org.apache.drill.exec.server.rest.auth.SpnegoConfig.java Source code

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Here is the source code for org.apache.drill.exec.server.rest.auth.SpnegoConfig.java

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/*
 * 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.drill.exec.server.rest.auth;

import org.apache.drill.common.config.DrillConfig;
import org.apache.drill.common.exceptions.DrillException;
import org.apache.drill.exec.ExecConstants;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.security.UserGroupInformation;

public class SpnegoConfig {

    private UserGroupInformation loggedInUgi;

    private final String principal;

    private final String keytab;

    // Optional parameter
    private final String clientNameMapping;

    public SpnegoConfig(DrillConfig config) {

        keytab = config.hasPath(ExecConstants.HTTP_SPNEGO_KEYTAB)
                ? config.getString(ExecConstants.HTTP_SPNEGO_KEYTAB)
                : null;

        principal = config.hasPath(ExecConstants.HTTP_SPNEGO_PRINCIPAL)
                ? config.getString(ExecConstants.HTTP_SPNEGO_PRINCIPAL)
                : null;

        // set optional user name mapping
        clientNameMapping = config.hasPath(ExecConstants.KERBEROS_NAME_MAPPING)
                ? config.getString(ExecConstants.KERBEROS_NAME_MAPPING)
                : null;
    }

    //Reads the SPNEGO principal from the config file
    public String getSpnegoPrincipal() {
        return principal;
    }

    public void validateSpnegoConfig() throws DrillException {

        StringBuilder errorMsg = new StringBuilder();

        if (principal != null && keytab != null) {
            return;
        }

        if (principal == null) {
            errorMsg.append("\nConfiguration ");
            errorMsg.append(ExecConstants.HTTP_SPNEGO_PRINCIPAL);
            errorMsg.append(" is not found");
        }

        if (keytab == null) {
            errorMsg.append("\nConfiguration ");
            errorMsg.append(ExecConstants.HTTP_SPNEGO_KEYTAB);
            errorMsg.append(" is not found");
        }

        throw new DrillException(errorMsg.toString());
    }

    public UserGroupInformation getLoggedInUgi() throws DrillException {

        if (loggedInUgi != null) {
            return loggedInUgi;
        }
        loggedInUgi = loginAndReturnUgi();
        return loggedInUgi;
    }

    //Performs the Server login to KDC for SPNEGO
    private UserGroupInformation loginAndReturnUgi() throws DrillException {

        validateSpnegoConfig();

        UserGroupInformation ugi;
        try {
            // Check if security is not enabled and try to set the security parameter to login the principal.
            // After the login is performed reset the static UGI state.
            if (!UserGroupInformation.isSecurityEnabled()) {
                final Configuration newConfig = new Configuration();
                newConfig.set(CommonConfigurationKeys.HADOOP_SECURITY_AUTHENTICATION,
                        UserGroupInformation.AuthenticationMethod.KERBEROS.toString());

                if (clientNameMapping != null) {
                    newConfig.set(CommonConfigurationKeys.HADOOP_SECURITY_AUTH_TO_LOCAL, clientNameMapping);
                }

                UserGroupInformation.setConfiguration(newConfig);
                ugi = UserGroupInformation.loginUserFromKeytabAndReturnUGI(principal, keytab);

                // Reset the original configuration for static UGI
                UserGroupInformation.setConfiguration(new Configuration());
            } else {
                // Let's not overwrite the rules here since it might be possible that CUSTOM security is configured for
                // JDBC/ODBC with default rules. If Kerberos was enabled then the correct rules must already be set
                ugi = UserGroupInformation.loginUserFromKeytabAndReturnUGI(principal, keytab);
            }
        } catch (Exception e) {
            throw new DrillException(String.format("Login failed for %s with given keytab", principal), e);
        }
        return ugi;
    }
}