/library/Zend/InfoCard/Xml/Security.php
PHP | 327 lines | 173 code | 56 blank | 98 comment | 21 complexity | a9c56cbadf1f4e9fc595acc3004aa82b MD5 | raw file
- <?php
- /**
- * Zend Framework
- *
- * LICENSE
- *
- * This source file is subject to the new BSD license that is bundled
- * with this package in the file LICENSE.txt.
- * It is also available through the world-wide-web at this URL:
- * http://framework.zend.com/license/new-bsd
- * If you did not receive a copy of the license and are unable to
- * obtain it through the world-wide-web, please send an email
- * to license@zend.com so we can send you a copy immediately.
- *
- * @category Zend
- * @package Zend_InfoCard
- * @subpackage Zend_InfoCard_Xml_Security
- * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- * @version $Id: Security.php 23775 2011-03-01 17:25:24Z ralph $
- */
- /**
- * Zend_InfoCard_Xml_Security_Transform
- */
- require_once 'Zend/InfoCard/Xml/Security/Transform.php';
- /**
- *
- * @category Zend
- * @package Zend_InfoCard
- * @subpackage Zend_InfoCard_Xml_Security
- * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- */
- class Zend_InfoCard_Xml_Security
- {
- /**
- * ASN.1 type INTEGER class
- */
- const ASN_TYPE_INTEGER = 0x02;
- /**
- * ASN.1 type BIT STRING class
- */
- const ASN_TYPE_BITSTRING = 0x03;
- /**
- * ASN.1 type SEQUENCE class
- */
- const ASN_TYPE_SEQUENCE = 0x30;
- /**
- * The URI for Canonical Method C14N Exclusive
- */
- const CANONICAL_METHOD_C14N_EXC = 'http://www.w3.org/2001/10/xml-exc-c14n#';
- /**
- * The URI for Signature Method SHA1
- */
- const SIGNATURE_METHOD_SHA1 = 'http://www.w3.org/2000/09/xmldsig#rsa-sha1';
- /**
- * The URI for Digest Method SHA1
- */
- const DIGEST_METHOD_SHA1 = 'http://www.w3.org/2000/09/xmldsig#sha1';
- /**
- * The Identifier for RSA Keys
- */
- const RSA_KEY_IDENTIFIER = '300D06092A864886F70D0101010500';
- /**
- * Constructor (disabled)
- *
- * @return void
- */
- private function __construct()
- {
- }
- /**
- * Validates the signature of a provided XML block
- *
- * @param string $strXMLInput An XML block containing a Signature
- * @return bool True if the signature validated, false otherwise
- * @throws Zend_InfoCard_Xml_Security_Exception
- */
- static public function validateXMLSignature($strXMLInput)
- {
- if(!extension_loaded('openssl')) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("You must have the openssl extension installed to use this class");
- }
- $sxe = simplexml_load_string($strXMLInput);
- if(!isset($sxe->Signature)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Could not identify XML Signature element");
- }
- if(!isset($sxe->Signature->SignedInfo)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a SignedInfo block");
- }
- if(!isset($sxe->Signature->SignatureValue)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a SignatureValue block");
- }
- if(!isset($sxe->Signature->KeyInfo)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a KeyInfo block");
- }
- if(!isset($sxe->Signature->KeyInfo->KeyValue)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a KeyValue block");
- }
- switch((string)$sxe->Signature->SignedInfo->CanonicalizationMethod['Algorithm']) {
- case self::CANONICAL_METHOD_C14N_EXC:
- $cMethod = (string)$sxe->Signature->SignedInfo->CanonicalizationMethod['Algorithm'];
- break;
- default:
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported CanonicalizationMethod Requested");
- break;
- }
- switch((string)$sxe->Signature->SignedInfo->SignatureMethod['Algorithm']) {
- case self::SIGNATURE_METHOD_SHA1:
- $sMethod = (string)$sxe->Signature->SignedInfo->SignatureMethod['Algorithm'];
- break;
- default:
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported SignatureMethod Requested");
- break;
- }
- switch((string)$sxe->Signature->SignedInfo->Reference->DigestMethod['Algorithm']) {
- case self::DIGEST_METHOD_SHA1:
- $dMethod = (string)$sxe->Signature->SignedInfo->Reference->DigestMethod['Algorithm'];
- break;
- default:
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported DigestMethod Requested");
- break;
- }
- $base64DecodeSupportsStrictParam = version_compare(PHP_VERSION, '5.2.0', '>=');
- if ($base64DecodeSupportsStrictParam) {
- $dValue = base64_decode((string)$sxe->Signature->SignedInfo->Reference->DigestValue, true);
- } else {
- $dValue = base64_decode((string)$sxe->Signature->SignedInfo->Reference->DigestValue);
- }
- if ($base64DecodeSupportsStrictParam) {
- $signatureValue = base64_decode((string)$sxe->Signature->SignatureValue, true);
- } else {
- $signatureValue = base64_decode((string)$sxe->Signature->SignatureValue);
- }
- $transformer = new Zend_InfoCard_Xml_Security_Transform();
- foreach($sxe->Signature->SignedInfo->Reference->Transforms->children() as $transform) {
- $transformer->addTransform((string)$transform['Algorithm']);
- }
- $transformed_xml = $transformer->applyTransforms($strXMLInput);
- $transformed_xml_binhash = pack("H*", sha1($transformed_xml));
- if(!self::_secureStringCompare($transformed_xml_binhash, $dValue)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Locally Transformed XML does not match XML Document. Cannot Verify Signature");
- }
- $public_key = null;
- switch(true) {
- case isset($sxe->Signature->KeyInfo->KeyValue->X509Certificate):
- $certificate = (string)$sxe->Signature->KeyInfo->KeyValue->X509Certificate;
- $pem = "-----BEGIN CERTIFICATE-----\n" .
