GSSName (Java SE 11 & JDK 11 )
Keywords: org.ietf.jgss.GSSName interface

Module java.security.jgss
Package org.ietf.jgss

## 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 `user@EXAMPLE.COM`, then a `ServicePermission` with service principal `host/www.example.com@EXAMPLE.COM` (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.