gnu-social/plugins/OStatus/extlib/Crypt/RSA/KeyPair.php

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2010-02-22 23:05:32 +09:00
<?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: KeyPair.php,v 1.7 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';
/**
* 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 $func_name
* - fromPEMString($str) - retrieves keypair from PEM-encoded string
* - toPEMString() - stores keypair to PEM-encoded string
* - isEqual($keypair2) - compares current keypair to $keypair2
*
* 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
* // before 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";
* }
*
* // read key pair from PEM-encoded string:
* $str = "-----BEGIN RSA PRIVATE KEY-----"
* . "MCsCAQACBHr5LDkCAwEAAQIEBc6jbQIDAOCfAgMAjCcCAk3pAgJMawIDAL41"
* . "-----END RSA PRIVATE KEY-----";
* $keypair = Crypt_RSA_KeyPair::fromPEMString($str);
*
* // read key pair from .pem file 'private.pem':
* $str = file_get_contents('private.pem');
* $keypair = Crypt_RSA_KeyPair::fromPEMString($str);
*
* // generate and write 1024-bit key pair to .pem file 'private_new.pem'
* $keypair = new Crypt_RSA_KeyPair(1024);
* $str = $keypair->toPEMString();
* file_put_contents('private_new.pem', $str);
*
* // compare $keypair1 to $keypair2
* if ($keypair1->isEqual($keypair2)) {
* echo "keypair1 = keypair2\n";
* }
* else {
* echo "keypair1 != keypair2\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_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;
/**
* RSA keypair attributes [version, n, e, d, p, q, dmp1, dmq1, iqmp] as associative array
*
* @var array
* @access private
*/
var $_attrs;
/**
* Returns names of keypair attributes from $this->_attrs array
*
* @return array Array of keypair attributes names
* @access private
*/
function _get_attr_names()
{
return array('version', 'n', 'e', 'd', 'p', 'q', 'dmp1', 'dmq1', 'iqmp');
}
/**
* Parses ASN.1 string [$str] starting form position [$pos].
* Returns tag and string value of parsed object.
*
* @param string $str
* @param int &$pos
* @param Crypt_RSA_ErrorHandler &$err_handler
*
* @return mixed Array('tag' => ..., 'str' => ...) on success, false on error
* @access private
*/
function _ASN1Parse($str, &$pos, &$err_handler)
{
$max_pos = strlen($str);
if ($max_pos < 2) {
$err_handler->pushError("ASN.1 string too short");
return false;
}
// get ASN.1 tag value
$tag = ord($str[$pos++]) & 0x1f;
if ($tag == 0x1f) {
$tag = 0;
do {
$n = ord($str[$pos++]);
$tag <<= 7;
$tag |= $n & 0x7f;
} while (($n & 0x80) && $pos < $max_pos);
}
if ($pos >= $max_pos) {
$err_handler->pushError("ASN.1 string too short");
return false;
}
// get ASN.1 object length
$len = ord($str[$pos++]);
if ($len & 0x80) {
$n = $len & 0x1f;
$len = 0;
while ($n-- && $pos < $max_pos) {
$len <<= 8;
$len |= ord($str[$pos++]);
}
}
if ($pos >= $max_pos || $len > $max_pos - $pos) {
$err_handler->pushError("ASN.1 string too short");
return false;
}
// get string value of ASN.1 object
$str = substr($str, $pos, $len);
return array(
'tag' => $tag,
'str' => $str,
);
}
/**
* Parses ASN.1 sting [$str] starting from position [$pos].
* Returns string representation of number, which can be passed
* in bin2int() function of math wrapper.