- wordwrap($certificate, 64, "\n", true) .
- "\n-----END CERTIFICATE-----";
- $public_key = openssl_pkey_get_public($pem);
- if(!$public_key) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Unable to extract and prcoess X509 Certificate from KeyValue");
- }
- break;
- case isset($sxe->Signature->KeyInfo->KeyValue->RSAKeyValue):
- if(!isset($sxe->Signature->KeyInfo->KeyValue->RSAKeyValue->Modulus) ||
- !isset($sxe->Signature->KeyInfo->KeyValue->RSAKeyValue->Exponent)) {
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("RSA Key Value not in Modulus/Exponent form");
- }
- $modulus = base64_decode((string)$sxe->Signature->KeyInfo->KeyValue->RSAKeyValue->Modulus);
- $exponent = base64_decode((string)$sxe->Signature->KeyInfo->KeyValue->RSAKeyValue->Exponent);
- $pem_public_key = self::_getPublicKeyFromModExp($modulus, $exponent);
- $public_key = openssl_pkey_get_public ($pem_public_key);
- break;
- default:
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Unable to determine or unsupported representation of the KeyValue block");
- }
- $transformer = new Zend_InfoCard_Xml_Security_Transform();
- $transformer->addTransform((string)$sxe->Signature->SignedInfo->CanonicalizationMethod['Algorithm']);
- // The way we are doing our XML processing requires that we specifically add this
- // (even though it's in the <Signature> parent-block).. otherwise, our canonical form
- // fails signature verification
- $sxe->Signature->SignedInfo->addAttribute('xmlns', 'http://www.w3.org/2000/09/xmldsig#');
- $canonical_signedinfo = $transformer->applyTransforms($sxe->Signature->SignedInfo->asXML());
- if(@openssl_verify($canonical_signedinfo, $signatureValue, $public_key)) {
- return (string)$sxe->Signature->SignedInfo->Reference['URI'];
- }
- return false;
- }
- /**
- * Transform an RSA Key in Modulus/Exponent format into a PEM encoding and
- * return an openssl resource for it
- *
- * @param string $modulus The RSA Modulus in binary format
- * @param string $exponent The RSA exponent in binary format
- * @return string The PEM encoded version of the key
- */
- static protected function _getPublicKeyFromModExp($modulus, $exponent)
- {
- $modulusInteger = self::_encodeValue($modulus, self::ASN_TYPE_INTEGER);
- $exponentInteger = self::_encodeValue($exponent, self::ASN_TYPE_INTEGER);
- $modExpSequence = self::_encodeValue($modulusInteger . $exponentInteger, self::ASN_TYPE_SEQUENCE);
- $modExpBitString = self::_encodeValue($modExpSequence, self::ASN_TYPE_BITSTRING);
- $binRsaKeyIdentifier = pack( "H*", self::RSA_KEY_IDENTIFIER );
- $publicKeySequence = self::_encodeValue($binRsaKeyIdentifier . $modExpBitString, self::ASN_TYPE_SEQUENCE);
- $publicKeyInfoBase64 = base64_encode( $publicKeySequence );
- $publicKeyString = "-----BEGIN PUBLIC KEY-----\n";
- $publicKeyString .= wordwrap($publicKeyInfoBase64, 64, "\n", true);
- $publicKeyString .= "\n-----END PUBLIC KEY-----\n";
- return $publicKeyString;
- }
- /**
- * Encode a limited set of data types into ASN.1 encoding format
- * which is used in X.509 certificates
- *
- * @param string $data The data to encode
- * @param const $type The encoding format constant
- * @return string The encoded value
- * @throws Zend_InfoCard_Xml_Security_Exception
- */
- static protected function _encodeValue($data, $type)
- {
- // Null pad some data when we get it (integer values > 128 and bitstrings)
- if( (($type == self::ASN_TYPE_INTEGER) && (ord($data) > 0x7f)) ||
- ($type == self::ASN_TYPE_BITSTRING)) {
- $data = "\0$data";
- }
- $len = strlen($data);
- // encode the value based on length of the string
- // I'm fairly confident that this is by no means a complete implementation
- // but it is enough for our purposes
- switch(true) {
- case ($len < 128):
- return sprintf("%c%c%s", $type, $len, $data);
- case ($len < 0x0100):
- return sprintf("%c%c%c%s", $type, 0x81, $len, $data);
- case ($len < 0x010000):
- return sprintf("%c%c%c%c%s", $type, 0x82, $len / 0x0100, $len % 0x0100, $data);
- default:
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Could not encode value");
- }
- require_once 'Zend/InfoCard/Xml/Security/Exception.php';
- throw new Zend_InfoCard_Xml_Security_Exception("Invalid code path");
- }
- /**
- * Securely compare two strings for equality while avoided C level memcmp()
- * optimisations capable of leaking timing information useful to an attacker
- * attempting to iteratively guess the unknown string (e.g. password) being
- * compared against.
- *
- * @param string $a
- * @param string $b
- * @return bool
- */
- static protected function _secureStringCompare($a, $b)
- {
- if (strlen($a) !== strlen($b)) {
- return false;
- }
- $result = 0;
- for ($i = 0; $i < strlen($a); $i++) {
- $result |= ord($a[$i]) ^ ord($b[$i]);
- }
- return $result == 0;
- }
- }