1 /* Sasl.java -- 2 Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package javax.security.sasl; 40 41 import java.security.Provider; 42 import java.security.Security; 43 import java.util.Enumeration; 44 import java.util.HashSet; 45 import java.util.Iterator; 46 import java.util.Map; 47 import java.util.Vector; 48 49 import javax.security.auth.callback.CallbackHandler; 50 51 /** 52 * <p>A static class for creating SASL clients and servers.</p> 53 * 54 * <p>This class defines the policy of how to locate, load, and instantiate SASL 55 * clients and servers.</p> 56 * 57 * <p>For example, an application or library gets a SASL client instance by 58 * doing something like:</p> 59 * 60 * <pre> 61 *SaslClient sc = 62 * Sasl.createSaslClient(mechanisms, authorizationID, protocol, 63 * serverName, props, callbackHandler); 64 * </pre> 65 * 66 * <p>It can then proceed to use the instance to create an authenticated 67 * connection.</p> 68 * 69 * <p>Similarly, a server gets a SASL server instance by using code that looks 70 * as follows:</p> 71 * 72 * <pre> 73 *SaslServer ss = 74 * Sasl.createSaslServer(mechanism, protocol, serverName, props, 75 * callbackHandler); 76 * </pre> 77 * 78 * @since 1.5 79 */ 80 public class Sasl 81 { 82 83 // Constants and variables 84 // ------------------------------------------------------------------------- 85 86 /** 87 * <p>The name of a property that specifies the quality-of-protection to use. 88 * The property contains a comma-separated, ordered list of quality-of- 89 * protection values that the client or server is willing to support. A qop 90 * value is one of:</p> 91 * 92 * <ul> 93 * <li><code>"auth"</code> - authentication only,</li> 94 * <li><code>"auth-int"</code> - authentication plus integrity 95 * protection,</li> 96 * <li><code>"auth-conf"</code> - authentication plus integrity and 97 * confidentiality protection.</li> 98 * </ul> 99 * 100 * <p>The order of the list specifies the preference order of the client or 101 * server.</p> 102 * 103 * <p>If this property is absent, the default qop is <code>"auth"</code>.</p> 104 * 105 * <p>The value of this constant is <code>"javax.security.sasl.qop"</code>.</p> 106 */ 107 public static final String QOP = "javax.security.sasl.qop"; 108 109 /** 110 * <p>The name of a property that specifies the cipher strength to use. The 111 * property contains a comma-separated, ordered list of cipher strength 112 * values that the client or server is willing to support. A strength value 113 * is one of:</p> 114 * 115 * <ul> 116 * <li><code>"low"</code>,</li> 117 * <li><code>"medium"</code>,</li> 118 * <li><code>"high"</code>.</li> 119 * </ul> 120 * 121 * <p>The order of the list specifies the preference order of the client or 122 * server. An implementation should allow configuration of the meaning of 123 * these values. An application may use the Java Cryptography Extension (JCE) 124 * with JCE-aware mechanisms to control the selection of cipher suites that 125 * match the strength values.</p> 126 * 127 * <p>If this property is absent, the default strength is 128 * <code>"high,medium,low"</code>.</p> 129 * 130 * <p>The value of this constant is <code>"javax.security.sasl.strength"</code>. 131 * </p> 132 */ 133 public static final String STRENGTH = "javax.security.sasl.strength"; 134 135 /** 136 * <p>The name of a property that specifies whether the server must authenticate 137 * to the client. The property contains <code>"true"</code> if the server 138 * must authenticate the to client; <code>"false"</code> otherwise. The 139 * default is <code>"false"</code>.</p> 140 * 141 * <p>The value of this constant is 142 * <code>"javax.security.sasl.server.authentication"</code>.</p> 143 */ 144 public static final String SERVER_AUTH = "javax.security.sasl.server.authentication"; 145 146 /** 147 * <p>The name of a property that specifies the maximum size of the receive 148 * buffer in bytes of {@link SaslClient}/{@link SaslServer}. The property 149 * contains the string representation of an integer.</p> 150 * 151 * <p>If this property is absent, the default size is defined by the 152 * mechanism.</p> 153 * 154 * <p>The value of this constant is <code>"javax.security.sasl.maxbuffer"</code>. 