*
* @param string $str
* @param int &$pos
* @param Crypt_RSA_ErrorHandler &$err_handler
*
* @return mixed string representation of parsed number on success, false on error
* @access private
*/
function _ASN1ParseInt($str, &$pos, &$err_handler)
{
$tmp = Crypt_RSA_KeyPair::_ASN1Parse($str, $pos, $err_handler);
if ($err_handler->isError()) {
return false;
}
if ($tmp['tag'] != 0x02) {
$errstr = sprintf("wrong ASN tag value: 0x%02x. Expected 0x02 (INTEGER)", $tmp['tag']);
$err_handler->pushError($errstr);
return false;
}
$pos += strlen($tmp['str']);
return strrev($tmp['str']);
}
/**
* Constructs ASN.1 string from tag $tag and object $str
*
* @param string $str ASN.1 object string
* @param int $tag ASN.1 tag value
* @param bool $is_constructed
* @param bool $is_private
*
* @return ASN.1-encoded string
* @access private
*/
function _ASN1Store($str, $tag, $is_constructed = false, $is_private = false)
{
$out = '';
// encode ASN.1 tag value
$tag_ext = ($is_constructed ? 0x20 : 0) | ($is_private ? 0xc0 : 0);
if ($tag < 0x1f) {
$out .= chr($tag | $tag_ext);
} else {
$out .= chr($tag_ext | 0x1f);
$tmp = chr($tag & 0x7f);
$tag >>= 7;
while ($tag) {
$tmp .= chr(($tag & 0x7f) | 0x80);
$tag >>= 7;
}
$out .= strrev($tmp);
}
// encode ASN.1 object length
$len = strlen($str);
if ($len < 0x7f) {
$out .= chr($len);
} else {
$tmp = '';
$n = 0;
while ($len) {
$tmp .= chr($len & 0xff);
$len >>= 8;
$n++;
}
$out .= chr($n | 0x80);
$out .= strrev($tmp);
}
return $out . $str;
}
/**
* Constructs ASN.1 string from binary representation of big integer
*
* @param string $str binary representation of big integer
*
* @return ASN.1-encoded string
* @access private
*/
function _ASN1StoreInt($str)
{
$str = strrev($str);
return Crypt_RSA_KeyPair::_ASN1Store($str, 0x02);
}
/**
* Crypt_RSA_KeyPair constructor.
*
* Wrapper: 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 int $key_len bit length of key pair, which will be generated in constructor
* @param string $wrapper_name wrapper name
* @param string $error_handler name of error handler function
* @param callback $random_generator function which will be used as random generator
*
* @access public
*/
function Crypt_RSA_KeyPair($key_len, $wrapper_name = 'default', $error_handler = '', $random_generator = null)
{
// set error handler
$this->setErrorHandler($error_handler);
// try to load math wrapper
$obj = &Crypt_RSA_MathLoader::loadWrapper($wrapper_name);
if ($this->isError($obj)) {
// error during loading of math wrapper
$this->pushError($obj);
return;
}
$this->_math_obj = &$obj;
// set random generator
if (!$this->setRandomGenerator($random_generator)) {
// error in setRandomGenerator() function
return;
}
if (is_array($key_len)) {
// ugly BC hack - it is possible to pass RSA private key attributes [version, n, e, d, p, q, dmp1, dmq1, iqmp]
// as associative array instead of key length to Crypt_RSA_KeyPair constructor
$rsa_attrs = $key_len;
// convert attributes to big integers
$attr_names = $this->_get_attr_names();
foreach ($attr_names as $attr) {
if (!isset($rsa_attrs[$attr])) {
$this->pushError("missing required RSA attribute [$attr]");
return;
}
${$attr} = $this->_math_obj->bin2int($rsa_attrs[$attr]);
}
// check primality of p and q
if (!$this->_math_obj->isPrime($p)) {
$this->pushError("[p] must be prime");
return;
}
if (!$this->_math_obj->isPrime($q)) {
$this->pushError("[q] must be prime");
return;
}
// check n = p * q
$n1 = $this->_math_obj->mul($p, $q);
if ($this->_math_obj->cmpAbs($n, $n1)) {
$this->pushError("n != p * q");
return;
}
// check e * d = 1 mod (p-1) * (q-1)
$p1 = $this->_math_obj->dec($p);
$q1 = $this->_math_obj->dec($q);
$p1q1 = $this->_math_obj->mul($p1, $q1);
$ed = $this->_math_obj->mul($e, $d);
$one = $this->_math_obj->mod($ed, $p1q1);
if (!$this->_math_obj->isOne($one)) {
$this->pushError("e * d != 1 mod (p-1)*(q-1)");
return;
}
// check dmp1 = d mod (p-1)
$dmp = $this->_math_obj->mod($d, $p1);
if ($this->_math_obj->cmpAbs($dmp, $dmp1)) {
$this->pushError("dmp1 != d mod (p-1)");
return;
}
// check dmq1 = d mod (q-1)
$dmq = $this->_math_obj->mod($d, $q1);
if ($this->_math_obj->cmpAbs($dmq, $dmq1)) {
$this->pushError("dmq1 != d mod (q-1)");
return;
}
// check iqmp = 1/q mod p
$q1 = $this->_math_obj->invmod($iqmp, $p);
if ($this->_math_obj->cmpAbs($q, $q1)) {
$this->pushError("iqmp != 1/q mod p");
return;
}
// try to create public key object
$public_key = &new Crypt_RSA_Key($rsa_attrs['n'], $rsa_attrs['e'], 'public', $wrapper_name, $error_handler);
if ($public_key->isError()) {
// error during creating public object
$this->pushError($public_key->getLastError());
return;
}
// try to create private key object
$private_key = &new Crypt_RSA_Key($rsa_attrs['n'], $rsa_attrs['d'], 'private', $wrapper_name, $error_handler);
if ($private_key->isError()) {
// error during creating private key object
$this->pushError($private_key->getLastError());
return;
}
$this->_public_key = $public_key;
$this->_private_key = $private_key;
$this->_key_len = $public_key->getKeyLength();
$this->_attrs = $rsa_attrs;
} else {
// generate key pair
if (!$this->generate($key_len)) {
// error during generating key pair
return;
}
}
}
/**
* Crypt_RSA_KeyPair factory.
