496 lines
23 KiB
PHP
496 lines
23 KiB
PHP
<?php
|
||
|
||
namespace WebAuthn;
|
||
use WebAuthn\Binary\ByteBuffer;
|
||
require_once 'WebAuthnException.php';
|
||
require_once 'Binary/ByteBuffer.php';
|
||
require_once 'Attestation/AttestationObject.php';
|
||
require_once 'Attestation/AuthenticatorData.php';
|
||
require_once 'Attestation/Format/FormatBase.php';
|
||
require_once 'Attestation/Format/None.php';
|
||
require_once 'Attestation/Format/AndroidKey.php';
|
||
require_once 'Attestation/Format/AndroidSafetyNet.php';
|
||
require_once 'Attestation/Format/Apple.php';
|
||
require_once 'Attestation/Format/Packed.php';
|
||
require_once 'Attestation/Format/Tpm.php';
|
||
require_once 'Attestation/Format/U2f.php';
|
||
require_once 'CBOR/CborDecoder.php';
|
||
|
||
/**
|
||
* WebAuthn
|
||
* @author Lukas Buchs
|
||
* @license https://github.com/lbuchs/WebAuthn/blob/master/LICENSE MIT
|
||
*/
|
||
class WebAuthn {
|
||
// relying party
|
||
private $_rpName;
|
||
private $_rpId;
|
||
private $_rpIdHash;
|
||
private $_challenge;
|
||
private $_signatureCounter;
|
||
private $_caFiles;
|
||
private $_formats;
|
||
|
||
/**
|
||
* Initialize a new WebAuthn server
|
||
* @param string $rpName the relying party name
|
||
* @param string $rpId the relying party ID = the domain name
|
||
* @param bool $useBase64UrlEncoding true to use base64 url encoding for binary data in json objects. Default is a RFC 1342-Like serialized string.
|
||
* @throws WebAuthnException
|
||
*/
|
||
public function __construct($rpName, $rpId, $allowedFormats=null, $useBase64UrlEncoding=false) {
|
||
$this->_rpName = $rpName;
|
||
$this->_rpId = $rpId;
|
||
$this->_rpIdHash = \hash('sha256', $rpId, true);
|
||
ByteBuffer::$useBase64UrlEncoding = !!$useBase64UrlEncoding;
|
||
$supportedFormats = array('android-key', 'android-safetynet', 'apple', 'fido-u2f', 'none', 'packed', 'tpm');
|
||
|
||
if (!\function_exists('\openssl_open')) {
|
||
throw new WebAuthnException('OpenSSL-Module not installed');;
|
||
}
|
||
|
||
if (!\in_array('SHA256', \array_map('\strtoupper', \openssl_get_md_methods()))) {
|
||
throw new WebAuthnException('SHA256 not supported by this openssl installation.');
|
||
}
|
||
|
||
// default: all format
|
||
if (!is_array($allowedFormats)) {
|
||
$allowedFormats = $supportedFormats;
|
||
}
|
||
$this->_formats = $allowedFormats;
|
||
|
||
// validate formats
|
||
$invalidFormats = \array_diff($this->_formats, $supportedFormats);
|
||
if (!$this->_formats || $invalidFormats) {
|
||
throw new WebAuthnException('invalid formats on construct: ' . implode(', ', $invalidFormats));
|
||
}
|
||
}
|
||
|
||
/**
|
||
* add a root certificate to verify new registrations
|
||
* @param string $path file path of / directory with root certificates
|
||
*/
|
||
public function addRootCertificates($path) {
|
||
if (!\is_array($this->_caFiles)) {
|
||
$this->_caFiles = array();
|
||
}
|
||
$path = \rtrim(\trim($path), '\\/');
|
||
if (\is_dir($path)) {
|
||
foreach (\scandir($path) as $ca) {
|
||
if (\is_file($path . '/' . $ca)) {
|
||
$this->addRootCertificates($path . '/' . $ca);
|
||
}
|
||
}
|
||
} else if (\is_file($path) && !\in_array(\realpath($path), $this->_caFiles)) {
|
||
$this->_caFiles[] = \realpath($path);
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Returns the generated challenge to save for later validation
|
||
* @return ByteBuffer
|
||
*/
|
||
public function getChallenge() {
|
||
return $this->_challenge;
|
||
}
|
||
|
||
/**
|
||
* generates the object for a key registration
|
||
* provide this data to navigator.credentials.create
|
||
* @param string $userId
|
||
* @param string $userName
|
||
* @param string $userDisplayName
|
||
* @param int $timeout timeout in seconds
|
||
* @param bool $requireResidentKey true, if the key should be stored by the authentication device
|
||
* @param bool|string $requireUserVerification indicates that you require user verification and will fail the operation
|
||
* if the response does not have the UV flag set.
