1 /* |
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2 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 /* |
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27 * |
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28 * (C) Copyright IBM Corp. 1999 All Rights Reserved. |
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29 * Copyright 1997 The Open Group Research Institute. All rights reserved. |
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30 */ |
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31 |
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32 package sun.security.krb5; |
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33 |
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34 import java.security.AccessController; |
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35 import java.security.PrivilegedAction; |
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36 import java.security.Security; |
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37 import java.util.Locale; |
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38 import sun.security.krb5.internal.Krb5; |
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39 import sun.security.krb5.internal.UDPClient; |
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40 import sun.security.krb5.internal.TCPClient; |
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41 import java.io.IOException; |
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42 import java.net.SocketTimeoutException; |
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43 import java.util.StringTokenizer; |
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44 import java.security.AccessController; |
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45 import java.security.PrivilegedExceptionAction; |
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46 import java.security.PrivilegedActionException; |
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47 import java.util.ArrayList; |
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48 import java.util.List; |
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49 import java.util.Set; |
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50 import java.util.HashSet; |
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51 |
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52 public abstract class KrbKdcReq { |
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53 |
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54 // The following settings can be configured in [libdefaults] |
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55 // section of krb5.conf, which are global for all realms. Each of |
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56 // them can also be defined in a realm, which overrides value here. |
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57 |
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58 /** |
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59 * max retry time for a single KDC, default Krb5.KDC_RETRY_LIMIT (3) |
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60 */ |
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61 private static int defaultKdcRetryLimit; |
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62 /** |
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63 * timeout requesting a ticket from KDC, in millisec, default 30 sec |
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64 */ |
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65 private static int defaultKdcTimeout; |
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66 /** |
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67 * max UDP packet size, default unlimited (-1) |
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68 */ |
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69 private static int defaultUdpPrefLimit; |
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70 |
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71 private static final boolean DEBUG = Krb5.DEBUG; |
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72 |
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73 private static final String BAD_POLICY_KEY = "krb5.kdc.bad.policy"; |
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74 |
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75 /** |
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76 * What to do when a KDC is unavailable, specified in the |
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77 * java.security file with key krb5.kdc.bad.policy. |
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78 * Possible values can be TRY_LAST or TRY_LESS. Reloaded when refreshed. |
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79 */ |
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80 private enum BpType { |
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81 NONE, TRY_LAST, TRY_LESS |
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82 } |
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83 private static int tryLessMaxRetries = 1; |
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84 private static int tryLessTimeout = 5000; |
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85 |
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86 private static BpType badPolicy; |
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87 |
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88 static { |
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89 initStatic(); |
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90 } |
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91 |
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92 /** |
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93 * Read global settings |
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94 */ |
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95 public static void initStatic() { |
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96 String value = AccessController.doPrivileged( |
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97 new PrivilegedAction<String>() { |
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98 public String run() { |
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99 return Security.getProperty(BAD_POLICY_KEY); |
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100 } |
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101 }); |
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102 if (value != null) { |
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103 value = value.toLowerCase(Locale.ENGLISH); |
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104 String[] ss = value.split(":"); |
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105 if ("tryless".equals(ss[0])) { |
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106 if (ss.length > 1) { |
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107 String[] params = ss[1].split(","); |
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108 try { |
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109 int tmp0 = Integer.parseInt(params[0]); |
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110 if (params.length > 1) { |
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111 tryLessTimeout = Integer.parseInt(params[1]); |
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112 } |
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113 // Assign here in case of exception at params[1] |
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114 tryLessMaxRetries = tmp0; |
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115 } catch (NumberFormatException nfe) { |
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116 // Ignored. Please note that tryLess is recognized and |
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117 // used, parameters using default values |
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118 if (DEBUG) { |
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119 System.out.println("Invalid " + BAD_POLICY_KEY + |
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120 " parameter for tryLess: " + |
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121 value + ", use default"); |
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122 } |
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123 } |
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124 } |
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125 badPolicy = BpType.TRY_LESS; |
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126 } else if ("trylast".equals(ss[0])) { |
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127 badPolicy = BpType.TRY_LAST; |
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128 } else { |
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129 badPolicy = BpType.NONE; |
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130 } |
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131 } else { |
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132 badPolicy = BpType.NONE; |
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133 } |
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134 |
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135 |
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136 int timeout = -1; |
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137 int max_retries = -1; |
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138 int udf_pref_limit = -1; |
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139 |
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140 try { |
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141 Config cfg = Config.getInstance(); |
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142 String temp = cfg.getDefault("kdc_timeout", "libdefaults"); |
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143 timeout = parsePositiveIntString(temp); |
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144 temp = cfg.getDefault("max_retries", "libdefaults"); |
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145 max_retries = parsePositiveIntString(temp); |
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146 temp = cfg.getDefault("udp_preference_limit", "libdefaults"); |
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147 udf_pref_limit = parsePositiveIntString(temp); |