*
* Wrapper - 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 int $key_len bit length of key pair, which will be generated in constructor
* @param string $wrapper_name wrapper name
* @param string $error_handler name of error handler function
* @param callback $random_generator function which will be used as random generator
*
* @return object new Crypt_RSA_KeyPair object on success or PEAR_Error object on failure
* @access public
*/
function &factory($key_len, $wrapper_name = 'default', $error_handler = '', $random_generator = null)
{
$obj = &new Crypt_RSA_KeyPair($key_len, $wrapper_name, $error_handler, $random_generator);
if ($obj->isError()) {
// error during creating a new object. Return 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)) {
$this->pushError('missing key_len parameter', CRYPT_RSA_ERROR_MISSING_KEY_LEN);
return false;
}
}
// minimal key length is 8 bit ;)
if ($key_len < 8) {
$key_len = 8;
}
// store key length in the _key_len property
$this->_key_len = $key_len;
// set [e] to 0x10001 (65537)
$e = $this->_math_obj->bin2int("\x01\x00\x01");
// generate [p], [q] and [n]
$p_len = intval(($key_len + 1) / 2);
$q_len = $key_len - $p_len;
$p1 = $q1 = 0;
do {
// generate prime number [$p] with length [$p_len] with the following condition:
// GCD($e, $p - 1) = 1
do {
$p = $this->_math_obj->getPrime($p_len, $this->_random_generator);
$p1 = $this->_math_obj->dec($p);
$tmp = $this->_math_obj->GCD($e, $p1);
} while (!$this->_math_obj->isOne($tmp));
// generate prime number [$q] with length [$q_len] with the following conditions:
// GCD($e, $q - 1) = 1
// $q != $p
do {
$q = $this->_math_obj->getPrime($q_len, $this->_random_generator);
$q1 = $this->_math_obj->dec($q);
$tmp = $this->_math_obj->GCD($e, $q1);
} while (!$this->_math_obj->isOne($tmp) && !$this->_math_obj->cmpAbs($q, $p));
// if (p < q), then exchange them
if ($this->_math_obj->cmpAbs($p, $q) < 0) {
$tmp = $p;
$p = $q;
$q = $tmp;
$tmp = $p1;
$p1 = $q1;
$q1 = $tmp;
}
// calculate n = p * q
$n = $this->_math_obj->mul($p, $q);
} while ($this->_math_obj->bitLen($n) != $key_len);
// calculate d = 1/e mod (p - 1) * (q - 1)
$pq = $this->_math_obj->mul($p1, $q1);
$d = $this->_math_obj->invmod($e, $pq);
// calculate dmp1 = d mod (p - 1)
$dmp1 = $this->_math_obj->mod($d, $p1);
// calculate dmq1 = d mod (q - 1)
$dmq1 = $this->_math_obj->mod($d, $q1);
// calculate iqmp = 1/q mod p
$iqmp = $this->_math_obj->invmod($q, $p);
// store RSA keypair attributes
$this->_attrs = array(
'version' => "\x00",
'n' => $this->_math_obj->int2bin($n),
'e' => $this->_math_obj->int2bin($e),
'd' => $this->_math_obj->int2bin($d),
'p' => $this->_math_obj->int2bin($p),
'q' => $this->_math_obj->int2bin($q),
'dmp1' => $this->_math_obj->int2bin($dmp1),
'dmq1' => $this->_math_obj->int2bin($dmq1),
'iqmp' => $this->_math_obj->int2bin($iqmp),
);
$n = $this->_attrs['n'];
$e = $this->_attrs['e'];
$d = $this->_attrs['d'];
// try to create public key object
$obj = &new Crypt_RSA_Key($n, $e, '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
$obj = &new Crypt_RSA_Key($n, $d, '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)) {
$this->pushError("can't find random generator function with name [{$random_generator}]");
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;
}
/**
* Retrieves RSA keypair from PEM-encoded string, containing RSA private key.
