139 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			139 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
| <?php
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| 
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| 
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| namespace WebAuthn\Attestation\Format;
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| use WebAuthn\WebAuthnException;
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| use WebAuthn\Binary\ByteBuffer;
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| 
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| class Packed extends FormatBase {
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|     private $_alg;
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|     private $_signature;
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|     private $_x5c;
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| 
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|     public function __construct($AttestionObject, \WebAuthn\Attestation\AuthenticatorData $authenticatorData) {
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|         parent::__construct($AttestionObject, $authenticatorData);
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| 
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|         // check packed data
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|         $attStmt = $this->_attestationObject['attStmt'];
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| 
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|         if (!\array_key_exists('alg', $attStmt) || $this->_getCoseAlgorithm($attStmt['alg']) === null) {
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|             throw new WebAuthnException('unsupported alg: ' . $attStmt['alg'], WebAuthnException::INVALID_DATA);
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|         }
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| 
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|         if (!\array_key_exists('sig', $attStmt) || !\is_object($attStmt['sig']) || !($attStmt['sig'] instanceof ByteBuffer)) {
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|             throw new WebAuthnException('no signature found', WebAuthnException::INVALID_DATA);
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|         }
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| 
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|         $this->_alg = $attStmt['alg'];
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|         $this->_signature = $attStmt['sig']->getBinaryString();
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| 
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|         // certificate for validation
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|         if (\array_key_exists('x5c', $attStmt) && \is_array($attStmt['x5c']) && \count($attStmt['x5c']) > 0) {
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| 
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|             // The attestation certificate attestnCert MUST be the first element in the array
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|             $attestnCert = array_shift($attStmt['x5c']);
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| 
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|             if (!($attestnCert instanceof ByteBuffer)) {
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|                 throw new WebAuthnException('invalid x5c certificate', WebAuthnException::INVALID_DATA);
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|             }
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| 
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|             $this->_x5c = $attestnCert->getBinaryString();
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| 
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|             // certificate chain
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|             foreach ($attStmt['x5c'] as $chain) {
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|                 if ($chain instanceof ByteBuffer) {
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|                     $this->_x5c_chain[] = $chain->getBinaryString();
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|                 }
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|             }
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|         }
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|     }
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| 
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| 
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|     /*
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|      * returns the key certificate in PEM format
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|      * @return string|null
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|      */
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|     public function getCertificatePem() {
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|         if (!$this->_x5c) {
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|             return null;
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|         }
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|         return $this->_createCertificatePem($this->_x5c);
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|     }
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| 
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|     /**
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|      * @param string $clientDataHash
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|      */
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|     public function validateAttestation($clientDataHash) {
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|         if ($this->_x5c) {
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|             return $this->_validateOverX5c($clientDataHash);
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|         } else {
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|             return $this->_validateSelfAttestation($clientDataHash);
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|         }
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|     }
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| 
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|     /**
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|      * validates the certificate against root certificates
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|      * @param array $rootCas
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|      * @return boolean
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|      * @throws WebAuthnException
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|      */
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|     public function validateRootCertificate($rootCas) {
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|         if (!$this->_x5c) {
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|             return false;
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|         }
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| 
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|         $chainC = $this->_createX5cChainFile();
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|         if ($chainC) {
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|             $rootCas[] = $chainC;
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|         }
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| 
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|         $v = \openssl_x509_checkpurpose($this->getCertificatePem(), -1, $rootCas);
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|         if ($v === -1) {
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|             throw new WebAuthnException('error on validating root certificate: ' . \openssl_error_string(), WebAuthnException::CERTIFICATE_NOT_TRUSTED);
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|         }
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|         return $v;
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|     }
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| 
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|     /**
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|      * validate if x5c is present
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|      * @param string $clientDataHash
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|      * @return bool
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|      * @throws WebAuthnException
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|      */
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|     protected function _validateOverX5c($clientDataHash) {
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|         $publicKey = \openssl_pkey_get_public($this->getCertificatePem());
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| 
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|         if ($publicKey === false) {
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|             throw new WebAuthnException('invalid public key: ' . \openssl_error_string(), WebAuthnException::INVALID_PUBLIC_KEY);
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|         }
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| 
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|         // Verify that sig is a valid signature over the concatenation of authenticatorData and clientDataHash
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|         // using the attestation public key in attestnCert with the algorithm specified in alg.
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|         $dataToVerify = $this->_authenticatorData->getBinary();
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|         $dataToVerify .= $clientDataHash;
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| 
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|         $coseAlgorithm = $this->_getCoseAlgorithm($this->_alg);
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| 
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|         // check certificate
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|         return \openssl_verify($dataToVerify, $this->_signature, $publicKey, $coseAlgorithm->openssl) === 1;
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|     }
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| 
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|     /**
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|      * validate if self attestation is in use
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|      * @param string $clientDataHash
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|      * @return bool
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|      */
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|     protected function _validateSelfAttestation($clientDataHash) {
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|         // Verify that sig is a valid signature over the concatenation of authenticatorData and clientDataHash
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|         // using the credential public key with alg.
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|         $dataToVerify = $this->_authenticatorData->getBinary();
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|         $dataToVerify .= $clientDataHash;
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| 
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|         $publicKey = $this->_authenticatorData->getPublicKeyPem();
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| 
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|         // check certificate
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|         return \openssl_verify($dataToVerify, $this->_signature, $publicKey, OPENSSL_ALGO_SHA256) === 1;
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|     }
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| }
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| 
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