|
||
* Valid values:
|
||
* true = required
|
||
* false = preferred
|
||
* string 'required' 'preferred' 'discouraged'
|
||
* @param bool|null $crossPlatformAttachment true for cross-platform devices (eg. fido usb),
|
||
* false for platform devices (eg. windows hello, android safetynet),
|
||
* null for both
|
||
* @param array $excludeCredentialIds a array of ids, which are already registered, to prevent re-registration
|
||
* @return \stdClass
|
||
*/
|
||
public function getCreateArgs($userId, $userName, $userDisplayName, $timeout=20, $requireResidentKey=false, $requireUserVerification=false, $crossPlatformAttachment=null, $excludeCredentialIds=array()) {
|
||
|
||
// validate User Verification Requirement
|
||
if (\is_bool($requireUserVerification)) {
|
||
$requireUserVerification = $requireUserVerification ? 'required' : 'preferred';
|
||
} else if (\is_string($requireUserVerification) && \in_array(\strtolower($requireUserVerification), ['required', 'preferred', 'discouraged'])) {
|
||
$requireUserVerification = \strtolower($requireUserVerification);
|
||
} else {
|
||
$requireUserVerification = 'preferred';
|
||
}
|
||
|
||
$args = new \stdClass();
|
||
$args->publicKey = new \stdClass();
|
||
|
||
// relying party
|
||
$args->publicKey->rp = new \stdClass();
|
||
$args->publicKey->rp->name = $this->_rpName;
|
||
$args->publicKey->rp->id = $this->_rpId;
|
||
|
||
$args->publicKey->authenticatorSelection = new \stdClass();
|
||
$args->publicKey->authenticatorSelection->userVerification = $requireUserVerification;
|
||
if ($requireResidentKey) {
|
||
$args->publicKey->authenticatorSelection->requireResidentKey = true;
|
||
}
|
||
if (is_bool($crossPlatformAttachment)) {
|
||
$args->publicKey->authenticatorSelection->authenticatorAttachment = $crossPlatformAttachment ? 'cross-platform' : 'platform';
|
||
}
|
||
|
||
// user
|
||
$args->publicKey->user = new \stdClass();
|
||
$args->publicKey->user->id = new ByteBuffer($userId); // binary
|
||
$args->publicKey->user->name = $userName;
|
||
$args->publicKey->user->displayName = $userDisplayName;
|
||
|
||
$args->publicKey->pubKeyCredParams = array();
|
||
$tmp = new \stdClass();
|
||
$tmp->type = 'public-key';
|
||
$tmp->alg = -7; // ES256
|
||
$args->publicKey->pubKeyCredParams[] = $tmp;
|
||
unset ($tmp);
|
||
|
||
$tmp = new \stdClass();
|
||
$tmp->type = 'public-key';
|
||
$tmp->alg = -257; // RS256
|
||
$args->publicKey->pubKeyCredParams[] = $tmp;
|
||
unset ($tmp);
|
||
|
||
// if there are root certificates added, we need direct attestation to validate
|
||
// against the root certificate. If there are no root-certificates added,
|
||
// anonymization ca are also accepted, because we can't validate the root anyway.
