org.ietf.jgss
Class GSSManager

java.lang.Object
  extended by org.ietf.jgss.GSSManager

public abstract class GSSManager
extends Object

The GSSManager class is an abstract class that serves as a factory for three GSS interfaces: GSSName, GSSCredential, and GSSContext. It also provides methods for applications to determine what mechanisms are available from the GSS implementation and what nametypes these mechanisms support. An instance of the default GSSManager subclass may be obtained through the static method getInstance(), but applications are free to instantiate other subclasses of GSSManager.

All but one method in this class are declared abstract. This means that subclasses have to provide the complete implementation for those methods. The only exception to this is the static method getInstance() which will have platform specific code to return an instance of the default subclass.

Platform providers of GSS are required not to add any constructors to this class, private, public, or protected. This will ensure that all subclasses invoke only the default constructor provided to the base class by the compiler.

A subclass extending the GSSManager abstract class may be implemented as a modular provider based layer that utilizes some well known service provider specification. The GSSManager API provides the application with methods to set provider preferences on such an implementation. These methods also allow the implementation to throw a well-defined exception in case provider based configuration is not supported. Applications that expect to be portable should be aware of this and recover cleanly by catching the exception.

It is envisioned that there will be three most common ways in which providers will be used:

  1. The application does not care about what provider is used (the default case).
  2. The application wants a particular provider to be used preferentially, either for a particular mechanism or all the time, irrespective of mechanism.
  3. The application wants to use the locally configured providers as far as possible but if support is missing for one or more mechanisms then it wants to fall back on its own provider.

The GSSManager class has two methods that enable these modes of usage: addProviderAtFront(java.security.Provider,org.ietf.jgss.Oid) and addProviderAtEnd(java.security.Provider,org.ietf.jgss.Oid). These methods have the effect of creating an ordered list of (provider, oid) pairs where each pair indicates a preference of provider for a given oid.

The use of these methods does not require any knowledge of whatever service provider specification the GSSManager subclass follows. It is hoped that these methods will serve the needs of most applications. Additional methods may be added to an extended GSSManager that could be part of a service provider specification that is standardized later.

Example Code

GSSManager mgr = GSSManager.getInstance();

// What mechs are available to us?
Oid[] supportedMechs = mgr.getMechs();

// Set a preference for the provider to be used when support is needed
// for the mechanisms "1.2.840.113554.1.2.2" and "1.3.6.1.5.5.1.1".

Oid krb = new Oid("1.2.840.113554.1.2.2");
Oid spkm1 = new Oid("1.3.6.1.5.5.1.1");

Provider p = (Provider) (new com.foo.security.Provider());

mgr.addProviderAtFront(p, krb);
mgr.addProviderAtFront(p, spkm1);

// What name types does this spkm implementation support?
Oid[] nameTypes = mgr.getNamesForMech(spkm1);


Constructor Summary
GSSManager()
           
