Package IMOOC;
Import Java.security.KeyFactory;
Import Java.security.KeyPair;
Import Java.security.KeyPairGenerator;
Import java.security.NoSuchAlgorithmException;
Import Java.security.PrivateKey;
Import Java.security.PublicKey;
Import Java.security.Signature;
Import Java.security.interfaces.DSAPrivateKey;
Import Java.security.interfaces.DSAPublicKey;
Import Java.security.spec.PKCS8EncodedKeySpec;
Import Java.security.spec.X509EncodedKeySpec;
Import Com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;
public class Imoocdsa {
private static String src = "IMOOC security DSA";
public static void Main (string[] args) {
JDKDSA ();
}
public static void Jdkdsa () {
try {
1. Initializing the key
Keypairgenerator keypairgenerator = keypairgenerator.getinstance ("DSA");
Keypairgenerator.initialize (512);
KeyPair KeyPair = Keypairgenerator.generatekeypair ();
Dsapublickey Dsapublickey = (dsapublickey) keypair.getpublic ();
Dsaprivatekey Dsaprivatekey = (dsaprivatekey) keypair.getprivate ();
2. Execute signature
Pkcs8encodedkeyspec Pkcs8encodedkeyspec = new Pkcs8encodedkeyspec (dsaprivatekey.getencoded ());
Keyfactory keyfactory = keyfactory.getinstance ("DSA");
Privatekey Privatekey = keyfactory.generateprivate (Pkcs8encodedkeyspec);
Signature Signature = signature.getinstance ("Sha1withdsa");
Signature.initsign (Privatekey);
Signature.update (Src.getbytes ());
Byte[] result = Signature.sign ();
System.out.println ("JDK DSA sign:" + hexbin.encode (result));
3. Verifying the signature
X509encodedkeyspec X509encodedkeyspec = new X509encodedkeyspec (dsapublickey.getencoded ());
Keyfactory = Keyfactory.getinstance ("DSA");
PublicKey publickey =keyfactory.generatepublic (X509ENCODEDKEYSPEC);
Signature=signature.getinstance ("Sha1withdsa");
Signature.initverify (PublicKey);
Signature.update (Src.getbytes ());
boolean bool = signature.verify (result);
System.out.println ("JDK DSA Verify:" + bool);
} catch (Exception e) {
TODO auto-generated Catch block
E.printstacktrace ();
}
}
}
Digital Signature Algorithm--2. Dsa
