OpenJDK 1.23 · javax.security.sasl.SaslClient · APIdia, the JavaDoc alternative

Performs SASL authentication as a client.

A protocol library such as one for LDAP gets an instance of this class in order to perform authentication defined by a specific SASL mechanism. Invoking methods on the SaslClient instance process challenges and create responses according to the SASL mechanism implemented by the SaslClient. As the authentication proceeds, the instance encapsulates the state of a SASL client's authentication exchange.

Here's an example of how an LDAP library might use a SaslClient. It first gets an instance of a SaslClient:

SaslClient sc = Sasl.createSaslClient(mechanisms,
    authorizationId, protocol, serverName, props, callbackHandler);

It can then proceed to use the client for authentication. For example, an LDAP library might use the client as follows:

// Get initial response and send to server
byte[] response = (sc.hasInitialResponse() ? sc.evaluateChallenge(new byte[0]) :
    null);
LdapResult res = ldap.sendBindRequest(dn, sc.getName(), response);
while (!sc.isComplete() &&
    (res.status == SASL_BIND_IN_PROGRESS || res.status == SUCCESS)) {
    response = sc.evaluateChallenge(res.getBytes());
    if (res.status == SUCCESS) {
        // we're done; don't expect to send another BIND
        if (response != null) {
            throw new SaslException(
                "Protocol error: attempting to send response after completion");
        }
        break;
    }
    res = ldap.sendBindRequest(dn, sc.getName(), response);
}
if (sc.isComplete() && res.status == SUCCESS) {
   String qop = (String) sc.getNegotiatedProperty(Sasl.QOP);
   if (qop != null
       && (qop.equalsIgnoreCase("auth-int")
           || qop.equalsIgnoreCase("auth-conf"))) {

     // Use SaslClient.wrap() and SaslClient.unwrap() for future
     // communication with server
     ldap.in = new SecureInputStream(sc, ldap.in);
     ldap.out = new SecureOutputStream(sc, ldap.out);
   }
}

If the mechanism has an initial response, the library invokes evaluateChallenge() with an empty challenge and to get initial response. Protocols such as IMAP4, which do not include an initial response with their first authentication command to the server, initiates the authentication without first calling hasInitialResponse() or evaluateChallenge(). When the server responds to the command, it sends an initial challenge. For a SASL mechanism in which the client sends data first, the server should have issued a challenge with no data. This will then result in a call (on the client) to evaluateChallenge() with an empty challenge.

Method Summary

Modifier and Type	Method and Description
public void	dispose() Disposes of any system resources or security-sensitive information the SaslClient might be using.
public byte[]	Returns: The possibly null response to send to the server. It is null if the challenge accompanied a "SUCCESS" status and the challenge only contains data for the client to update its state and no response needs to be sent to the server. The response is a zero-length byte array if the client is to send a response with no data. evaluateChallenge(byte[] The non-null challenge sent from the server. The challenge array may have zero length. challenge) Evaluates the challenge data and generates a response.
public String	Returns: A non-null string representing the IANA-registered mechanism name. getMechanismName() Returns the IANA-registered mechanism name of this SASL client.
public Object	Returns: The value of the negotiated property. If null, the property was not negotiated or is not applicable to this mechanism. getNegotiatedProperty(String The non-null property name. propName) Retrieves the negotiated property.
public boolean	Returns: true if this mechanism has an initial response. hasInitialResponse() Determines whether this mechanism has an optional initial response.
public boolean	Returns: true if the authentication exchange has completed; false otherwise. isComplete() Determines whether the authentication exchange has completed.
public byte[]	Returns: A non-null byte array containing the decoded bytes. unwrap(byte[] A non-null byte array containing the encoded bytes from the server. incoming, int The starting position at `incoming` of the bytes to use. offset, int The number of bytes from `incoming` to use. len) Unwraps a byte array received from the server.
public byte[]	Returns: A non-null byte array containing the encoded bytes. wrap(byte[] A non-null byte array containing the bytes to encode. outgoing, int The starting position at `outgoing` of the bytes to use. offset, int The number of bytes from `outgoing` to use. len) Wraps a byte array to be sent to the server.

Method Detail

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

dispose

back to summary

public void dispose() throws SaslException

Disposes of any system resources or security-sensitive information the SaslClient might be using. Invoking this method invalidates the SaslClient instance. This method is idempotent.

