Source for javax.security.sasl.SaslServer

   1: /* SaslServer.java
   2:    Copyright (C) 2003, 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: /**
  42:  * <p>Performs SASL authentication as a server.</p>
  43:  *
  44:  * <p>A server such as an LDAP server gets an instance of this class in order to
  45:  * perform authentication defined by a specific SASL mechanism. Invoking methods
  46:  * on the <code>SaslServer</code> instance generates challenges corresponding to
  47:  * the SASL mechanism implemented by the <code>SaslServer</code> instance. As
  48:  * the authentication proceeds, the instance encapsulates the state of a SASL
  49:  * server's authentication exchange.</p>
  50:  *
  51:  * <p>Here's an example of how an LDAP server might use a <code>SaslServer</code>
  52:  * instance. It first gets an instance of a <code>SaslServer</code> for the SASL
  53:  * mechanism requested by the client:</p>
  54:  *
  55:  * <pre>
  56:  *SaslServer ss =
  57:  *      Sasl.createSaslServer(mechanism, "ldap", myFQDN, props, callbackHandler);
  58:  * </pre>
  59:  *
  60:  * <p>It can then proceed to use the server for authentication. For example,
  61:  * suppose the LDAP server received an LDAP BIND request containing the name of
  62:  * the SASL mechanism and an (optional) initial response. It then might use the
  63:  * server as follows:</p>
  64:  *
  65:  * <pre>
  66:  *while (!ss.isComplete()) {
  67:  *   try {
  68:  *      byte[] challenge = ss.evaluateResponse(response);
  69:  *      if (ss.isComplete()) {
  70:  *         status = ldap.sendBindResponse(mechanism, challenge, SUCCESS);
  71:  *      } else {
  72:  *         status = ldap.sendBindResponse(mechanism, challenge, SASL_BIND_IN_PROGRESS);
  73:  *         response = ldap.readBindRequest();
  74:  *      }
  75:  *   } catch (SaslException x) {
  76:  *      status = ldap.sendErrorResponse(x);
  77:  *      break;
  78:  *   }
  79:  *}
  80:  *if (ss.isComplete() && (status == SUCCESS)) {
  81:  *   String qop = (String) sc.getNegotiatedProperty(Sasl.QOP);
  82:  *   if (qop != null
  83:  *         && (qop.equalsIgnoreCase("auth-int")
  84:  *            || qop.equalsIgnoreCase("auth-conf"))) {
  85:  *      // Use SaslServer.wrap() and SaslServer.unwrap() for future
  86:  *      // communication with client
  87:  *      ldap.in = new SecureInputStream(ss, ldap.in);
  88:  *      ldap.out = new SecureOutputStream(ss, ldap.out);
  89:  *   }
  90:  *}
  91:  * </pre>
  92:  *
  93:  * @see Sasl
  94:  * @see SaslServerFactory
  95:  *
  96:  * @since 1.5
  97:  */
  98: public interface SaslServer
  99: {
 100: 
 101:   /**
 102:    * Returns the IANA-registered mechanism name of this SASL server (e.g.
 103:    * "CRAM-MD5", "GSSAPI").
 104:    *
 105:    * @return a non-null string representing the IANA-registered mechanism name.
 106:    */
 107:   String getMechanismName();
 108: 
 109:   /**
 110:    * Evaluates the response data and generates a challenge. If a response is
 111:    * received from the client during the authentication process, this method is
 112:    * called to prepare an appropriate next challenge to submit to the client.
 113:    * The challenge is <code>null</code> if the authentication has succeeded and
 114:    * no more challenge data is to be sent to the client. It is non-null if the
 115:    * authentication must be continued by sending a challenge to the client, or
 116:    * if the authentication has succeeded but challenge data needs to be
 117:    * processed by the client. {@link #isComplete()} should be called after each
 118:    * call to <code>evaluateResponse()</code>,to determine if any further
 119:    * response is needed from the client.
 120:    *
 121:    * @param response the non-null (but possibly empty) response sent by the
 122:    * client.
 123:    * @return the possibly <code>null</code> challenge to send to the client.
 124:    * It is <code>null</code> if the authentication has succeeded and there is
 125:    * no more challenge data to be sent to the client.
 126:    * @throws SaslException if an error occurred while processing the response
 127:    * or generating a challenge.
 128:    */
 129:   byte[] evaluateResponse(byte[] response) throws SaslException;
 130: 
 131:   /**
 132:    * Determines if the authentication exchange has completed. This method is
 133:    * typically called after each invocation of {@link #evaluateResponse(byte[])}
 134:    * to determine whether the authentication has completed successfully or
 135:    * should be continued.
