数字签名算法--3.ECDSA

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.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.security.Signature;


import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;
//import com.sun.org.apache.bcel.internal.classfile.Signature;


public class ImoocECDSA {


private static String src = "imooc security ecdsa";
public static void main(String[] args) {
jdkECDSA();
}
//java7以后使用
public static void jdkECDSA()
{
try {
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");
keyPairGenerator.initialize(256);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic();
ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate();

PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("EC");
PrivateKey privateKey =keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Signature  signature = Signature.getInstance("SHA1withECDSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
byte[] result = signature.sign();
System.out.println("jdk ecdsa sign:"+HexBin.encode(result));

X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("EC");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
signature =Signature.getInstance("SHA1withECDSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
boolean bool = signature.verify(result);
System.out.println("jdk ecdsa verify:"+bool);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}