数字签名编程与实现

刺骨的言语ヽ痛彻心扉 2022-06-15 05:50 271阅读 0赞

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