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Diffstat (limited to 'Crypt/RSA/Key.php')
-rw-r--r-- | Crypt/RSA/Key.php | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/Crypt/RSA/Key.php b/Crypt/RSA/Key.php new file mode 100644 index 000000000..72a71e2d0 --- /dev/null +++ b/Crypt/RSA/Key.php @@ -0,0 +1,314 @@ +<?php +/** + * 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 CVS: $Id: Key.php,v 1.6 2009/01/05 08:30:29 clockwerx Exp $ + * @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'; + +/** + * Crypt_RSA_Key class, derived from Crypt_RSA_ErrorHandler + * + * Provides the following functions: + * - getKeyLength() - returns bit key length + * - getExponent() - returns key exponent as binary string + * - getModulus() - returns key modulus as binary string + * - getKeyType() - returns type of the key (public or private) + * - toString() - returns serialized key as string + * - fromString($key_str) - static function; returns key, unserialized from string + * - isValid($key) - static function for validating of $key + * + * Example usage: + * // create new 1024-bit key pair + * $key_pair = new Crypt_RSA_KeyPair(1024); + * + * // get public key (its class is Crypt_RSA_Key) + * $key = $key_pair->getPublicKey(); + * + * // get key length + * $len = $key->getKeyLength(); + * + * // get modulus as string + * $modulus = $key->getModulus(); + * + * // get exponent as string + * $exponent = $key->getExponent(); + * + * // get string represenation of key (use it instead of serialization of Crypt_RSA_Key object) + * $key_in_str = $key->toString(); + * + * // restore key object from string using 'BigInt' math wrapper + * $key = Crypt_RSA_Key::fromString($key_in_str, 'BigInt'); + * + * // error check + * if ($key->isError()) { + * echo "error while unserializing key object:\n"; + * $erorr = $key->getLastError(); + * echo $error->getMessage(), "\n"; + * } + * + * // validate key + * if (Crypt_RSA_Key::isValid($key)) echo 'valid key'; + * else echo 'invalid key'; + * + * // using factory() method instead of constructor (it returns PEAR_Error object on failure) + * $rsa_obj = &Crypt_RSA_Key::factory($modulus, $exp, $key_type); + * if (PEAR::isError($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 + * @version Release: @package_version@ + * @link http://pear.php.net/package/Crypt_RSA + * @access public + */ +class Crypt_RSA_Key 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; + + /** + * shared modulus + * + * @var string + * @access private + */ + var $_modulus; + + /** + * exponent + * + * @var string + * @access private + */ + var $_exp; + + /** + * key type (private or public) + * + * @var string + * @access private + */ + var $_key_type; + + /** + * key length in bits + * + * @var int + * @access private + */ + var $_key_len; + + /** + * Crypt_RSA_Key constructor. + * + * You should pass in the 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 $modulus key modulus + * @param string $exp key exponent + * @param string $key_type type of the key (public or private) + * @param string $wrapper_name wrapper to use + * @param string $error_handler name of error handler function + * + * @access public + */ + function Crypt_RSA_Key($modulus, $exp, $key_type, $wrapper_name = 'default', $error_handler = '') + { + // set error handler + $this->setErrorHandler($error_handler); + // try to load math wrapper $wrapper_name + $obj = &Crypt_RSA_MathLoader::loadWrapper($wrapper_name); + if ($this->isError($obj)) { + // error during loading of math wrapper + $this->pushError($obj); // push error object into error list + return; + } + $this->_math_obj = &$obj; + + $this->_modulus = $modulus; + $this->_exp = $exp; + + if (!in_array($key_type, array('private', 'public'))) { + $this->pushError('invalid key type. It must be private or public', CRYPT_RSA_ERROR_WRONG_KEY_TYPE); + return; + } + $this->_key_type = $key_type; + + /* check length of modulus & exponent ( abs(modulus) > abs(exp) ) */ + $mod_num = $this->_math_obj->bin2int($this->_modulus); + $exp_num = $this->_math_obj->bin2int($this->_exp); + + if ($this->_math_obj->cmpAbs($mod_num, $exp_num) <= 0) { + $this->pushError('modulus must be greater than exponent', CRYPT_RSA_ERROR_EXP_GE_MOD); + return; + } + // determine key length + $this->_key_len = $this->_math_obj->bitLen($mod_num); + } + + /** + * Crypt_RSA_Key factory. + * + * @param string $modulus key modulus + * @param string $exp key exponent + * @param string $key_type type of the key (public or private) + * @param string $wrapper_name wrapper to use + * @param string $error_handler name of error handler function + * + * @return object new Crypt_RSA_Key object on success or PEAR_Error object on failure + * @access public + */ + function factory($modulus, $exp, $key_type, $wrapper_name = 'default', $error_handler = '') + { + $obj = new Crypt_RSA_Key($modulus, $exp, $key_type, $wrapper_name, $error_handler); + if ($obj->isError()) { + // error during creating a new object. Retrurn PEAR_Error object + return $obj->getLastError(); + } + // object created successfully. Return it + return $obj; + } + + /** + * Calculates bit length of the key + * + * @return int bit length of key + * @access public + */ + function getKeyLength() + { + return $this->_key_len; + } + + /** + * Returns modulus part of the key as binary string, + * which can be used to construct new Crypt_RSA_Key object. + * + * @return string modulus as binary string + * @access public + */ + function getModulus() + { + return $this->_modulus; + } + + /** + * Returns exponent part of the key as binary string, + * which can be used to construct new Crypt_RSA_Key object. + * + * @return string exponent as binary string + * @access public + */ + function getExponent() + { + return $this->_exp; + } + + /** + * Returns key type (public, private) + * + * @return string key type (public, private) + * @access public + */ + function getKeyType() + { + return $this->_key_type; + } + + /** + * Returns string representation of key + * + * @return string key, serialized to string + * @access public + */ + function toString() + { + return base64_encode( + serialize( + array($this->_modulus, $this->_exp, $this->_key_type) + ) + ); + } + + /** + * Returns Crypt_RSA_Key object, unserialized from + * string representation of key. + * + * optional parameter $wrapper_name - is the name of math wrapper, + * which will be used during unserialization of this object. + * + * This function can be called statically: + * $key = Crypt_RSA_Key::fromString($key_in_string, 'BigInt'); + * + * @param string $key_str RSA key, serialized into string + * @param string $wrapper_name optional math wrapper name + * + * @return object key as Crypt_RSA_Key object + * @access public + * @static + */ + function fromString($key_str, $wrapper_name = 'default') + { + list($modulus, $exponent, $key_type) = unserialize(base64_decode($key_str)); + $obj = new Crypt_RSA_Key($modulus, $exponent, $key_type, $wrapper_name); + return $obj; + } + + /** + * Validates key + * This function can be called statically: + * $is_valid = Crypt_RSA_Key::isValid($key) + * + * Returns true, if $key is valid Crypt_RSA key, else returns false + * + * @param object $key Crypt_RSA_Key object for validating + * + * @return bool true if $key is valid, else false + * @access public + */ + function isValid($key) + { + return (is_object($key) && strtolower(get_class($key)) === strtolower(__CLASS__)); + } +} + +?> |