 
Method Summary
abstract  void addProviderAtEnd(Provider p, Oid mech)
          This method is used to indicate to the GSSManager that the application would like a particular provider to be used if no other provider can be found that supports the given mechanism.
abstract  void addProviderAtFront(Provider p, Oid mech)
          This method is used to indicate to the GSSManager that the application would like a particular provider to be used ahead of all others when support is desired for the given mechanism.
abstract  GSSContext createContext(byte[] interProcessToken)
          Factory method for creating a previously exported context.
abstract  GSSContext createContext(GSSCredential myCred)
          Factory method for creating a context on the acceptor' side.
abstract  GSSContext createContext(GSSName peer, Oid mech, GSSCredential myCred, int lifetime)
          Factory method for creating a context on the initiator's side.
abstract  GSSCredential createCredential(GSSName aName, int lifetime, Oid[] mechs, int usage)
          Factory method for acquiring credentials over a set of mechanisms.
abstract  GSSCredential createCredential(GSSName aName, int lifetime, Oid mech, int usage)
          Factory method for acquiring a single mechanism credential.
abstract  GSSCredential createCredential(int usage)
          Factory method for acquiring default credentials.
abstract  GSSName createName(byte[] name, Oid nameType)
          Factory method to convert a contiguous byte array containing a name from the specified namespace to a GSSName object.
abstract  GSSName createName(byte[] name, Oid nameType, Oid mech)
          Factory method to convert a contiguous byte array containing a name from the specified namespace to a GSSName object that is an MN.
abstract  GSSName createName(String nameStr, Oid nameType)
          Factory method to convert a contiguous string name from the specified namespace to a GSSName object.
abstract  GSSName createName(String nameStr, Oid nameType, Oid mech)
          Factory method to convert a contiguous string name from the specified namespace to an GSSName object that is a mechanism name (MN).
static GSSManager getInstance()
          Returns the default GSSManager implementation.
abstract  Oid[] getMechs()
          Returns an array of Oid objects indicating mechanisms available to GSS-API callers.
abstract  Oid[] getMechsForName(Oid name)
          Returns an array of Oid objects corresponding to the mechanisms that support the specific name type.
abstract  Oid[] getNamesForMech(Oid mechanism)
          Returns name type Oid's supported by the specified mechanism.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

GSSManager

public GSSManager()
Method Detail

getInstance

public static GSSManager getInstance()
Returns the default GSSManager implementation.

Returns:
The default GSSManager implementation.

addProviderAtEnd

public abstract void addProviderAtEnd(Provider p,
                                      Oid mech)
                               throws GSSException

This method is used to indicate to the GSSManager that the application would like a particular provider to be used if no other provider can be found that supports the given mechanism. When a value of null is used instead of an Oid for the mechanism, the GSSManager must use the indicated provider for any mechanism.

Calling this method repeatedly preserves the older settings but raises them above newer ones in preference thus forming an ordered list of providers and Oid pairs that grows at the bottom. Thus the older provider settings will be utilized first before this one is.

If there are any previously existing preferences that conflict with the preference being set here, then the GSSManager should ignore this request.

If the GSSManager implementation does not support an SPI with a pluggable provider architecture it should throw a GSSException with the status code GSSException.UNAVAILABLE to indicate that the operation is unavailable.

Parameters:
p - The provider instance that should be used whenever support is needed for mech.
mech - The mechanism for which the provider is being set.
Throws:
GSSException - If this service is unavailable.

addProviderAtFront

public abstract void addProviderAtFront(Provider p,
                                        Oid mech)
                                 throws GSSException

This method is used to indicate to the GSSManager that the application would like a particular provider to be used ahead of all others when support is desired for the given mechanism. When a value of null is used instead of an Oid for the mechanism, the GSSManager must use the indicated provider ahead of all others no matter what the mechanism is. Only when the indicated provider does not support the needed mechanism should the GSSManager move on to a different provider.

Calling this method repeatedly preserves the older settings but lowers them in preference thus forming an ordered list of provider and Oid pairs that grows at the top.

Calling addProviderAtFront with a null Oid will remove all previous preferences that were set for this provider in the GSSManager instance. Calling addProviderAtFront with a non-null Oid will remove any previous preference that was set using this mechanism and this provider together.

If the GSSManager implementation does not support an SPI with a pluggable provider architecture it should throw a GSSException with the status code GSSException.UNAVAILABLE to indicate that the operation is unavailable.

Parameters:
p - The provider instance that should be used whenever support is needed for mech.
mech - The mechanism for which the provider is being set.
Throws:
GSSException - If this service is unavailable.

createContext

public abstract GSSContext createContext(byte[] interProcessToken)
                                  throws GSSException
Factory method for creating a previously exported context. The context properties will be determined from the input token and can't be modified through the set methods.

Parameters:
interProcessToken - The token previously emitted from the export method.
Returns:
The context.
Throws:
GSSException - If this operation fails.

createContext

public abstract GSSContext createContext(GSSCredential myCred)
                                  throws GSSException
Factory method for creating a context on the acceptor' side. The context's properties will be determined from the input token supplied to the accept method.

