@Override
public SecurityKeyData processRegistrationResponse(
RegistrationResponse registrationResponse, long currentTimeInMillis) throws U2FException {
Log.info(">> processRegistrationResponse");
String sessionId = registrationResponse.getSessionId();
String clientDataBase64 = registrationResponse.getClientData();
String rawRegistrationDataBase64 = registrationResponse.getRegistrationData();
Log.info(">> rawRegistrationDataBase64: " + rawRegistrationDataBase64);
EnrollSessionData sessionData = dataStore.getEnrollSessionData(sessionId);
if (sessionData == null) {
throw new U2FException("Unknown session_id");
}
String appId = sessionData.getAppId();
String clientData = new String(Base64.decodeBase64(clientDataBase64));
byte[] rawRegistrationData = Base64.decodeBase64(rawRegistrationDataBase64);
Log.info("-- Input --");
Log.info(" sessionId: " + sessionId);
Log.info(" challenge: " + Hex.encodeHexString(sessionData.getChallenge()));
Log.info(" accountName: " + sessionData.getAccountName());
Log.info(" clientData: " + clientData);
Log.info(" rawRegistrationData: " + Hex.encodeHexString(rawRegistrationData));
RegisterResponse registerResponse = RawMessageCodec.decodeRegisterResponse(rawRegistrationData);
byte[] userPublicKey = registerResponse.getUserPublicKey();
byte[] keyHandle = registerResponse.getKeyHandle();
X509Certificate attestationCertificate = registerResponse.getAttestationCertificate();
byte[] signature = registerResponse.getSignature();
List<Transports> transports = null;
try {
transports = U2fAttestation.Parse(attestationCertificate).getTransports();
} catch (CertificateParsingException e) {
Log.warning("Could not parse transports extension " + e.getMessage());
}
Log.info("-- Parsed rawRegistrationResponse --");
Log.info(" userPublicKey: " + Hex.encodeHexString(userPublicKey));
Log.info(" keyHandle: " + Hex.encodeHexString(keyHandle));
Log.info(" attestationCertificate: " + attestationCertificate.toString());
Log.info(" transports: " + transports);
try {
Log.info(
" attestationCertificate bytes: "
+ Hex.encodeHexString(attestationCertificate.getEncoded()));
} catch (CertificateEncodingException e) {
throw new U2FException("Cannot encode certificate", e);
}
Log.info(" signature: " + Hex.encodeHexString(signature));
byte[] appIdSha256 = cryto.computeSha256(appId.getBytes());
byte[] clientDataSha256 = cryto.computeSha256(clientData.getBytes());
byte[] signedBytes =
RawMessageCodec.encodeRegistrationSignedBytes(
appIdSha256, clientDataSha256, keyHandle, userPublicKey);
Set<X509Certificate> trustedCertificates = dataStore.getTrustedCertificates();
if (!trustedCertificates.contains(attestationCertificate)) {
Log.warning("attestion cert is not trusted");
}
verifyBrowserData(
new JsonParser().parse(clientData), "navigator.id.finishEnrollment", sessionData);
Log.info("Verifying signature of bytes " + Hex.encodeHexString(signedBytes));
if (!cryto.verifySignature(attestationCertificate, signedBytes, signature)) {
throw new U2FException("Signature is invalid");
}
// The first time we create the SecurityKeyData, we set the counter value to 0.
// We don't actually know what the counter value of the real device is - but it will
// be something bigger (or equal) to 0, so subsequent signatures will check out ok.
SecurityKeyData securityKeyData =
new SecurityKeyData(
currentTimeInMillis,
transports,
keyHandle,
userPublicKey,
attestationCertificate, /* initial counter value */
0);
dataStore.addSecurityKeyData(sessionData.getAccountName(), securityKeyData);
Log.info("<< processRegistrationResponse");
return securityKeyData;
}
@Override
public SecurityKeyData processSignResponse(SignResponse signResponse) throws U2FException {
Log.info(">> processSignResponse");
String sessionId = signResponse.getSessionId();
String browserDataBase64 = signResponse.getClientData();
String rawSignDataBase64 = signResponse.getSignatureData();
SignSessionData sessionData = dataStore.getSignSessionData(sessionId);
if (sessionData == null) {
throw new U2FException("Unknown session_id");
}
String appId = sessionData.getAppId();
SecurityKeyData securityKeyData = null;
for (SecurityKeyData temp : dataStore.getSecurityKeyData(sessionData.getAccountName())) {
if (Arrays.equals(sessionData.getPublicKey(), temp.getPublicKey())) {
securityKeyData = temp;
break;
}
}
if (securityKeyData == null) {
throw new U2FException("No security keys registered for this user");
}
String browserData = new String(Base64.decodeBase64(browserDataBase64));
byte[] rawSignData = Base64.decodeBase64(rawSignDataBase64);
Log.info("-- Input --");
Log.info(" sessionId: " + sessionId);
Log.info(" publicKey: " + Hex.encodeHexString(securityKeyData.getPublicKey()));
Log.info(" challenge: " + Hex.encodeHexString(sessionData.getChallenge()));
Log.info(" accountName: " + sessionData.getAccountName());
Log.info(" browserData: " + browserData);
Log.info(" rawSignData: " + Hex.encodeHexString(rawSignData));
verifyBrowserData(
new JsonParser().parse(browserData), "navigator.id.getAssertion", sessionData);
AuthenticateResponse authenticateResponse =
RawMessageCodec.decodeAuthenticateResponse(rawSignData);
byte userPresence = authenticateResponse.getUserPresence();
int counter = authenticateResponse.getCounter();
byte[] signature = authenticateResponse.getSignature();
Log.info("-- Parsed rawSignData --");
Log.info(" userPresence: " + Integer.toHexString(userPresence & 0xFF));
Log.info(" counter: " + counter);
Log.info(" signature: " + Hex.encodeHexString(signature));
if ((userPresence & UserPresenceVerifier.USER_PRESENT_FLAG) == 0) {
throw new U2FException("User presence invalid during authentication");
}
if (counter <= securityKeyData.getCounter()) {
throw new U2FException("Counter value smaller than expected!");
}
byte[] appIdSha256 = cryto.computeSha256(appId.getBytes());
byte[] browserDataSha256 = cryto.computeSha256(browserData.getBytes());
byte[] signedBytes =
RawMessageCodec.encodeAuthenticateSignedBytes(
appIdSha256, userPresence, counter, browserDataSha256);
Log.info("Verifying signature of bytes " + Hex.encodeHexString(signedBytes));
if (!cryto.verifySignature(
cryto.decodePublicKey(securityKeyData.getPublicKey()), signedBytes, signature)) {
throw new U2FException("Signature is invalid");
}
dataStore.updateSecurityKeyCounter(
sessionData.getAccountName(), securityKeyData.getPublicKey(), counter);
Log.info("<< processSignResponse");
return securityKeyData;
}