<? /* * Calculate the effective registered domain of a fully qualified domain name. * * <@LICENSE> * 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. * </@LICENSE> * * Florian Sager, 25.07.2008, sager@agitos.de */ /* * Remove subdomains from a signing domain to get the registered domain. * * dkim-reputation.org blocks signing domains on the level of registered domains * to rate senders who use e.g. a.spamdomain.tld, b.spamdomain.tld, ... under * the most common identifier - the registered domain - finally. * * This function returns NULL if $signingDomain is TLD itself */ function getRegisteredDomain($signingDomain) { global $tldTree; $signingDomainParts = split('\.', $signingDomain); $result = findRegisteredDomain($signingDomainParts, $tldTree); if ($result===NULL || $result=="") { // this is an invalid domain name return NULL; } // assure there is at least 1 TLD in the stripped signing domain if (!strpos($result, '.')) { $cnt = count($signingDomainParts); if ($cnt==1 || $signingDomainParts[$cnt-2]=="") return NULL; return $signingDomainParts[$cnt-2].'.'.$signingDomainParts[$cnt-1]; } return $result; } // recursive helper method function findRegisteredDomain($remainingSigningDomainParts, &$treeNode) { $sub = array_pop($remainingSigningDomainParts); $result = NULL; if (isset($treeNode['!'])) { return '#'; } else if (is_array($treeNode) && array_key_exists($sub, $treeNode)) { $result = findRegisteredDomain($remainingSigningDomainParts, $treeNode[$sub]); } else if (is_array($treeNode) && array_key_exists('*', $treeNode)) { $result = findRegisteredDomain($remainingSigningDomainParts, $treeNode['*']); } else { return $sub; } // this is a hack 'cause PHP interpretes '' as NULL if ($result == '#') { return $sub; } else if (strlen($result)>0) { return $result.'.'.$sub; } return NULL; } ?>