Java tutorial
/* * Copyright 2016 Crown Copyright * * Licensed 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 gaffer.graph.hook; import gaffer.commonutil.exception.UnauthorisedException; import gaffer.operation.Operation; import gaffer.operation.OperationChain; import gaffer.user.User; import org.apache.commons.io.IOUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.IOException; import java.io.InputStream; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.StandardOpenOption; import java.util.ArrayList; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.Map; import java.util.Properties; import java.util.Set; /* * An <code>OperationChainLimiter</code> is a {@link GraphHook} that checks a * user is authorised to execute an operation chain based on that user's maximum chain score and the configured score value for each operation in the chain. * This class requires a map of operation scores, these can be added using setOpScores(Map<Class,Integer>) or * addOpScore(Class, Integer...). Alternatively a properties file can be provided. * When using a properties file the last entry in the file that an operation can be assigned to will be the score that is used for that operation. * containing the operations and the score. * E.g if you put gaffer.operation.impl.add.AddElements = 8 * And then gaffer.operation.impl.add = 1 * The add elements will have a score of 1 not 8. * So make sure to write your properties file in class hierarchical order. * * This class also requires a map of authorisation scores, * this is the score value someone with that auth can have, the maximum score value of a users auths is used. * These can be added using setAuthScores(Map<String, Integer>) or * addAuthScore(String, Integer). Alternatively a properties file can be provided * containing the authorisations and the score. */ public class OperationChainLimiter implements GraphHook { private static final int DEFAULT_OPERATION_SCORE = 1; private static final Logger LOGGER = LoggerFactory.getLogger(OperationChainLimiter.class); private final Map<Class<? extends Operation>, Integer> operationScores = new LinkedHashMap<>(); private final Map<String, Integer> authScores = new HashMap<>(); /** * Default constructor. * Use setOpScores or addOpScore to add operation scores. * And Use setAuthScores or * addAuthScore to add Authorisation scores. */ public OperationChainLimiter() { } /** * Constructs an {@link OperationAuthoriser} with the authorisations * defined in the property file from the {@link Path} provided. * * @param operationScorePropertiesFileLocation path to operation scores property file * @param operationAuthorisationScoreLimitFileLocation path to authorisation scores property file */ public OperationChainLimiter(final Path operationScorePropertiesFileLocation, final Path operationAuthorisationScoreLimitFileLocation) { this(readProperties(operationScorePropertiesFileLocation), readProperties(operationAuthorisationScoreLimitFileLocation)); } /** * Constructs an {@link OperationAuthoriser} with the authorisations * defined in the property file from the {@link InputStream} provided. * * @param operationScorePropertiesStream input stream of operation scores property file * @param operationAuthorisationScoreLimitStream input stream of authorisation scores property file */ public OperationChainLimiter(final InputStream operationScorePropertiesStream, final InputStream operationAuthorisationScoreLimitStream) { this(readProperties(operationScorePropertiesStream), readProperties(operationAuthorisationScoreLimitStream)); } /** * Constructs an {@link OperationAuthoriser} with the authorisations * defined in the provided authorisations property file. * * @param operationScorePropertiesFile authorisation scores property file * @param operationAuthorisationScoreLimitPropertiesFile authorisation scores property file */ public OperationChainLimiter(final Properties operationScorePropertiesFile, final Properties operationAuthorisationScoreLimitPropertiesFile) { loadMapsFromProperties(operationScorePropertiesFile, operationAuthorisationScoreLimitPropertiesFile); } /** * Checks the {@link OperationChain} * is allowed to be executed by the user. * This is done by checking the user's auths against the auth scores getting the users maximum score limit value. * Then checking the operation score of all operations in the chain and comparing the total score value of the chain against a users maximum score limit. * If an operation cannot be executed then an {@link IllegalAccessError} is thrown. * * @param user the user to authorise. * @param opChain the operation chain. */ @Override public void preExecute(final OperationChain<?