org.ietf.jgss
Class GSSManager
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:
- The application does not care about what provider is used (the
default case).
- The application wants a particular provider to be used
preferentially, either for a particular mechanism or all the
time, irrespective of mechanism.
- 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(Provider,Oid)
and
addProviderAtEnd(Provider,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);
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(int usage)- Factory method for acquiring default credentials.
|
abstract GSSCredential | createCredential(GSSName aName, int lifetime, Oid mech, int usage)- Factory method for acquiring a single mechanism credential.
|
abstract GSSCredential | createCredential(GSSName aName, int lifetime, Oid[] mechs, int usage)- Factory method for acquiring credentials over a set of mechanisms.
|
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.
|
clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait |
GSSManager
public GSSManager()
The basic constructor. Object is special, because it has no
superclass, so there is no call to super().
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.
p - The provider instance that should be used whenever
support is needed for mech.mech - The mechanism for which the provider is being set.
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.
p - The provider instance that should be used whenever
support is needed for mech.mech - The mechanism for which the provider is being set.
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.
interProcessToken - The token previously emitted from the
export method.
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.
myCred - Credentials for the acceptor. Use null to
act as a default acceptor principal.
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.
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.
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,
GSSCredential.ACCEPT_ONLY,
GSSCredential.INITIATE_ONLY.
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.
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.
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[],Oid) and then also
GSSName.canonicalize(Oid).
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.
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.
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.
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(String,Oid)
and then also
GSSName.canonicalize(Oid).
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.
getInstance
public static GSSManager getInstance()
Returns the default GSSManager implementation.
- The default GSSManager implementation.
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).
- 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.
name - The Oid object for the name type.
- 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.
mechanism - The Oid object for the mechanism to query.
- The name type Oid's supported by the mechanism.
GSSManager.java -- manager class for the GSS-API.
Copyright (C) 2004 Free Software Foundation, Inc.
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The documentation comments of this class are derived from the text
of RFC 2853: Generic Security Service API Version 2: Java Bindings.
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