|
||
$attestation = 'indirect';
|
||
if (\is_array($this->_caFiles)) {
|
||
$attestation = 'direct';
|
||
}
|
||
|
||
$args->publicKey->attestation = \count($this->_formats) === 1 && \in_array('none', $this->_formats) ? 'none' : $attestation;
|
||
$args->publicKey->extensions = new \stdClass();
|
||
$args->publicKey->extensions->exts = true;
|
||
$args->publicKey->timeout = $timeout * 1000; // microseconds
|
||
$args->publicKey->challenge = $this->_createChallenge(); // binary
|
||
|
||
//prevent re-registration by specifying existing credentials
|
||
$args->publicKey->excludeCredentials = array();
|
||
|
||
if (is_array($excludeCredentialIds)) {
|
||
foreach ($excludeCredentialIds as $id) {
|
||
$tmp = new \stdClass();
|
||
$tmp->id = $id instanceof ByteBuffer ? $id : new ByteBuffer($id); // binary
|
||
$tmp->type = 'public-key';
|
||
$tmp->transports = array('usb', 'ble', 'nfc', 'internal');
|
||
$args->publicKey->excludeCredentials[] = $tmp;
|
||
unset ($tmp);
|
||
}
|
||
}
|
||
|
||
return $args;
|
||
}
|
||
|
||
/**
|
||
* generates the object for key validation
|
||
* Provide this data to navigator.credentials.get
|
||
* @param array $credentialIds binary
|
||
* @param int $timeout timeout in seconds
|
||
* @param bool $allowUsb allow removable USB
|
||
* @param bool $allowNfc allow Near Field Communication (NFC)
|
||
* @param bool $allowBle allow Bluetooth
|
||
* @param bool $allowInternal allow client device-specific transport. These authenticators are not removable from the client device.
|
||
* @param bool|string $requireUserVerification indicates that you require user verification and will fail the operation
|
||
* if the response does not have the UV flag set.
|
||
* Valid values:
|
||
* true = required
|
||
* false = preferred
|
||
* string 'required' 'preferred' 'discouraged'
|
||
* @return \stdClass
|
||
*/
|
||
public function getGetArgs($credentialIds=array(), $timeout=20, $allowUsb=true, $allowNfc=true, $allowBle=true, $allowInternal=true, $requireUserVerification=false) {
|
||
|
||
// validate User Verification Requirement
|
||
if (\is_bool($requireUserVerification)) {
|
||
$requireUserVerification = $requireUserVerification ? 'required' : 'preferred';
|
||
} else if (\is_string($requireUserVerification) && \in_array(\strtolower($requireUserVerification), ['required', 'preferred', 'discouraged'])) {
|
||
$requireUserVerification = \strtolower($requireUserVerification);
|
||
} else {
|
||
$requireUserVerification = 'preferred';
|
||
}
|
||
|
||
$args = new \stdClass();
|
||
$args->publicKey = new \stdClass();
|
||
$args->publicKey->timeout = $timeout * 1000; // microseconds
|
||
$args->publicKey->challenge = $this->_createChallenge(); // binary
|
||
$args->publicKey->userVerification = $requireUserVerification;
|
||
$args->publicKey->rpId = $this->_rpId;
|
||
|
||
if (\is_array($credentialIds) && \count($credentialIds) > 0) {
|
||
$args->publicKey->allowCredentials = array();
|
||
|
||
foreach ($credentialIds as $id) {
|
||
$tmp = new \stdClass();
|
||
$tmp->id = $id instanceof ByteBuffer ? $id : new ByteBuffer($id); // binary
|
||
$tmp->transports = array();
|
||
|
||
if ($allowUsb) {
|
||
$tmp->transports[] = 'usb';
|
||
}
|
||
if ($allowNfc) {
|
||
$tmp->transports[] = 'nfc';
|
||
}
|
||
if ($allowBle) {
|
||
$tmp->transports[] = 'ble';
|
||
}
|
||
if ($allowInternal) {
|
||
$tmp->transports[] = 'internal';
|
||
}
|
||
|
||
$tmp->type = 'public-key';
|
||
$args->publicKey->allowCredentials[] = $tmp;
|
||
unset ($tmp);
|
||
}
|
||
}
|
||
|
||
return $args;
|
||
}
|
||
|
||
/**
|
||
* returns the new signature counter value.