155 * </p> 156 */ 157 public static final String MAX_BUFFER = "javax.security.sasl.maxbuffer"; 158 159 /** 160 * <p>The name of a property that specifies the maximum size of the raw send 161 * buffer in bytes of {@link SaslClient}/{@link SaslServer}. The property 162 * contains the string representation of an integer. The value of this 163 * property is negotiated between the client and server during the 164 * authentication exchange.</p> 165 * 166 * <p>The value of this constant is <code>"javax.security.sasl.rawsendsize"</code>. 167 * </p> 168 */ 169 public static final String RAW_SEND_SIZE = "javax.security.sasl.rawsendsize"; 170 171 /** 172 * <p>The name of a property that specifies whether mechanisms susceptible 173 * to simple plain passive attacks (e.g., "PLAIN") are not permitted. The 174 * property contains <code>"true"</code> if such mechanisms are not 175 * permitted; <code>"false"</code> if such mechanisms are permitted. The 176 * default is <code>"false"</code>.</p> 177 * 178 * <p>The value of this constant is <code>"javax.security.sasl.policy.noplaintext"</code>. 179 * </p> 180 */ 181 public static final String POLICY_NOPLAINTEXT = "javax.security.sasl.policy.noplaintext"; 182 183 /** 184 * <p>The name of a property that specifies whether mechanisms susceptible to 185 * active (non-dictionary) attacks are not permitted. The property contains 186 * <code>"true"</code> if mechanisms susceptible to active attacks are not 187 * permitted; <code>"false"</code> if such mechanisms are permitted. The 188 * default is <code>"false"</code>.</p> 189 * 190 * <p>The value of this constant is <code>"javax.security.sasl.policy.noactive"</code>. 191 * </p> 192 */ 193 public static final String POLICY_NOACTIVE = "javax.security.sasl.policy.noactive"; 194 195 /** 196 * <p>The name of a property that specifies whether mechanisms susceptible to 197 * passive dictionary attacks are not permitted. The property contains 198 * <code>"true"</code> if mechanisms susceptible to dictionary attacks are 199 * not permitted; <code>"false"</code> if such mechanisms are permitted. The 200 * default is <code>"false"</code>.</p> 201 * 202 * <p>The value of this constant is <code>"javax.security.sasl.policy.nodictionary"</code>. 203 * </p> 204 */ 205 public static final String POLICY_NODICTIONARY = "javax.security.sasl.policy.nodictionary"; 206 207 /** 208 * <p>The name of a property that specifies whether mechanisms that accept 209 * anonymous login are not permitted. The property contains <code>"true"</code> 210 * if mechanisms that accept anonymous login are not permitted; <code>"false" 211 * </code> if such mechanisms are permitted. The default is <code>"false"</code>. 212 * </p> 213 * 214 * <p>The value of this constant is <code>"javax.security.sasl.policy.noanonymous"</code>. 215 * </p> 216 */ 217 public static final String POLICY_NOANONYMOUS = "javax.security.sasl.policy.noanonymous"; 218 219 /** 220 * The name of a property that specifies whether mechanisms that implement 221 * forward secrecy between sessions are required. Forward secrecy means that 222 * breaking into one session will not automatically provide information for 223 * breaking into future sessions. The property contains <code>"true"</code> 224 * if mechanisms that implement forward secrecy between sessions are 225 * required; <code>"false"</code> if such mechanisms are not required. The 226 * default is <code>"false"</code>. 227 * 228 * <p>The value of this constant is <code>"javax.security.sasl.policy.forward"</code>. 229 * </p> 230 */ 231 public static final String POLICY_FORWARD_SECRECY = "javax.security.sasl.policy.forward"; 232 233 /** 234 * The name of a property that specifies whether mechanisms that pass client 235 * credentials are required. The property contains <code>"true"</code> if 236 * mechanisms that pass client credentials are required; <code>"false"</code> 237 * if such mechanisms are not required. The default is <code>"false"</code>. 238 * 239 * <p>The value of this constant is <code>"javax.security.sasl.policy.credentials"</code>. 