> opChain, final User user) { if (null != opChain) { Integer chainScore = 0; Integer maxAuthScore = getMaxUserAuthScore(user.getOpAuths()); for (final Operation operation : opChain.getOperations()) { chainScore += authorise(operation); if (chainScore > maxAuthScore) { throw new UnauthorisedException("The maximum score limit for this user is " + maxAuthScore + ".\n" + "The requested operation chain exceeded this score limit."); } } } } /** * Iterates through each of the users operation authorisations listed in the config file and returns the highest score * associated with those auths. * <p/> * Defaults to 0. * * @param opAuths a set of operation authorisations * @return maxUserScore the highest score associated with any of the supplied user auths */ private Integer getMaxUserAuthScore(final Set<String> opAuths) { Integer maxUserScore = 0; for (final String opAuth : opAuths) { Integer authScore = authScores.get(opAuth); if (null != authScore) { if (authScore > maxUserScore) { maxUserScore = authScore; } } } LOGGER.info("Returning users max operation chain limit score of " + maxUserScore); return maxUserScore; } @Override public void postExecute(final Object result, final OperationChain<?> opChain, final User user) { // This method can be overridden to add additional authorisation checks on the results. } protected Integer authorise(final Operation operation) { if (null != operation) { final Class<? extends Operation> opClass = operation.getClass(); ArrayList<Class<? extends Operation>> keys = new ArrayList<>(operationScores.keySet()); for (int i = keys.size() - 1; i >= 0; i--) { Class<? extends Operation> key = keys.get(i); if (key.isAssignableFrom(opClass)) { return operationScores.get(key); } } LOGGER.warn("The operation '" + operation.getClass().getName() + "' was not found in the config file provided the configured default value of " + DEFAULT_OPERATION_SCORE + " will be used"); } else { LOGGER.warn("A Null operation was passed to the OperationChainLimiter graph hook"); } return DEFAULT_OPERATION_SCORE; } private static Properties readProperties(final Path propFileLocation) { Properties props; if (null != propFileLocation) { try { props = readProperties(Files.newInputStream(propFileLocation, StandardOpenOption.READ)); } catch (IOException e) { throw new IllegalArgumentException(e); } } else { props = new Properties(); } return props; } private static Properties readProperties(final InputStream stream) { final Properties props = new Properties(); if (null != stream) { try { props.load(stream); } catch (IOException e) { throw new IllegalArgumentException("Failed to load store properties file : " + e.getMessage(), e); } finally { IOUtils.closeQuietly(stream); } } return props; } private void loadMapsFromProperties(final Properties operationScorePropertiesFile, final Properties operationAuthorisationScoreLimitPropertiesFile) { Map<Class<? extends Operation>, Integer> opScores = new LinkedHashMap<>(); for (final String opClassName : operationScorePropertiesFile.stringPropertyNames()) { final Class<? extends Operation> opClass; try { opClass = Class.forName(opClassName).asSubclass(Operation.class); } catch (ClassNotFoundException e) { LOGGER.error("An operation class could not be found for operation score property " + opClassName); throw new IllegalArgumentException(e); } final Integer score = Integer.parseInt(operationScorePropertiesFile.getProperty(opClassName)); opScores.put(opClass, score); } setOpScores(opScores); Map<String, Integer> authScores = new HashMap<>(); for (final String authName : operationAuthorisationScoreLimitPropertiesFile.stringPropertyNames()) { final Integer score = Integer .parseInt(operationAuthorisationScoreLimitPropertiesFile.getProperty(authName)); authScores.put(authName, score); } setAuthScores(authScores); } /** * Set the operation scores. * * @param opScores a map of operation classes to scores */ public void setOpScores(final Map<Class<? extends Operation>, Integer> opScores) { operationScores.putAll(opScores); } /** * Add a score for a given operation class. * * @param opClass the operation class * @param score the score for the operation class */ public void addOpScore(final Class<? extends Operation> opClass, final Integer score) { operationScores.put(opClass, score); } /** * Set the authorisation scores. * * @param authScores a map of authorisations to scores */ public void setAuthScores(final Map<String, Integer> authScores) { this.authScores.putAll(authScores); } /** * Add a score for a given operation class. * * @param auth the authorisation * @param score the score for the operation class */ public void addAuthScore(final String auth, final Integer score) { authScores.put(auth, score); } }