Exceptions

SaslException:: If a problem was encountered while disposing the resources.

evaluateChallenge	back to summary
public byte[] evaluateChallenge(byte[] challenge) throws SaslException Evaluates the challenge data and generates a response. If a challenge is received from the server during the authentication process, this method is called to prepare an appropriate next response to submit to the server. Parameters challenge:byte[] The non-null challenge sent from the server. The challenge array may have zero length. Returns:byte[] The possibly null response to send to the server. It is null if the challenge accompanied a "SUCCESS" status and the challenge only contains data for the client to update its state and no response needs to be sent to the server. The response is a zero-length byte array if the client is to send a response with no data. Exceptions SaslException: If an error occurred while processing the challenge or generating a response.

evaluateChallenge

back to summary

public byte[] evaluateChallenge(byte[] challenge) throws SaslException

Evaluates the challenge data and generates a response. If a challenge is received from the server during the authentication process, this method is called to prepare an appropriate next response to submit to the server.

Parameters

challenge:byte[]: The non-null challenge sent from the server. The challenge array may have zero length.

Returns:byte[]

The possibly null response to send to the server. It is null if the challenge accompanied a "SUCCESS" status and the challenge only contains data for the client to update its state and no response needs to be sent to the server. The response is a zero-length byte array if the client is to send a response with no data.

Exceptions

SaslException:: If an error occurred while processing the challenge or generating a response.

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

getMechanismName

back to summary

public String getMechanismName()

Returns the IANA-registered mechanism name of this SASL client. (e.g. "CRAM-MD5", "GSSAPI").

Returns:String: A non-null string representing the IANA-registered mechanism name.

getNegotiatedProperty back to summary

getNegotiatedProperty	back to summary
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. The `Sasl` class includes several well-known property names (For example, `Sasl#QOP`). A SASL provider can support other properties which are specific to the vendor and/or a mechanism. Parameters propName:String The non-null property name. Returns:Object The value of the negotiated property. If null, the property was not negotiated or is not applicable to this mechanism. Exceptions IllegalStateException: if this authentication exchange has not completed

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.

The Sasl class includes several well-known property names (For example, Sasl#QOP). A SASL provider can support other properties which are specific to the vendor and/or a mechanism.

Parameters

propName:String: The non-null property name.

Returns:Object

The value of the negotiated property. If null, the property was not negotiated or is not applicable to this mechanism.

Exceptions

IllegalStateException:: if this authentication exchange has not completed

hasInitialResponse back to summary

hasInitialResponse	back to summary
public boolean hasInitialResponse() Determines whether this mechanism has an optional initial response. If true, caller should call `evaluateChallenge()` with an empty array to get the initial response. Returns:boolean true if this mechanism has an initial response.

public boolean hasInitialResponse()

Determines whether this mechanism has an optional initial response. If true, caller should call evaluateChallenge() with an empty array to get the initial response.

Returns:boolean: true if this mechanism has an initial response.

isComplete	back to summary
public boolean isComplete() Determines whether the authentication exchange has completed. This method may be called at any time, but typically, it will not be called until the caller has received indication from the server (in a protocol-specific manner) that the exchange has completed. Returns:boolean true if the authentication exchange has completed; false otherwise.

isComplete

back to summary

public boolean isComplete()

Determines whether the authentication exchange has completed. This method may be called at any time, but typically, it will not be called until the caller has received indication from the server (in a protocol-specific manner) that the exchange has completed.

Returns:boolean: true if the authentication exchange has completed; false otherwise.

unwrap back to summary

unwrap	back to summary
public byte[] unwrap(byte[] incoming, int offset, int len) throws SaslException Unwraps a byte array received from the server. 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:byte[] A non-null byte array containing the encoded bytes from the server. offset:int The starting position at `incoming` of the bytes to use. len:int The number of bytes from `incoming` to use. Returns:byte[] A non-null byte array containing the decoded bytes. Exceptions 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.

public byte[] unwrap(byte[] incoming, int offset, int len) throws SaslException

Unwraps a byte array received from the server. 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:byte[]: A non-null byte array containing the encoded bytes from the server.
offset:int: The starting position at incoming of the bytes to use.
len:int: The number of bytes from incoming to use.

Returns:byte[]

A non-null byte array containing the decoded bytes.

Exceptions

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 back to summary

wrap	back to summary
public byte[] wrap(byte[] outgoing, int offset, int len) throws SaslException Wraps a byte array to be sent to the server. 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:byte[] A non-null byte array containing the bytes to encode. offset:int The starting position at `outgoing` of the bytes to use. len:int The number of bytes from `outgoing` to use. Returns:byte[] A non-null byte array containing the encoded bytes. Exceptions 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.

public byte[] wrap(byte[] outgoing, int offset, int len) throws SaslException

Wraps a byte array to be sent to the server. 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:byte[]: A non-null byte array containing the bytes to encode.
offset:int: The starting position at outgoing of the bytes to use.
len:int: The number of bytes from outgoing to use.

Returns:byte[]

A non-null byte array containing the encoded bytes.

Exceptions

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.

public Interface SaslClient

Method Summary

Method Detail