Parameters:
myCred - Credentials for the acceptor. Use null to act as a default acceptor principal.
Returns:
The context.
Throws:
GSSException - If this operation fails.

createContext

public abstract GSSContext createContext(GSSName peer,
                                         Oid mech,
                                         GSSCredential myCred,
                                         int lifetime)
                                  throws GSSException
Factory method for creating a context on the initiator's side. Context flags may be modified through the mutator methods prior to calling GSSContext.initSecContext(java.io.InputStream,java.io.OutputStream).

Parameters:
peer - Name of the target peer.
mech - Oid of the desired mechanism. Use null to request default mechanism.
myCred - Credentials of the initiator. Use null default initiator principal.
lifetime - The request lifetime, in seconds, for the context. Use GSSContext.INDEFINITE_LIFETIME and GSSContext.DEFAULT_LIFETIME to request indefinite or default context lifetime.
Returns:
The context.
Throws:
GSSException - If this operation fails.

createCredential

public abstract GSSCredential createCredential(int usage)
                                        throws GSSException
Factory method for acquiring default credentials. This will cause the GSS-API to use system specific defaults for the set of mechanisms, name, and a DEFAULT lifetime.

Parameters:
usage - The intended usage for this credential object. The value of this parameter must be one of: GSSCredential#ACCEPT_AND_INITIATE, GSSCredential.ACCEPT_ONLY, GSSCredential.INITIATE_ONLY.
Returns:
The credential.
Throws:
GSSException - If this operation fails.

createCredential

public abstract GSSCredential createCredential(GSSName aName,
                                               int lifetime,
                                               Oid mech,
                                               int usage)
                                        throws GSSException
Factory method for acquiring a single mechanism credential.

Parameters:
aName - Name of the principal for whom this credential is to be acquired. Use null to specify the default principal.
lifetime - The number of seconds that credentials should remain valid. Use GSSCredential.INDEFINITE_LIFETIME to request that the credentials have the maximum permitted lifetime. Use GSSCredential.DEFAULT_LIFETIME to request default credential lifetime.
mech - The oid of the desired mechanism. Use null to request the default mechanism(s).
usage - The intended usage for this credential object. The value of this parameter must be one of: GSSCredential#ACCEPT_AND_INITIATE, GSSCredential.ACCEPT_ONLY, GSSCredential.INITIATE_ONLY.
Returns:
The credential.
Throws:
GSSException - If this operation fails.

createCredential

public abstract GSSCredential createCredential(GSSName aName,
                                               int lifetime,
                                               Oid[] mechs,
                                               int usage)
                                        throws GSSException
Factory method for acquiring credentials over a set of mechanisms. Acquires credentials for each of the mechanisms specified in the array called mechs. To determine the list of mechanisms' for which the acquisition of credentials succeeded, the caller should use the GSSCredential.getMechs() method.

Parameters:
aName - Name of the principal for whom this credential is to be acquired. Use null to specify the default principal.
lifetime - The number of seconds that credentials should remain valid. Use GSSCredential.INDEFINITE_LIFETIME to request that the credentials have the maximum permitted lifetime. Use GSSCredential.DEFAULT_LIFETIME to request default credential lifetime.
mechs - The array of mechanisms over which the credential is to be acquired. Use null for requesting a system specific default set of mechanisms.
usage - The intended usage for this credential object. The value of this parameter must be one of: GSSCredential#ACCEPT_AND_INITIATE, GSSCredential.ACCEPT_ONLY, GSSCredential.INITIATE_ONLY.
Returns:
The credential.
Throws:
GSSException - If this operation fails.

createName

public abstract GSSName createName(byte[] name,
                                   Oid nameType)
                            throws GSSException
Factory method to convert a contiguous byte array containing a name from the specified namespace to a GSSName object. In general, the GSSName object created will not be an MN; two examples that are exceptions to this are when the namespace type parameter indicates GSSName.NT_EXPORT_NAME or when the GSS-API implementation is not multi-mechanism.

