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Provides a basic API for algorithms to generate Public/Private keypairs,
and Key Agreement schemes.


Package overview

The contents of this package hierarchy is organised as follows:


   interfaces that describe the visible methods of concrete implementations
   of those interfaces,
   Factory classes that generate specific instances given a canonical
   name.
   common classes used by two or more concrete implementations,
   separate sub-packages for each implemented algorithm.


The four key-pair generation algorithms currently implemented in this
library are:


   Diffie-Hellman: gnu.crypto.key.dh,
   Digital Signature Scheme: gnu.crypto.key.dss,
   Rivest, Shamir and Adleman (RSA): gnu.crypto.key.rsa,
   Secure Remote Password 6: gnu.crypto.key.srp6.


The Key Agreement protocols currently implemented in this library are:


   Diffie-Hellman
      
         Basic version: also described in
         RFC-2631 as
         Static-Static mode, and
         ElGamal version: also known as half-certified Diffie-Hellman, or
         Ephemeral-Static mode in 
         RFC-2631.
      
   

   Secure Remote Password
      
         Basic version: described, by Thomas J. Wu, in
         SRP Protocol Design,
         and
         The version adopted for use as a SASL (Simple Authentication and
         Security Layer) mechanism in the internet draft
         
         Secure Remote Password Authentication Mechanism.
      
   


The following diagram shows the important classes participating in key-pair
generation:



The next diagram shows the important classes participating in key agreements:



The next two diagrams show the sequences involved in generating a keypair,
and establishing a key agreement protocol.





The following example shows the code that can be used to generate a key-
pair:

import gnu.crypto.sig.rsa.RSA;
import gnu.crypto.key.rsa.RSAKeyPairGenerator;

import java.math.BigInteger;
import java.security.KeyPair;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPublicKey;
import java.util.HashMap;
import java.util.Random;

...
RSAKeyPairGenerator kpg = new RSAKeyPairGenerator();
HashMap map = new HashMap();
map.put(RSAKeyPairGenerator.MODULUS_LENGTH, new Integer(1024));
kpg.setup(map);

KeyPair kp = kpg.generate();

BigInteger n1 = ((RSAPublicKey) kp.getPublic()).getModulus();
BigInteger e =  ((RSAPublicKey) kp.getPublic()).getPublicExponent();

BigInteger n2 = ((RSAPrivateKey) kp.getPrivate()).getModulus();
BigInteger d =  ((RSAPrivateKey) kp.getPrivate()).getPrivateExponent();

BigInteger p =    ((RSAPrivateCrtKey) kp.getPrivate()).getPrimeP();
BigInteger q =    ((RSAPrivateCrtKey) kp.getPrivate()).getPrimeQ();
BigInteger dP =   ((RSAPrivateCrtKey) kp.getPrivate()).getPrimeExponentP();
BigInteger dQ =   ((RSAPrivateCrtKey) kp.getPrivate()).getPrimeExponentQ();
BigInteger qInv = ((RSAPrivateCrtKey) kp.getPrivate()).getCrtCoefficient();