240 * </p> 241 */ 242 public static final String POLICY_PASS_CREDENTIALS = "javax.security.sasl.policy.credentials"; 243 244 /** 245 * <p>The name of a property that specifies whether to reuse previously 246 * authenticated session information. The property contains <code>"true"</code> 247 * if the mechanism implementation may attempt to reuse previously 248 * authenticated session information; it contains <code>"false"</code> if the 249 * implementation must not reuse previously authenticated session information. 250 * A setting of <code>"true"</code> serves only as a hint; it does not 251 * necessarily entail actual reuse because reuse might not be possible due to 252 * a number of reasons, including, but not limited to, lack of mechanism 253 * support for reuse, expiration of reusable information, and the peer's 254 * refusal to support reuse. The property's default value is <code>"false"</code>. 255 * </p> 256 * 257 * <p>The value of this constant is <code>"javax.security.sasl.reuse"</code>. 258 * Note that all other parameters and properties required to create a SASL 259 * client/server instance must be provided regardless of whether this 260 * property has been supplied. That is, you cannot supply any less 261 * information in anticipation of reuse. Mechanism implementations that 262 * support reuse might allow customization of its implementation for factors 263 * such as cache size, timeouts, and criteria for reuseability. Such 264 * customizations are implementation-dependent.</p> 265 */ 266 public static final String REUSE = "javax.security.sasl.reuse"; 267 268 private static final String CLIENT_FACTORY_SVC = "SaslClientFactory."; 269 private static final String SERVER_FACTORY_SVC = "SaslServerFactory."; 270 private static final String ALIAS = "Alg.Alias."; 271 272 // Constructor(s) 273 // ------------------------------------------------------------------------- 274 Sasl()275 private Sasl() 276 { 277 super(); 278 } 279 280 // Class methods 281 // ------------------------------------------------------------------------- 282 283 /** 284 * Creates a {@link SaslClient} for the specified mechanism. 285 * 286 * <p>This method uses the JCA Security Provider Framework, described in the 287 * "Java Cryptography Architecture API Specification & Reference", for 288 * locating and selecting a {@link SaslClient} implementation.</p> 289 * 290 * <p>First, it obtains an ordered list of {@link SaslClientFactory} 291 * instances from the registered security providers for the 292 * <code>"SaslClientFactory"</code> service and the specified mechanism. It 293 * then invokes <code>createSaslClient()</code> on each factory instance on 294 * the list until one produces a non-null {@link SaslClient} instance. It 295 * returns the non-null {@link SaslClient} instance, or <code>null</code> if 296 * the search fails to produce a non-null {@link SaslClient} instance.</p> 297 * 298 * <p>A security provider for <code>SaslClientFactory</code> registers with 299 * the JCA Security Provider Framework keys of the form:</p> 300 * 301 * <pre> 302 * SaslClientFactory.mechanism_name 303 * </pre> 304 * 305 * <p>and values that are class names of implementations of {@link 306 * SaslClientFactory}.</p> 307 * 308 * <p>For example, a provider that contains a factory class, 309 * <code>com.wiz.sasl.digest.ClientFactory</code>, that supports the 310 * <code>"DIGEST-MD5"</code> mechanism would register the following entry 311 * with the JCA:</p> 312 * 313 * <pre> 314 * SaslClientFactory.DIGEST-MD5 com.wiz.sasl.digest.ClientFactory 315 * </pre> 316 * 317 * <p>See the "Java Cryptography Architecture API Specification & 318 * Reference" for information about how to install and configure security 319 * service providers.</p> 320 * 321 * @param mechanisms the non-null list of mechanism names to try. Each is the 322 * IANA-registered name of a SASL mechanism. (e.g. "GSSAPI", "CRAM-MD5"). 323 * @param authorizationID the possibly <code>null</code> protocol-dependent 324 * identification to be used for authorization. If <code>null</code> or 325 * empty, the server derives an authorization ID from the client's 326 * authentication credentials. When the SASL authentication completes 327 * successfully, the specified entity is granted access. 328 * @param protocol the non-null string name of the protocol for which the 329 * authentication is being performed (e.g. "ldap"). 