 136:    *
 137:    * @return <code>true</code> if the authentication exchange has completed;
 138:    * <code>false</code> otherwise.
 139:    */
 140:   boolean isComplete();
 141: 
 142:   /**
 143:    * Reports the authorization ID in effect for the client of this session This
 144:    * method can only be called if {@link #isComplete()} returns <code>true</code>.
 145:    *
 146:    * @return the authorization ID of the client.
 147:    * @throws IllegalStateException if this authentication session has not
 148:    * completed.
 149:    */
 150:   String getAuthorizationID();
 151: 
 152:   /**
 153:    * <p>Unwraps a byte array received from the client. This method can be called
 154:    * only after the authentication exchange has completed (i.e., when
 155:    * {@link #isComplete()} returns <code>true</code>) and only if the
 156:    * authentication exchange has negotiated integrity and/or privacy as the
 157:    * quality of protection; otherwise, an {@link IllegalStateException} is
 158:    * thrown.</p>
 159:    *
 160:    * <p><code>incoming</code> is the contents of the SASL buffer as defined in
 161:    * RFC 2222 without the leading four octet field that represents the length.
 162:    * <code>offset</code> and <code>len</code> specify the portion of incoming
 163:    * to use.</p>
 164:    *
 165:    * @param incoming a non-null byte array containing the encoded bytes from
 166:    * the client.
 167:    * @param offset the starting position at <code>incoming</code> of the bytes
 168:    * to use.
 169:    * @param len the number of bytes from <code>incoming</code> to use.
 170:    * @return a non-null byte array containing the decoded bytes.
 171:    * @throws SaslException if <code>incoming</code> cannot be successfully
 172:    * unwrapped.
 173:    * @throws IllegalStateException if the authentication exchange has not
 174:    * completed, or if the negotiated quality of protection has neither
 175:    * integrity nor privacy.
 176:    */
 177:   byte[] unwrap(byte[] incoming, int offset, int len) throws SaslException;
 178: 
 179:   /**
 180:    * <p>Wraps a byte array to be sent to the client. This method can be called
 181:    * only after the authentication exchange has completed (i.e., when
 182:    * {@link #isComplete()} returns <code>true</code>) and only if the
 183:    * authentication exchange has negotiated integrity and/or privacy as the
 184:    * quality of protection; otherwise, an {@link IllegalStateException} is
 185:    * thrown.</p>
 186:    *
 187:    * <p>The result of this method will make up the contents of the SASL buffer
 188:    * as defined in RFC 2222 without the leading four octet field that
 189:    * represents the length. <code>offset</code> and <code>len</code> specify
 190:    * the portion of <code>outgoing</code> to use.
 191:    *
 192:    * @param outgoing a non-null byte array containing the bytes to encode.
 193:    * @param offset the starting position at <code>outgoing</code> of the bytes
 194:    * to use.
 195:    * @param len the number of bytes from <code>outgoing</code> to use.
 196:    * @return a non-null byte array containing the encoded bytes.
 197:    * @throws SaslException if <code>outgoing</code> cannot be successfully
 198:    * wrapped.
 199:    * @throws IllegalStateException if the authentication exchange has not
 200:    * completed, or if the negotiated quality of protection has neither
 201:    * integrity nor privacy.
 202:    */
 203:   byte[] wrap(byte[] outgoing, int offset, int len) throws SaslException;
 204: 
 205:   /**
 206:    * Retrieves the negotiated property. This method can be called only after
 207:    * the authentication exchange has completed (i.e., when
 208:    * {@link #isComplete()} returns <code>true</code>); otherwise, an
 209:    * {@link IllegalStateException} is thrown.
 210:    *
 211:    * @return the value of the negotiated property. If <code>null</code>, the
 212:    * property was not negotiated or is not applicable to this mechanism.
 213:    * @throws IllegalStateException if this authentication exchange has not
 214:    * completed.
 215:    */
 216:   Object getNegotiatedProperty(String propName);
 217: 
 218:   /**
 219:    * Disposes of any system resources or security-sensitive information the
 220:    * <code>SaslServer</code> might be using. Invoking this method invalidates
 221:    * the <code>SaslServer</code> instance. This method is idempotent.
 222:    *
 223:    * @throws SaslException if a problem was encountered while disposing of the
 224:    * resources.
 225:    */
 226:   void dispose() throws SaslException;
 227: }