generator function with name [{$random_generator}]");
$this->pushError($obj);
return false;
}
$this->_random_generator = $random_generator;
} else {
// set default random generator
$this->_random_generator = is_null($default_random_generator) ?
($default_random_generator = create_function('', '$a=explode(" ",microtime());return(int)($a[0]*1000000);')) :
$default_random_generator;
}
return true;
}
/**
* Returns length of each key in the key pair
*
* @return int bit length of each key in key pair
* @access public
*/
function getKeyLength()
{
return $this->_key_len;
}
}
?>
|