GSSManagerImpl

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.

Suppose an application desired that when a mechanism of Oid m1 is needed the system default providers always be checked first, and only when they do not support m1 should a provider A be checked. It would then make the call:

         GSSManager mgr = GSSManager.getInstance();
         mgr.addProviderAtEnd(A, m1);
 

         mgr.addProviderAtEnd(B, null);
 

Suppose at a later time the following call is made to the same GSSManager instance:

         mgr.addProviderAtEnd(B, m2)
 

Please note, however, that the following call:

         mgr.addProviderAtEnd(A, null)
 

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.

Suppose an application desired that the provider A always be checked first when any mechanism is needed, it would call:

         GSSManager mgr = GSSManager.getInstance();
         // mgr may at this point have its own pre-configured list
         // of provider preferences. The following will prepend to
         // any such list:

         mgr.addProviderAtFront(A, null);
 

         mgr.addProviderAtFront(B, m1);
 

Suppose at a later time the following call is made to the same GSSManager instance:

         mgr.addProviderAtFront(B, null)
 

Please note, however, that the following call:

         mgr.addProviderAtFront(A, m3)
 

Factory method for creating a context on the initiator's side. Some mechanism providers might require that the caller be granted permission to initiate a security context. A failed permission check might cause a SecurityException to be thrown from this method.

Non-default values for lifetime cannot always be honored by the underlying mechanism, thus applications should be prepared to call getLifetime on the returned context.

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. Some mechanism providers might require that the caller be granted permission to accept a security context. A failed permission check might cause a SecurityException to be thrown from this method.

Factory method for creating a previously exported context. The context properties will be determined from the input token and cannot be modified through the set methods.

Implementations are not required to support the inter-process transfer of security contexts. Before exporting a context, calling the GSSContext.isTransferable will indicate if the context is transferable. Calling this method in an implementation that does not support it will result in a GSSException with the error code GSSException.UNAVAILABLE. Some mechanism providers might require that the caller be granted permission to initiate or accept a security context. A failed permission check might cause a SecurityException to be thrown from this method.

Factory method for acquiring credentials over a set of mechanisms. This method attempts to acquire 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.

GSS-API mechanism providers must impose a local access-control policy on callers to prevent unauthorized callers from acquiring credentials to which they are not entitled. The kinds of permissions needed by different mechanism providers will be documented on a per-mechanism basis. A failed permission check might cause a SecurityException to be thrown from this method.

Non-default values for lifetime cannot always be honored by the underlying mechanisms, thus applications should be prepared to call getRemainingLifetime on the returned credential.

Factory method for acquiring a single mechanism credential.

GSS-API mechanism providers must impose a local access-control policy on callers to prevent unauthorized callers from acquiring credentials to which they are not entitled. The kinds of permissions needed by different mechanism providers will be documented on a per-mechanism basis. A failed permission check might cause a SecurityException to be thrown from this method.

Non-default values for lifetime cannot always be honored by the underlying mechanisms, thus applications should be prepared to call getRemainingLifetime on the returned credential.

Factory method for acquiring default credentials. This will cause the GSS-API to use system specific defaults for the set of mechanisms, name, and lifetime.

GSS-API mechanism providers must impose a local access-control policy on callers to prevent unauthorized callers from acquiring credentials to which they are not entitled. The kinds of permissions needed by different mechanism providers will be documented on a per-mechanism basis. A failed permission check might cause a SecurityException to be thrown from this method.

Factory method to convert a byte array containing a name from the specified namespace to a GSSName object and canonicalize it at the same time for a mechanism. In other words, this method is a utility that does the equivalent of two steps: the createName and then also GSSName.canonicalize.

Factory method to convert a string name from the specified namespace to a GSSName object. In general, the GSSName object created will contain multiple representations of the name, one for each mechanism that is supported; two examples that are exceptions to this are when the namespace type parameter indicates NT_EXPORT_NAME or when the GSS-API implementation is not multi-mechanism. It is not recommended to use this method with a NT_EXPORT_NAME type because representing a previously exported name consisting of abitrary bytes as a String might cause problems with character encoding schemes. In such cases it is recommended that the bytes be passed in directly to the overloaded form of this method createName.

Factory method to convert a string name from the specified namespace to a GSSName object and canonicalize it at the same time for a mechanism. In other words, this method is a utility that does the equivalent of two steps: the createName and then also the GSSName.canonicalize.

Factory method to convert a byte array containing a name from the specified namespace to a GSSName object. In general, the GSSName object created will contain multiple representations of the name, one for each mechanism that is supported; two examples that are exceptions to this are when the namespace type parameter indicates NT_EXPORT_NAME or when the GSS-API implementation is not multi-mechanism. The bytes that are passed in are interpreted by each underlying mechanism according to some encoding scheme of its choice for the given nametype.

Returns a list of mechanisms that are available to GSS-API callers through this GSSManager. The default GSSManager obtained from the getInstance() method includes the Oid "1.2.840.113554.1.2.2" in its list. This Oid identifies the Kerberos v5 GSS-API mechanism that is defined in RFC 1964.

Returns a list of mechanisms that support the indicated name type.

The Kerberos v5 mechanism ("1.2.840.113554.1.2.2") will always be returned in this list when the indicated nametype is one of GSSName.NT_HOSTBASED_SERVICE, GSSName.NT_EXPORT_NAME, or "1.2.840.113554.1.2.2.1".

Returns then name types supported by the indicated mechanism.

The default GSSManager instance includes support for the Kerberos v5 mechanism. When this mechanism ("1.2.840.113554.1.2.2") is indicated, the returned list will contain at least the following nametypes: GSSName.NT_HOSTBASED_SERVICE, GSSName.NT_EXPORT_NAME, and the Kerberos v5 specific Oid "1.2.840.113554.1.2.2.1". The namespace for the Oid "1.2.840.113554.1.2.2.1" is defined in RFC 1964.