com.google.api.server.spi.PeerAuth.java Source code

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Here is the source code for com.google.api.server.spi.PeerAuth.java

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/*
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * 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 com.google.api.server.spi;

import com.google.api.server.spi.auth.EndpointsPeerAuthenticator;
import com.google.api.server.spi.config.PeerAuthenticator;
import com.google.api.server.spi.config.Singleton;
import com.google.api.server.spi.config.model.ApiMethodConfig;
import com.google.api.server.spi.request.Attribute;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Function;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.http.HttpServletRequest;

/**
 * Utilities used to do peer authorization.
 */
public class PeerAuth {
    private static final Logger logger = Logger.getLogger(PeerAuth.class.getName());

    private static volatile Map<Class<? extends PeerAuthenticator>, PeerAuthenticator> peerAuthenticatorInstances = new HashMap<Class<? extends PeerAuthenticator>, PeerAuthenticator>();

    private static final PeerAuthenticator DEFAULT_PEER_AUTHENTICATOR = new EndpointsPeerAuthenticator();

    private static final Function<Class<? extends PeerAuthenticator>, PeerAuthenticator> INSTANTIATE_PEER_AUTHENTICATOR = new Function<Class<? extends PeerAuthenticator>, PeerAuthenticator>() {
        @Override
        public PeerAuthenticator apply(Class<? extends PeerAuthenticator> clazz) {
            try {
                if (clazz.getAnnotation(Singleton.class) != null) {
                    if (!peerAuthenticatorInstances.containsKey(clazz)) {
                        peerAuthenticatorInstances.put(clazz, clazz.newInstance());
                    }
                    return peerAuthenticatorInstances.get(clazz);
                } else {
                    return clazz.newInstance();
                }
            } catch (IllegalAccessException | InstantiationException e) {
                logger.log(Level.WARNING, "Could not instantiate peer authenticator: " + clazz.getName());
                return null;
            }
        }
    };

    private final HttpServletRequest request;
    private final Attribute attr;
    private final ApiMethodConfig config;

    @VisibleForTesting
    PeerAuth(HttpServletRequest request) {
        this.request = request;
        attr = Attribute.from(request);
        config = (ApiMethodConfig) attr.get(Attribute.API_METHOD_CONFIG);
    }

    static PeerAuth from(HttpServletRequest request) {
        return new PeerAuth(request);
    }

    @VisibleForTesting
    Iterable<PeerAuthenticator> getPeerAuthenticatorInstances() {
        List<Class<? extends PeerAuthenticator>> classes = config.getPeerAuthenticators();
        return classes == null ? ImmutableList.of(DEFAULT_PEER_AUTHENTICATOR)
                : Iterables.filter(Iterables.transform(classes, INSTANTIATE_PEER_AUTHENTICATOR),
                        Predicates.notNull());
    }

    boolean authorizePeer() {
        if (!attr.isEnabled(Attribute.RESTRICT_SERVLET)) {
            return true;
        }
        Iterable<PeerAuthenticator> peerAuthenticators = getPeerAuthenticatorInstances();
        if (peerAuthenticators != null) {
            for (PeerAuthenticator peerAuthenticator : peerAuthenticators) {
                if (!peerAuthenticator.authenticate(request)) {
                    return false;
                }
            }
        }
        return true;
    }
}