java实验报告五

import java.net.*; import java.io.*; import java.security.*; import java.security.spec.*; import javax.crypto.*; import javax.crypto.spec.*; import javax.crypto.interfaces.*; import java.security.interfaces.*; import java.math.*; public class ComputeTCPServer{ public static void main(String srgs[]) throws Exception { ServerSocket sc = null; Socket socket=null; try { sc= new ServerSocket(4420);//创建服务器套接字 System.out.println("端口号:" + sc.getLocalPort()); System.out.println("服务器已经启动..."); socket = sc.accept(); //等待客户端连接 System.out.println("已经建立连接"); //获得网络输入流对象的引用 BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); ////获得网络输出流对象的引用 PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true); String aline2=in.readLine(); BigInteger c=new BigInteger(aline2); FileInputStream f=new FileInputStream("Skey_RSA_priv.dat"); ObjectInputStream b=new ObjectInputStream(f); RSAPrivateKey prk=(RSAPrivateKey)b.readObject( ); BigInteger d=prk.getPrivateExponent(); BigInteger n=prk.getModulus(); //System.out.println("d= "+d); //System.out.println("n= "+n); BigInteger m=c.modPow(d,n); //System.out.println("m= "+m); byte[] keykb=m.toByteArray(); //String aline3=new String(mt,"UTF8"); //String aline3=parseByte2HexStr(byte buf[]); String aline=in.readLine();//读取客户端传送来的数据 //FileInputStream f2=new FileInputStream("keykb1.dat"); //int num2=f2.available(); //byte[] keykb=new byte[num2]; //f2.read(keykb); byte[] ctext=parseHexStr2Byte(aline); Key k=new SecretKeySpec(keykb,"DESede"); Cipher cp=Cipher.getInstance("DESede"); cp.init(Cipher.DECRYPT_MODE, k); byte []ptext=cp.doFinal(ctext); String p=new String(ptext,"UTF8"); System.out.println("从客户端接收到信息为："+p); //通过网络输出流返回结果给客户端 /*String aline2=in.readLine(); BigInteger c=new BigInteger(aline2); FileInputStream f=new FileInputStream("Skey_RSA_priv.dat"); ObjectInputStream b=new ObjectInputStream(f); RSAPrivateKey prk=(RSAPrivateKey)b.readObject( ); BigInteger d=prk.getPrivateExponent(); BigInteger n=prk.getModulus(); //System.out.println("d= "+d); //System.out.println("n= "+n); BigInteger m=c.modPow(d,n); //System.out.println("m= "+m); byte[] mt=m.toByteArray(); //String aline3=new String(mt,"UTF8");*/ String aline3=in.readLine(); String x=p; 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); if(aline3.equals(result)){ System.out.println("匹配成功"); } out.println("匹配成功"); out.close(); in.close(); sc.close(); } catch (Exception e) { System.out.println(e); } } 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 * 16 + low); } return result; } }