website-2008-computer-shopping-3 /library/Zend/InfoCard/Xml/Security.php

Language PHP Lines 292
MD5 Hash 8e63e49875b2fc8408147ee96280b928 Estimated Cost $3,505 (why?)
Repository https://bitbucket.org/baruffaldi/website-2008-computer-shopping-3.git View Raw File View Project SPDX
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
<?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) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Security.php 9094 2008-03-30 18:36:55Z thomas $
 */

/**
 * Zend_InfoCard_Xml_Security_Exception
 */
require_once 'Zend/InfoCard/Xml/Security/Exception.php';

/**
 * 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) 2005-2008 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')) {
            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)) {
            throw new Zend_InfoCard_Xml_Security_Exception("Could not identify XML Signature element");
        }

        if(!isset($sxe->Signature->SignedInfo)) {
            throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a SignedInfo block");
        }

        if(!isset($sxe->Signature->SignatureValue)) {
            throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a SignatureValue block");
        }

        if(!isset($sxe->Signature->KeyInfo)) {
            throw new Zend_InfoCard_Xml_Security_Exception("Signature is missing a KeyInfo block");
        }

        if(!isset($sxe->Signature->KeyInfo->KeyValue)) {
            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:
                throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported CanonicalizationMethod Requested");
        }

        switch((string)$sxe->Signature->SignedInfo->SignatureMethod['Algorithm']) {
            case self::SIGNATURE_METHOD_SHA1:
                $sMethod = (string)$sxe->Signature->SignedInfo->SignatureMethod['Algorithm'];
                break;
            default:
                throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported SignatureMethod Requested");
        }

        switch((string)$sxe->Signature->SignedInfo->Reference->DigestMethod['Algorithm']) {
            case self::DIGEST_METHOD_SHA1:
                $dMethod = (string)$sxe->Signature->SignedInfo->Reference->DigestMethod['Algorithm'];
                break;
            default:
                throw new Zend_InfoCard_Xml_Security_Exception("Unknown or unsupported DigestMethod Requested");
        }

        $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($transformed_xml_binhash != $dValue) {
            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) {
                    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)) {
                    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:
                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:
                throw new Zend_InfoCard_Xml_Security_Exception("Could not encode value");
        }

        throw new Zend_InfoCard_Xml_Security_Exception("Invalid code path");
    }
}
Back to Top