Java by API/java.security/KeyPairGenerator

KeyPairGenerator: generateKeyPair()

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.SecureRandom; public class Main {

 public static void main(String[] args) throws Exception {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA");
   kpg.initialize(1024, new SecureRandom());
   KeyPair dsaKeyPair = kpg.generateKeyPair();
 }

}

 </source>
   
  
 
  

KeyPairGenerator: genKeyPair()

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class Main {

 public static void main(String[] args) {
   if (args.length != 2) {
     String err = "Usage: KeyGeneratorApp algorithmName keySize";
     System.out.println(err);
     System.exit(0);
   }
   int keySize = (new Integer(args[1])).intValue();
   SecretKey skey = null;
   KeyPair keys = null;
   String algorithm = args[0];
   try {
     KeyPairGenerator kpg = KeyPairGenerator.getInstance(algorithm);
     kpg.initialize(keySize);
     keys = kpg.genKeyPair();
   } catch (NoSuchAlgorithmException ex1) {
     try {
       KeyGenerator kg = KeyGenerator.getInstance(algorithm);
       kg.init(keySize);
       skey = kg.generateKey();
     } catch (NoSuchAlgorithmException ex2) {
       System.out.println("Algorithm not supported: " + algorithm);
       System.exit(0);
     }
   }
 }

}

 </source>
   
  
 
  

KeyPairGenerator: getInstance(String algorithm) throws NoSuchAlgorithmException

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class Main {

 public static void main(String[] args) {
   if (args.length != 2) {
     String err = "Usage: KeyGeneratorApp algorithmName keySize";
     System.out.println(err);
     System.exit(0);
   }
   int keySize = (new Integer(args[1])).intValue();
   SecretKey skey = null;
   KeyPair keys = null;
   String algorithm = args[0];
   try {
     KeyPairGenerator kpg = KeyPairGenerator.getInstance(algorithm);
     kpg.initialize(keySize);
     keys = kpg.genKeyPair();
   } catch (NoSuchAlgorithmException ex1) {
     try {
       KeyGenerator kg = KeyGenerator.getInstance(algorithm);
       kg.init(keySize);
       skey = kg.generateKey();
     } catch (NoSuchAlgorithmException ex2) {
       System.out.println("Algorithm not supported: " + algorithm);
       System.exit(0);
     }
   }
 }

}

 </source>
   
  
 
  

KeyPairGenerator: initialize(int keysize)

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class Main {

 public static void main(String[] args) {
   if (args.length != 2) {
     String err = "Usage: KeyGeneratorApp algorithmName keySize";
     System.out.println(err);
     System.exit(0);
   }
   int keySize = (new Integer(args[1])).intValue();
   SecretKey skey = null;
   KeyPair keys = null;
   String algorithm = args[0];
   try {
     KeyPairGenerator kpg = KeyPairGenerator.getInstance(algorithm);
     kpg.initialize(keySize);
     keys = kpg.genKeyPair();
   } catch (NoSuchAlgorithmException ex1) {
     try {
       KeyGenerator kg = KeyGenerator.getInstance(algorithm);
       kg.init(keySize);
       skey = kg.generateKey();
     } catch (NoSuchAlgorithmException ex2) {
       System.out.println("Algorithm not supported: " + algorithm);
       System.exit(0);
     }
   }
 }

}

 </source>