WebAuthn4J

A portable Java library for WebAuthn server side verification

Conformance

All mandatory test cases and optional Android Key attestation test cases of FIDO2 Test Tools provided by FIDO Alliance
are passed.

Supported Attestation statement format

All attestation statement formats are supported.

• Packed attestation
• FIDO U2F attestation
• Android Key attestation
• Android SafetyNet attestation
• TPM attestation
• None attestation

Projects using WebAuthn4J

• Keycloak

Documentation

You can find out more details from the reference.

Getting from Maven Central

If you are using Maven, just add the webauthn4j as a dependency:

<properties>
  ...
  <!-- Use the latest version whenever possible. -->
  <webauthn4j.version>0.10.1.RELEASE</webauthn4j.version>
  ...
</properties>

<dependencies>
  ...
  <dependency>
    <groupId>com.webauthn4j</groupId>
    <artifactId>webauthn4j-core</artifactId>
    <version>${webauthn4j.version}</version>
  </dependency>
  ...
</dependencies>

Build from source

WebAuthn4J uses a Gradle based build system.
In the instructions below, gradlew is invoked from the root of the source tree and serves as a cross-platform,
self-contained bootstrap mechanism for the build.

Prerequisites

• Java8 or later

Checkout sources

git clone https://github.com/webauthn4j/webauthn4j

Build all jars

./gradlew build

How to use

Parse and Validation on Registration

// Client properties
byte[] attestationObject = null /* set attestationObject */;
byte[] clientDataJSON = null /* set clientDataJSON */;
String clientExtensionJSON = null;  /* set clientExtensionJSON */;
Set<String> transports = null /* set transports */;

// Server properties
Origin origin = null /* set origin */;
String rpId = null /* set rpId */;
Challenge challenge = null /* set challenge */;
byte[] tokenBindingId = null /* set tokenBindingId */;
ServerProperty serverProperty = new ServerProperty(origin, rpId, challenge, tokenBindingId);

// expectations
boolean userVerificationRequired = false;
boolean userPresenceRequired = true;
List<String> expectedExtensionIds = Collections.emptyList();

RegistrationRequest registrationRequest = new RegistrationRequest(attestationObject, clientDataJSON, clientExtensionJSON, transports);
RegistrationParameters registrationParameters = new RegistrationParameters(serverProperty, userVerificationRequired, userPresenceRequired, expectedExtensionIds);
RegistrationData registrationData;
try{
    registrationData = webAuthnManager.parse(registrationRequest);
}
catch (DataConversionException e){
    // If you would like to handle WebAuthn data structure parse error, please catch DataConversionException
    throw e;
}
try{
    webAuthnManager.validate(registrationData, registrationParameters);
}
catch (ValidationException e){
    // If you would like to handle WebAuthn data validation error, please catch ValidationException
    throw e;
}

// please persist Authenticator object, which will be used in the authentication process.
Authenticator authenticator =
        new AuthenticatorImpl( // You may create your own Authenticator implementation to save friendly authenticator name
                registrationData.getAttestationObject().getAuthenticatorData().getAttestedCredentialData(),
                registrationData.getAttestationObject().getAttestationStatement(),
                registrationData.getAttestationObject().getAuthenticatorData().getSignCount()
        );
save(authenticator); // please persist authenticator in your manner

Parse and Validation on authentication

// Client properties
byte[] credentialId = null /* set credentialId */;
byte[] userHandle = null /* set userHandle */;
byte[] authenticatorData = null /* set authenticatorData */;
byte[] clientDataJSON = null /* set clientDataJSON */;
String clientExtensionJSON = null /* set clientExtensionJSON */;
byte[] signature = null /* set signature */;

// Server properties
Origin origin = null /* set origin */;
String rpId = null /* set rpId */;
Challenge challenge = null /* set challenge */;
byte[] tokenBindingId = null /* set tokenBindingId */;
ServerProperty serverProperty = new ServerProperty(origin, rpId, challenge, tokenBindingId);

// expectations
boolean userVerificationRequired = true;
boolean userPresenceRequired = true;
List<String> expectedExtensionIds = Collections.emptyList();

Authenticator authenticator = load(credentialId); // please load authenticator object persisted in the registration process in your manner

AuthenticationRequest authenticationRequest =
        new AuthenticationRequest(
                credentialId,
                userHandle,
                authenticatorData,
                clientDataJSON,
                clientExtensionJSON,
                signature
        );
AuthenticationParameters authenticationParameters =
        new AuthenticationParameters(
                serverProperty,
                authenticator,
                userVerificationRequired,
                userPresenceRequired,
                expectedExtensionIds
        );

AuthenticationData authenticationData;
try{
    authenticationData = webAuthnManager.parse(authenticationRequest);
}
catch (DataConversionException e){
    // If you would like to handle WebAuthn data structure parse error, please catch DataConversionException
    throw e;
}
try{
    webAuthnManager.validate(authenticationData, authenticationParameters);
}
catch (ValidationException e){
    // If you would like to handle WebAuthn data validation error, please catch ValidationException
    throw e;
}
// please update the counter of the authenticator record
updateCounter(
        authenticationData.getAuthenticatorData().getAttestedCredentialData().getCredentialId(),
        authenticationData.getAuthenticatorData().getSignCount()
);

Sample application

Spring Security WebAuthn is built on the top of WebAuthn4J, and its sample application demonstrates WebAuthn4J feature well.
Please see Spring Security WebAuthn sample application.

License

WebAuthn4J is Open Source software released under the
Apache 2.0 license.

Contributing

Interested in helping out with WebAuthn4J? Great! Your participation in the community is much appreciated!
Please feel free to open issues and send pull-requests.