1 /* 2 * Copyright (c) 2019, Red Hat, Inc. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.security.krb5.internal; 27 28 import java.util.Date; 29 import java.util.HashMap; 30 import java.util.LinkedList; 31 import java.util.List; 32 import java.util.Map; 33 import java.util.Map.Entry; 34 35 import sun.security.krb5.Credentials; 36 import sun.security.krb5.PrincipalName; 37 38 final class ReferralsCache { 39 40 private static Map<PrincipalName, Map<String, ReferralCacheEntry>> referralsMap = 41 new HashMap<>(); 42 43 static final class ReferralCacheEntry { 44 private final Credentials creds; 45 private final String toRealm; 46 ReferralCacheEntry(Credentials creds, String toRealm) { 47 this.creds = creds; 48 this.toRealm = toRealm; 49 } 50 Credentials getCreds() { 51 return creds; 52 } 53 String getToRealm() { 54 return toRealm; 55 } 56 } 57 58 static synchronized void put(PrincipalName service, 59 String fromRealm, String toRealm, Credentials creds) { 60 pruneExpired(service); 61 if (creds.getEndTime().before(new Date())) { 62 return; 63 } 64 Map<String, ReferralCacheEntry> entries = referralsMap.get(service); 65 if (entries == null) { 66 entries = new HashMap<String, ReferralCacheEntry>(); 67 referralsMap.put(service, entries); 68 } 69 entries.remove(fromRealm); 70 ReferralCacheEntry newEntry = new ReferralCacheEntry(creds, toRealm); 71 entries.put(fromRealm, newEntry); 72 73 // Remove loops within the cache 74 ReferralCacheEntry current = newEntry; 75 List<ReferralCacheEntry> seen = new LinkedList<>(); 76 while (current != null) { 77 if (seen.contains(current)) { 78 // Loop found. Remove the first referral to cut the loop. 79 entries.remove(newEntry.getToRealm()); 80 break; 81 } 82 seen.add(current); 83 current = entries.get(current.getToRealm()); 84 } 85 } 86 87 static synchronized ReferralCacheEntry get(PrincipalName service, 88 String fromRealm) { 89 pruneExpired(service); 90 Map<String, ReferralCacheEntry> entries = referralsMap.get(service); 91 if (entries != null) { 92 ReferralCacheEntry toRef = entries.get(fromRealm); 93 if (toRef != null) { 94 return toRef; 95 } 96 } 97 return null; 98 } 99 100 private static void pruneExpired(PrincipalName service) { 101 Date now = new Date(); 102 Map<String, ReferralCacheEntry> entries = referralsMap.get(service); 103 if (entries != null) { 104 for (Entry<String, ReferralCacheEntry> mapEntry : 105 entries.entrySet()) { 106 if (mapEntry.getValue().getCreds().getEndTime().before(now)) { 107 entries.remove(mapEntry.getKey()); 108 } 109 } 110 } 111 } 112 }