public static void KeyGenerator() throws Exception {
// //初始化簽名
System.out.println("系統(tǒng)正在初始化……");
 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");
 keyPairGenerator.initialize(256);
 KeyPair keyPair = keyPairGenerator.generateKeyPair();
 ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic();
 ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate();
//把公鑰和私鑰分別存儲(chǔ)在publicKey.key和privateKey.key文件里
String path = new File("").getCanonicalPath();
out(path + "\\privateKey.key", Base64.getEncoder().encodeToString(ecPrivateKey.getEncoded()));
out(path + "\\publicKey.key",Base64.getEncoder().encodeToString(ecPublicKey.getEncoded()));
 System.out.println("你的公鑰存放在：" + path + "\\publicKey.key");
 System.out.println("你的私鑰存放在：" + path + "\\privateKey.key");
 System.out.println("系統(tǒng)已完成初始化。");
 }

//執(zhí)行簽名過(guò)程

public static byte[] SignGen(byte[] ECprivateKey) throws Exception {
KeyFactory keyFactory = KeyFactory.getInstance("EC");
 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ECprivateKey);
 PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
 Signature signature = Signature.getInstance("SHA1withECDSA");
 signature.initSign(privateKey);
 signature.update(data.getBytes());
byte[] result = signature.sign();
return result;
}

//驗(yàn)證簽名過(guò)程

public static booleanVerifiGen(byte[] ECpublicKey, byte[] result) throws Exception {
 KeyFactory keyFactory = KeyFactory.getInstance("EC");
 X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ECpublicKey);
 PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
 Signature signature = Signature.getInstance("SHA1withECDSA");
 signature.initVerify(publicKey);
 signature.update(data.getBytes());
boolean bool = signature.verify(result);
return bool;
}

package ECDSA.demo;

import java.io.*;
import java.security.*;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.Scanner;

public class ECDSA {
private static String data ;
//初始化系統(tǒng)
public static void KeyGenerator() throws Exception {
 System.out.println("系統(tǒng)正在初始化……");
 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");
 keyPairGenerator.initialize(256);
 KeyPair keyPair = keyPairGenerator.generateKeyPair();
 ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic();
 ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate();
//把公鑰和私鑰分別存儲(chǔ)在publicKey.key和privateKey.key文件里
String path = new File("").getCanonicalPath();
out(path + "\\privateKey.key", Base64.getEncoder().encodeToString(ecPrivateKey.getEncoded()));
out(path + "\\publicKey.key",Base64.getEncoder().encodeToString(ecPublicKey.getEncoded()));
 System.out.println("你的公鑰存放在：" + path + "\\publicKey.key");
 System.out.println("你的私鑰存放在：" + path + "\\privateKey.key");
 System.out.println("系統(tǒng)已完成初始化。");
 }
//執(zhí)行簽名過(guò)程
public static byte[] SignGen(byte[] ECprivateKey) throws Exception {
 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ECprivateKey);
 KeyFactory keyFactory = KeyFactory.getInstance("EC");
 PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
 Signature signature = Signature.getInstance("SHA1withECDSA");
 signature.initSign(privateKey);
 signature.update(data.getBytes());
byte[] result = signature.sign();
return result;
 }
//驗(yàn)證簽名過(guò)程
public static boolean VerifiGen(byte[] ECpublicKey, byte[] result) throws Exception {
 X509EncodedKeySpec x509encodedkeyspec= new X509EncodedKeySpec(ECpublicKey);
 KeyFactory keyFactory = KeyFactory.getInstance("EC");
 PublicKey publicKey = keyFactory.generatePublic(x509encodedkeyspec);
 Signature signature = Signature.getInstance("SHA1withECDSA");
 signature.initVerify(publicKey);
 signature.update(data.getBytes());
boolean bool = signature.verify(result);
return bool;
 }
//封裝輸出流
public static void out(String path, String val) {
try {
  val = Base64.getEncoder().encodeToString(val.getBytes("utf-8"));
  FileWriter fw = new FileWriter(path);
  BufferedWriter bw = new BufferedWriter(fw);
  PrintWriter outs = new PrintWriter(bw);
  outs.println(val);
  outs.flush();
  outs.close();
 } catch (Exception ex) {
  ex.printStackTrace();
 }
 }

// 從文件中讀取公私鑰
public static byte[] read(String path){
byte[] sk = null;
try {
  File f=new File(path);
  FileReader fr=new FileReader(f);
  BufferedReader br=new BufferedReader(fr);
  String line=null;
  StringBuffer sb=new StringBuffer();
while((line=br.readLine())!=null) {
byte[] b = Base64.getDecoder().decode(line);
  String[] key = new String(b,"utf-8").split(",,,,,,");
  System.out.println("\n");
if(key.length == 1){
   sk = Base64.getDecoder().decode(key[0]);
  }
else{
throw new Exception("文件錯(cuò)誤");
  }
  }
  br.close();
return sk;
 }
catch(Exception ex)
 {
  ex.printStackTrace();
 }
return sk;
 }

public static void main(String[] args) {
// TODO Auto-generated method stub
try {
KeyGenerator();

  Scanner sc = new Scanner(System.in);
  String str = "";
//輸入要簽名的信息
sc.useDelimiter("\n");
  System.out.print("\n"+"請(qǐng)輸入輸入要簽名的信息按回車結(jié)束：");
if (sc.hasNext()) {
data = sc.next();
  }
//獲取私鑰地址
sc.useDelimiter("\n");
  System.out.print("\n"+"請(qǐng)輸入私鑰地址按回車結(jié)束：");
if (sc.hasNext()) {
  str = sc.next();
  }
//獲取私鑰
byte[] ECprivateKey = read(str.substring(0,str.length()-1));
//產(chǎn)生簽名
byte[] result = SignGen(ECprivateKey);
  System.out.println("數(shù)字簽名的結(jié)果："+ Base64.getEncoder().encodeToString(result));
new Scanner(System.in);
  sc.useDelimiter("\n");
  System.out.print("\n"+"請(qǐng)輸入公鑰地址按回車結(jié)束：");
if (sc.hasNext()) {
  str = sc.next();
  }
//獲取公鑰
byte[] ECpublicKey = read(str.substring(0,str.length()-1));
boolean bool = VerifiGen(ECpublicKey, result);
if(bool == true){
  System.out.println("數(shù)字簽名的驗(yàn)證結(jié)果：通過(guò)驗(yàn)證！");
  }
else {
  System.out.println("請(qǐng)檢查地址輸入地址是否有誤或文件內(nèi)容是否被篡改！");
  }
 } catch (Exception ex) {
  System.out.println("請(qǐng)檢查地址輸入地址是否有誤或文件內(nèi)容是否被篡改！");
//  System.out.println(ex);
}
 }
}