* Example of such string:
* -----BEGIN RSA PRIVATE KEY-----
* MCsCAQACBHtvbSECAwEAAQIEeYrk3QIDAOF3AgMAjCcCAmdnAgJMawIDALEk
* -----END RSA PRIVATE KEY-----
*
* Wrapper: 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 $str PEM-encoded string
* @param string $wrapper_name Wrapper name
* @param string $error_handler name of error handler function
*
* @return Crypt_RSA_KeyPair object on success, PEAR_Error object on error
* @access public
* @static
*/
function &fromPEMString($str, $wrapper_name = 'default', $error_handler = '')
{
if (isset($this)) {
if ($wrapper_name == 'default') {
$wrapper_name = $this->_math_obj->getWrapperName();
}
if ($error_handler == '') {
$error_handler = $this->_error_handler;
}
}
$err_handler = &new Crypt_RSA_ErrorHandler;
$err_handler->setErrorHandler($error_handler);
// search for base64-encoded private key
if (!preg_match('/-----BEGIN RSA PRIVATE KEY-----([^-]+)-----END RSA PRIVATE KEY-----/', $str, $matches)) {
$err_handler->pushError("can't find RSA private key in the string [{$str}]");
return $err_handler->getLastError();
}
// parse private key. It is ASN.1-encoded
$str = base64_decode($matches[1]);
$pos = 0;
$tmp = Crypt_RSA_KeyPair::_ASN1Parse($str, $pos, $err_handler);
if ($err_handler->isError()) {
return $err_handler->getLastError();
}
if ($tmp['tag'] != 0x10) {
$errstr = sprintf("wrong ASN tag value: 0x%02x. Expected 0x10 (SEQUENCE)", $tmp['tag']);
$err_handler->pushError($errstr);
return $err_handler->getLastError();
}
// parse ASN.1 SEQUENCE for RSA private key
$attr_names = Crypt_RSA_KeyPair::_get_attr_names();
$n = sizeof($attr_names);
$rsa_attrs = array();
for ($i = 0; $i < $n; $i++) {
$tmp = Crypt_RSA_KeyPair::_ASN1ParseInt($str, $pos, $err_handler);
if ($err_handler->isError()) {
return $err_handler->getLastError();
}
$attr = $attr_names[$i];
$rsa_attrs[$attr] = $tmp;
}
// create Crypt_RSA_KeyPair object.
$keypair = &new Crypt_RSA_KeyPair($rsa_attrs, $wrapper_name, $error_handler);
if ($keypair->isError()) {
return $keypair->getLastError();
}
return $keypair;
}
/**
* converts keypair to PEM-encoded string, which can be stroed in
* .pem compatible files, contianing RSA private key.
*
* @return string PEM-encoded keypair on success, false on error
* @access public
*/
function toPEMString()
{
// store RSA private key attributes into ASN.1 string
$str = '';
$attr_names = $this->_get_attr_names();
$n = sizeof($attr_names);
$rsa_attrs = $this->_attrs;
for ($i = 0; $i < $n; $i++) {
$attr = $attr_names[$i];
if (!isset($rsa_attrs[$attr])) {
$this->pushError("Cannot find value for ASN.1 attribute [$attr]");
return false;
}
$tmp = $rsa_attrs[$attr];
$str .= Crypt_RSA_KeyPair::_ASN1StoreInt($tmp);
}
// prepend $str by ASN.1 SEQUENCE (0x10) header
$str = Crypt_RSA_KeyPair::_ASN1Store($str, 0x10, true);
// encode and format PEM string
$str = base64_encode($str);
$str = chunk_split($str, 64, "\n");
return "-----BEGIN RSA PRIVATE KEY-----\n$str-----END RSA PRIVATE KEY-----\n";
}
/**
* Compares keypairs in Crypt_RSA_KeyPair objects $this and $key_pair
*
* @param Crypt_RSA_KeyPair $key_pair keypair to compare
*
* @return bool true, if keypair stored in $this equal to keypair stored in $key_pair
* @access public
*/
function isEqual($key_pair)
{
$attr_names = $this->_get_attr_names();
foreach ($attr_names as $attr) {
if ($this->_attrs[$attr] != $key_pair->_attrs[$attr]) {
return false;
}
}
return true;
}
}
?>