|
||
* returns null if there is no counter
|
||
* @return ?int
|
||
*/
|
||
public function getSignatureCounter() {
|
||
return \is_int($this->_signatureCounter) ? $this->_signatureCounter : null;
|
||
}
|
||
|
||
/**
|
||
* process a create request and returns data to save for future logins
|
||
* @param string $clientDataJSON binary from browser
|
||
* @param string $attestationObject binary from browser
|
||
* @param string|ByteBuffer $challenge binary used challange
|
||
* @param bool $requireUserVerification true, if the device must verify user (e.g. by biometric data or pin)
|
||
* @param bool $requireUserPresent false, if the device must NOT check user presence (e.g. by pressing a button)
|
||
* @return \stdClass
|
||
* @throws WebAuthnException
|
||
*/
|
||
public function processCreate($clientDataJSON, $attestationObject, $challenge, $requireUserVerification=false, $requireUserPresent=true) {
|
||
$clientDataHash = \hash('sha256', $clientDataJSON, true);
|
||
$clientData = \json_decode($clientDataJSON);
|
||
$challenge = $challenge instanceof ByteBuffer ? $challenge : new ByteBuffer($challenge);
|
||
|
||
// security: https://www.w3.org/TR/webauthn/#registering-a-new-credential
|
||
|
||
// 2. Let C, the client data claimed as collected during the credential creation,
|
||
// be the result of running an implementation-specific JSON parser on JSONtext.
|
||
if (!\is_object($clientData)) {
|
||
throw new WebAuthnException('invalid client data', WebAuthnException::INVALID_DATA);
|
||
}
|
||
|
||
// 3. Verify that the value of C.type is webauthn.create.
|
||
if (!\property_exists($clientData, 'type') || $clientData->type !== 'webauthn.create') {
|
||
throw new WebAuthnException('invalid type', WebAuthnException::INVALID_TYPE);
|
||
}
|
||
|
||
// 4. Verify that the value of C.challenge matches the challenge that was sent to the authenticator in the create() call.
|
||
if (!\property_exists($clientData, 'challenge') || ByteBuffer::fromBase64Url($clientData->challenge)->getBinaryString() !== $challenge->getBinaryString()) {
|
||
throw new WebAuthnException('invalid challenge', WebAuthnException::INVALID_CHALLENGE);
|
||
}
|
||
|
||
// 5. Verify that the value of C.origin matches the Relying Party's origin.
|
||
if (!\property_exists($clientData, 'origin') || !$this->_checkOrigin($clientData->origin)) {
|
||
throw new WebAuthnException('invalid origin', WebAuthnException::INVALID_ORIGIN);
|
||
}
|
||
|
||
// Attestation
|
||
$attestationObject = new Attestation\AttestationObject($attestationObject, $this->_formats);
|
||
|
||
// 9. Verify that the RP ID hash in authData is indeed the SHA-256 hash of the RP ID expected by the RP.
|
||
if (!$attestationObject->validateRpIdHash($this->_rpIdHash)) {
|
||
throw new WebAuthnException('invalid rpId hash', WebAuthnException::INVALID_RELYING_PARTY);
|
||
}
|
||
|
||
// 14. Verify that attStmt is a correct attestation statement, conveying a valid attestation signature
|
||
if (!$attestationObject->validateAttestation($clientDataHash)) {
|
||
throw new WebAuthnException('invalid certificate signature', WebAuthnException::INVALID_SIGNATURE);
|
||
}
|
||
|
||
// 15. If validation is successful, obtain a list of acceptable trust anchors
|
||
if (is_array($this->_caFiles) && !$attestationObject->validateRootCertificate($this->_caFiles)) {
|
||
throw new WebAuthnException('invalid root certificate', WebAuthnException::CERTIFICATE_NOT_TRUSTED);
|
||
}
|
||
|
||
// 10. Verify that the User Present bit of the flags in authData is set.
|
||
if ($requireUserPresent && !$attestationObject->getAuthenticatorData()->getUserPresent()) {
|
||
throw new WebAuthnException('user not present during authentication', WebAuthnException::USER_PRESENT);
|
||
}
|
||
|
||
// 11. If user verification is required for this registration, verify that the User Verified bit of the flags in authData is set.
