KeyPairGenerator

KeyPairGenerator

java.security

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Java 1.1

This class generates a public/private key pair for a specified cryptographic algorithm. To create a KeyPairGenerator , call one of the static getInstance( ) methods , specifying the name of the algorithm and, optionally , the name or Provider object of the security provider to use. The default "SUN" provider shipped with Java 1.2 supports only the "DSA" algorithm. The "SunJCE" provider of the Java Cryptography Extension (JCE) additionally supports the "DiffieHellman" algorithm.

Once you have created a KeyPairGenerator , initialize it by calling initialize( ) . You can perform an algorithm-independent initialization by simply specifying the desired key size in bits. Alternatively, you can do an algorithm-dependent initialization by providing an appropriate AlgorithmParameterSpec object for the key-generation algorithm. In either case, you may optionally provide your own source of randomness in the guise of a SecureRandom object. Once you have created and initialized a KeyPairGenerator , call genKeyPair( ) to create a KeyPair object. Remember that the KeyPair contains a PrivateKey that must be kept private.

For historical reasons, KeyPairGenerator extends KeyPairGeneratorSpi . Applications should not use any methods inherited from that class.

Figure 14-21. java.security.KeyPairGenerator

 public abstract class  KeyPairGenerator  extends KeyPairGeneratorSpi {  // Protected Constructors  protected  KeyPairGenerator  (String  algorithm  );  // Public Class Methods  public static KeyPairGenerator  getInstance  (String  algorithm  )          throws NoSuchAlgorithmException;  1.4  public static KeyPairGenerator  getInstance  (String  algorithm  ,          Provider  provider  ) throws NoSuchAlgorithmException;        public static KeyPairGenerator  getInstance  (String  algorithm  ,          String  provider  )  throws NoSuchAlgorithmException, NoSuchProviderException;  // Public Instance Methods   1.2  public final KeyPair  genKeyPair  ( );        public String  getAlgorithm  ( );  1.2  public final Provider  getProvider  ( );  1.2  public void  initialize  (java.security.spec.AlgorithmParameterSpec  params  )          throws InvalidAlgorithmParameterException;        public void  initialize  (int  keysize  );  // Public Methods Overriding KeyPairGeneratorSpi  public KeyPair  generateKeyPair  ( );  constant   1.2  public void  initialize  (java.security.spec.AlgorithmParameterSpec  params  ,          SecureRandom  random  )          throws InvalidAlgorithmParameterException;  empty  public void  initialize  (int  keysize  , SecureRandom  random  );  empty  }