| /* |
| * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * |
| * (C) Copyright IBM Corp. 1999 All Rights Reserved. |
| * Copyright 1997 The Open Group Research Institute. All rights reserved. |
| */ |
| |
| package sun.security.krb5; |
| |
| import java.security.PrivilegedAction; |
| import java.security.Security; |
| import java.util.Locale; |
| import sun.security.krb5.internal.Krb5; |
| import sun.security.krb5.internal.NetClient; |
| import java.io.IOException; |
| import java.net.SocketTimeoutException; |
| import java.util.StringTokenizer; |
| import java.security.AccessController; |
| import java.security.PrivilegedExceptionAction; |
| import java.security.PrivilegedActionException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import sun.security.krb5.internal.KRBError; |
| |
| /** |
| * KDC-REQ/KDC-REP communication. No more base class for KrbAsReq and |
| * KrbTgsReq. This class is now communication only. |
| */ |
| public final class KdcComm { |
| |
| // The following settings can be configured in [libdefaults] |
| // section of krb5.conf, which are global for all realms. Each of |
| // them can also be defined in a realm, which overrides value here. |
| |
| /** |
| * max retry time for a single KDC, default Krb5.KDC_RETRY_LIMIT (3) |
| */ |
| private static int defaultKdcRetryLimit; |
| /** |
| * timeout requesting a ticket from KDC, in millisec, default 30 sec |
| */ |
| private static int defaultKdcTimeout; |
| /** |
| * max UDP packet size, default unlimited (-1) |
| */ |
| private static int defaultUdpPrefLimit; |
| |
| private static final boolean DEBUG = Krb5.DEBUG; |
| |
| private static final String BAD_POLICY_KEY = "krb5.kdc.bad.policy"; |
| |
| /** |
| * What to do when a KDC is unavailable, specified in the |
| * java.security file with key krb5.kdc.bad.policy. |
| * Possible values can be TRY_LAST or TRY_LESS. Reloaded when refreshed. |
| */ |
| private enum BpType { |
| NONE, TRY_LAST, TRY_LESS |
| } |
| private static int tryLessMaxRetries = 1; |
| private static int tryLessTimeout = 5000; |
| |
| private static BpType badPolicy; |
| |
| static { |
| initStatic(); |
| } |
| |
| /** |
| * Read global settings |
| */ |
| public static void initStatic() { |
| String value = AccessController.doPrivileged( |
| new PrivilegedAction<String>() { |
| public String run() { |
| return Security.getProperty(BAD_POLICY_KEY); |
| } |
| }); |
| if (value != null) { |
| value = value.toLowerCase(Locale.ENGLISH); |
| String[] ss = value.split(":"); |
| if ("tryless".equals(ss[0])) { |
| if (ss.length > 1) { |
| String[] params = ss[1].split(","); |
| try { |
| int tmp0 = Integer.parseInt(params[0]); |
| if (params.length > 1) { |
| tryLessTimeout = Integer.parseInt(params[1]); |
| } |
| // Assign here in case of exception at params[1] |
| tryLessMaxRetries = tmp0; |
| } catch (NumberFormatException nfe) { |
| // Ignored. Please note that tryLess is recognized and |
| // used, parameters using default values |
| if (DEBUG) { |
| System.out.println("Invalid " + BAD_POLICY_KEY + |
| " parameter for tryLess: " + |
| value + ", use default"); |
| } |
| } |
| } |
| badPolicy = BpType.TRY_LESS; |
| } else if ("trylast".equals(ss[0])) { |
| badPolicy = BpType.TRY_LAST; |
| } else { |
| badPolicy = BpType.NONE; |
| } |
| } else { |
| badPolicy = BpType.NONE; |
| } |
| |
| |
| int timeout = -1; |
| int max_retries = -1; |
| int udp_pref_limit = -1; |
| |
| try { |
| Config cfg = Config.getInstance(); |
| String temp = cfg.get("libdefaults", "kdc_timeout"); |
| timeout = parseTimeString(temp); |
| |
| temp = cfg.get("libdefaults", "max_retries"); |
| max_retries = parsePositiveIntString(temp); |
| temp = cfg.get("libdefaults", "udp_preference_limit"); |
