| /* |
| * 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.unomi.scripting; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.util.Set; |
| import java.util.regex.Pattern; |
| |
| /** |
| * An expression filter is used to allow/deny scripts for execution. |
| */ |
| public class ExpressionFilter { |
| private static final Logger logger = LoggerFactory.getLogger(ExpressionFilter.class.getName()); |
| |
| private final Set<Pattern> allowedExpressionPatterns; |
| private final Set<Pattern> forbiddenExpressionPatterns; |
| |
| public ExpressionFilter(Set<Pattern> allowedExpressionPatterns, Set<Pattern> forbiddenExpressionPatterns) { |
| this.allowedExpressionPatterns = allowedExpressionPatterns; |
| this.forbiddenExpressionPatterns = forbiddenExpressionPatterns; |
| } |
| |
| public String filter(String expression) { |
| if (forbiddenExpressionPatterns != null && expressionMatches(expression, forbiddenExpressionPatterns)) { |
| logger.warn("Expression filtered because forbidden. See debug log level for more information"); |
| if (logger.isDebugEnabled()) { |
| logger.debug("Expression {} is forbidden by expression filter", expression); |
| } |
| |
| return null; |
| } |
| if (allowedExpressionPatterns != null && !expressionMatches(expression, allowedExpressionPatterns)) { |
| logger.warn("Expression filtered because not allowed. See debug log level for more information"); |
| if (logger.isDebugEnabled()) { |
| logger.debug("Expression {} is not allowed by expression filter", expression); |
| } |
| |
| return null; |
| } |
| return expression; |
| } |
| |
| private boolean expressionMatches(String expression, Set<Pattern> patterns) { |
| for (Pattern pattern : patterns) { |
| if (pattern.matcher(expression).matches()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| } |