RangerAuthorizationFilter.java

/*
 * 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.ranger.authorization.hbase;

import java.io.IOException;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

import com.google.common.base.Objects;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.filter.FilterBase;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.ranger.audit.model.AuthzAuditEvent;

public class RangerAuthorizationFilter extends FilterBase {

	private static final Log LOG = LogFactory.getLog(RangerAuthorizationFilter.class.getName());
	final Set<String> _familiesAccessAllowed;
	final Set<String> _familiesAccessDenied;
	final Set<String> _familiesAccessIndeterminate;
	final Map<String, Set<String>> _columnsAccessAllowed;
	final AuthorizationSession _session;
	final HbaseAuditHandler _auditHandler = HbaseFactory.getInstance().getAuditHandler();

	public RangerAuthorizationFilter(AuthorizationSession session, Set<String> familiesAccessAllowed, Set<String> familiesAccessDenied, Set<String> familiesAccessIndeterminate,
									 Map<String, Set<String>> columnsAccessAllowed) {
		// the class assumes that all of these can be empty but none of these can be null
		_familiesAccessAllowed = familiesAccessAllowed;
		_familiesAccessDenied = familiesAccessDenied;
		_familiesAccessIndeterminate = familiesAccessIndeterminate;
		_columnsAccessAllowed = columnsAccessAllowed;
		// this session should have everything set on it except family and column which would be altered based on need
		_session = session;
		// we don't want to audit denial, so we need to make sure the hander is what we need it to be.
		_session.auditHandler(_auditHandler);
	}
	
	@SuppressWarnings("deprecation")
	@Override
	public ReturnCode filterKeyValue(Cell kv) throws IOException {

		if (LOG.isDebugEnabled()) {
			LOG.debug("==> filterKeyValue");
		}

		String family = null;
		byte[] familyBytes = kv.getFamily();
		if (familyBytes != null && familyBytes.length > 0) {
			family = Bytes.toString(familyBytes);
			if (LOG.isDebugEnabled()) {
				LOG.debug("filterKeyValue: evaluating family[" + family + "].");
			}
		}
		String column = null;
		if (kv.getQualifier() != null && kv.getQualifier().length > 0) {
			column = Bytes.toString(kv.getQualifier());
			if (LOG.isDebugEnabled()) {
				LOG.debug("filterKeyValue: evaluating column[" + column + "].");
			}
		} else {
			LOG.warn("filterKeyValue: empty/null column set! Unexpected!");
		}

		ReturnCode result = ReturnCode.NEXT_COL;
		boolean authCheckNeeded = false;
		if (family == null) {
			LOG.warn("filterKeyValue: Unexpected - null/empty family! Access denied!");
		} else if (_familiesAccessDenied.contains(family)) {
			LOG.debug("filterKeyValue: family found in access denied families cache.  Access denied.");
		} else if (_columnsAccessAllowed.containsKey(family)) {
			LOG.debug("filterKeyValue: family found in column level access results cache.");
			if (_columnsAccessAllowed.get(family).contains(column)) {
				LOG.debug("filterKeyValue: family/column found in column level access results cache. Access allowed.");
				result = ReturnCode.INCLUDE;
			} else {
				LOG.debug("filterKeyValue: family/column not in column level access results cache. Access denied.");
			}
		} else if (_familiesAccessAllowed.contains(family)) {
			LOG.debug("filterKeyValue: family found in access allowed families cache.  Must re-authorize for correct audit generation.");
			authCheckNeeded = true;
		} else if (_familiesAccessIndeterminate.contains(family)) {
			LOG.debug("filterKeyValue: family found in indeterminate families cache.  Evaluating access...");
			authCheckNeeded = true;
		} else {
			LOG.warn("filterKeyValue: Unexpected - alien family encountered that wasn't seen by pre-hook!  Access Denied.!");
		}

		if (authCheckNeeded) {
			LOG.debug("filterKeyValue: Checking authorization...");
			_session.columnFamily(family)
					.column(column)
					.buildRequest()
					.authorize();
			// must always purge the captured audit event out of the audit handler to avoid messing up the next check
			AuthzAuditEvent auditEvent = _auditHandler.getAndDiscardMostRecentEvent();
			if (_session.isAuthorized()) {
				LOG.debug("filterKeyValue: Access granted.");
				result = ReturnCode.INCLUDE;
				if (auditEvent != null) {
					LOG.debug("filterKeyValue: access is audited.");
					_auditHandler.logAuthzAudits(Collections.singletonList(auditEvent));
				} else {
					LOG.debug("filterKeyValue: no audit event returned.  Access not audited.");
				}
			} else {
				LOG.debug("filterKeyValue: Access denied.  Denial not audited.");
			}
		}
		if (LOG.isDebugEnabled()) {
			LOG.debug("filterKeyValue: " + result);
		}
		return result;
	}

	@Override
	public String toString() {
		return Objects.toStringHelper(getClass())
				.add("familiesAccessAllowed", _familiesAccessAllowed)
				.add("familiesAccessDenied", _familiesAccessDenied)
				.add("familiesAccessUnknown", _familiesAccessIndeterminate)
				.add("columnsAccessAllowed", _columnsAccessAllowed)
				.toString();

	}

}