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 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.elasticsearch.http;

import org.apache.http.message.BasicHeader;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.ResponseException;
import org.elasticsearch.common.network.NetworkModule;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
import org.elasticsearch.test.ESIntegTestCase.Scope;

import java.io.IOException;

import static org.elasticsearch.http.HttpTransportSettings.SETTING_CORS_ALLOW_CREDENTIALS;
import static org.elasticsearch.http.HttpTransportSettings.SETTING_CORS_ALLOW_METHODS;
import static org.elasticsearch.http.HttpTransportSettings.SETTING_CORS_ALLOW_ORIGIN;
import static org.elasticsearch.http.HttpTransportSettings.SETTING_CORS_ENABLED;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.nullValue;

/**
 * Test CORS where the allow origin value is a regular expression.
 */
@ClusterScope(scope = Scope.SUITE, supportsDedicatedMasters = false, numDataNodes = 1)
public class CorsRegexIT extends HttpSmokeTestCase {

    @Override
    protected Settings nodeSettings(int nodeOrdinal) {
        return Settings.builder()
                .put(super.nodeSettings(nodeOrdinal))
                .put(SETTING_CORS_ALLOW_ORIGIN.getKey(), "/https?:\\/\\/localhost(:[0-9]+)?/")
                .put(SETTING_CORS_ALLOW_CREDENTIALS.getKey(), true)
                .put(SETTING_CORS_ALLOW_METHODS.getKey(), "get, options, post")
                .put(SETTING_CORS_ENABLED.getKey(), true)
                .put(NetworkModule.HTTP_ENABLED.getKey(), true)
                .build();
    }

    public void testThatRegularExpressionWorksOnMatch() throws IOException {
        String corsValue = "http://localhost:9200";
        Response response = getRestClient().performRequest("GET", "/",
                new BasicHeader("User-Agent", "Mozilla Bar"), new BasicHeader("Origin", corsValue));
        assertResponseWithOriginheader(response, corsValue);

        corsValue = "https://localhost:9200";
        response = getRestClient().performRequest("GET", "/",
                new BasicHeader("User-Agent", "Mozilla Bar"), new BasicHeader("Origin", corsValue));
        assertResponseWithOriginheader(response, corsValue);
        assertThat(response.getHeader("Access-Control-Allow-Credentials"), is("true"));
    }

    public void testThatRegularExpressionReturnsForbiddenOnNonMatch() throws IOException {
        try {
            getRestClient().performRequest("GET", "/", new BasicHeader("User-Agent", "Mozilla Bar"),
                    new BasicHeader("Origin", "http://evil-host:9200"));
            fail("request should have failed");
        } catch(ResponseException e) {
            Response response = e.getResponse();
            // a rejected origin gets a FORBIDDEN - 403
            assertThat(response.getStatusLine().getStatusCode(), is(403));
            assertThat(response.getHeader("Access-Control-Allow-Origin"), nullValue());
        }
    }

    public void testThatSendingNoOriginHeaderReturnsNoAccessControlHeader() throws IOException {
        Response response = getRestClient().performRequest("GET", "/", new BasicHeader("User-Agent", "Mozilla Bar"));
        assertThat(response.getStatusLine().getStatusCode(), is(200));
        assertThat(response.getHeader("Access-Control-Allow-Origin"), nullValue());
    }

    public void testThatRegularExpressionIsNotAppliedWithoutCorrectBrowserOnMatch() throws IOException {
        Response response = getRestClient().performRequest("GET", "/");
        assertThat(response.getStatusLine().getStatusCode(), is(200));
        assertThat(response.getHeader("Access-Control-Allow-Origin"), nullValue());
    }

    public void testThatPreFlightRequestWorksOnMatch() throws IOException {
        String corsValue = "http://localhost:9200";
        Response response = getRestClient().performRequest("OPTIONS", "/",
                new BasicHeader("User-Agent", "Mozilla Bar"), new BasicHeader("Origin", corsValue),
                new BasicHeader("Access-Control-Request-Method", "GET"));
        assertResponseWithOriginheader(response, corsValue);
        assertNotNull(response.getHeader("Access-Control-Allow-Methods"));
    }

    public void testThatPreFlightRequestReturnsNullOnNonMatch() throws IOException {
        try {
            getRestClient().performRequest("OPTIONS", "/", new BasicHeader("User-Agent", "Mozilla Bar"),
                    new BasicHeader("Origin", "http://evil-host:9200"),
                    new BasicHeader("Access-Control-Request-Method", "GET"));
            fail("request should have failed");
        } catch(ResponseException e) {
            Response response = e.getResponse();
            // a rejected origin gets a FORBIDDEN - 403
            assertThat(response.getStatusLine().getStatusCode(), is(403));
            assertThat(response.getHeader("Access-Control-Allow-Origin"), nullValue());
            assertThat(response.getHeader("Access-Control-Allow-Methods"), nullValue());
        }
    }

    protected static void assertResponseWithOriginheader(Response response, String expectedCorsHeader) {
        assertThat(response.getStatusLine().getStatusCode(), is(200));
        assertThat(response.getHeader("Access-Control-Allow-Origin"), is(expectedCorsHeader));
    }
}