Interface GSSName

public interface GSSName

This interface encapsulates a single GSS-API principal entity. The application obtains an implementation of this interface through one of the createName methods that exist in the GSSManager class. Conceptually a GSSName contains many representations of the entity or many primitive name elements, one for each supported underlying mechanism. In GSS terminology, a GSSName that contains an element from just one mechanism is called a Mechanism Name (MN)

Since different authentication mechanisms may employ different namespaces for identifying their principals, GSS-API's naming support is necessarily complex in multi-mechanism environments (or even in some single-mechanism environments where the underlying mechanism supports multiple namespaces). Different name formats and their definitions are identified with Oid's and some standard types are defined in this interface. The format of the names can be derived based on the unique Oid of its name type.

Included below are code examples utilizing the GSSName interface. The code below creates a GSSName, converts it to an MN, performs a comparison, obtains a printable representation of the name, exports it to a byte array and then re-imports to obtain a new GSSName.

GSSManager manager = GSSManager.getInstance();

      // create a host based service name
      GSSName name = manager.createName("service@host",
                   GSSName.NT_HOSTBASED_SERVICE);

      Oid krb5 = new Oid("1.2.840.113554.1.2.2");

      GSSName mechName = name.canonicalize(krb5);

      // the above two steps are equivalent to the following
      GSSName mechName = manager.createName("service@host",
                      GSSName.NT_HOSTBASED_SERVICE, krb5);

      // perform name comparison
      if (name.equals(mechName))
              print("Names are equals.");

      // obtain textual representation of name and its printable
      // name type
      print(mechName.toString() +
                      mechName.getStringNameType().toString());

      // export and re-import the name
      byte [] exportName = mechName.export();

      // create a new name object from the exported buffer
      GSSName newName = manager.createName(exportName,
                      GSSName.NT_EXPORT_NAME);

If a security manager is installed, in order to create a GSSName that contains a Kerberos name element without providing its realm, a ServicePermission must be granted and the service principal of the permission must minimally be inside the Kerberos name element's realm. For example, if the result of createName("user", NT_USER_NAME) contains a Kerberos name element [email protected], then a ServicePermission with service principal host/[email protected] (and any action) must be granted. Otherwise, the creation will throw a GSSException containing the GSSException.FAILURE error code.

Since:: 1.4
See Also:: export(), equals(GSSName), GSSManager.createName(String, Oid), GSSManager.createName(String, Oid, Oid), GSSManager.createName(byte[], Oid)

Field Summary

Fields
Modifier and Type	Field	Description
`static Oid`	`NT_ANONYMOUS`	Name type for representing an anonymous entity.
`static Oid`	`NT_EXPORT_NAME`	Name type used to indicate an exported name produced by the export method.
`static Oid`	`NT_HOSTBASED_SERVICE`	Oid indicating a host-based service name form.
`static Oid`	`NT_MACHINE_UID_NAME`	Name type to indicate a numeric user identifier corresponding to a user on a local system.
`static Oid`	`NT_STRING_UID_NAME`	Name type to indicate a string of digits representing the numeric user identifier of a user on a local system.
`static Oid`	`NT_USER_NAME`	Name type to indicate a named user on a local system.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`GSSName`	`canonicalize(Oid mech)`	Creates a name that is canonicalized for some mechanism.
`boolean`	`equals(Object another)`	Compares this `GSSName` object to another Object that might be a `GSSName`.
`boolean`	`equals(GSSName another)`	Compares two `GSSName` objects to determine if they refer to the same entity.
`byte[]`	`export()`	Returns a canonical contiguous byte representation of a mechanism name (MN), suitable for direct, byte by byte comparison by authorization functions.
`Oid`	`getStringNameType()`	Returns the name type of the printable representation of this name that can be obtained from the `toString` method.
`int`	`hashCode()`	Returns a hashcode value for this GSSName.
`boolean`	`isAnonymous()`	Tests if this name object represents an anonymous entity.
`boolean`	`isMN()`	Tests if this name object represents a Mechanism Name (MN).
`String`	`toString()`	Returns a textual representation of the `GSSName` object.

Field Detail

NT_HOSTBASED_SERVICE

static final Oid NT_HOSTBASED_SERVICE

Oid indicating a host-based service name form. It is used to represent services associated with host computers. This name form is constructed using two elements, "service" and "hostname", as follows: service@hostname.

It represents the following Oid value:
{ iso(1) member-body(2) United States(840) mit(113554) infosys(1) gssapi(2) generic(1) service_name(4) }

NT_USER_NAME

static final Oid NT_USER_NAME

Name type to indicate a named user on a local system.

