430 lines
15 KiB
PHP
Executable File
430 lines
15 KiB
PHP
Executable File
<?php
|
|
/**
|
|
* Created by IntelliJ IDEA.
|
|
* User: samuel
|
|
* Date: 09/12/2016
|
|
* Time: 14:40
|
|
*/
|
|
namespace Samyoul\U2F\U2FServer;
|
|
|
|
class U2FServer
|
|
{
|
|
/** Constant for the version of the u2f protocol */
|
|
const VERSION = "U2F_V2";
|
|
|
|
/** @internal */
|
|
const PUBKEY_LEN = 65;
|
|
|
|
/** @internal */
|
|
private static $FIXCERTS = [
|
|
'349bca1031f8c82c4ceca38b9cebf1a69df9fb3b94eed99eb3fb9aa3822d26e8',
|
|
'dd574527df608e47ae45fbba75a2afdd5c20fd94a02419381813cd55a2a3398f',
|
|
'1d8764f0f7cd1352df6150045c8f638e517270e8b5dda1c63ade9c2280240cae',
|
|
'd0edc9a91a1677435a953390865d208c55b3183c6759c9b5a7ff494c322558eb',
|
|
'6073c436dcd064a48127ddbf6032ac1a66fd59a0c24434f070d4e564c124c897',
|
|
'ca993121846c464d666096d35f13bf44c1b05af205f9b4a1e00cf6cc10c5e511'
|
|
];
|
|
|
|
/**
|
|
* @throws U2FException If OpenSSL older than 1.0.0 is used
|
|
*/
|
|
public static function checkOpenSSLVersion()
|
|
{
|
|
if(OPENSSL_VERSION_NUMBER < 0x10000000) {
|
|
throw new U2FException(
|
|
'OpenSSL has to be at least version 1.0.0, this is ' . OPENSSL_VERSION_TEXT,
|
|
U2FException::OLD_OPENSSL
|
|
);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Called to get a registration request to send to a user.
|
|
* Returns an array of one registration request and a array of sign requests.
|
|
*
|
|
* @param string $appId Application id for the running application, Basically the app's URL
|
|
* @param array $registrations List of current registrations for this
|
|
* user, to prevent the user from registering the same authenticator several
|
|
* times.
|
|
* @return array An array of two elements, the first containing a
|
|
* RegisterRequest the second being an array of SignRequest
|
|
* @throws U2FException
|
|
*/
|
|
public static function makeRegistration($appId, array $registrations = array())
|
|
{
|
|
$request = new RegistrationRequest(static::createChallenge(), $appId);
|
|
$signatures = static::makeAuthentication($registrations, $appId);
|
|
return [
|
|
"request" => $request,
|
|
"signatures" => $signatures
|
|
];
|
|
}
|
|
|
|
/**
|
|
* Called to verify and unpack a registration message.
|
|
*
|
|
* @param RegistrationRequest $request this is a reply to
|
|
* @param object $response response from a user
|
|
* @param string $attestDir
|
|
* @param bool $includeCert set to true if the attestation certificate should be
|
|
* included in the returned Registration object
|
|
* @return Registration
|
|
* @throws U2FException
|
|
*/
|
|
public static function register(RegistrationRequest $request, $response, $attestDir = null, $includeCert = true)
|
|
{
|
|
// Parameter Checks
|
|
if( !is_object( $request ) ) {
|
|
throw new \InvalidArgumentException('$request of register() method only accepts object.');
|
|
}
|
|
|
|
if( !is_object( $response ) ) {
|
|
throw new \InvalidArgumentException('$response of register() method only accepts object.');
|
|
}
|
|
|
|
if( property_exists( $response, 'errorCode') && $response->errorCode !== 0 ) {
|
|
throw new U2FException(
|
|
'User-agent returned error. Error code: ' . $response->errorCode,
|
|
U2FException::BAD_UA_RETURNING
|
|
);
|
|
}
|
|
|
|
if( !is_bool( $includeCert ) ) {
|
|
throw new \InvalidArgumentException('$include_cert of register() method only accepts boolean.');
|
|
}
|
|
|
|
// Unpack the registration data coming from the client-side token
|
|
$rawRegistration = static::base64u_decode($response->registrationData);
|
|
$registrationData = array_values(unpack('C*', $rawRegistration));
|
|
$clientData = static::base64u_decode($response->clientData);
|
|
$clientToken = json_decode($clientData);
|
|
|
|
// Check Client's challenge matches the original request's challenge
|
|
if($clientToken->challenge !== $request->challenge()) {
|
|
throw new U2FException(
|
|
'Registration challenge does not match',
|
|
U2FException::UNMATCHED_CHALLENGE
|
|
);
|
|
}
|
|
|
|
// Begin validating and building the registration
|
|
$registration = new Registration();
|
|
$offset = 1;
|
|
$pubKey = substr($rawRegistration, $offset, static::PUBKEY_LEN);
|
|
$offset += static::PUBKEY_LEN;
|
|
|
|
// Validate and set the public key
|
|
if(static::publicKeyToPem($pubKey) === null) {
|
|
throw new U2FException(
|
|
'Decoding of public key failed',
|
|
U2FException::PUBKEY_DECODE
|
|
);
|
|
}
|
|
$registration->setPublicKey(base64_encode($pubKey));
|
|
|
|
// Build and set the key handle.
