Java tutorial
/* * 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 org.apache.commons.collections.CollectionUtils; import org.apache.commons.collections.MapUtils; import org.apache.commons.io.FilenameUtils; 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; import java.util.ArrayList; import java.util.List; /** * This is a sample implementation of a condition Evaluator. It works in conjunction with the sample context enricher * <code>RangerSampleProjectProvider</code>. This is how it would be specified in the service definition: { ... ... service definition ... "policyConditions": [ { "itemId": 1, "name": "user-in-project", "evaluator": "org.apache.ranger.plugin.conditionevaluator.RangerSimpleMatcher", "evaluatorOptions": { CONTEXT_NAME=PROJECT}, "validationRegEx":"", "validationMessage": "", "uiHint":"", "label": "Project Matcher", "description": "Projects" } } * * Name of this class is specified via the "evaluator" of the policy condition definition. Significant evaluator option * for this evaluator is the CONTEXT_NAME which indicates the name under which it would look for value for the condition. * It is also use to lookup the condition values specified in the policy. This example uses CONTEXT_NAME of PROJECT * which matches the value under which context is enriched by its companion class <code>RangerSampleProjectProvider</code>. * * Note that the same Condition Evaluator can be used to process Context enrichment done by <code>RangerSampleCountryProvider</code> * provided the CONTEXT_NAME evaluator option is set to COUNTRY which is same as the value used by its companion Context * Enricher <code>RangerSampleCountryProvider</code>. Which serves as an example of how a single Condition Evaluator * implementation can be used to model multiple policy conditions. * * For matching context value against policy values it uses <code>FilenameUtils.wildcardMatch()</code> which allows policy authors * flexibility to specify policy conditions using wildcards. Take a look at * {@link org.apache.ranger.plugin.conditionevaluator.RangerSampleSimpleMatcherTest#testIsMatched_happyPath() testIsMatched_happyPath} * test for examples of what sorts of matching is afforded by this use. * */ public class RangerSampleSimpleMatcher extends RangerAbstractConditionEvaluator { private static final Log LOG = LogFactory.getLog(RangerSampleSimpleMatcher.class); public static final String CONTEXT_NAME = "CONTEXT_NAME"; private boolean _allowAny = false; private String _contextName = null; private List<String> _values = new ArrayList<String>(); @Override public void init() { if (LOG.isDebugEnabled()) { LOG.debug("==> RangerSampleSimpleMatcher.init(" + condition + ")"); } super.init(); if (condition == null) { LOG.debug("init: null policy condition! Will match always!"); _allowAny = true; } else if (conditionDef == null) { LOG.debug("init: null policy condition definition! 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 if (MapUtils.isEmpty(conditionDef.getEvaluatorOptions())) { LOG.debug( "init: Evaluator options were empty. Can't determine what value to use from context. Will match always."); _allowAny = true; } else if (StringUtils.isEmpty(conditionDef.getEvaluatorOptions().get(CONTEXT_NAME))) { LOG.debug( "init: CONTEXT_NAME is not specified in evaluator options. Can't determine what value to use from context. Will match always."); _allowAny = true; } else { _contextName = conditionDef.getEvaluatorOptions().get(CONTEXT_NAME); for (String value : condition.getValues()) { _values.add(value); } } if (LOG.isDebugEnabled()) { LOG.debug("<== RangerSampleSimpleMatcher.init(" + condition + "): values[" + _values + "]"); } } @Override public boolean isMatched(RangerAccessRequest request) { if (LOG.isDebugEnabled()) { LOG.debug("==> RangerSampleSimpleMatcher.isMatched(" + request + ")"); } boolean matched = false; if (_allowAny) { matched = true; } else { String requestValue = extractValue(request, _contextName); if (StringUtils.isNotBlank(requestValue)) { for (String policyValue : _values) { if (FilenameUtils.wildcardMatch(requestValue, policyValue)) { matched = true; break; } } } } if (LOG.isDebugEnabled()) { LOG.debug("<== RangerSampleSimpleMatcher.isMatched(" + request + "): " + matched); } return matched; } String extractValue(final RangerAccessRequest request, String key) { if (LOG.isDebugEnabled()) { LOG.debug("==> RangerSampleSimpleMatcher.extractValue(" + request + ")"); } String value = null; if (request == null) { LOG.debug("isMatched: Unexpected: null request. Returning null!"); } else if (request.getContext() == null) { LOG.debug("isMatched: Context map of request is null. Ok. Returning null!"); } else if (CollectionUtils.isEmpty(request.getContext().entrySet())) { LOG.debug("isMatched: Missing context on request. Ok. Condition isn't applicable. Returning null!"); } else if (!request.getContext().containsKey(key)) { if (LOG.isDebugEnabled()) { LOG.debug("isMatched: Unexpected: Context did not have data for condition[" + key + "]. Returning null!"); } } else { value = (String) request.getContext().get(key); } if (LOG.isDebugEnabled()) { LOG.debug("<== RangerSampleSimpleMatcher.extractValue(" + request + "): " + value); } return value; } }