/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.nifi.web.security.x509;

import org.apache.nifi.web.security.NiFiAuthenticationFilter;
import org.apache.nifi.web.security.ProxiedEntitiesUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.core.Authentication;
import org.springframework.security.web.authentication.preauth.x509.X509PrincipalExtractor;

import javax.servlet.http.HttpServletRequest;
import java.security.cert.X509Certificate;

/**
 * Custom X509 filter that will inspect the HTTP headers for a proxied user before extracting the user details from the client certificate.
 */
public class X509AuthenticationFilter extends NiFiAuthenticationFilter {

    private static final Logger logger = LoggerFactory.getLogger(X509AuthenticationFilter.class);

    private X509CertificateExtractor certificateExtractor;
    private X509PrincipalExtractor principalExtractor;

    @Override
    public Authentication attemptAuthentication(final HttpServletRequest request) {
        // only suppport x509 login when running securely
        if (!request.isSecure()) {
            return null;
        }

        // look for a client certificate
        final X509Certificate[] certificates = certificateExtractor.extractClientCertificate(request);
        if (certificates == null) {
            return null;
        }

        final String proxiedEntitiesChain = request.getHeader(ProxiedEntitiesUtils.PROXY_ENTITIES_CHAIN);
        logger.debug("Raw {} - {}", ProxiedEntitiesUtils.PROXY_ENTITIES_CHAIN, proxiedEntitiesChain);

        final String proxiedEntityIdpGroups = request.getHeader(ProxiedEntitiesUtils.PROXY_ENTITY_GROUPS);
        logger.debug("Raw {} - {}", ProxiedEntitiesUtils.PROXY_ENTITY_GROUPS, proxiedEntityIdpGroups);

        return new X509AuthenticationRequestToken(proxiedEntitiesChain, proxiedEntityIdpGroups, principalExtractor, certificates, request.getRemoteAddr());
    }

    /* setters */
    public void setCertificateExtractor(X509CertificateExtractor certificateExtractor) {
        this.certificateExtractor = certificateExtractor;
    }

    public void setPrincipalExtractor(X509PrincipalExtractor principalExtractor) {
        this.principalExtractor = principalExtractor;
    }

}