|
|
$keyHandleLength = $registrationData[$offset++];
|
|
$keyHandle = substr($rawRegistration, $offset, $keyHandleLength);
|
|
$offset += $keyHandleLength;
|
|
$registration->setKeyHandle(static::base64u_encode($keyHandle));
|
|
|
|
// Build certificate
|
|
// Set certificate length
|
|
// Note: length of certificate is stored in byte 3 and 4 (excluding the first 4 bytes)
|
|
$certLength = 4;
|
|
$certLength += ($registrationData[$offset + 2] << 8);
|
|
$certLength += $registrationData[$offset + 3];
|
|
|
|
// Write the certificate from the returning registration data
|
|
$rawCert = static::fixSignatureUnusedBits(substr($rawRegistration, $offset, $certLength));
|
|
$offset += $certLength;
|
|
$pemCert = "-----BEGIN CERTIFICATE-----\r\n";
|
|
$pemCert .= chunk_split(base64_encode($rawCert), 64);
|
|
$pemCert .= "-----END CERTIFICATE-----";
|
|
if($includeCert) {
|
|
$registration->setCertificate( base64_encode($rawCert) );
|
|
}
|
|
|
|
// If we've set the attestDir, check the given certificate can be used.
|
|
if($attestDir) {
|
|
if(openssl_x509_checkpurpose($pemCert, -1, static::get_certs($attestDir)) !== true) {
|
|
throw new U2FException(
|
|
'Attestation certificate can not be validated',
|
|
U2FException::ATTESTATION_VERIFICATION
|
|
);
|
|
}
|
|
}
|
|
|
|
// Attempt to extract public key from the certificate, if we can't something went wrong in making it.
|
|
if(!openssl_pkey_get_public($pemCert)) {
|
|
throw new U2FException(
|
|
'Decoding of public key failed',
|
|
U2FException::PUBKEY_DECODE
|
|
);
|
|
}
|
|
|
|
// Generate signature from the remaining part of the raw registration data
|
|
$signature = substr($rawRegistration, $offset);
|
|
|
|
// Build a verification string from the components we've made in this function
|
|
$dataToVerify = chr(0);
|
|
$dataToVerify .= hash('sha256', $request->appId(), true);
|
|
$dataToVerify .= hash('sha256', $clientData, true);
|
|
$dataToVerify .= $keyHandle;
|
|
$dataToVerify .= $pubKey;
|
|
|
|
// Verify our data against the signature and the certificate, on success return the registration object
|
|
if(openssl_verify($dataToVerify, $signature, $pemCert, 'sha256') === 1) {
|
|
return $registration;
|
|
} else {
|
|
throw new U2FException(
|
|
'Attestation signature does not match',
|
|
U2FException::ATTESTATION_SIGNATURE
|
|
);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Called to get an authentication request.
|
|
*
|
|
* @param array $registrations An array of the registrations to create authentication requests for.