| udp_pref_limit = parsePositiveIntString(temp); |
| } catch (Exception exc) { |
| // ignore any exceptions; use default values |
| if (DEBUG) { |
| System.out.println ("Exception in getting KDC communication " + |
| "settings, using default value " + |
| exc.getMessage()); |
| } |
| } |
| defaultKdcTimeout = timeout > 0 ? timeout : 30*1000; // 30 seconds |
| defaultKdcRetryLimit = |
| max_retries > 0 ? max_retries : Krb5.KDC_RETRY_LIMIT; |
| |
| if (udp_pref_limit < 0) { |
| defaultUdpPrefLimit = Krb5.KDC_DEFAULT_UDP_PREF_LIMIT; |
| } else if (udp_pref_limit > Krb5.KDC_HARD_UDP_LIMIT) { |
| defaultUdpPrefLimit = Krb5.KDC_HARD_UDP_LIMIT; |
| } else { |
| defaultUdpPrefLimit = udp_pref_limit; |
| } |
| |
| KdcAccessibility.reset(); |
| } |
| |
| /** |
| * The instance fields |
| */ |
| private String realm; |
| |
| public KdcComm(String realm) throws KrbException { |
| if (realm == null) { |
| realm = Config.getInstance().getDefaultRealm(); |
| if (realm == null) { |
| throw new KrbException(Krb5.KRB_ERR_GENERIC, |
| "Cannot find default realm"); |
| } |
| } |
| this.realm = realm; |
| } |
| |
| public byte[] send(byte[] obuf) |
| throws IOException, KrbException { |
| int udpPrefLimit = getRealmSpecificValue( |
| realm, "udp_preference_limit", defaultUdpPrefLimit); |
| |
| boolean useTCP = (udpPrefLimit > 0 && |
| (obuf != null && obuf.length > udpPrefLimit)); |
| |
| return send(obuf, useTCP); |
| } |
| |
| private byte[] send(byte[] obuf, boolean useTCP) |
| throws IOException, KrbException { |
| |
| if (obuf == null) |
| return null; |
| Config cfg = Config.getInstance(); |
| |
| if (realm == null) { |
| realm = cfg.getDefaultRealm(); |
| if (realm == null) { |
| throw new KrbException(Krb5.KRB_ERR_GENERIC, |
| "Cannot find default realm"); |
| } |
| } |
| |
| String kdcList = cfg.getKDCList(realm); |
| if (kdcList == null) { |
| throw new KrbException("Cannot get kdc for realm " + realm); |
| } |
| // tempKdc may include the port number also |
| Iterator<String> tempKdc = KdcAccessibility.list(kdcList).iterator(); |
| if (!tempKdc.hasNext()) { |
| throw new KrbException("Cannot get kdc for realm " + realm); |
| } |
| byte[] ibuf = null; |
| try { |
| ibuf = sendIfPossible(obuf, tempKdc.next(), useTCP); |
| } catch(Exception first) { |
| boolean ok = false; |
| while(tempKdc.hasNext()) { |
| try { |
| ibuf = sendIfPossible(obuf, tempKdc.next(), useTCP); |
| ok = true; |
| break; |
| } catch(Exception ignore) {} |
| } |
| if (!ok) throw first; |
| } |
| if (ibuf == null) { |
| throw new IOException("Cannot get a KDC reply"); |
| } |
| return ibuf; |
| } |
| |
| // send the AS Request to the specified KDC |
| // failover to using TCP if useTCP is not set and response is too big |
| private byte[] sendIfPossible(byte[] obuf, String tempKdc, boolean useTCP) |
| throws IOException, KrbException { |
| |
| try { |
| byte[] ibuf = send(obuf, tempKdc, useTCP); |
| KRBError ke = null; |
| try { |
| ke = new KRBError(ibuf); |
| } catch (Exception e) { |
| // OK |
| } |
| if (ke != null && ke.getErrorCode() == |
| Krb5.KRB_ERR_RESPONSE_TOO_BIG) { |
| ibuf = send(obuf, tempKdc, true); |
| } |
| KdcAccessibility.removeBad(tempKdc); |
| return ibuf; |
| } catch(Exception e) { |
| if (DEBUG) { |
| System.out.println(">>> KrbKdcReq send: error trying " + |
| tempKdc); |
| e.printStackTrace(System.out); |
| } |
| KdcAccessibility.addBad(tempKdc); |
| throw e; |
| } |
| } |
| |
| // send the AS Request to the specified KDC |
| |
| private byte[] send(byte[] obuf, String tempKdc, boolean useTCP) |
| throws IOException, KrbException { |
| |
| if (obuf == null) |
| return null; |
| |
| int port = Krb5.KDC_INET_DEFAULT_PORT; |