330 * @param serverName the non-null fully-qualified host name of the server to 331 * authenticate to. 332 * @param props the possibly null set of properties used to select the SASL 333 * mechanism and to configure the authentication exchange of the selected 334 * mechanism. For example, if props contains the {@link Sasl#POLICY_NOPLAINTEXT} 335 * property with the value <code>"true"</code>, then the selected SASL 336 * mechanism must not be susceptible to simple plain passive attacks. In 337 * addition to the standard properties declared in this class, other, 338 * possibly mechanism-specific, properties can be included. Properties not 339 * relevant to the selected mechanism are ignored. 340 * @param cbh the possibly <code>null</code> callback handler to used by the 341 * SASL mechanisms to get further information from the application/library to 342 * complete the authentication. For example, a SASL mechanism might require 343 * the authentication ID, password and realm from the caller. The 344 * authentication ID is requested by using a 345 * {@link javax.security.auth.callback.NameCallback}. The password is 346 * requested by using a {@link javax.security.auth.callback.PasswordCallback}. 347 * The realm is requested by using a {@link RealmChoiceCallback} if there is 348 * a list of realms to choose from, and by using a {@link RealmCallback} if 349 * the realm must be entered. 350 * @return a possibly <code>null</code> {@link SaslClient} created using the 351 * parameters supplied. If <code>null</code>, the method could not find a 352 * {@link SaslClientFactory} that will produce one. 353 * @throws SaslException if a {@link SaslClient} cannot be created because 354 * of an error. 355 */ createSaslClient(String[] mechanisms, String authorizationID, String protocol, String serverName, Map props, CallbackHandler cbh)356 public static SaslClient createSaslClient(String[] mechanisms, 357 String authorizationID, 358 String protocol, 359 String serverName, Map props, 360 CallbackHandler cbh) 361 throws SaslException 362 { 363 if (mechanisms == null) 364 { 365 return null; 366 } 367 Provider[] providers = Security.getProviders(); 368 if (providers == null || providers.length == 0) 369 { 370 return null; 371 } 372 373 SaslClient result = null; 374 SaslClientFactory factory = null; 375 String m, clazz = null, upper, alias; 376 int j; 377 Provider p; 378 for (int i = 0; i < mechanisms.length; i++) 379 { 380 m = mechanisms[i]; 381 if (m == null) 382 continue; 383 for (j = 0; j < providers.length; j++) 384 { 385 p = providers[j]; 386 if (p != null) 387 { 388 // try the name as is 389 clazz = p.getProperty(CLIENT_FACTORY_SVC + m); 390 if (clazz == null) // try all uppercase 391 { 392 upper = m.toUpperCase(); 393 clazz = p.getProperty(CLIENT_FACTORY_SVC + upper); 394 if (clazz == null) // try if it's an alias 395 { 396 alias = p.getProperty(ALIAS + CLIENT_FACTORY_SVC + m); 397 if (alias == null) // try all-uppercase alias name 398 { 399 alias = p.getProperty(ALIAS + CLIENT_FACTORY_SVC + upper); 400 if (alias == null) // spit the dummy 401 continue; 402 } 403 clazz = p.getProperty(CLIENT_FACTORY_SVC + alias); 404 } 405 } 406 if (clazz == null) 407 continue; 408 else 409 clazz = clazz.trim(); 410 } 411 412 try 413 { 414 result = null; 415 factory = (SaslClientFactory) Class.forName(clazz).newInstance(); 416 result = factory.createSaslClient(mechanisms, authorizationID, 417 protocol, serverName, props, cbh); 418 } 419 catch (ClassCastException ignored) // ignore instantiation exceptions 420 { 421 } 422 catch (ClassNotFoundException ignored) 423 { 424 } 425 catch (InstantiationException ignored) 426 { 427 } 428 catch (IllegalAccessException ignored) 429 { 430 } 431 if (result != null) 432 return result; 433 } 434 } 435 return null; 436 } 437 438 /** 439 * Gets an enumeration of known factories for producing a {@link SaslClient} 440 * instance. This method uses the same sources for locating factories as 441 * <code>createSaslClient()</code>. 442 * 443 * @return a non-null {@link Enumeration} of known factories for producing a 444 * {@link SaslClient} instance. 