|
|
* @param string $appId Application id for the running application, Basically the app's URL
|
|
* @return array An array of SignRequest
|
|
* @throws \InvalidArgumentException
|
|
*/
|
|
public static function makeAuthentication(array $registrations, $appId)
|
|
{
|
|
$signatures = [];
|
|
$challenge = static::createChallenge();
|
|
foreach ($registrations as $reg) {
|
|
if( !is_object( $reg ) ) {
|
|
throw new \InvalidArgumentException('$registrations of makeAuthentication() method only accepts array of object.');
|
|
}
|
|
|
|
$signatures[] = new SignRequest([
|
|
'appId' => $appId,
|
|
'keyHandle' => $reg->keyHandle,
|
|
'challenge' => $challenge,
|
|
]);
|
|
}
|
|
return $signatures;
|
|
}
|
|
|
|
/**
|
|
* Called to verify an authentication response
|
|
*
|
|
* @param array $requests An array of outstanding authentication requests
|
|
* @param array <Registration> $registrations An array of current registrations
|
|
* @param object $response A response from the authenticator
|
|
* @return \stdClass
|
|
* @throws U2FException
|
|
*
|
|
* The Registration object returned on success contains an updated counter
|
|
* that should be saved for future authentications.
|
|
* If the Error returned is ERR_COUNTER_TOO_LOW this is an indication of
|
|
* token cloning or similar and appropriate action should be taken.
|
|
*/
|
|
public static function authenticate(array $requests, array $registrations, $response)
|
|
{
|
|
// Parameter checks
|
|
if( !is_object( $response ) ) {
|
|
throw new \InvalidArgumentException('$response of authenticate() method only accepts object.');
|
|
}
|
|
|
|
if( property_exists( $response, 'errorCode') && $response->errorCode !== 0 ) {
|
|
throw new U2FException(
|
|
'User-agent returned error. Error code: ' . $response->errorCode,
|
|
U2FException::BAD_UA_RETURNING
|
|
);
|
|
}
|
|
|
|
// Set default values to null, so we get fails by default
|
|
/** @var object|null $req */
|
|
$req = null;
|
|
|
|
/** @var object|null $reg */
|
|
$reg = null;
|
|
|
|
// Extract client response data
|
|
$clientData = static::base64u_decode($response->clientData);
|
|
$decodedClient = json_decode($clientData);
|
|
|
|
// Check we have a match among the requests and the response
|
|
foreach ($requests as $req) {
|
|
if( !is_object( $req ) ) {
|
|
throw new \InvalidArgumentException('$requests of authenticate() method only accepts an array of objects.');
|
|
}
|
|
|
|
if($req->keyHandle() === $response->keyHandle && $req->challenge() === $decodedClient->challenge) {
|
|
break;
|
|
}
|
|
|
|
$req = null;
|
|
}
|
|
if($req === null) {
|
|
throw new U2FException(
|
|
'No matching request found',
|
|
U2FException::NO_MATCHING_REQUEST
|
|
);
|
|
}
|
|
|
|
// Check for a match for the response among a list of registrations
|
|
foreach ($registrations as $reg) {
|
|
if( !is_object( $reg ) ) {
|
|
throw new \InvalidArgumentException('$registrations of authenticate() method only accepts an array of objects.');
|
|
}
|
|
|
|
if($reg->keyHandle === $response->keyHandle) {
|
|
break;
|
|
}
|
|
$reg = null;
|
|
}
|
|
if($reg === null) {
|
|
throw new U2FException(
|
|
'No matching registration found',
|
|
U2FException::NO_MATCHING_REGISTRATION
|
|
);
|
|
}
|
|
|
|
// On Success, check we have a valid public key
|
|
$pemKey = static::publicKeyToPem(static::base64u_decode($reg->publicKey));
|
|
if($pemKey === null) {
|
|
throw new U2FException(
|
|
'Decoding of public key failed',