| int retries = getRealmSpecificValue( |
| realm, "max_retries", defaultKdcRetryLimit); |
| int timeout = getRealmSpecificValue( |
| realm, "kdc_timeout", defaultKdcTimeout); |
| if (badPolicy == BpType.TRY_LESS && |
| KdcAccessibility.isBad(tempKdc)) { |
| if (retries > tryLessMaxRetries) { |
| retries = tryLessMaxRetries; // less retries |
| } |
| if (timeout > tryLessTimeout) { |
| timeout = tryLessTimeout; // less time |
| } |
| } |
| |
| String kdc = null; |
| String portStr = null; |
| |
| if (tempKdc.charAt(0) == '[') { // Explicit IPv6 in [] |
| int pos = tempKdc.indexOf(']', 1); |
| if (pos == -1) { |
| throw new IOException("Illegal KDC: " + tempKdc); |
| } |
| kdc = tempKdc.substring(1, pos); |
| if (pos != tempKdc.length() - 1) { // with port number |
| if (tempKdc.charAt(pos+1) != ':') { |
| throw new IOException("Illegal KDC: " + tempKdc); |
| } |
| portStr = tempKdc.substring(pos+2); |
| } |
| } else { |
| int colon = tempKdc.indexOf(':'); |
| if (colon == -1) { // Hostname or IPv4 host only |
| kdc = tempKdc; |
| } else { |
| int nextColon = tempKdc.indexOf(':', colon+1); |
| if (nextColon > 0) { // >=2 ":", IPv6 with no port |
| kdc = tempKdc; |
| } else { // 1 ":", hostname or IPv4 with port |
| kdc = tempKdc.substring(0, colon); |
| portStr = tempKdc.substring(colon+1); |
| } |
| } |
| } |
| if (portStr != null) { |
| int tempPort = parsePositiveIntString(portStr); |
| if (tempPort > 0) |
| port = tempPort; |
| } |
| |
| if (DEBUG) { |
| System.out.println(">>> KrbKdcReq send: kdc=" + kdc |
| + (useTCP ? " TCP:":" UDP:") |
| + port + ", timeout=" |
| + timeout |
| + ", number of retries =" |
| + retries |
| + ", #bytes=" + obuf.length); |
| } |
| |
| KdcCommunication kdcCommunication = |
| new KdcCommunication(kdc, port, useTCP, timeout, retries, obuf); |
| try { |
| byte[] ibuf = AccessController.doPrivileged(kdcCommunication); |
| if (DEBUG) { |
| System.out.println(">>> KrbKdcReq send: #bytes read=" |
| + (ibuf != null ? ibuf.length : 0)); |
| } |
| return ibuf; |
| } catch (PrivilegedActionException e) { |
| Exception wrappedException = e.getException(); |
| if (wrappedException instanceof IOException) { |
| throw (IOException) wrappedException; |
| } else { |
| throw (KrbException) wrappedException; |
| } |
| } |
| } |
| |
| private static class KdcCommunication |
| implements PrivilegedExceptionAction<byte[]> { |
| |
| private String kdc; |
| private int port; |
| private boolean useTCP; |
| private int timeout; |
| private int retries; |
| private byte[] obuf; |
| |
| public KdcCommunication(String kdc, int port, boolean useTCP, |
| int timeout, int retries, byte[] obuf) { |
| this.kdc = kdc; |
| this.port = port; |
| this.useTCP = useTCP; |
| this.timeout = timeout; |
| this.retries = retries; |
| this.obuf = obuf; |
| } |
| |
| // The caller only casts IOException and KrbException so don't |
| // add any new ones! |
| |
| public byte[] run() throws IOException, KrbException { |
| |
| byte[] ibuf = null; |
| |
| for (int i=1; i <= retries; i++) { |
| String proto = useTCP?"TCP":"UDP"; |
| if (DEBUG) { |
| System.out.println(">>> KDCCommunication: kdc=" + kdc |
| + " " + proto + ":" |
| + port + ", timeout=" |
| + timeout |
| + ",Attempt =" + i |
| + ", #bytes=" + obuf.length); |
| } |
| try (NetClient kdcClient = NetClient.getInstance( |
| proto, kdc, port, timeout)) { |
| kdcClient.send(obuf); |
| ibuf = kdcClient.receive(); |
| break; |
| } catch (SocketTimeoutException se) { |
| if (DEBUG) { |
| System.out.println ("SocketTimeOutException with " + |
| "attempt: " + i); |
| } |
| if (i == retries) { |
| ibuf = null; |
| throw se; |
| } |
| } |
| } |
| return ibuf; |
| } |
| } |
| |
| /** |
