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javax.security.sasl

Interface SaslServer

public interface SaslServer
Performs SASL authentication as a server.

A server such as an LDAP server gets an instance of this class in order to perform authentication defined by a specific SASL mechanism. Invoking methods on the SaslServer instance generates challenges corresponding to the SASL mechanism implemented by the SaslServer instance. As the authentication proceeds, the instance encapsulates the state of a SASL server's authentication exchange.

Here's an example of how an LDAP server might use a SaslServer instance. It first gets an instance of a SaslServer for the SASL mechanism requested by the client: 

SaslServer ss =
      Sasl.createSaslServer(mechanism, "ldap", myFQDN, props, callbackHandler);

It can then proceed to use the server for authentication. For example, suppose the LDAP server received an LDAP BIND request containing the name of the SASL mechanism and an (optional) initial response. It then might use the server as follows: 

while (!ss.isComplete()) {
   try {
      byte[] challenge = ss.evaluateResponse(response);
      if (ss.isComplete()) {
         status = ldap.sendBindResponse(mechanism, challenge, SUCCESS);
      } else {
         status = ldap.sendBindResponse(mechanism, challenge, SASL_BIND_IN_PROGRESS);
         response = ldap.readBindRequest();
      }
   } catch (SaslException x) {
      status = ldap.sendErrorResponse(x);
      break;
   }
}
if (ss.isComplete() && (status == SUCCESS)) {
   String qop = (String) sc.getNegotiatedProperty(Sasl.QOP);
   if (qop != null
         && (qop.equalsIgnoreCase("auth-int")
            || qop.equalsIgnoreCase("auth-conf"))) {
      // Use SaslServer.wrap() and SaslServer.unwrap() for future
      // communication with client
      ldap.in = new SecureInputStream(ss, ldap.in);
      ldap.out = new SecureOutputStream(ss, ldap.out);
   }
}
Since:
1.5
See Also:
Sasl, SaslServerFactory

Method Summary

void
dispose()
Disposes of any system resources or security-sensitive information the SaslServer might be using.
byte[]
evaluateResponse(byte[] response)
Evaluates the response data and generates a challenge.
String
getAuthorizationID()
Reports the authorization ID in effect for the client of this session This method can only be called if isComplete() returns true.
String
getMechanismName()
Returns the IANA-registered mechanism name of this SASL server (e.g.
Object
getNegotiatedProperty(String propName)
Retrieves the negotiated property.
boolean
isComplete()
Determines if the authentication exchange has completed.
byte[]
unwrap(byte[] incoming, int offset, int len)
Unwraps a byte array received from the client.
byte[]
wrap(byte[] outgoing, int offset, int len)
Wraps a byte array to be sent to the client.

Method Details

dispose

public void dispose()
            throws SaslException
Disposes of any system resources or security-sensitive information the SaslServer might be using. Invoking this method invalidates the SaslServer instance. This method is idempotent.
Throws:
SaslException - if a problem was encountered while disposing of the resources.

evaluateResponse

public byte[] evaluateResponse(byte[] response)
            throws SaslException
Evaluates the response data and generates a challenge. If a response is received from the client during the authentication process, this method is called to prepare an appropriate next challenge to submit to the client. The challenge is null if the authentication has succeeded and no more challenge data is to be sent to the client. It is non-null if the authentication must be continued by sending a challenge to the client, or if the authentication has succeeded but challenge data needs to be processed by the client. isComplete() should be called after each call to evaluateResponse(),to determine if any further response is needed from the client.
Parameters:
response - the non-null (but possibly empty) response sent by the client.
Returns:
the possibly null challenge to send to the client. It is null if the authentication has succeeded and there is no more challenge data to be sent to the client.
Throws:
SaslException - if an error occurred while processing the response or generating a challenge.

getAuthorizationID

public String getAuthorizationID()
Reports the authorization ID in effect for the client of this session This method can only be called if isComplete() returns true.
Returns:
the authorization ID of the client.
Throws:
IllegalStateException - if this authentication session has not completed.

getMechanismName

public String getMechanismName()
Returns the IANA-registered mechanism name of this SASL server (e.g. "CRAM-MD5", "GSSAPI").
Returns:
a non-null string representing the IANA-registered mechanism name.

getNegotiatedProperty

public Object getNegotiatedProperty(String propName)
Retrieves the negotiated property. This method can be called only after the authentication exchange has completed (i.e., when isComplete() returns true); otherwise, an IllegalStateException is thrown.
Returns:
the value of the negotiated property. If null, the property was not negotiated or is not applicable to this mechanism.
Throws:
IllegalStateException - if this authentication exchange has not completed.

isComplete

public boolean isComplete()
Determines if the authentication exchange has completed. This method is typically called after each invocation of evaluateResponse(byte[]) to determine whether the authentication has completed successfully or should be continued.
Returns:
true if the authentication exchange has completed; false otherwise.

unwrap

public byte[] unwrap(byte[] incoming,
                     int offset,
                     int len)
            throws SaslException
Unwraps a byte array received from the client. This method can be called only after the authentication exchange has completed (i.e., when isComplete() returns true) and only if the authentication exchange has negotiated integrity and/or privacy as the quality of protection; otherwise, an IllegalStateException is thrown.

incoming is the contents of the SASL buffer as defined in RFC 2222 without the leading four octet field that represents the length. offset and len specify the portion of incoming to use.

Parameters:
incoming - a non-null byte array containing the encoded bytes from the client.
offset - the starting position at incoming of the bytes to use.
len - the number of bytes from incoming to use.
Returns:
a non-null byte array containing the decoded bytes.
Throws:
SaslException - if incoming cannot be successfully unwrapped.
IllegalStateException - if the authentication exchange has not completed, or if the negotiated quality of protection has neither integrity nor privacy.

wrap

public byte[] wrap(byte[] outgoing,
                   int offset,
                   int len)
            throws SaslException
Wraps a byte array to be sent to the client. This method can be called only after the authentication exchange has completed (i.e., when isComplete() returns true) and only if the authentication exchange has negotiated integrity and/or privacy as the quality of protection; otherwise, an IllegalStateException is thrown.

The result of this method will make up the contents of the SASL buffer as defined in RFC 2222 without the leading four octet field that represents the length. offset and len specify the portion of outgoing to use.

Parameters:
outgoing - a non-null byte array containing the bytes to encode.
offset - the starting position at outgoing of the bytes to use.
len - the number of bytes from outgoing to use.
Returns:
a non-null byte array containing the encoded bytes.
Throws:
SaslException - if outgoing cannot be successfully wrapped.
IllegalStateException - if the authentication exchange has not completed, or if the negotiated quality of protection has neither integrity nor privacy.
SaslServer.java Copyright (C) 2003, 2005, Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

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