gnu.crypto.key.srp6
Class SRPPublicKey

java.lang.Object
  gnu.crypto.key.srp6.SRPKey
      gnu.crypto.key.srp6.SRPPublicKey

All Implemented Interfaces:

java.security.Key, java.security.PublicKey, java.io.Serializable

public class SRPPublicKey

extends SRPKey

implements java.security.PublicKey

A representation of an SRP ephemeral public key.

Reference:

1. SRP Protocol Design
   Thomas J. Wu.

Version:

$Revision: 1.2 $

See Also:

Serialized Form

Field Summary

Fields inherited from class gnu.crypto.key.srp6.SRPKey

g, N

Fields inherited from interface java.security.PublicKey

serialVersionUID

Constructor Summary

(package private)	SRPPublicKey(java.math.BigInteger[] params) Default constructor.
	SRPPublicKey(java.math.BigInteger N, java.math.BigInteger g, java.math.BigInteger Y) Public constructor for use from outside this package.

Method Summary

boolean	equals(java.lang.Object obj) Returns true if the designated object is an instance of SRPPublicKeyand has the same SRP parameter values as this one.
byte[]	getEncoded(int format) Returns the encoded form of this public key according to the designated format.
java.math.BigInteger	getY() Returns the public exponent of the key as a BigInteger.
static SRPPublicKey	valueOf(byte[] k) A class method that takes the output of the encodePublicKey() method of an SRP keypair codec object (an instance implementing IKeyPairCodec for SRP keys, and re-constructs an instance of this object.

Methods inherited from class gnu.crypto.key.srp6.SRPKey

getAlgorithm, getEncoded, getFormat, getG, getN

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.security.Key

getAlgorithm, getEncoded, getFormat

Constructor Detail

SRPPublicKey

public SRPPublicKey(java.math.BigInteger N,
                    java.math.BigInteger g,
                    java.math.BigInteger Y)

Public constructor for use from outside this package.

Parameters:

N - the public shared modulus.

g - the generator.

Y - the public exponent of the ephemeral key.

SRPPublicKey

SRPPublicKey(java.math.BigInteger[] params)

Default constructor. Assumes that N and g are already validated.

Parameters:

params - an array of 3 values representing N, g and Y; the latter being the client's or server's public exponent.

Method Detail

valueOf

public static SRPPublicKey valueOf(byte[] k)

A class method that takes the output of the encodePublicKey() method of an SRP keypair codec object (an instance implementing IKeyPairCodec for SRP keys, and re-constructs an instance of this object.

Parameters:

k - the contents of a previously encoded instance of this object.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if there is not enough bytes, in k, to represent a valid encoding of an instance of this object.

java.lang.IllegalArgumentException - if the byte sequence does not represent a valid encoding of an instance of this object.

getY

public java.math.BigInteger getY()

Returns the public exponent of the key as a BigInteger.

Returns:

the public exponent of the key as a BigInteger.

getEncoded

public byte[] getEncoded(int format)

Returns the encoded form of this public key according to the designated format.

Specified by:

getEncoded in class SRPKey

Parameters:

format - the desired format identifier of the resulting encoding.

Returns:

the byte sequence encoding this key according to the designated format.

Throws:

java.lang.IllegalArgumentException - if the format is not supported.

equals

public boolean equals(java.lang.Object obj)

Returns true if the designated object is an instance of SRPPublicKeyand has the same SRP parameter values as this one.

Overrides:

equals in class SRPKey

Parameters:

obj - the other non-null SRP key to compare to.

Returns:

true if the designated object is of the same type and value as this one.