It represents the following Oid value:
{ iso(1) member-body(2) United States(840) mit(113554) infosys(1) gssapi(2) generic(1) user_name(1) }

NT_MACHINE_UID_NAME

static final Oid NT_MACHINE_UID_NAME

Name type to indicate a numeric user identifier corresponding to a user on a local system. (e.g. Uid).

It represents the following Oid value:
{ iso(1) member-body(2) United States(840) mit(113554) infosys(1) gssapi(2) generic(1) machine_uid_name(2) }

NT_STRING_UID_NAME

static final Oid NT_STRING_UID_NAME

Name type to indicate a string of digits representing the numeric user identifier of a user on a local system.

It represents the following Oid value:
{ iso(1) member-body(2) United States(840) mit(113554) infosys(1) gssapi(2) generic(1) string_uid_name(3) }

NT_ANONYMOUS

static final Oid NT_ANONYMOUS

Name type for representing an anonymous entity.

It represents the following Oid value:
{ 1(iso), 3(org), 6(dod), 1(internet), 5(security), 6(nametypes), 3(gss-anonymous-name) }

NT_EXPORT_NAME

static final Oid NT_EXPORT_NAME

Name type used to indicate an exported name produced by the export method.

It represents the following Oid value:
{ 1(iso), 3(org), 6(dod), 1(internet), 5(security), 6(nametypes), 4(gss-api-exported-name) }

Method Detail

equals

boolean equals(GSSName another)
        throws GSSException

Compares two GSSName objects to determine if they refer to the same entity.

Parameters:: another - the GSSName to compare this name with
Returns:: true if the two names contain at least one primitive element in common. If either of the names represents an anonymous entity, the method will return false.
Throws:: GSSException - when the names cannot be compared, containing the following major error codes: GSSException.BAD_NAMETYPE, GSSException.FAILURE

equals

boolean equals(Object another)

Compares this GSSName object to another Object that might be a GSSName. The behaviour is exactly the same as in equals except that no GSSException is thrown; instead, false will be returned in the situation where an error occurs.

Overrides:: equals in class Object
Parameters:: another - the object to compare this name to
Returns:: true if the object to compare to is also a GSSName and the two names refer to the same entity.
See Also:: equals(GSSName)

hashCode

int hashCode()

Returns a hashcode value for this GSSName.

Overrides:: hashCode in class Object
Returns:: a hashCode value
See Also:: Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

canonicalize

GSSName canonicalize(Oid mech)
              throws GSSException

Creates a name that is canonicalized for some mechanism.

Parameters:: mech - the oid for the mechanism for which the canonical form of the name is requested.
Returns:: a GSSName that contains just one primitive element representing this name in a canonicalized form for the desired mechanism.
Throws:: GSSException - containing the following major error codes: GSSException.BAD_MECH, GSSException.BAD_NAMETYPE, GSSException.BAD_NAME, GSSException.FAILURE

export

byte[] export()
       throws GSSException

Returns a canonical contiguous byte representation of a mechanism name (MN), suitable for direct, byte by byte comparison by authorization functions. If the name is not an MN, implementations may throw a GSSException with the NAME_NOT_MN status code. If an implementation chooses not to throw an exception, it should use some system specific default mechanism to canonicalize the name and then export it. Structurally, an exported name object consists of a header containing an OID identifying the mechanism that authenticated the name, and a trailer containing the name itself, where the syntax of the trailer is defined by the individual mechanism specification. The format of the header of the output buffer is specified in RFC 2743.

The exported name is useful when used in large access control lists where the overhead of creating a GSSName object on each name and invoking the equals method on each name from the ACL may be prohibitive.

Exported names may be re-imported by using the byte array factory method GSSManager.createName and specifying the NT_EXPORT_NAME as the name type object identifier. The resulting GSSName name will also be a MN.

Returns:: a byte[] containing the exported name. RFC 2743 defines the "Mechanism-Independent Exported Name Object Format" for these bytes.
Throws:: GSSException - containing the following major error codes: GSSException.BAD_NAME, GSSException.BAD_NAMETYPE, GSSException.FAILURE

toString

String toString()

Returns a textual representation of the GSSName object. To retrieve the printed name format, which determines the syntax of the returned string, use the getStringNameType method.

Overrides:: toString in class Object
Returns:: a String representing this name in printable form.

getStringNameType

Oid getStringNameType()
               throws GSSException

Returns the name type of the printable representation of this name that can be obtained from the toString method.

Returns:: an Oid representing the namespace of the name returned from the toString method.
Throws:: GSSException - containing the following major error codes: GSSException.FAILURE

isAnonymous

boolean isAnonymous()

Tests if this name object represents an anonymous entity.

Returns:: true if this is an anonymous name, false otherwise.

isMN

boolean isMN()

Tests if this name object represents a Mechanism Name (MN). An MN is a GSSName the contains exactly one mechanism's primitive name element.

Returns:: true if this is an MN, false otherwise.