001 /****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one *
003 * or more contributor license agreements. See the NOTICE file *
004 * distributed with this work for additional information *
005 * regarding copyright ownership. The ASF licenses this file *
006 * to you under the Apache License, Version 2.0 (the *
007 * "License"); you may not use this file except in compliance *
008 * with the License. You may obtain a copy of the License at *
009 * *
010 * http://www.apache.org/licenses/LICENSE-2.0 *
011 * *
012 * Unless required by applicable law or agreed to in writing, *
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014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
015 * KIND, either express or implied. See the License for the *
016 * specific language governing permissions and limitations *
017 * under the License. *
018 ****************************************************************/
019
020 package org.apache.james.jspf.policies;
021
022 import org.apache.james.jspf.core.DNSLookupContinuation;
023 import org.apache.james.jspf.core.DNSRequest;
024 import org.apache.james.jspf.core.DNSResponse;
025 import org.apache.james.jspf.core.SPF1Constants;
026 import org.apache.james.jspf.core.SPF1Record;
027 import org.apache.james.jspf.core.SPF1Utils;
028 import org.apache.james.jspf.core.SPFChecker;
029 import org.apache.james.jspf.core.SPFCheckerDNSResponseListener;
030 import org.apache.james.jspf.core.SPFSession;
031 import org.apache.james.jspf.core.exceptions.NeutralException;
032 import org.apache.james.jspf.core.exceptions.NoneException;
033 import org.apache.james.jspf.core.exceptions.PermErrorException;
034 import org.apache.james.jspf.core.exceptions.TempErrorException;
035 import org.apache.james.jspf.core.exceptions.TimeoutException;
036
037 import java.util.Iterator;
038 import java.util.List;
039
040 /**
041 * Get the raw dns txt or spf entry which contains a spf entry
042 */
043 public class SPFRetriever implements SPFChecker {
044
045 private static final class SPFRecordHandlerDNSResponseListener implements SPFCheckerDNSResponseListener {
046
047 /**
048 * @see org.apache.james.jspf.core.SPFCheckerDNSResponseListener#onDNSResponse(org.apache.james.jspf.core.DNSResponse, org.apache.james.jspf.core.SPFSession)
049 */
050 public DNSLookupContinuation onDNSResponse(
051 DNSResponse response, SPFSession session)
052 throws PermErrorException,
053 NoneException, TempErrorException,
054 NeutralException {
055
056 List<String> spfR;
057 try {
058 spfR = response.getResponse();
059 String record = extractSPFRecord(spfR);
060 if (record != null) {
061 session.setAttribute(SPF1Utils.ATTRIBUTE_SPF1_RECORD, new SPF1Record(record));
062 }
063 } catch (TimeoutException e) {
064 throw new TempErrorException("Timeout querying dns");
065 }
066 return null;
067
068 }
069
070 }
071
072 private static final class SPFRetrieverDNSResponseListener implements SPFCheckerDNSResponseListener {
073
074 /**
075 * @see org.apache.james.jspf.core.SPFCheckerDNSResponseListener#onDNSResponse(org.apache.james.jspf.core.DNSResponse, org.apache.james.jspf.core.SPFSession)
076 */
077 public DNSLookupContinuation onDNSResponse(
078 DNSResponse response, SPFSession session)
079 throws PermErrorException, NoneException,
080 TempErrorException, NeutralException {
081 try {
082 List<String> spfR = response.getResponse();
083
084 if (spfR == null || spfR.isEmpty()) {
085
086 String currentDomain = session.getCurrentDomain();
087 return new DNSLookupContinuation(new DNSRequest(currentDomain, DNSRequest.TXT), new SPFRecordHandlerDNSResponseListener());
088
089 } else {
090
091 String record = extractSPFRecord(spfR);
092 if (record != null) {
093 session.setAttribute(SPF1Utils.ATTRIBUTE_SPF1_RECORD, new SPF1Record(record));
094 }
095
096 }
097
098 return null;
099
100 } catch (TimeoutException e) {
101 throw new TempErrorException("Timeout querying dns");
102 }
103 }
104
105 }
106
107 /**
108 * This is used for testing purpose. Setting this to true will skip the initial
109 * lookups for SPF records and instead will simply check the TXT records.
110 */
111 private static final boolean CHECK_ONLY_TXT_RECORDS = false;
112
113 /**
114 * Return the extracted SPF-Record
115 *
116 * @param spfR the List which holds TXT/SPF - Records
117 * @return returnValue the extracted SPF-Record
118 * @throws PermErrorException if more then one SPF - Record was found in the
119 * given List.
120 */
121 protected static String extractSPFRecord(List<String> spfR) throws PermErrorException {
122 if (spfR == null || spfR.isEmpty()) return null;
123
124 String returnValue = null;
125 Iterator<String> all = spfR.iterator();
126
127 while (all.hasNext()) {
128 // DO NOT trim the result!
129 String compare = all.next();
130
131 // We trim the compare value only for the comparison
132 if (compare.toLowerCase().trim().startsWith(SPF1Constants.SPF_VERSION1 + " ") || compare.trim().equalsIgnoreCase(SPF1Constants.SPF_VERSION1)) {
133 if (returnValue == null) {
134 returnValue = compare;
135 } else {
136 throw new PermErrorException(
137 "More than 1 SPF record found");
138 }
139 }
140 }
141
142 return returnValue;
143 }
144
145
146 /**
147 * @see org.apache.james.jspf.core.SPFChecker#checkSPF(org.apache.james.jspf.core.SPFSession)
148 */
149 public DNSLookupContinuation checkSPF(SPFSession spfData)
150 throws PermErrorException, TempErrorException, NeutralException,
151 NoneException {
152 SPF1Record res = (SPF1Record) spfData.getAttribute(SPF1Utils.ATTRIBUTE_SPF1_RECORD);
153 if (res == null) {
154 String currentDomain = spfData.getCurrentDomain();
155 if (CHECK_ONLY_TXT_RECORDS) {
156 return new DNSLookupContinuation(new DNSRequest(currentDomain, DNSRequest.TXT), new SPFRecordHandlerDNSResponseListener());
157 } else {
158 return new DNSLookupContinuation(new DNSRequest(currentDomain, DNSRequest.SPF), new SPFRetrieverDNSResponseListener());
159 }
160
161 }
162 return null;
163 }
164
165 }