JWTClientAuthenticator.java
/*
* Copyright 2016 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.keycloak.authentication.authenticators.client;
import java.security.PublicKey;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import jakarta.ws.rs.core.Response;
import org.keycloak.OAuthErrorException;
import org.keycloak.authentication.AuthenticationFlowError;
import org.keycloak.authentication.ClientAuthenticationFlowContext;
import org.keycloak.jose.jws.JWSInput;
import org.keycloak.keys.loader.PublicKeyStorageManager;
import org.keycloak.models.AuthenticationExecutionModel;
import org.keycloak.models.ClientModel;
import org.keycloak.models.RealmModel;
import org.keycloak.protocol.oidc.OIDCConfigAttributes;
import org.keycloak.protocol.oidc.OIDCLoginProtocol;
import org.keycloak.protocol.oidc.OIDCLoginProtocolService;
import org.keycloak.protocol.oidc.grants.ciba.CibaGrantType;
import org.keycloak.protocol.oidc.par.endpoints.ParEndpoint;
import org.keycloak.provider.ProviderConfigProperty;
import org.keycloak.representations.JsonWebToken;
import org.keycloak.services.ServicesLogger;
import org.keycloak.services.Urls;
/**
* Client authentication based on JWT signed by client private key .
* See <a href="https://tools.ietf.org/html/rfc7519">specs</a> for more details.
*
* This is server side, which verifies JWT from client_assertion parameter, where the assertion was created on adapter side by
* org.keycloak.adapters.authentication.JWTClientCredentialsProvider
*
* @author <a href="mailto:mposolda@redhat.com">Marek Posolda</a>
*/
public class JWTClientAuthenticator extends AbstractClientAuthenticator {
public static final String PROVIDER_ID = "client-jwt";
public static final String ATTR_PREFIX = "jwt.credential";
public static final String CERTIFICATE_ATTR = "jwt.credential.certificate";
@Override
public void authenticateClient(ClientAuthenticationFlowContext context) {
JWTClientValidator validator = new JWTClientValidator(context);
if (!validator.clientAssertionParametersValidation()) return;
try {
validator.readJws();
if (!validator.validateClient()) return;
if (!validator.validateSignatureAlgorithm()) return;
RealmModel realm = validator.getRealm();
ClientModel client = validator.getClient();
JWSInput jws = validator.getJws();
JsonWebToken token = validator.getToken();
String clientAssertion = validator.getClientAssertion();
// Get client key and validate signature
PublicKey clientPublicKey = getSignatureValidationKey(client, context, jws);
if (clientPublicKey == null) {
// Error response already set to context
return;
}
boolean signatureValid;
try {
JsonWebToken jwt = context.getSession().tokens().decodeClientJWT(clientAssertion, client, JsonWebToken.class);
signatureValid = jwt != null;
} catch (RuntimeException e) {
Throwable cause = e.getCause() != null ? e.getCause() : e;
throw new RuntimeException("Signature on JWT token failed validation", cause);
}
if (!signatureValid) {
throw new RuntimeException("Signature on JWT token failed validation");
}
// Allow both "issuer" or "token-endpoint" as audience
List<String> expectedAudiences = getExpectedAudiences(context, realm);
if (!token.hasAnyAudience(expectedAudiences)) {
throw new RuntimeException("Token audience doesn't match domain. Expected audiences are any of " + expectedAudiences
+ " but audience from token is '" + Arrays.asList(token.getAudience()) + "'");
}
validator.validateToken();
validator.validateTokenReuse();
context.success();
} catch (Exception e) {
ServicesLogger.LOGGER.errorValidatingAssertion(e);
Response challengeResponse = ClientAuthUtil.errorResponse(Response.Status.BAD_REQUEST.getStatusCode(), OAuthErrorException.INVALID_CLIENT, "Client authentication with signed JWT failed: " + e.getMessage());
context.failure(AuthenticationFlowError.INVALID_CLIENT_CREDENTIALS, challengeResponse);
}
}
protected PublicKey getSignatureValidationKey(ClientModel client, ClientAuthenticationFlowContext context, JWSInput jws) {
PublicKey publicKey = PublicKeyStorageManager.getClientPublicKey(context.getSession(), client, jws);
if (publicKey == null) {
Response challengeResponse = ClientAuthUtil.errorResponse(Response.Status.BAD_REQUEST.getStatusCode(), OAuthErrorException.INVALID_CLIENT, "Unable to load public key");
context.failure(AuthenticationFlowError.CLIENT_CREDENTIALS_SETUP_REQUIRED, challengeResponse);
return null;
} else {
return publicKey;
}
}
@Override
public String getDisplayType() {
return "Signed Jwt";
}
@Override
public boolean isConfigurable() {
return false;
}
@Override
public AuthenticationExecutionModel.Requirement[] getRequirementChoices() {
return REQUIREMENT_CHOICES;
}
@Override
public String getHelpText() {
return "Validates client based on signed JWT issued by client and signed with the Client private key";
}
@Override
public List<ProviderConfigProperty> getConfigProperties() {
return new LinkedList<>();
}
@Override
public List<ProviderConfigProperty> getConfigPropertiesPerClient() {
// This impl doesn't use generic screen in admin console, but has its own screen. So no need to return anything here
return Collections.emptyList();
}
@Override
public Map<String, Object> getAdapterConfiguration(ClientModel client) {
Map<String, Object> props = new HashMap<>();
props.put("client-keystore-file", "REPLACE WITH THE LOCATION OF YOUR KEYSTORE FILE");
props.put("client-keystore-type", "jks");
props.put("client-keystore-password", "REPLACE WITH THE KEYSTORE PASSWORD");
props.put("client-key-password", "REPLACE WITH THE KEY PASSWORD IN KEYSTORE");
props.put("client-key-alias", client.getClientId());
props.put("token-timeout", 10);
String algorithm = client.getAttribute(OIDCConfigAttributes.TOKEN_ENDPOINT_AUTH_SIGNING_ALG);
if (algorithm != null) {
props.put("algorithm", algorithm);
}
Map<String, Object> config = new HashMap<>();
config.put("jwt", props);
return config;
}
@Override
public String getId() {
return PROVIDER_ID;
}
@Override
public Set<String> getProtocolAuthenticatorMethods(String loginProtocol) {
if (loginProtocol.equals(OIDCLoginProtocol.LOGIN_PROTOCOL)) {
Set<String> results = new HashSet<>();
results.add(OIDCLoginProtocol.PRIVATE_KEY_JWT);
return results;
} else {
return Collections.emptySet();
}
}
private List<String> getExpectedAudiences(ClientAuthenticationFlowContext context, RealmModel realm) {
String issuerUrl = Urls.realmIssuer(context.getUriInfo().getBaseUri(), realm.getName());
String tokenUrl = OIDCLoginProtocolService.tokenUrl(context.getUriInfo().getBaseUriBuilder()).build(realm.getName()).toString();
String parEndpointUrl = ParEndpoint.parUrl(context.getUriInfo().getBaseUriBuilder()).build(realm.getName()).toString();
List<String> expectedAudiences = new ArrayList<>(Arrays.asList(issuerUrl, tokenUrl, parEndpointUrl));
String backchannelAuthenticationUrl = CibaGrantType.authorizationUrl(context.getUriInfo().getBaseUriBuilder()).build(realm.getName()).toString();
expectedAudiences.add(backchannelAuthenticationUrl);
return expectedAudiences;
}
}