des密码java版本.doc

代码：主函数所在类：package ning.hao;import java.io.FileNotFoundException;import java.io.UnsupportedEncodingException;public class Application public static void main(String args) throws UnsupportedEncodingExceptionSkey_DES k_DES=new Skey_DES();/get keyk_DES.getKey();SEnc en=new SEnc();en.getPlainText();en.displayPlaintext();en.encryptionAndStoreToFile();en.displayCrytionText();try SDec de=new SDec();de.displayPlaintext();catch (FileNotFoundException e) 其他类：（1）package ning.hao;import java.io.*;import javax.crypto.*;import javax.crypto.spec.SecretKeySpec;public class SDec FileInputStream f;int num;int num1;byte cText;FileInputStream f2;byte keykb;byte pText;SecretKeySpec k;Cipher cp;ObjectInputStream oI;SDec() throws FileNotFoundExceptiontryf=new FileInputStream(SEnc.dat);/read from file SEnc.datnum=f.available();cText=new bytenum;f.read(cText);/read in cTextf2=new FileInputStream(key1.dat);oI=new ObjectInputStream(f2);/num1=f2.available();/keykb=new bytenum1;k=(SecretKeySpec)oI.readObject();/强制类型转换/k=new SecretKeySpec(keykb,DESede);/密钥空间cp=Cipher.getInstance(DESede);cp.init(Cipher.DECRYPT_MODE, k);pText=cp.doFinal(cText);catch(Exception e)void displayPlaintext() throws UnsupportedEncodingExceptionString p=new String(pText);System.out.println(afer encryption:);System.out.println(p);（2）package ning.hao;import java.io.*;import java.security.Key;import java.util.Scanner;import javax.crypto.*;public class SEnc String s;FileInputStream f;ObjectInputStream b;Cipher cp;Key k;byte pText;/store plainTextbyte cText;SEnc()trys=new String();f=new FileInputStream(key1.dat);b=new ObjectInputStream(f);k=(Key)b.readObject();cp=Cipher.getInstance(DESede);/initialize Cipher objectcp.init(Cipher.ENCRYPT_MODE, k);/set encryption modecatch(Exception e)e.printStackTrace();System.out.println(ERROR);void getPlainText() throws UnsupportedEncodingExceptionSystem.out.println(Enter a plainText,stop ends with #);Scanner sc=new Scanner(System.in);while(!s.endsWith(#)s=sc.next();pText=s.getBytes(UTF8);void displayPlaintext()System.out.println(plaintext:);for(int i=0;ipText.length;i+)System.out.print(pTexti);System.out.println();void displayCrytionText()System.out.println(ciphertext);for(int i=0;ipText.length;i+)System.out.print(cTexti);System.out.println();void encryptionAndStoreToFile()try cText=cp.doFinal(pText);FileOutputStream f=new FileOutputStream(SEnc.dat); f.write(cText); catch (Exception e) System.out.println(Have error when encryption!); （3）package ning.hao;import java.io.*;import javax.crypto.*;public class Skey_DES KeyGenerator kg; SecretKey k; FileOutputStream f; ObjectOutputStream b; Skey_DES() try kg=KeyGenerator.getInstance(DESede); kg.init(168); catch(Exception e) System.out.println(Mabye error); void getKey() tr