package com.alex.security;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
public class DigitalSignature {
public static void main(String[] args) throws Exception{
//得到keyPairGenerator 的实例对象,并调用其generateKeyPair()方法得到KeyPair对象
KeyPair keyPair= KeyPairGenerator.getInstance("RSA").generateKeyPair();
//调用KeyPair对象的getPrivate和getPublic方法,分别得到PrivateKey对象和PublicKey对象。
PrivateKey privateKey = keyPair.getPrivate();
PublicKey publicKey = keyPair.getPublic();
sign(privateKey);
verifySign(publicKey);
}
private static void verifySign(PublicKey publicKey) throws Exception{
//调用Signature对象的initVerify()方法和指定PublicKey对象,然后调用update方法和verify()方法对原始数据的签名进行验证
Signature signature = Signature.getInstance("SHA1withRSA");
signature.initVerify(publicKey);
signature.update("这是数字签名".getBytes());
byte[] verifyData = readData("D:/signature.data");
System.out.println("数字签名检验结果:"+signature.verify(verifyData));
}
private static void sign(PrivateKey privateKey) throws Exception {
//得到Signature的实例对象,调用其initSign()方法和指定PrivateKey对象,然后调用update方法和sign方法产生签名
Signature signature = Signature.getInstance("SHA1withRSA");
signature.initSign(privateKey);
signature.update("这是数字签名".getBytes());
byte[] signData = signature.sign();
savaData(signData,"D:/signature.data");
}
private static void savaData(byte[] data,String dataPath) throws Exception{
FileOutputStream fos = new FileOutputStream(dataPath);
fos.write(data);
fos.close();
}
private static byte[] readData(String dataPath) throws Exception{
FileInputStream fis = new FileInputStream(dataPath);
byte[] src = new byte[fis.available()];
int total=0;
int len = 0;
while(total<src.length){
total = total+len;
len=fis.read(src, total, src.length-total);
}
fis.close();
return src;
}
}
运行结果:
数字签名检验结果:true