RangerTimeOfDayMatcher.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.plugin.conditionevaluator;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ranger.plugin.policyengine.RangerAccessRequest;

public class RangerTimeOfDayMatcher extends RangerAbstractConditionEvaluator {
	private static final Log LOG = LogFactory.getLog(RangerTimeOfDayMatcher.class);
	boolean _allowAny;
	List<int[]> _durations = new ArrayList<>();
	
	@Override
	public void init() {
		if(LOG.isDebugEnabled()) {
			LOG.debug("==> RangerTimeOfDayMatcher.init(" + condition + ")");
		}

		super.init();

		if (condition == null) {
			LOG.debug("init: null policy condition! Will match always!");
			_allowAny = true;
		} else if (CollectionUtils.isEmpty(condition.getValues())) {
			LOG.debug("init: empty conditions collection on policy condition!  Will match always!");
			_allowAny = true;
		} else {
			for (String value : condition.getValues()) {
				if (StringUtils.isEmpty(value)) {
					LOG.warn("init: Unexpected: one of the value in condition is null or empty!");
				} else {
					int[] aDuration = extractDuration(value);
					if (aDuration != null) {
						_durations.add(aDuration);
					}
				}
			}
		}
		
		if (_durations.isEmpty()) {
			LOG.debug("No valid durations found.  Will always match!");
			_allowAny = true;
		}

		if(LOG.isDebugEnabled()) {
			LOG.debug("<== RangerTimeOfDayMatcher.init(" + condition + "): durations[" + toString() + "]");
		}
	}

	// match "9am-5pm", "9 Am - 5 PM", "9 am.- 5 P.M", "9:30 AM - 4:00p.m." etc. spaces around - and after digits are allowed and dots in am/pm string in mixed cases is allowed
	static final Pattern _Pattern = Pattern.compile(" *(\\d{1,2})(:(\\d{1,2}))? *([aApP])\\.?[mM]\\.? *- *(\\d{1,2})(:(\\d{1,2}))? *([aApP])\\.?[mM]\\.? *");

	int[] extractDuration(String value) {
		if(LOG.isDebugEnabled()) {
			LOG.debug("==> RangerTimeOfDayMatcher.extractDuration(" + value + ")");
		}
		
		int[] result = null;
		if (value == null) {
			LOG.warn("extractDuration: null input value!");
		} else {
			Matcher m = _Pattern.matcher(value);
			if (!m.matches()) {
				LOG.warn("extractDuration: input[" + value + "] did not match pattern!");
			} else {
				int startHour = Integer.parseInt(m.group(1));
				int startMin = 0;
				if (m.group(3) != null) {
					startMin = Integer.parseInt(m.group(3));
				}
				String startType = m.group(4).toUpperCase();
				
				int endHour = Integer.parseInt(m.group(5));
				int endMinute = 0;
				if (m.group(7) != null) {
					endMinute = Integer.parseInt(m.group(7));
				}
				String endType = m.group(8).toUpperCase();
				if(startHour == 12) {
					if("A".equals(startType)) {
						startHour = 0;
					}
				} else if ("P".equals(startType)) {
					startHour += 12;
				}

				if(endHour == 12) {
					if("A".equals(endType)) {
						endHour = 0;
					}
				} else if ("P".equals(endType)) {
					endHour += 12;
				}

				result = new int[] { (startHour*60)+startMin, (endHour*60)+endMinute };
			}
		}

		if(LOG.isDebugEnabled()) {
			LOG.debug("<== RangerTimeOfDayMatcher.extractDuration(" + value + "): duration:" + Arrays.toString(result));
		}
		return result;
	}

	@Override
	public boolean isMatched(RangerAccessRequest request) {
		
		if(LOG.isDebugEnabled()) {
			LOG.debug("==> RangerTimeOfDayMatcher.isMatched(" + request + ")");
		}

		boolean matched = true;
		if (_allowAny) {
			LOG.debug("isMatched: allowAny flag is true.  Matched!");
		} else if (request == null) {
			LOG.warn("isMatched: Unexpected: Request is null!  Implicitly matched!");
		} else if (request.getAccessTime() == null) {
			LOG.warn("isMatched: Unexpected: Accesstime on the request is null!  Implicitly matched!");
		} else {
			Date date = request.getAccessTime();
			Calendar calendar = GregorianCalendar.getInstance();
			calendar.setTime(date);
			int hourOfDay = calendar.get(Calendar.HOUR_OF_DAY);
			int minutes = calendar.get(Calendar.MINUTE);
			if (! durationMatched(_durations, hourOfDay, minutes)) {
				matched = false;

				if (LOG.isDebugEnabled()) {
					LOG.debug("isMatched: None of the durations contains this hour of day[" + hourOfDay + "] and minutes[" + minutes + "]");
				}
			}
		}
		
		if(LOG.isDebugEnabled()) {
			LOG.debug("<== RangerTimeOfDayMatcher.isMatched(" + request+ "): " + matched);
		}

		return matched;
	}

	boolean durationMatched(List<int[]> durations, int hourOfDay, int minutes) {
		for (int[] aDuration : durations) {
			int start = aDuration[0];
			int end = aDuration[1];
			int minutesOfDay = hourOfDay*60 + minutes;
			if(start < end) {
				if (start <= minutesOfDay && minutesOfDay <= end) {
					return true;
				}
			} else {
				if(start <= minutesOfDay || minutesOfDay <= end) {
					return true;
				}
			}
		}
		return false;
	}

	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();

		sb.append("RangerTimeOfDayMatcher {");
		sb.append("_allowAny=").append(_allowAny).append(" ");
		sb.append("_durations=[");
		for(int[] duration : _durations) {
			sb.append("{start=").append(duration[0]).append("; end=").append(duration[1]).append("} ");
		}
		sb.append("]");
		sb.append("}");

		return sb.toString();
	}
}