public virtual void TestEncodeAuthenticateSignedBytes()
{
var encodedBytes = RawMessageCodec.EncodeKeySignSignedBytes(APP_ID_SIGN_SHA256,
UserPresenceVerifierConstants.UserPresentFlag, COUNTER_VALUE, BROWSER_DATA_SIGN_SHA256);
CollectionAssert.AreEqual(EXPECTED_AUTHENTICATE_SIGNED_BYTES, encodedBytes);
}
/// <exception cref="U2FException" />
public KeySignResponse Authenticate(KeySignRequest keySignRequest)
{
if (keySignRequest == null)
{
throw new ArgumentNullException(nameof(keySignRequest));
}
log.Info(">> authenticate");
var applicationSha256 = keySignRequest.ApplicationSha256;
var challengeSha256 = keySignRequest.ChallengeSha256;
var keyHandle = keySignRequest.KeyHandle;
log.Info(" -- Inputs --");
log.Info(" applicationSha256: " + applicationSha256.ToHexString());
log.Info(" challengeSha256: " + challengeSha256.ToHexString());
log.Info(" keyHandle: " + keyHandle.ToHexString());
var keyPair = dataStore.GetKeyPair(keyHandle);
var counter = dataStore.IncrementCounter();
var userPresence = userPresenceVerifier.VerifyUserPresence();
var signedData = RawMessageCodec.EncodeKeySignSignedBytes(applicationSha256, userPresence, counter,
challengeSha256);
log.Info("Signing bytes " + signedData.ToHexString());
var signature = crypto.Sign(signedData, keyPair.PrivateKey);
log.Info(" -- Outputs --");
log.Info(" userPresence: " + userPresence);
log.Info(" counter: " + counter);
log.Info(" signature: " + signature.ToHexString());
log.Info("<< authenticate");
return(new KeySignResponse(userPresence, counter, signature));
}
public Task <KeyResponse <KeySignResponse> > SignAsync(KeySignRequest request, CancellationToken cancellationToken = new CancellationToken(),
bool noWink = false)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
log.Info(">> authenticate");
var applicationSha256 = request.ApplicationSha256;
var challengeSha256 = request.ChallengeSha256;
var keyHandle = request.KeyHandle;
log.Info(" -- Inputs --");
log.Info(" applicationSha256: " + applicationSha256.ToHexString());
log.Info(" challengeSha256: " + challengeSha256.ToHexString());
log.Info(" keyHandle: " + keyHandle.ToHexString());
var keyPair = dataStore.GetKeyPair(keyHandle);
var counter = dataStore.IncrementCounter();
var userPresent = userPresenceVerifier.VerifyUserPresence();
if ((userPresent & UserPresenceVerifierConstants.UserPresentFlag) == 0)
{
return(TestOfUserPresenceRequired <KeySignResponse>());
}
var signedData = RawMessageCodec.EncodeKeySignSignedBytes(applicationSha256, userPresent, counter,
challengeSha256);
log.Info("Signing bytes " + signedData.ToHexString());
var signature = crypto.Sign(signedData, keyPair.PrivateKey);
log.Info(" -- Outputs --");
log.Info(" userPresence: " + userPresent);
log.Info(" counter: " + counter);
log.Info(" signature: " + signature.ToHexString());
log.Info("<< authenticate");
var response = new KeySignResponse(userPresent, counter, signature);
var responseData = RawMessageCodec.EncodeKeySignResponse(response).Segment();
var apdu = new ApduResponse(ApduResponseStatus.NoError, responseData);
var keyResponse = new KeyResponse <KeySignResponse>(apdu, response, KeyResponseStatus.Success);
return(TaskEx.FromResult(keyResponse));
}
public SecurityKeyData ProcessSignResponse(SignResponse signResponse)
{
log.Info(">> processSignResponse");
var sessionId = signResponse.SessionId;
var browserDataBase64 = signResponse.Bd;
var rawSignDataBase64 = signResponse.Sign;
var sessionData = dataStore.GetSignSessionData(sessionId);
if (sessionData == null)
{
throw new U2FException("Unknown session_id");
}
var appId = sessionData.AppId;
var securityKeyData = dataStore
.GetSecurityKeyData(sessionData.AccountName)
.FirstOrDefault(k => sessionData.GetPublicKey().SequenceEqual(k.PublicKey));
if (securityKeyData == null)
{
throw new U2FException("No security keys registered for this user");
}
var browserDataBytes = WebSafeBase64Converter.FromBase64String(browserDataBase64);
var browserData = Encoding.UTF8.GetString(browserDataBytes, 0, browserDataBytes.Length);
var rawSignData = WebSafeBase64Converter.FromBase64String(rawSignDataBase64);
log.Info("-- Input --");
log.Info(" sessionId: " + sessionId);
log.Info(" publicKey: " + securityKeyData.PublicKey.ToHexString());
log.Info(" challenge: " + sessionData.Challenge.ToHexString());
log.Info(" accountName: " + sessionData.AccountName);
log.Info(" browserData: " + browserData);
log.Info(" rawSignData: " + rawSignData.ToHexString());
VerifyBrowserData(browserData, "navigator.id.getAssertion", sessionData);
var authenticateResponse = RawMessageCodec.DecodeKeySignResponse(rawSignData.Segment());
var userPresence = authenticateResponse.UserPresence;
var counter = authenticateResponse.Counter;
var signature = authenticateResponse.Signature;
log.Info("-- Parsed rawSignData --");
log.Info(" userPresence: " + userPresence.ToString("X2"));
log.Info(" counter: " + counter);
log.Info(" signature: " + signature.ToHexString());
if (userPresence != UserPresenceVerifierConstants.UserPresentFlag)
{
throw new U2FException("User presence invalid during authentication");
}
if (counter <= securityKeyData.Counter)
{
throw new U2FException("Counter value smaller than expected!");
}
var appIdSha256 = cryto.ComputeSha256(Encoding.UTF8.GetBytes(appId));
var browserDataSha256 = cryto.ComputeSha256(Encoding.UTF8.GetBytes(browserData));
var signedBytes = RawMessageCodec.EncodeKeySignSignedBytes(appIdSha256, userPresence, counter,
browserDataSha256);
log.Info("Verifying signature of bytes " + signedBytes.ToHexString());
if (!cryto.VerifySignature(cryto.DecodePublicKey(securityKeyData.PublicKey), signedBytes, signature))
{
throw new U2FException("Signature is invalid");
}
dataStore.UpdateSecurityKeyCounter(sessionData.AccountName, securityKeyData.PublicKey, counter);
log.Info("<< processSignResponse");
return(securityKeyData);
}