445 * @see #createSaslClient(String[],String,String,String,Map,CallbackHandler) 446 */ getSaslClientFactories()447 public static Enumeration getSaslClientFactories() 448 { 449 Vector result = new Vector(); 450 HashSet names = new HashSet(); 451 Provider[] providers = Security.getProviders(); 452 Iterator it; 453 if (providers != null) 454 { 455 Provider p; 456 String key; 457 for (int i = 0; i < providers.length; i++) 458 { 459 p = providers[i]; 460 for (it = p.keySet().iterator(); it.hasNext(); ) 461 { 462 key = (String) it.next(); 463 // add key's binding (a) it is a class of a client factory, 464 // and (b) the key does not include blanks 465 if (key.startsWith(CLIENT_FACTORY_SVC) && key.indexOf(" ") == -1) 466 { 467 names.add(p.getProperty(key)); 468 break; 469 } 470 } 471 } 472 } 473 // we have the factory class names in names; instantiate and enumerate 474 String c; 475 for (it = names.iterator(); it.hasNext(); ) 476 { 477 c = (String) it.next(); 478 try 479 { 480 SaslClientFactory f = (SaslClientFactory) Class.forName(c).newInstance(); 481 if (f != null) 482 result.add(f); 483 } catch (ClassCastException ignored) { // ignore instantiation exceptions 484 } catch (ClassNotFoundException ignored) { 485 } catch (InstantiationException ignored) { 486 } catch (IllegalAccessException ignored) { 487 } 488 } 489 490 return result.elements(); 491 } 492 493 /** 494 * Creates a {@link SaslServer} for the specified mechanism. 495 * 496 * <p>This method uses the JCA Security Provider Framework, described in the 497 * "Java Cryptography Architecture API Specification & Reference", for 498 * locating and selecting a SaslServer implementation.</p> 499 * 500 * <p>First, it obtains an ordered list of {@link SaslServerFactory} 501 * instances from the registered security providers for the 502 * <code>"SaslServerFactory"</code> service and the specified mechanism. It 503 * then invokes <code>createSaslServer()</code> on each factory instance on 504 * the list until one produces a non-null {@link SaslServer} instance. It 505 * returns the non-null {@link SaslServer} instance, or <code>null</code> if 506 * the search fails to produce a non-null {@link SaslServer} instance.</p> 507 * 508 * <p>A security provider for {@link SaslServerFactory} registers with the 509 * JCA Security Provider Framework keys of the form:</p> 510 * 511 * <pre> 512 * SaslServerFactory.mechanism_name 513 * </pre> 514 * 515 * <p>and values that are class names of implementations of {@link 516 * SaslServerFactory}.</p> 517 * 518 * <p>For example, a provider that contains a factory class, 519 * <code>com.wiz.sasl.digest.ServerFactory</code>, that supports the 520 * <code>"DIGEST-MD5"</code> mechanism would register the following entry 521 * with the JCA:</p> 522 * 523 * <pre> 524 * SaslServerFactory.DIGEST-MD5 com.wiz.sasl.digest.ServerFactory 525 * </pre> 526 * 527 * <p>See the "Java Cryptography Architecture API Specification & 528 * Reference" for information about how to install and configure security 529 * service providers.</p> 530 * 531 * @param mechanism the non-null mechanism name. It must be an 532 * IANA-registered name of a SASL mechanism. (e.g. "GSSAPI", "CRAM-MD5"). 533 * @param protocol the non-null string name of the protocol for which the 534 * authentication is being performed (e.g. "ldap"). 535 * @param serverName the non-null fully qualified host name of the server. 536 * @param props the possibly <code>null</code> set of properties used to 537 * select the SASL mechanism and to configure the authentication exchange of 538 * the selected mechanism. For example, if props contains the {@link 539 * Sasl#POLICY_NOPLAINTEXT} property with the value <code>"true"</code>, then 540 * the selected SASL mechanism must not be susceptible to simple plain 541 * passive attacks. In addition to the standard properties declared in this 542 * class, other, possibly mechanism-specific, properties can be included. 543 * Properties not relevant to the selected mechanism are ignored. 544 * @param cbh the possibly <code>null</code> callback handler to used by the 545 * SASL mechanisms to get further information from the application/library to 546 * complete the authentication. For example, a SASL mechanism might require 547 * the authentication ID, password and realm from the caller. The 548 * authentication ID is requested by using a 549 * {@link javax.security.auth.callback.NameCallback}. The password is 550 * requested by using a {@link javax.security.auth.callback.PasswordCallback}. 