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148 } catch (Exception exc) { |
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149 // ignore any exceptions; use default values |
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150 if (DEBUG) { |
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151 System.out.println ("Exception in getting KDC communication " + |
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152 "settings, using default value " + |
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153 exc.getMessage()); |
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154 } |
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155 } |
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156 defaultKdcTimeout = timeout > 0 ? timeout : 30*1000; // 30 seconds |
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157 defaultKdcRetryLimit = |
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158 max_retries > 0 ? max_retries : Krb5.KDC_RETRY_LIMIT; |
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159 defaultUdpPrefLimit = udf_pref_limit; |
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160 |
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161 KdcAccessibility.reset(); |
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162 } |
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163 |
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164 protected byte[] obuf; |
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165 protected byte[] ibuf; |
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166 |
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167 /** |
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168 * Sends the provided data to the KDC of the specified realm. |
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169 * Returns the response from the KDC. |
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170 * Default realm/KDC is used if realm is null. |
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171 * @param realm the realm of the KDC where data is to be sent. |
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172 * @returns the kdc to which the AS request was sent to |
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173 * @exception InterruptedIOException if timeout expires |
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174 * @exception KrbException |
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175 */ |
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176 |
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177 public String send(String realm) |
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178 throws IOException, KrbException { |
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179 int udpPrefLimit = getRealmSpecificValue( |
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180 realm, "udp_preference_limit", defaultUdpPrefLimit); |
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181 |
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182 boolean useTCP = (udpPrefLimit > 0 && |
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183 (obuf != null && obuf.length > udpPrefLimit)); |
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184 |
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185 return (send(realm, useTCP)); |
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186 } |
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187 |
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188 public String send(String realm, boolean useTCP) |
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189 throws IOException, KrbException { |
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190 |
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191 if (obuf == null) |
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192 return null; |
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193 Exception savedException = null; |
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194 Config cfg = Config.getInstance(); |
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195 |
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196 if (realm == null) { |
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197 realm = cfg.getDefaultRealm(); |
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198 if (realm == null) { |
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199 throw new KrbException(Krb5.KRB_ERR_GENERIC, |
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200 "Cannot find default realm"); |
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201 } |
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202 } |
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203 |
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204 String kdcList = cfg.getKDCList(realm); |
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205 if (kdcList == null) { |
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206 throw new KrbException("Cannot get kdc for realm " + realm); |
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207 } |
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208 String tempKdc = null; // may include the port number also |
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209 for (String tmp: KdcAccessibility.list(kdcList)) { |
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210 tempKdc = tmp; |
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211 try { |
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212 send(realm,tempKdc,useTCP); |
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213 KdcAccessibility.removeBad(tempKdc); |
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214 break; |
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215 } catch (Exception e) { |
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216 if (DEBUG) { |
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217 System.out.println(">>> KrbKdcReq send: error trying " + |
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218 tempKdc); |
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219 e.printStackTrace(System.out); |
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220 } |
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221 KdcAccessibility.addBad(tempKdc); |
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222 savedException = e; |
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223 } |
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224 } |
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225 if (ibuf == null && savedException != null) { |
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226 if (savedException instanceof IOException) { |
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227 throw (IOException) savedException; |
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228 } else { |
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229 throw (KrbException) savedException; |
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230 } |
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231 } |
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232 return tempKdc; |
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233 } |
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234 |
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235 // send the AS Request to the specified KDC |
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236 |
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237 public void send(String realm, String tempKdc, boolean useTCP) |
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238 throws IOException, KrbException { |
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239 |
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240 if (obuf == null) |
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241 return; |
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242 |
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243 int port = Krb5.KDC_INET_DEFAULT_PORT; |
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244 int retries = getRealmSpecificValue( |
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245 realm, "max_retries", defaultKdcRetryLimit); |
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246 int timeout = getRealmSpecificValue( |
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247 realm, "kdc_timeout", defaultKdcTimeout); |
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248 if (badPolicy == BpType.TRY_LESS && |
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249 KdcAccessibility.isBad(tempKdc)) { |
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250 if (retries > tryLessMaxRetries) { |
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251 retries = tryLessMaxRetries; // less retries |
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252 } |
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253 if (timeout > tryLessTimeout) { |
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254 timeout = tryLessTimeout; // less time |
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255 } |
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256 } |
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257 |
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258 String kdc = null; |
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259 String portStr = null; |
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260 |
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261 if (tempKdc.charAt(0) == '[') { // Explicit IPv6 in [] |
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262 int pos = tempKdc.indexOf(']', 1); |
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263 if (pos == -1) { |
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264 throw new IOException("Illegal KDC: " + tempKdc); |
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265 } |
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266 kdc = tempKdc.substring(1, pos); |
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267 if (pos != tempKdc.length() - 1) { // with port number |
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268 if (tempKdc.charAt(pos+1) != ':') { |
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269 throw new IOException("Illegal KDC: " + tempKdc); |
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270 } |
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271 portStr = tempKdc.substring(pos+2); |
