实习二 数字签名与认证的实现.doc

.实习二 数字签名与认证的实现一、实习目的1理解数字签名的概念和作用；2理解身份认证的基本方式和方法；3掌握Hash函数和数字签名的实现。二、实习要求1实习前认真预习第3章的有关内容；2复习数字签名和身份认证相关内容；3熟悉Java平台的JCE包有关类。三、 实习内容假定两个用户A、B，他们的公私钥对分别是KPUa、KPRa和KPUb、KPRb，分发的消息为M，哈希函数h(x)。请基于RSA算法实现数字签名，阶梯任务如下：以本地两个目录模拟两个用户，实现消息M和签名的模拟分发；实现过程：发送接收方BMM的签名发送方A消息明文MA的私钥加密MM的签名A的公钥解密对比是否是A发送的A将信息M用自己的私钥加密后与M本身一起发送给B,B将签名用A的公钥解密，得出的信息与M对比，如果一致，说明消息就是A发的，因为只有A知道自己的私钥。运行结果：以MD5、SHA-1等哈希函数，实现消息M的摘要，实现M及摘要签名的模拟分发；实现过程：接收方B发送送摘要摘要签名A的公钥解密对比是否是A发送的散列函数求摘要摘要摘要签名消息明文MA的私钥加密A对消息M用散列函数求出摘要，再用自己的私钥对摘要进行签名，将摘要和摘要的签名一起发送给B，B接受后用A的公钥解密摘要签名，将得出的摘要与发送的摘要对比，判断是否是A发送的。MD5：SHA-1：实现M密文状态下的签名与模拟分发；实现过程：B的私钥解密接收方B摘要摘要签名A的公钥解密对比是否是A发送的发送送散列函数求摘要摘要摘要签名消息明文MA的私钥加密密文B的公钥加密明文MA对消息M用B的公钥进行加密，将密文用散列函数求出摘要，再用自己的私钥对摘要进行签名，将密文摘要和摘要的签名一起发送给B，B接受后用A的公钥解密摘要签名，将得出的摘要与发送的摘要对比，判断是否是A发送的，之后再使用自己的私钥解密得到的密文，最终得到明文消息M。运行结果：采用SSL，建立安全通信过程，实现Socket通信的签名分发；将方案移植到某个web应用中，实现实用的签名分发。4、 实验总结 通过这次实验，对于数字签名的方式有了更多了解，认识到非对称密钥体系真的是一个很好的体系，既可以做签名，也可以进行加解密，功能很多。附代码：SKey_RSA.javapackage cn.test.key;import java.io.FileOutputStream;import java.io.ObjectOutputStream;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.PrivateKey;import java.security.PublicKey;public class SKey_RSA public void key_RSA() throws ExceptionKeyPairGenerator kpg = KeyPairGenerator.getInstance(RSA);kpg.initialize(1024);KeyPair kp = kpg.genKeyPair();PublicKey pbkey = kp.getPublic();PrivateKey prkey = kp.getPrivate();FileOutputStream f1 = new FileOutputStream(Skey_RSA_pub1.dat);ObjectOutputStream oo1 = new ObjectOutputStream(f1);oo1.writeObject(pbkey);FileOutputStream f2 = new FileOutputStream(Skey_RSA_pri1.dat);ObjectOutputStream oo2 = new ObjectOutputStream(f2);oo2.writeObject(prkey);oo1.close();oo2.close();f1.close();f2.close();Rsa_Op.javapackage cn.test.key;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.InputStreamReader;import java.io.ObjectInputStream;import java.io.OutputStreamWriter;import java.math.BigInteger;import java.security.Key;import erfaces.RSAPrivateKey;import erfaces.RSAPublicKey;public class Rsa_Op int flag = 0;public byte enc_pub(String s) throws Exceptionbyte b = s.getBytes(UTF8);FileInputStream f = new FileInputStream(Skey_RSA_pub1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPublicKey pbk = (RSAPublicKey)oi.readObject();oi.close();BigInteger e = pbk.getPublicExponent();BigInteger n = pbk.getModulus();BigInteger m = new BigInteger(b);BigInteger m1 = new BigInteger(0);if(pareTo(m1)=-1)m = m.negate();flag = 1;BigInteger c = m.modPow(e, n);System.out.println(M用公钥加密后的密文:);System.out.println(c=+c);byte re = c.toByteArray();String cs = c.toString();BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(Enc_pub_RSA1.dat);bw.write(cs, 0, cs.length();bw.close();return re;public void enc_pri(String s) throws Exceptionbyte b = s.getBytes(UTF8);FileInputStream f = new FileInputStream(Skey_RSA_pri1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPrivateKey prk = (RSAPrivateKey)oi.readObject();oi.close();BigInteger e = prk.getPrivateExponent();BigInteger n = prk.getModulus();BigInteger m = new BigInteger(b);System.out.println(签名前的M=+m);BigInteger m1 = new BigInteger(0);if(pareTo(m1)=-1)m = m.negate();flag = 1;BigInteger c = m.modPow(e, n);System.out.println(签名后的M=+c);/System.out.println(将密钥加密后的密文c=+c);String cs = c.toString();BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(Enc_pri_RSA1.dat);bw.write(cs, 0, cs.length();bw.close();public byte dec_pri() throws ExceptionBufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(Enc_pub_RSA1.dat);String ctext = br.readLine();br.close();BigInteger c = new BigInteger(ctext);FileInputStream f = new FileInputStream(Skey_RSA_pri1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPrivateKey prk = (RSAPrivateKey)oi.readObject();BigInteger d = prk.getPrivateExponent();BigInteger n = prk.getModulus();BigInteger m = c.modPow(d, n);if(flag = 1)m = m.negate();flag = 0;System.out.println(将c解密后得： );System.out.println(m=+m);byte mt = m.toByteArray();oi.close();f.close();return mt;public byte dec_pub() throws ExceptionBufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(Enc_pri_RSA1.dat);String ctext = br.readLine();br.close();BigInteger c = new BigInteger(ctext);FileInputStream f = new FileInputStream(Skey_RSA_pub1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPublicKey pbk = (RSAPublicKey)oi.readObject();BigInteger d = pbk.getPublicExponent();BigInteger n = pbk.getModulus();BigInteger m = c.modPow(d, n);if(flag = 1)m = m.negate();flag = 0;System.out.println(公钥解密后的M=+m);byte b = m.toByteArray();oi.close();f.close();return b;Sig.java:package cn.test.key;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.FileReader;import java.io.ObjectInputStream;import java.security.NoSuchAlgorithmException;import java.security.Signature;import erfaces.RSAPrivateKey;public class Sig public void sigNoz(String s,Rsa_Op ro) throws ExceptionSKey_RSA sr = new SKey_RSA();sr.key_RSA();ro.enc_pri(s);public void sigWithz(String algorithm,String msg) throws ExceptionFileInputStream f = new FileInputStream(Skey_RSA_pri1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPrivateKey prk = (RSAPrivateKey)oi.readObject();oi.close();Signature s=Signature.getInstance(algorithm); s.initSign(prk);byte b = msg.getBytes(UTF8);s.update(b);byte b1 = s.sign();System.out.println(摘要签名：);for(int i=0;ib1.length;i+)System.out.print(b1i+,);FileOutputStream f3=new FileOutputStream(Sign.dat); f3.write(b1); public void sigWithz(String algorithm,byte msg) throws ExceptionFileInputStream f = new FileInputStream(Skey_RSA_pri1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPrivateKey prk = (RSAPrivateKey)oi.readObject();oi.close();Signature s=Signature.getInstance(algorithm); s.initSign(prk);s.update(msg);byte b1 = s.sign();System.out.println(密文摘要签名：);for(int i=0;ib1.length;i+)System.out.print(b1i+,);FileOutputStream f3=new FileOutputStream(Sign.dat); f3.write(b1); Dec_Sig.java:package cn.test.key;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.ObjectInputStream;import java.security.Signature;import erfaces.RSAPublicKey;public class Dec_Sig public String dec_SigNoz(Rsa_Op ro) throws Exceptionbyte ss = ro.dec_pub();String s = new String(ss,UTF8);return s;public boolean dec_SigWithz(String msg,String algorithm) throws Exceptionbyte data = msg.getBytes(UTF8);FileInputStream f2=new FileInputStream(Sign.dat); int num = f2.available();byte b = new bytenum;f2.read(b);FileInputStream f = new FileInputStream(Skey_RSA_pub1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPublicKey pbk = (RSAPublicKey)oi.readObject();Signature s=Signature.getInstance(algorithm); s.initVerify(pbk);s.update(data);boolean result = s.verify(b);return result;public boolean dec_SigWithz(byte msg,String algorithm) throws ExceptionFileInputStream f2=new FileInputStream(Sign.dat); int num = f2.available();byte b = new bytenum;f2.read(b);FileInputStream f = new FileInputStream(Skey_RSA_pub1.dat);ObjectInputStream oi = new ObjectInputStream(f);RSAPublicKey pbk = (RSAPublicKey)oi.readObject();Signature s=Signature.getInstance(algorithm); s.initVerify(pbk);s.update(msg);boolean result = s.verify(b);return result;Test1.java:package cn.test.key;import java.io.BufferedReader;import java.io.FileReader;public class Test1 public static void main(String args) throws Exception / TODO Auto-generated method stubFileReader f = new FileReader(消息M.txt);BufferedReader br =new BufferedReader(f);String ss = br.readLine();Rsa_Op ro =new Rsa_Op();Sig s = new Sig();s.sigNoz(ss,ro);Dec_Sig ds = new Dec_Sig();String decs = ds.dec_SigNoz(ro);System.out.println(签名解密后得到的消息M=+decs);if(ss.equals(decs)System.out.println(验证签名成功！);Test2.java:package cn.test.key;import java.io.BufferedReader;import java.io.FileNotFoundException;import java.io.FileReader;public class Test2 public static void main(String args) throws Exception / TODO Auto-generated method stubSKey_RSA sr = new SKey_RSA();sr.key_RSA();FileReader f = new FileReader(消息M.txt);BufferedReader br =new BufferedReader(f);String ss = br.readLine();Rsa_Op ro =new Rsa_Op();Sig