551 * The realm is requested by using a {@link RealmChoiceCallback} if there is 552 * a list of realms to choose from, and by using a {@link RealmCallback} if 553 * the realm must be entered. 554 * @return a possibly <code>null</code> {@link SaslServer} created using the 555 * parameters supplied. If <code>null</code>, the method cannot find a 556 * {@link SaslServerFactory} instance that will produce one. 557 * @throws SaslException if a {@link SaslServer} instance cannot be created 558 * because of an error. 559 */ createSaslServer(String mechanism, String protocol, String serverName, Map props, CallbackHandler cbh)560 public static SaslServer createSaslServer(String mechanism, String protocol, 561 String serverName, 562 Map props, CallbackHandler cbh) 563 throws SaslException 564 { 565 if (mechanism == null) 566 return null; 567 Provider[] providers = Security.getProviders(); 568 if (providers == null || providers.length == 0) 569 return null; 570 571 SaslServer result = null; 572 SaslServerFactory factory = null; 573 String clazz = null, upper, alias = null; 574 int j; 575 Provider p; 576 for (j = 0; j < providers.length; j++) 577 { 578 p = providers[j]; 579 if (p != null) 580 { 581 // try the name as is 582 clazz = p.getProperty(SERVER_FACTORY_SVC + mechanism); 583 if (clazz == null) // try all uppercase 584 { 585 upper = mechanism.toUpperCase(); 586 clazz = p.getProperty(SERVER_FACTORY_SVC + upper); 587 if (clazz == null) // try if it's an alias 588 { 589 alias = p.getProperty(ALIAS + SERVER_FACTORY_SVC + mechanism); 590 if (alias == null) // try all-uppercase alias name 591 { 592 alias = p.getProperty(ALIAS + SERVER_FACTORY_SVC + upper); 593 if (alias == null) // spit the dummy 594 continue; 595 } 596 } 597 clazz = p.getProperty(SERVER_FACTORY_SVC + alias); 598 } 599 } 600 if (clazz == null) 601 continue; 602 else 603 clazz = clazz.trim(); 604 605 try 606 { 607 result = null; 608 factory = (SaslServerFactory) Class.forName(clazz).newInstance(); 609 result = 610 factory.createSaslServer(mechanism, protocol, serverName, props, cbh); 611 } 612 catch (ClassCastException ignored) // ignore instantiation exceptions 613 { 614 } 615 catch (ClassNotFoundException ignored) 616 { 617 } 618 catch (InstantiationException ignored) 619 { 620 } 621 catch (IllegalAccessException ignored) 622 { 623 } 624 if (result != null) 625 return result; 626 } 627 return null; 628 } 629 630 /** 631 * Gets an enumeration of known factories for producing a {@link SaslServer} 632 * instance. This method uses the same sources for locating factories as 633 * <code>createSaslServer()</code>. 634 * 635 * @return a non-null {@link Enumeration} of known factories for producing a 636 * {@link SaslServer} instance. 637 * @see #createSaslServer(String,String,String,Map,CallbackHandler) 638 */ getSaslServerFactories()639 public static Enumeration getSaslServerFactories() 640 { 641 Vector result = new Vector(); 642 HashSet names = new HashSet(); 643 Provider[] providers = Security.getProviders(); 644 Iterator it; 645 if (providers != null) 646 { 647 Provider p; 648 String key; 649 for (int i = 0; i < providers.length; i++) 650 { 651 p = providers[i]; 652 for (it = p.keySet().iterator(); it.hasNext(); ) 653 { 654 key = (String) it.next(); 655 // add key's binding (a) it is a class of a server factory, 656 // and (b) the key does not include blanks 657 if (key.startsWith(SERVER_FACTORY_SVC) && key.indexOf(" ") == -1) 658 { 659 names.add(p.getProperty(key)); 660 break; 661 } 662 } 663 } 664 } 665 // we have the factory class names in names; instantiate and enumerate 666 String c; 667 for (it = names.iterator(); it.hasNext(); ) 668 { 669 c = (String) it.next(); 670 try 671 { 672 SaslServerFactory f = (SaslServerFactory) Class.forName(c).newInstance(); 673 if (f != null) 674 result.add(f); 675 } 676 catch (ClassCastException ignored) // ignore instantiation exceptions 677 { 678 } 679 catch (ClassNotFoundException ignored) 680 { 681 } 682 catch (InstantiationException ignored) 683 { 684 } 685 catch (IllegalAccessException ignored) 686 { 687 } 688 } 689 690 return result.elements(); 691 } 692 } 693