Java Test Four

Beijing Institute of Electronic Technology (BESTI)

Lab Report

Course: Java class: 1352 Name: Zhu No.: 20135237

Score: Instructor: Lou Jia Peng Experimental Date: 2015.6.11

Experiment level: Preview degree: Experiment time: 15:30~18:00

Instrument Group: 37 Compulsory/elective: Elective experiment serial number: (four)

Experiment Name: Java Object-oriented programming

Experimental Purpose:

1. Mastering the Java Network programming method;

2. Master the method of Java security programming;

3. Comprehensive use of various technologies;

Experiment Content One:

1. Run the textbook on TCP code, pair, one-man server, one-person client.

2. Use the encryption and decryption code package, compile run code, client-side encryption, server decryption.

3. The client encrypts plaintext and sends ciphertext over TCP.

4. Encryption uses Des,des encryption key to send to the server, using the server's public key encryption, public key algorithm using RSA, verify the integrity of sending information using MD5.

Pair network programming

Server:

Client:

Experiment Code:

Server:

Import java.net.*;
Import java.io.*;
Import java.security.*;
Import javax.crypto.*;
Import javax.crypto.spec.*;
Import java.security.spec.*;
Import javax.crypto.interfaces.*;
Import java.security.interfaces.*;
Import java.math.*;
public class Computetcpclient {
public static void Main (String srgs[]) throws exception{
try {
Keygenerator kg=keygenerator.getinstance ("Desede");
Kg.init (168);
Secretkey K=kg.generatekey ();
Byte[] ptext2=k.getencoded ();
String Kstr=parsebyte2hexstr (KB);

To create a socket object that connects to a specified port on a specific server
Socket socket = new Socket ("10.1.0.243", 4410);
Get the network input stream from the server side
BufferedReader in = new BufferedReader (New InputStreamReader (Socket.getinputstream ()));
Obtain a network output stream from the client to the server-side output data
PrintWriter out=new PrintWriter (New BufferedWriter (OutputStreamWriter ()), true);
Create a keyboard input stream so that clients can enter information from the keyboard
BufferedReader stdin = new BufferedReader (new InputStreamReader (system.in));

FileInputStream f3=new FileInputStream ("Skey_rsa_pub.dat");
ObjectInputStream b2=new ObjectInputStream (F3);
Rsapublickey pbk= (Rsapublickey) b2.readobject ();
BigInteger e=pbk.getpublicexponent ();
BigInteger N=pbk.getmodulus ();
System.out.println ("e=" +e);
System.out.println ("n=" +n);
Byte ptext2[]=kstr.getbytes ("UTF8");
BigInteger m=new BigInteger (PTEXT2);
BigInteger C=m.modpow (e,n);
System.out.println ("c=" +c);
String cs=c.tostring ();
OUT.PRINTLN (CS); Transfer over the network to the server

System.out.print ("Please enter data to be sent:");
String S=stdin.readline (); Read the data to be sent from the keyboard
Cipher cp=cipher.getinstance ("Desede");
Cp.init (Cipher.encrypt_mode, k);
Byte ptext[]=s.getbytes ("UTF8");
Byte ctext[]=cp.dofinal (ptext);
String str=parsebyte2hexstr (Ctext);
Out.println (str); Transfer over the network to the server

String x=s;
MessageDigest m2=messagedigest.getinstance ("MD5");
M2.update (X.getbytes ());
byte a[]=m2.digest ();
String result= "";
for (int i=0; i<a.length; i++) {
Result+=integer.tohexstring (0X000000FF & A[i]) |
0XFFFFFF00). substring (6);
}
SYSTEM.OUT.PRINTLN (result);
OUT.PRINTLN (result);

/*s=result;
FileInputStream f3=new FileInputStream ("Skey_rsa_pub.dat");
ObjectInputStream b2=new ObjectInputStream (F3);
Rsapublickey pbk= (Rsapublickey) b2.readobject ();
BigInteger e=pbk.getpublicexponent ();
BigInteger N=pbk.getmodulus ();
System.out.println ("e=" +e);
System.out.println ("n=" +n);
Byte ptext2[]=s.getbytes ("UTF8");
BigInteger m=new BigInteger (PTEXT2);
BigInteger C=m.modpow (e,n);
System.out.println ("c=" +c);
String cs=c.tostring ();
OUT.PRINTLN (CS); Transfer to server via network */

Str=in.readline ();//Read results from the network input stream
SYSTEM.OUT.PRINTLN ("The result received from the server is:" +STR); Results returned by the output server
}
catch (Exception e) {
System.out.println (e);
}
finally{
Stdin.close ();
In.close ();
Out.close ();
Socket.close ();
}

}
public static String Parsebyte2hexstr (byte buf[]) {
StringBuffer sb = new StringBuffer ();
for (int i = 0; i < buf.length; i++) {
String hex = integer.tohexstring (Buf[i] & 0xFF);
if (hex.length () = = 1) {
Hex = ' 0 ' + hex;
}
Sb.append (Hex.touppercase ());
}
return sb.tostring ();
}
public static byte[] Parsehexstr2byte (String hexstr) {
if (Hexstr.length () < 1)
return null;
Byte[] result = new Byte[hexstr.length ()/2];
for (int i = 0;i< hexstr.length ()/2; i++) {
int high = Integer.parseint (Hexstr.substring (i*2, i*2+1), 16);
int low = Integer.parseint (Hexstr.substring (i*2+1, i*2+2), 16);
Result[i] = (byte) (high * + low);
}
return result;
}
}