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272 } |
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273 } else { |
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274 int colon = tempKdc.indexOf(':'); |
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275 if (colon == -1) { // Hostname or IPv4 host only |
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276 kdc = tempKdc; |
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277 } else { |
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278 int nextColon = tempKdc.indexOf(':', colon+1); |
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279 if (nextColon > 0) { // >=2 ":", IPv6 with no port |
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280 kdc = tempKdc; |
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281 } else { // 1 ":", hostname or IPv4 with port |
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282 kdc = tempKdc.substring(0, colon); |
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283 portStr = tempKdc.substring(colon+1); |
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284 } |
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285 } |
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286 } |
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287 if (portStr != null) { |
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288 int tempPort = parsePositiveIntString(portStr); |
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289 if (tempPort > 0) |
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290 port = tempPort; |
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291 } |
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292 |
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293 if (DEBUG) { |
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294 System.out.println(">>> KrbKdcReq send: kdc=" + kdc |
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295 + (useTCP ? " TCP:":" UDP:") |
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296 + port + ", timeout=" |
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297 + timeout |
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298 + ", number of retries =" |
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299 + retries |
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300 + ", #bytes=" + obuf.length); |
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301 } |
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302 |
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303 KdcCommunication kdcCommunication = |
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304 new KdcCommunication(kdc, port, useTCP, timeout, retries, obuf); |
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305 try { |
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306 ibuf = AccessController.doPrivileged(kdcCommunication); |
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307 if (DEBUG) { |
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308 System.out.println(">>> KrbKdcReq send: #bytes read=" |
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309 + (ibuf != null ? ibuf.length : 0)); |
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310 } |
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311 } catch (PrivilegedActionException e) { |
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312 Exception wrappedException = e.getException(); |
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313 if (wrappedException instanceof IOException) { |
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314 throw (IOException) wrappedException; |
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315 } else { |
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316 throw (KrbException) wrappedException; |
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317 } |
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318 } |
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319 if (DEBUG) { |
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320 System.out.println(">>> KrbKdcReq send: #bytes read=" |
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321 + (ibuf != null ? ibuf.length : 0)); |
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322 } |
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323 } |
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324 |
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325 private static class KdcCommunication |
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326 implements PrivilegedExceptionAction<byte[]> { |
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327 |
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328 private String kdc; |
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329 private int port; |
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330 private boolean useTCP; |
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331 private int timeout; |
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332 private int retries; |
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333 private byte[] obuf; |
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334 |
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335 public KdcCommunication(String kdc, int port, boolean useTCP, |
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336 int timeout, int retries, byte[] obuf) { |
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337 this.kdc = kdc; |
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338 this.port = port; |
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339 this.useTCP = useTCP; |
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340 this.timeout = timeout; |
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341 this.retries = retries; |
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342 this.obuf = obuf; |
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343 } |
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344 |
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345 // The caller only casts IOException and KrbException so don't |
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346 // add any new ones! |
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347 |
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348 public byte[] run() throws IOException, KrbException { |
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349 |
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350 byte[] ibuf = null; |
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351 |
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352 if (useTCP) { |
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353 TCPClient kdcClient = new TCPClient(kdc, port); |
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354 if (DEBUG) { |
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355 System.out.println(">>> KDCCommunication: kdc=" + kdc |
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356 + " TCP:" |
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357 + port |
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358 + ", #bytes=" + obuf.length); |
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359 } |
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360 try { |
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361 /* |
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362 * Send the data to the kdc. |
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363 */ |
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364 kdcClient.send(obuf); |
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365 /* |
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366 * And get a response. |
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367 */ |
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368 ibuf = kdcClient.receive(); |
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369 } finally { |
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370 kdcClient.close(); |
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371 } |
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372 |
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373 } else { |
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374 // For each KDC we try defaultKdcRetryLimit times to |
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375 // get the response |
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376 for (int i=1; i <= retries; i++) { |
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377 UDPClient kdcClient = new UDPClient(kdc, port, timeout); |
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378 |
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379 if (DEBUG) { |
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380 System.out.println(">>> KDCCommunication: kdc=" + kdc |
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381 + (useTCP ? " TCP:":" UDP:") |
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382 + port + ", timeout=" |
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383 + timeout |
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384 + ",Attempt =" + i |
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385 + ", #bytes=" + obuf.length); |
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386 } |
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387 try { |
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388 /* |
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389 * Send the data to the kdc. |
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390 */ |
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391 |
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392 kdcClient.send(obuf); |
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393 |
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394 /* |
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395 * And get a response. |
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396 */ |
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397 try { |
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398 ibuf = kdcClient.receive(); |
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399 break; |
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400 } catch (SocketTimeoutException se) { |
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401 if (DEBUG) { |
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402 System.out.println ("SocketTimeOutException with " + |