| * Parses a time value string. If it ends with "s", parses as seconds. |
| * Otherwise, parses as milliseconds. |
| * @param s the time string |
| * @return the integer value in milliseconds, or -1 if input is null or |
| * has an invalid format |
| */ |
| private static int parseTimeString(String s) { |
| if (s == null) { |
| return -1; |
| } |
| if (s.endsWith("s")) { |
| int seconds = parsePositiveIntString(s.substring(0, s.length()-1)); |
| return (seconds < 0) ? -1 : (seconds*1000); |
| } else { |
| return parsePositiveIntString(s); |
| } |
| } |
| |
| /** |
| * Returns krb5.conf setting of {@code key} for a specific realm, |
| * which can be: |
| * 1. defined in the sub-stanza for the given realm inside [realms], or |
| * 2. defined in [libdefaults], or |
| * 3. defValue |
| * @param realm the given realm in which the setting is requested. Returns |
| * the global setting if null |
| * @param key the key for the setting |
| * @param defValue default value |
| * @return a value for the key |
| */ |
| private int getRealmSpecificValue(String realm, String key, int defValue) { |
| int v = defValue; |
| |
| if (realm == null) return v; |
| |
| int temp = -1; |
| try { |
| String value = |
| Config.getInstance().get("realms", realm, key); |
| if (key.equals("kdc_timeout")) { |
| temp = parseTimeString(value); |
| } else { |
| temp = parsePositiveIntString(value); |
| } |
| } catch (Exception exc) { |
| // Ignored, defValue will be picked up |
| } |
| |
| if (temp > 0) v = temp; |
| |
| return v; |
| } |
| |
| private static int parsePositiveIntString(String intString) { |
| if (intString == null) |
| return -1; |
| |
| int ret = -1; |
| |
| try { |
| ret = Integer.parseInt(intString); |
| } catch (Exception exc) { |
| return -1; |
| } |
| |
| if (ret >= 0) |
| return ret; |
| |
| return -1; |
| } |
| |
| /** |
| * Maintains a KDC accessible list. Unavailable KDCs are put into a |
| * blacklist, when a KDC in the blacklist is available, it's removed |
| * from there. No insertion order in the blacklist. |
| * |
| * There are two methods to deal with KDCs in the blacklist. 1. Only try |
| * them when there's no KDC not on the blacklist. 2. Still try them, but |
| * with lesser number of retries and smaller timeout value. |
| */ |
| static class KdcAccessibility { |
| // Known bad KDCs |
| private static Set<String> bads = new HashSet<>(); |
| |
| private static synchronized void addBad(String kdc) { |
| if (DEBUG) { |
| System.out.println(">>> KdcAccessibility: add " + kdc); |
| } |
| bads.add(kdc); |
| } |
| |
| private static synchronized void removeBad(String kdc) { |
| if (DEBUG) { |
| System.out.println(">>> KdcAccessibility: remove " + kdc); |
| } |
| bads.remove(kdc); |
| } |
| |
| private static synchronized boolean isBad(String kdc) { |
| return bads.contains(kdc); |
| } |
| |
| private static synchronized void reset() { |
| if (DEBUG) { |
| System.out.println(">>> KdcAccessibility: reset"); |
| } |
| bads.clear(); |
| } |
| |
| // Returns a preferred KDC list by putting the bad ones at the end |
| private static synchronized List<String> list(String kdcList) { |
| StringTokenizer st = new StringTokenizer(kdcList); |
| List<String> list = new ArrayList<>(); |
| if (badPolicy == BpType.TRY_LAST) { |
| List<String> badkdcs = new ArrayList<>(); |
| while (st.hasMoreTokens()) { |
| String t = st.nextToken(); |
| if (bads.contains(t)) badkdcs.add(t); |
| else list.add(t); |
| } |
| // Bad KDCs are put at last |
| list.addAll(badkdcs); |
| } else { |
| // All KDCs are returned in their original order, |
| // This include TRY_LESS and NONE |
| while (st.hasMoreTokens()) { |
| list.add(st.nextToken()); |
| } |
| } |
| return list; |
| } |
| } |
| } |
| |