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EDITING: Packed.php

<?php

namespace lbuchs\WebAuthn\Attestation\Format;
use lbuchs\WebAuthn\Attestation\AuthenticatorData;
use lbuchs\WebAuthn\WebAuthnException;
use lbuchs\WebAuthn\Binary\ByteBuffer;

class Packed extends FormatBase {
    private $_alg;
    private $_signature;
    private $_x5c;

public function __construct($AttestionObject, AuthenticatorData $authenticatorData) {
        parent::__construct($AttestionObject, $authenticatorData);

// check packed data
        $attStmt = $this->_attestationObject['attStmt'];

if (!\array_key_exists('alg', $attStmt) || $this->_getCoseAlgorithm($attStmt['alg']) === null) {
            throw new WebAuthnException('unsupported alg: ' . $attStmt['alg'], WebAuthnException::INVALID_DATA);
        }

if (!\array_key_exists('sig', $attStmt) || !\is_object($attStmt['sig']) || !($attStmt['sig'] instanceof ByteBuffer)) {
            throw new WebAuthnException('no signature found', WebAuthnException::INVALID_DATA);
        }

$this->_alg = $attStmt['alg'];
        $this->_signature = $attStmt['sig']->getBinaryString();

// certificate for validation
        if (\array_key_exists('x5c', $attStmt) && \is_array($attStmt['x5c']) && \count($attStmt['x5c']) > 0) {

// The attestation certificate attestnCert MUST be the first element in the array
            $attestnCert = array_shift($attStmt['x5c']);

if (!($attestnCert instanceof ByteBuffer)) {
                throw new WebAuthnException('invalid x5c certificate', WebAuthnException::INVALID_DATA);
            }

$this->_x5c = $attestnCert->getBinaryString();

// certificate chain
            foreach ($attStmt['x5c'] as $chain) {
                if ($chain instanceof ByteBuffer) {
                    $this->_x5c_chain[] = $chain->getBinaryString();
                }
            }
        }
    }

/*
     * returns the key certificate in PEM format
     * @return string|null
     */
    public function getCertificatePem() {
        if (!$this->_x5c) {
            return null;
        }
        return $this->_createCertificatePem($this->_x5c);
    }

/**
     * @param string $clientDataHash
     */
    public function validateAttestation($clientDataHash) {
        if ($this->_x5c) {
            return $this->_validateOverX5c($clientDataHash);
        } else {
            return $this->_validateSelfAttestation($clientDataHash);
        }
    }

/**
     * validates the certificate against root certificates
     * @param array $rootCas
     * @return boolean
     * @throws WebAuthnException
     */
    public function validateRootCertificate($rootCas) {
        if (!$this->_x5c) {
            return false;
        }

$chainC = $this->_createX5cChainFile();
        if ($chainC) {
            $rootCas[] = $chainC;
        }

$v = \openssl_x509_checkpurpose($this->getCertificatePem(), -1, $rootCas);
        if ($v === -1) {
            throw new WebAuthnException('error on validating root certificate: ' . \openssl_error_string(), WebAuthnException::CERTIFICATE_NOT_TRUSTED);
        }
        return $v;
    }

/**
     * validate if x5c is present
     * @param string $clientDataHash
     * @return bool
     * @throws WebAuthnException
     */
    protected function _validateOverX5c($clientDataHash) {
        $publicKey = \openssl_pkey_get_public($this->getCertificatePem());

if ($publicKey === false) {
            throw new WebAuthnException('invalid public key: ' . \openssl_error_string(), WebAuthnException::INVALID_PUBLIC_KEY);
        }

// Verify that sig is a valid signature over the concatenation of authenticatorData and clientDataHash
        // using the attestation public key in attestnCert with the algorithm specified in alg.
        $dataToVerify = $this->_authenticatorData->getBinary();
        $dataToVerify .= $clientDataHash;

$coseAlgorithm = $this->_getCoseAlgorithm($this->_alg);

// check certificate
        return \openssl_verify($dataToVerify, $this->_signature, $publicKey, $coseAlgorithm->openssl) === 1;
    }

/**
     * validate if self attestation is in use
     * @param string $clientDataHash
     * @return bool
     */
    protected function _validateSelfAttestation($clientDataHash) {
        // Verify that sig is a valid signature over the concatenation of authenticatorData and clientDataHash
        // using the credential public key with alg.
        $dataToVerify = $this->_authenticatorData->getBinary();
        $dataToVerify .= $clientDataHash;

$publicKey = $this->_authenticatorData->getPublicKeyPem();

// check certificate
        return \openssl_verify($dataToVerify, $this->_signature, $publicKey, OPENSSL_ALGO_SHA256) === 1;
    }
}

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📄 AndroidKey.php	PHP	3.5 KB	2026-02-11 01:44	EDIT
📄 AndroidSafetyNet.php	PHP	5.7 KB	2026-02-11 01:44	EDIT
📄 Apple.php	PHP	5.1 KB	2026-02-11 01:44	EDIT
📄 FormatBase.php	PHP	5.9 KB	2026-02-11 01:44	EDIT
📄 None.php	PHP	950 B	2026-02-11 01:44	EDIT
📄 Packed.php	PHP	4.7 KB	2026-02-11 01:44	EDIT
📄 Tpm.php	PHP	6.5 KB	2026-02-11 01:44	EDIT
📄 U2f.php	PHP	3.4 KB	2026-02-11 01:44	EDIT