|
||
if ($requireUserVerification && !$attestationObject->getAuthenticatorData()->getUserVerified()) {
|
||
throw new WebAuthnException('user not verificated during authentication', WebAuthnException::USER_VERIFICATED);
|
||
}
|
||
|
||
$signCount = $attestationObject->getAuthenticatorData()->getSignCount();
|
||
if ($signCount > 0) {
|
||
$this->_signatureCounter = $signCount;
|
||
}
|
||
|
||
// prepare data to store for future logins
|
||
$data = new \stdClass();
|
||
$data->rpId = $this->_rpId;
|
||
$data->credentialId = $attestationObject->getAuthenticatorData()->getCredentialId();
|
||
$data->credentialPublicKey = $attestationObject->getAuthenticatorData()->getPublicKeyPem();
|
||
$data->certificateChain = $attestationObject->getCertificateChain();
|
||
$data->certificate = $attestationObject->getCertificatePem();
|
||
$data->certificateIssuer = $attestationObject->getCertificateIssuer();
|
||
$data->certificateSubject = $attestationObject->getCertificateSubject();
|
||
$data->signatureCounter = $this->_signatureCounter;
|
||
$data->AAGUID = $attestationObject->getAuthenticatorData()->getAAGUID();
|
||
return $data;
|
||
}
|
||
|
||
|
||
/**
|
||
* process a get request
|
||
* @param string $clientDataJSON binary from browser
|
||
* @param string $authenticatorData binary from browser
|
||
* @param string $signature binary from browser
|
||
* @param string $credentialPublicKey string PEM-formated public key from used credentialId
|
||
* @param string|ByteBuffer $challenge binary from used challange
|
||
* @param int $prevSignatureCnt signature count value of the last login
|
||
* @param bool $requireUserVerification true, if the device must verify user (e.g. by biometric data or pin)
|
||
* @param bool $requireUserPresent true, if the device must check user presence (e.g. by pressing a button)
|
||
* @return boolean true if get is successful
|
||
* @throws WebAuthnException
|
||
*/
|
||
public function processGet($clientDataJSON, $authenticatorData, $signature, $credentialPublicKey, $challenge, $prevSignatureCnt=null, $requireUserVerification=false, $requireUserPresent=true) {
|
||
$authenticatorObj = new Attestation\AuthenticatorData($authenticatorData);
|
||
$clientDataHash = \hash('sha256', $clientDataJSON, true);
|
||
$clientData = \json_decode($clientDataJSON);
|
||
$challenge = $challenge instanceof ByteBuffer ? $challenge : new ByteBuffer($challenge);
|
||
|
||
// https://www.w3.org/TR/webauthn/#verifying-assertion
|
||
|
||
// 1. If the allowCredentials option was given when this authentication ceremony was initiated,
|
||
// verify that credential.id identifies one of the public key credentials that were listed in allowCredentials.
|
||
// -> TO BE VERIFIED BY IMPLEMENTATION
|
||
|
||
// 2. If credential.response.userHandle is present, verify that the user identified
|
||
// by this value is the owner of the public key credential identified by credential.id.
|
||
// -> TO BE VERIFIED BY IMPLEMENTATION
|
||
|
||
// 3. Using credential’s id attribute (or the corresponding rawId, if base64url encoding is
|
||
// inappropriate for your use case), look up the corresponding credential public key.
|
||
// -> TO BE LOOKED UP BY IMPLEMENTATION
|
||
|
||
// 5. Let JSONtext be the result of running UTF-8 decode on the value of cData.
|
||
if (!\is_object($clientData)) {
|
||
throw new WebAuthnException('invalid client data', WebAuthnException::INVALID_DATA);
|
||
}
|
||
|
||
// 7. Verify that the value of C.type is the string webauthn.get.
|
||
if (!\property_exists($clientData, 'type') || $clientData->type !== 'webauthn.get') {
|
||
throw new WebAuthnException('invalid type', WebAuthnException::INVALID_TYPE);
|
||
}
|
||
|
||
// 8. Verify that the value of C.challenge matches the challenge that was sent to the
|
||
// authenticator in the PublicKeyCredentialRequestOptions passed to the get() call.
|
||
if (!\property_exists($clientData, 'challenge') || ByteBuffer::fromBase64Url($clientData->challenge)->getBinaryString() !== $challenge->getBinaryString()) {
|
||
throw new WebAuthnException('invalid challenge', WebAuthnException::INVALID_CHALLENGE);
|
||
}
|
||
|
||
// 9. Verify that the value of C.origin matches the Relying Party's origin.
