数字签名算法DSA

import org.apache.commons.codec.binary.Hex;

import java.security.*;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
* Created by pengchao on 2017/10/19.
*/
public class IMoocDSA {
private static String src ="imooc security dsa";
public static void  main(String[] args) {
jdkDSA();
}
public static void  jdkDSA(){
try {
//初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DSA");
keyPairGenerator.initialize(512);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
DSAPublicKey dsaPublicKey = (DSAPublicKey) keyPair.getPublic();
DSAPrivateKey dsaPrivateKey = (DSAPrivateKey) keyPair.getPrivate();

//2.执行签名
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[] bytes = signature.sign();
System.out.println("jdk dsa sign:" + Hex.encodeHexString(bytes));

//3.验证签名
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(bytes);
System.out.println("jdk dsa verify :" + bool);
} catch (Exception e) {
e.printStackTrace();
}

}
}