java基础---->数字签名算法的介绍

​ 数字签名（又称公钥数字签名）是一种类似写在纸上的普通的物理签名，但是使用了公钥加密领域的技术实现，用于鉴别数字信息的方法。关于数字签名的介绍，可以参见百度百科：http://baike.baidu.com/view/7626.htm。今天，我们就开始学习java中数字签名的使用。

项目结构如下：

DSA算法

一、 HuhxDSA.java

package com.huhx.security;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

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

/**
 * writer: huhx
 */
public class HuhxDSA {
    private final static String src = "http://www.cnblogs.com/huhx";

    public static void main(String[] args) {
        // 初始化签名
        try {
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DSA");
            keyPairGenerator.initialize(512);
            KeyPair keyPair = keyPairGenerator.generateKeyPair();
            DSAPublicKey dsaPublicKey = (DSAPublicKey) keyPair.getPublic();
            DSAPrivateKey dsaPrivateKey = (DSAPrivateKey) keyPair.getPrivate();

            // 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[] result = signature.sign();
            System.out.println("jdk dsa sign: " + Hex.encodeHexString(result));

            // 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(result);
            System.out.println("jdk dsa: " + bool);

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

二、 运行结果如下：

jdk dsa sign: 302d0215009461ae45922c11159d3b6dc4c70eb0748763d23202146f5f9a5eedb36a760cf8b9b1d1d1fdc10636aafe
jdk dsa: true

RSA算法

一、 HuhxRSA.java

package com.huhx.security;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

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

/**
 * writer: huhx
 */
public class HuhxRSA {
    private final static String src = "http://www.cnblogs.com/huhx";

    public static void main(String[] args) {
        try {
            // 初始化签名
            KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
            generator.initialize(512);
            KeyPair keyPair = generator.generateKeyPair();
            RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();

            // 执行签名
            PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey privateKey = keyFactory.generatePrivate(encodedKeySpec);
            Signature signature = Signature.getInstance("MD5withRSA");
            signature.initSign(privateKey);
            signature.update(src.getBytes());
            byte[] result = signature.sign();
            System.out.println("jdk rsa sign: " + Hex.encodeHexString(result));

            // 验证签名
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
            keyFactory = KeyFactory.getInstance("RSA");
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
            signature = Signature.getInstance("MD5withRSA");
            signature.initVerify(publicKey);
            signature.update(src.getBytes());
            boolean bool = signature.verify(result);
            System.out.println("jdk rsa: " + bool);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

二、 运行结果如下：

jdk rsa sign: 564dc7f96c85a7a42e579ae191997c892f234272d220e3f062cf52071e827164fadd52720b69704979fc11810bdbf92b01dd3f5f26a621ffe699ef601d08fb6c
jdk rsa: true

ECDSA算法

一、 HuhxECDSA.java

package com.huhx.security;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

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

/**
 * writer: huhx
 */
public class HuhxECDSA {
    private final static String src = "mhttp://www.cnblogs.com/huhx";

    public static void main(String[] args) {
        try {
            // 初始化签名
            KeyPairGenerator generator = KeyPairGenerator.getInstance("EC");
            generator.initialize(256);
            KeyPair keyPair = generator.generateKeyPair();
            ECPublicKey ecPublicKey = (ECPublicKey) keyPair.getPublic();
            ECPrivateKey ecPrivateKey = (ECPrivateKey) keyPair.getPrivate();

            // 执行签名
            PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());
            KeyFactory keyFactory = KeyFactory.getInstance("EC");
            PrivateKey privateKey = keyFactory.generatePrivate(encodedKeySpec);
            Signature signature = Signature.getInstance("SHA1withECDSA");
            signature.initSign(privateKey);
            signature.update(src.getBytes());
            byte[] result = signature.sign();
            System.out.println("jdk ecdsa sign: " + Hex.encodeHexString(result));

            // 验证签名
            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: " + bool);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

二、 运行结果如下：

jdk ecdsa sign: 30460221009b80596c51ccdf19c5e8e825aca6d85e549a30ee72a1e9b094f7b3a8c8b9310902210098e8dcc6ea932142d8cd9dd80c08fff7359f796571f8a973d3ca6e2dc0931904
jdk ecdsa: true