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403 "attempt: " + i); |
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404 } |
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405 if (i == retries) { |
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406 ibuf = null; |
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407 throw se; |
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408 } |
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409 } |
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410 } finally { |
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411 kdcClient.close(); |
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412 } |
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413 } |
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414 } |
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415 return ibuf; |
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416 } |
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417 } |
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418 |
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419 /** |
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420 * Returns krb5.conf setting of {@code key} for a specfic realm, |
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421 * which can be: |
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422 * 1. defined in the sub-stanza for the given realm inside [realms], or |
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423 * 2. defined in [libdefaults], or |
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424 * 3. defValue |
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425 * @param realm the given realm in which the setting is requested. Returns |
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426 * the global setting if null |
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427 * @param key the key for the setting |
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428 * @param defValue default value |
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429 * @return a value for the key |
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430 */ |
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431 private int getRealmSpecificValue(String realm, String key, int defValue) { |
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432 int v = defValue; |
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433 |
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434 if (realm == null) return v; |
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435 |
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436 int temp = -1; |
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437 try { |
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438 String value = |
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439 Config.getInstance().getDefault(key, realm); |
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440 temp = parsePositiveIntString(value); |
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441 } catch (Exception exc) { |
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442 // Ignored, defValue will be picked up |
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443 } |
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444 |
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445 if (temp > 0) v = temp; |
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446 |
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447 return v; |
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448 } |
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449 |
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450 private static int parsePositiveIntString(String intString) { |
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451 if (intString == null) |
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452 return -1; |
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453 |
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454 int ret = -1; |
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455 |
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456 try { |
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457 ret = Integer.parseInt(intString); |
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458 } catch (Exception exc) { |
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459 return -1; |
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460 } |
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461 |
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462 if (ret >= 0) |
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463 return ret; |
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464 |
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465 return -1; |
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466 } |
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467 |
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468 /** |
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469 * Maintains a KDC accessible list. Unavailable KDCs are put into a |
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470 * blacklist, when a KDC in the blacklist is available, it's removed |
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471 * from there. No insertion order in the blacklist. |
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472 * |
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473 * There are two methods to deal with KDCs in the blacklist. 1. Only try |
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474 * them when there's no KDC not on the blacklist. 2. Still try them, but |
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475 * with lesser number of retries and smaller timeout value. |
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476 */ |
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477 static class KdcAccessibility { |
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478 // Known bad KDCs |
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479 private static Set<String> bads = new HashSet<String>(); |
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480 |
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481 private static synchronized void addBad(String kdc) { |
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482 if (DEBUG) { |
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483 System.out.println(">>> KdcAccessibility: add " + kdc); |
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484 } |
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485 bads.add(kdc); |
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486 } |
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487 |
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488 private static synchronized void removeBad(String kdc) { |
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489 if (DEBUG) { |
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490 System.out.println(">>> KdcAccessibility: remove " + kdc); |
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491 } |
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492 bads.remove(kdc); |
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493 } |
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494 |
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495 private static synchronized boolean isBad(String kdc) { |
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496 return bads.contains(kdc); |
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497 } |
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498 |
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499 private static synchronized void reset() { |
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500 if (DEBUG) { |
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501 System.out.println(">>> KdcAccessibility: reset"); |
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502 } |
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503 bads.clear(); |
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504 } |
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505 |
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506 // Returns a preferred KDC list by putting the bad ones at the end |
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507 private static synchronized String[] list(String kdcList) { |
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508 StringTokenizer st = new StringTokenizer(kdcList); |
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509 List<String> list = new ArrayList<String>(); |
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510 if (badPolicy == BpType.TRY_LAST) { |
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511 List<String> badkdcs = new ArrayList<String>(); |
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512 while (st.hasMoreTokens()) { |
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513 String t = st.nextToken(); |
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514 if (bads.contains(t)) badkdcs.add(t); |
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515 else list.add(t); |
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516 } |
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517 // Bad KDCs are put at last |
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518 list.addAll(badkdcs); |
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519 } else { |
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520 // All KDCs are returned in their original order, |
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521 // This include TRY_LESS and NONE |
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522 while (st.hasMoreTokens()) { |
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523 list.add(st.nextToken()); |
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524 } |
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525 } |
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526 return list.toArray(new String[list.size()]); |
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527 } |
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528 } |
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529 } |
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530 |
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