Parameters:
name - The byte array containing the name to create.
nameType - The Oid specifying the namespace of the name supplied in the byte array. Note that nameType serves to describe and qualify the interpretation of the input name byte array, it does not necessarily imply a type for the output GSSName implementation. "null" value can be used to specify that a mechanism specific default syntax should be assumed by each mechanism that examines the byte array.
Returns:
The name.
Throws:
GSSException - If this operation fails.

createName

public abstract GSSName createName(byte[] name,
                                   Oid nameType,
                                   Oid mech)
                            throws GSSException
Factory method to convert a contiguous byte array containing a name from the specified namespace to a GSSName object that is an MN. In other words, this method is a utility that does the equivalent of two steps: createName(byte[],org.ietf.jgss.Oid) and then also GSSName.canonicalize(org.ietf.jgss.Oid).

Parameters:
name - The byte array representing the name to create.
nameType - The Oid specifying the namespace of the name supplied in the byte array. Note that nameType serves to describe and qualify the interpretation of the input name byte array, it does not necessarily imply a type for the output GSSName implementation. "null" value can be used to specify that a mechanism specific default syntax should be assumed by each mechanism that examines the byte array.
mech - Oid specifying the mechanism for which this name should be created.
Returns:
The name.
Throws:
GSSException - If this operation fails.

createName

public abstract GSSName createName(String nameStr,
                                   Oid nameType)
                            throws GSSException
Factory method to convert a contiguous string name from the specified namespace to a GSSName object. In general, the GSSName object created will not be an MN; two examples that are exceptions to this are when the namespace type parameter indicates GSSName.NT_EXPORT_NAME or when the GSS-API implementation is not multi-mechanism.

Parameters:
nameStr - The string representing a printable form of the name to create.
nameType - The Oid specifying the namespace of the printable name supplied. Note that nameType serves to describe and qualify the interpretation of the input nameStr, it does not necessarily imply a type for the output GSSName implementation. "null" value can be used to specify that a mechanism specific default printable syntax should be assumed by each mechanism that examines nameStr.
Returns:
The name.
Throws:
GSSException - If this operation fails.

createName

public abstract GSSName createName(String nameStr,
                                   Oid nameType,
                                   Oid mech)
                            throws GSSException
Factory method to convert a contiguous string name from the specified namespace to an GSSName object that is a mechanism name (MN). In other words, this method is a utility that does the equivalent of two steps: the createName(java.lang.String,org.ietf.jgss.Oid) and then also GSSName.canonicalize(org.ietf.jgss.Oid).

Parameters:
nameStr - The string representing a printable form of the name to create.
nameType - The Oid specifying the namespace of the printable name supplied. Note that nameType serves to describe and qualify the interpretation of the input nameStr, it does not necessarily imply a type for the output GSSName implementation. "null" value can be used to specify that a mechanism specific default printable syntax should be assumed when the mechanism examines nameStr.
mech - Oid specifying the mechanism for which this name should be created.
Returns:
The name.
Throws:
GSSException - If this operation fails.

getMechs

public abstract Oid[] getMechs()
Returns an array of Oid objects indicating mechanisms available to GSS-API callers. A null value is returned when no mechanism are available (an example of this would be when mechanism are dynamically configured, and currently no mechanisms are installed).

Returns:
The array of available mechanisms, or null.

getMechsForName

public abstract Oid[] getMechsForName(Oid name)
Returns an array of Oid objects corresponding to the mechanisms that support the specific name type. null is returned when no mechanisms are found to support the specified name type.

Parameters:
name - The Oid object for the name type.
Returns:
The array of mechanisms, or null.

getNamesForMech

public abstract Oid[] getNamesForMech(Oid mechanism)
                               throws GSSException
Returns name type Oid's supported by the specified mechanism.

Parameters:
mechanism - The Oid object for the mechanism to query.
Returns:
The name type Oid's supported by the mechanism.
Throws:
GSSException - If this operation fails.