mailcow/data/web/inc/lib/WebAuthn/Attestation/Format/AndroidKey.php
2022-01-12 21:09:18 +01:00

97 lines
3.5 KiB
PHP

<?php
namespace lbuchs\WebAuthn\Attestation\Format;
use lbuchs\WebAuthn\Attestation\AuthenticatorData;
use lbuchs\WebAuthn\WebAuthnException;
use lbuchs\WebAuthn\Binary\ByteBuffer;
class AndroidKey extends FormatBase {
private $_alg;
private $_signature;
private $_x5c;
public function __construct($AttestionObject, AuthenticatorData $authenticatorData) {
parent::__construct($AttestionObject, $authenticatorData);
// check u2f 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);
}
if (!\array_key_exists('x5c', $attStmt) || !\is_array($attStmt['x5c']) || \count($attStmt['x5c']) < 1) {
throw new WebAuthnException('invalid x5c certificate', WebAuthnException::INVALID_DATA);
}
if (!\is_object($attStmt['x5c'][0]) || !($attStmt['x5c'][0] instanceof ByteBuffer)) {
throw new WebAuthnException('invalid x5c certificate', WebAuthnException::INVALID_DATA);
}
$this->_alg = $attStmt['alg'];
$this->_signature = $attStmt['sig']->getBinaryString();
$this->_x5c = $attStmt['x5c'][0]->getBinaryString();
if (count($attStmt['x5c']) > 1) {
for ($i=1; $i<count($attStmt['x5c']); $i++) {
$this->_x5c_chain[] = $attStmt['x5c'][$i]->getBinaryString();
}
unset ($i);
}
}
/*
* returns the key certificate in PEM format
* @return string
*/
public function getCertificatePem() {
return $this->_createCertificatePem($this->_x5c);
}
/**
* @param string $clientDataHash
*/
public function validateAttestation($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;
}
/**
* validates the certificate against root certificates
* @param array $rootCas
* @return boolean
* @throws WebAuthnException
*/
public function validateRootCertificate($rootCas) {
$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;
}
}