org.ietf.jgss

Class Oid


public class Oid
extends Object

This class represents Universal Object Identifiers (Oids) and their associated operations.

Oids are hierarchically globally-interpretable identifiers used within the GSS-API framework to identify mechanisms and name formats.

The structure and encoding of Oids is defined in ISOIEC-8824 and ISOIEC-8825. For example the Oid representation of Kerberos V5 mechanism is "1.2.840.113554.1.2.2".

The GSSName name class contains public static Oid objects representing the standard name types defined in GSS-API.

Constructor Summary

Oid(byte[] derOid)
Creates an Oid object from its DER encoding.
Oid(InputStream derOid)
Creates an Oid object from its DER encoding.
Oid(String strOid)
Creates an Oid object from a string representation of its integer components (e.g. "1.2.840.113554.1.2.2").

Method Summary

boolean
containedIn(Oid[] oids)
A utility method to test if an Oid object is contained within the supplied Oid object array.
boolean
equals(Object o)
Determine whether this Object is semantically equal to another Object.
byte[]
getDER()
Returns the full ASN.1 DER encoding for this oid object, which includes the tag and length.
int
hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.
String
toString()
Returns a string representation of the oid's integer components in dot separated notation (e.g. "1.2.840.113554.1.2.2").

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Oid

public Oid(byte[] derOid)
            throws GSSException
Creates an Oid object from its DER encoding. This refers to the full encoding including tag and length. The structure and encoding of Oids is defined in ISOIEC-8824 and ISOIEC-8825. This method is identical in functionality to its streaming counterpart.
Parameters:
derOid - Byte array storing a DER encoded oid.
Throws:
GSSException - If the DER bytes are badly formed.

Oid

public Oid(InputStream derOid)
            throws GSSException
Creates an Oid object from its DER encoding. This refers to the full encoding including tag and length. The structure and encoding of Oids is defined in ISOIEC-8824 and ISOIEC-8825. This method is identical in functionality to its byte array counterpart.
Parameters:
derOid - Stream containing the DER encoded oid.
Throws:
GSSException - If the DER stream is badly formed, or if the input stream throws an exception.

Oid

public Oid(String strOid)
            throws GSSException
Creates an Oid object from a string representation of its integer components (e.g. "1.2.840.113554.1.2.2").
Parameters:
strOid - The string representation for the oid.
Throws:
GSSException - If the argument is badly formed.

Method Details

containedIn

public boolean containedIn(Oid[] oids)
A utility method to test if an Oid object is contained within the supplied Oid object array.
Parameters:
oids - An array of oids to search.
Returns:
True if this oid is contained in the given array.

equals

public boolean equals(Object o)
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

  • It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
  • It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
  • It must be reflexive. a.equals(a) must always be true.
  • It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
  • a.equals(null) must be false.
  • It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:
equals in interface Object
Parameters:
Returns:
whether this Object is semantically equal to another

getDER

public byte[] getDER()
            throws GSSException
Returns the full ASN.1 DER encoding for this oid object, which includes the tag and length.
Returns:
The ASN.1 DER encoding for this oid.
Throws:
GSSException - If encoding fails.

hashCode

public int hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

  • Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
  • It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:
hashCode in interface Object
Returns:
the hash code for this Object

toString

public String toString()
Returns a string representation of the oid's integer components in dot separated notation (e.g. "1.2.840.113554.1.2.2").
Overrides:
toString in interface Object
Returns:
The string representation of this oid.

Oid.java -- Object identifier class. Copyright (C) 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. The documentation comments of this class are derived from the text of RFC 2853: Generic Security Service API Version 2: Java Bindings. That document is covered under the following license notice: Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.