Java by API/java.security/Signature

Signature: initSign(PrivateKey privateKey) throws InvalidKeyException

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.Signature; import sun.misc.BASE64Encoder; public class Main {

 public static void main(String[] args) throws Exception {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
   kpg.initialize(1024);
   KeyPair keyPair = kpg.genKeyPair();
   byte[] data = "test".getBytes("UTF8");
   Signature sig = Signature.getInstance("MD5WithRSA");
   sig.initSign(keyPair.getPrivate());
   sig.update(data);
   byte[] signatureBytes = sig.sign();
   System.out.println("Singature:" + new BASE64Encoder().encode(signatureBytes));
   sig.initVerify(keyPair.getPublic());
   sig.update(data);
   System.out.println(sig.verify(signatureBytes));
 }

}

 </source>
   
  
 
  

Signature: sign() throws SignatureException

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.Signature; import sun.misc.BASE64Encoder; public class Main {

 public static void main(String[] args) throws Exception {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
   kpg.initialize(1024);
   KeyPair keyPair = kpg.genKeyPair();
   byte[] data = "test".getBytes("UTF8");
   Signature sig = Signature.getInstance("MD5WithRSA");
   sig.initSign(keyPair.getPrivate());
   sig.update(data);
   byte[] signatureBytes = sig.sign();
   System.out.println("Singature:" + new BASE64Encoder().encode(signatureBytes));
   sig.initVerify(keyPair.getPublic());
   sig.update(data);
   System.out.println(sig.verify(signatureBytes));
 }

}

 </source>
   
  
 
  

Signature: update(byte[] data) throws SignatureException

   <source lang="java">
 

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.Signature; import sun.misc.BASE64Encoder; public class Main {

 public static void main(String[] args) throws Exception {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
   kpg.initialize(1024);
   KeyPair keyPair = kpg.genKeyPair();
   byte[] data = "test".getBytes("UTF8");
   Signature sig = Signature.getInstance("MD5WithRSA");
   sig.initSign(keyPair.getPrivate());
   sig.update(data);
   byte[] signatureBytes = sig.sign();
   System.out.println("Singature:" + new BASE64Encoder().encode(signatureBytes));
   sig.initVerify(keyPair.getPublic());
   sig.update(data);
   System.out.println(sig.verify(signatureBytes));
 }

}

 </source>