|
|
U2FException::PUBKEY_DECODE
|
|
);
|
|
}
|
|
|
|
// Build signature and data from response
|
|
$signData = static::base64u_decode($response->signatureData);
|
|
$dataToVerify = hash('sha256', $req->appId(), true);
|
|
$dataToVerify .= substr($signData, 0, 5);
|
|
$dataToVerify .= hash('sha256', $clientData, true);
|
|
$signature = substr($signData, 5);
|
|
|
|
// Verify the response data against the public key
|
|
if(openssl_verify($dataToVerify, $signature, $pemKey, 'sha256') === 1) {
|
|
$ctr = unpack("Nctr", substr($signData, 1, 4));
|
|
$counter = $ctr['ctr'];
|
|
/* TODO: wrap-around should be handled somehow.. */
|
|
if($counter > $reg->counter) {
|
|
$reg->counter = $counter;
|
|
return $reg;
|
|
} else {
|
|
throw new U2FException(
|
|
'Counter too low.',
|
|
U2FException::COUNTER_TOO_LOW
|
|
);
|
|
}
|
|
} else {
|
|
throw new U2FException(
|
|
'Authentication failed',
|
|
U2FException::AUTHENTICATION_FAILURE
|
|
);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param string $attestDir
|
|
* @return array
|
|
*/
|
|
private static function get_certs($attestDir)
|
|
{
|
|
$files = [];
|
|
$dir = $attestDir;
|
|
if($dir && $handle = opendir($dir)) {
|
|
while(false !== ($entry = readdir($handle))) {
|
|
if(is_file("$dir/$entry")) {
|
|
$files[] = "$dir/$entry";
|
|
}
|
|
}
|
|
closedir($handle);
|
|
}
|
|
return $files;
|
|
}
|
|
|
|
/**
|
|
* @param string $data
|
|
* @return string
|
|
*/
|
|
private static function base64u_encode($data)
|
|
{
|
|
return trim(strtr(base64_encode($data), '+/', '-_'), '=');
|
|
}
|
|
|
|
/**
|
|
* @param string $data
|
|
* @return string
|
|
*/
|
|
private static function base64u_decode($data)
|
|
{
|
|
return base64_decode(strtr($data, '-_', '+/'));
|
|
}
|
|
|
|
/**
|
|
* @param string $key
|
|
* @return null|string
|
|
*/
|
|
private static function publicKeyToPem($key)
|
|
{
|
|
if(strlen($key) !== static::PUBKEY_LEN || $key[0] !== "\x04") {
|
|
return null;
|
|
}
|
|
|
|
/*
|
|
* Convert the public key to binary DER format first
|
|
* Using the ECC SubjectPublicKeyInfo OIDs from RFC 5480
|
|
*
|
|
* SEQUENCE(2 elem) 30 59
|
|
* SEQUENCE(2 elem) 30 13
|
|
* OID1.2.840.10045.2.1 (id-ecPublicKey) 06 07 2a 86 48 ce 3d 02 01
|
|
* OID1.2.840.10045.3.1.7 (secp256r1) 06 08 2a 86 48 ce 3d 03 01 07
|
|
* BIT STRING(520 bit) 03 42 ..key..
|
|
*/
|
|
$der = "\x30\x59\x30\x13\x06\x07\x2a\x86\x48\xce\x3d\x02\x01";
|
|
$der .= "\x06\x08\x2a\x86\x48\xce\x3d\x03\x01\x07\x03\x42";
|
|
$der .= "\0".$key;
|
|
|
|
$pem = "-----BEGIN PUBLIC KEY-----\r\n";
|
|
$pem .= chunk_split(base64_encode($der), 64);
|
|
$pem .= "-----END PUBLIC KEY-----";
|
|
|
|
return $pem;
|
|
}
|
|
|
|
/**
|
|
* @return string
|
|
* @throws U2FException
|
|
*/
|
|
private static function createChallenge()
|
|
{
|
|
$challenge = openssl_random_pseudo_bytes(32, $crypto_strong );
|
|
if( $crypto_strong !== true ) {
|
|
throw new U2FException(
|
|
'Unable to obtain a good source of randomness',
|
|
U2FException::BAD_RANDOM
|
|
);
|
|
}
|
|
|
|
$challenge = static::base64u_encode( $challenge );
|
|
|
|
return $challenge;
|
|
}
|
|
|
|
/**
|
|
* Fixes a certificate where the signature contains unused bits.
|
|
*
|
|
* @param string $cert
|
|
* @return mixed
|
|
*/
|
|
private static function fixSignatureUnusedBits($cert)
|
|
{
|
|
if(in_array(hash('sha256', $cert), static::$FIXCERTS)) {
|
|
$cert[strlen($cert) - 257] = "\0";
|
|
}
|
|
return $cert;
|
|
}
|
|
|
|
}
|