|
||
if (!\property_exists($clientData, 'origin') || !$this->_checkOrigin($clientData->origin)) {
|
||
throw new WebAuthnException('invalid origin', WebAuthnException::INVALID_ORIGIN);
|
||
}
|
||
|
||
// 11. Verify that the rpIdHash in authData is the SHA-256 hash of the RP ID expected by the Relying Party.
|
||
if ($authenticatorObj->getRpIdHash() !== $this->_rpIdHash) {
|
||
throw new WebAuthnException('invalid rpId hash', WebAuthnException::INVALID_RELYING_PARTY);
|
||
}
|
||
|
||
// 12. Verify that the User Present bit of the flags in authData is set
|
||
if ($requireUserPresent && !$authenticatorObj->getUserPresent()) {
|
||
throw new WebAuthnException('user not present during authentication', WebAuthnException::USER_PRESENT);
|
||
}
|
||
|
||
// 13. If user verification is required for this assertion, verify that the User Verified bit of the flags in authData is set.
|
||
if ($requireUserVerification && !$authenticatorObj->getUserVerified()) {
|
||
throw new WebAuthnException('user not verificated during authentication', WebAuthnException::USER_VERIFICATED);
|
||
}
|
||
|
||
// 14. Verify the values of the client extension outputs
|
||
// (extensions not implemented)
|
||
|
||
// 16. Using the credential public key looked up in step 3, verify that sig is a valid signature
|
||
// over the binary concatenation of authData and hash.
|
||
$dataToVerify = '';
|
||
$dataToVerify .= $authenticatorData;
|
||
$dataToVerify .= $clientDataHash;
|
||
|
||
$publicKey = \openssl_pkey_get_public($credentialPublicKey);
|
||
if ($publicKey === false) {
|
||
throw new WebAuthnException('public key invalid', WebAuthnException::INVALID_PUBLIC_KEY);
|
||
}
|
||
|
||
if (\openssl_verify($dataToVerify, $signature, $publicKey, OPENSSL_ALGO_SHA256) !== 1) {
|
||
throw new WebAuthnException('invalid signature', WebAuthnException::INVALID_SIGNATURE);
|
||
}
|
||
|
||
// 17. If the signature counter value authData.signCount is nonzero,
|
||
// if less than or equal to the signature counter value stored,
|
||
// is a signal that the authenticator may be cloned
|
||
$signatureCounter = $authenticatorObj->getSignCount();
|
||
if ($signatureCounter > 0) {
|
||
$this->_signatureCounter = $signatureCounter;
|
||
if ($prevSignatureCnt !== null && $prevSignatureCnt >= $signatureCounter) {
|
||
throw new WebAuthnException('signature counter not valid', WebAuthnException::SIGNATURE_COUNTER);
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
// -----------------------------------------------
|
||
// PRIVATE
|
||
// -----------------------------------------------
|
||
|
||
/**
|
||
* checks if the origin matchs the RP ID
|
||
* @param string $origin
|
||
* @return boolean
|
||
* @throws WebAuthnException
|
||
*/
|
||
private function _checkOrigin($origin) {
|
||
// https://www.w3.org/TR/webauthn/#rp-id
|
||
|
||
// The origin's scheme must be https
|
||
if ($this->_rpId !== 'localhost' && \parse_url($origin, PHP_URL_SCHEME) !== 'https') {
|
||
return false;
|
||
}
|
||
|
||
// extract host from origin
|
||
$host = \parse_url($origin, PHP_URL_HOST);
|
||
$host = \trim($host, '.');
|
||
|
||
// The RP ID must be equal to the origin's effective domain, or a registrable
|
||
// domain suffix of the origin's effective domain.
|
||
return \preg_match('/' . \preg_quote($this->_rpId) . '$/i', $host) === 1;
|
||
}
|
||
|
||
/**
|
||
* generates a new challange
|
||
* @param int $length
|
||
* @return string
|
||
* @throws WebAuthnException
|
||
*/
|
||
private function _createChallenge($length = 32) {
|
||
if (!$this->_challenge) {
|
||
$this->_challenge = ByteBuffer::randomBuffer($length);
|
||
}
|
||
return $this->_challenge;
|
||
}
|
||
}
|