Client:

Import java.net.*;
Import java.io.*;
Import java.security.*;
Import javax.crypto.*;
Import javax.crypto.spec.*;
Import java.security.spec.*;
Import javax.crypto.interfaces.*;
Import java.security.interfaces.*;
Import java.math.*;
public class Computetcpclient {
public static void Main (String srgs[]) throws exception{
try {
Keygenerator kg=keygenerator.getinstance ("Desede");
Kg.init (168);
Secretkey K=kg.generatekey ();
Byte[] ptext2=k.getencoded ();
String Kstr=parsebyte2hexstr (KB);

To create a socket object that connects to a specified port on a specific server
Socket socket = new Socket ("10.1.0.243", 4410);
Get the network input stream from the server side
BufferedReader in = new BufferedReader (New InputStreamReader (Socket.getinputstream ()));
Obtain a network output stream from the client to the server-side output data
PrintWriter out=new PrintWriter (New BufferedWriter (OutputStreamWriter ()), true);
Create a keyboard input stream so that clients can enter information from the keyboard
BufferedReader stdin = new BufferedReader (new InputStreamReader (system.in));

FileInputStream f3=new FileInputStream ("Skey_rsa_pub.dat");
ObjectInputStream b2=new ObjectInputStream (F3);
Rsapublickey pbk= (Rsapublickey) b2.readobject ();
BigInteger e=pbk.getpublicexponent ();
BigInteger N=pbk.getmodulus ();
System.out.println ("e=" +e);
System.out.println ("n=" +n);
Byte ptext2[]=kstr.getbytes ("UTF8");
BigInteger m=new BigInteger (PTEXT2);
BigInteger C=m.modpow (e,n);
System.out.println ("c=" +c);
String cs=c.tostring ();
OUT.PRINTLN (CS); Transfer over the network to the server

System.out.print ("Please enter data to be sent:");
String S=stdin.readline (); Read the data to be sent from the keyboard
Cipher cp=cipher.getinstance ("Desede");
Cp.init (Cipher.encrypt_mode, k);
Byte ptext[]=s.getbytes ("UTF8");
Byte ctext[]=cp.dofinal (ptext);
String str=parsebyte2hexstr (Ctext);
Out.println (str); Transfer over the network to the server

String x=s;
MessageDigest m2=messagedigest.getinstance ("MD5");
M2.update (X.getbytes ());
byte a[]=m2.digest ();
String result= "";
for (int i=0; i<a.length; i++) {
Result+=integer.tohexstring (0X000000FF & A[i]) |
0XFFFFFF00). substring (6);
}
SYSTEM.OUT.PRINTLN (result);
OUT.PRINTLN (result);

/*s=result;
FileInputStream f3=new FileInputStream ("Skey_rsa_pub.dat");
ObjectInputStream b2=new ObjectInputStream (F3);
Rsapublickey pbk= (Rsapublickey) b2.readobject ();
BigInteger e=pbk.getpublicexponent ();
BigInteger N=pbk.getmodulus ();
System.out.println ("e=" +e);
System.out.println ("n=" +n);
Byte ptext2[]=s.getbytes ("UTF8");
BigInteger m=new BigInteger (PTEXT2);
BigInteger C=m.modpow (e,n);
System.out.println ("c=" +c);
String cs=c.tostring ();
OUT.PRINTLN (CS); Transfer to server via network */

Str=in.readline ();//Read results from the network input stream
SYSTEM.OUT.PRINTLN ("The result received from the server is:" +STR); Results returned by the output server
}
catch (Exception e) {
System.out.println (e);
}
finally{
Stdin.close ();
In.close ();
Out.close ();
Socket.close ();
}

}
public static String Parsebyte2hexstr (byte buf[]) {
StringBuffer sb = new StringBuffer ();
for (int i = 0; i < buf.length; i++) {
String hex = integer.tohexstring (Buf[i] & 0xFF);
if (hex.length () = = 1) {
Hex = ' 0 ' + hex;
}
Sb.append (Hex.touppercase ());
}
return sb.tostring ();
}
public static byte[] Parsehexstr2byte (String hexstr) {
if (Hexstr.length () < 1)
return null;
Byte[] result = new Byte[hexstr.length ()/2];
for (int i = 0;i< hexstr.length ()/2; i++) {
int high = Integer.parseint (Hexstr.substring (i*2, i*2+1), 16);
int low = Integer.parseint (Hexstr.substring (i*2+1, i*2+2), 16);
Result[i] = (byte) (high * + low);
}
return result;
}
}

Statistics for PSP (Personal software Process) Time:

Steps	time-consuming ( min )	Percentage
Demand analysis	30	12.5%
Design	70	29.2%
Code implementation	70	29.2%
Test	40	16.7%
Analysis Summary	30	12.5%

Problems encountered in the experiment:

To this test is still not very likely, through a large number of students, and their own search online always got it. Port consistency is required for both client and server settings.

Group members:

Lu Songhon: http://www.cnblogs.com/lv-20135229/p/4553600.html

Wong Wai Yip: http://www.cnblogs.com/1551127024hwy/

Java Test Four