我必须基本上设计一个echo程序。服务器中的哪个位置侦听端口。收到它得到的东西。解密它，显示它，加密它接收的内容并将其发送回客户端。我正在将数据发送到套接字的方式出错了。因为我认为加密文本可能包含各种垃圾，因此将其作为字符串发送是不可行的，因此我想将其作为字节发送。 我的服务器程序无法读取客户端发送给它的加密文本。
有人可以纠正我吗？
服务器代码
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
import java.net.*;
public class socket_server_simple {
public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
// You cannot create an array using a long type.
// It needs to be an int type.
// Before converting to an int type, check
// to ensure that file is not larger than Integer.MAX_VALUE.
if (length > Integer.MAX_VALUE) {
// File is too large
}
// Create the byte array to hold the data
byte[] bytes = new byte[(int)length];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}
public static String asHex (byte buf[]) {
StringBuffer strbuf = new StringBuffer(buf.length * 2);
int i;
for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10)
strbuf.append("0");
strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}
return strbuf.toString();
}
public static String aes_run(String message, String username, int mode) throws Exception
{
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(256); // 192 and 256 bits may not be available
// Generate the secret key specs.
SecretKey skey = kgen.generateKey();
String keyfilepath=new String(username+".key");
File keyfile = new File(keyfilepath);
byte[] raw = getBytesFromFile(keyfile);
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
System.out.println("Key file found\n\n");
// Instantiate the cipher
byte[] encdecres;
String encdecresstr=new String();
Cipher cipher = Cipher.getInstance("AES");
if(mode==0)
{
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
encdecres= cipher.doFinal(message.getBytes());
encdecresstr= new String(encdecres);
}
else if(mode==1)
{
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
encdecres = cipher.doFinal(message.getBytes());
encdecresstr= new String(encdecres);
}
return encdecresstr;
}
public static void main(String args[]) throws Exception
{
char[] buffer = new char[3000];
String message;
String username;
String orgmsg;
char encryptedmsg[] = new char[400];
if(args.length<1)
{
System.out.println("Usage: java socket_server_simple <port_num>");
System.exit(1);
}
ServerSocket serversock = new ServerSocket(Integer.parseInt(args[0])); //can be any port
System.out.println("Socket Instantiated!\n");
Socket connsock = serversock.accept();
InputStreamReader instr = new InputStreamReader(connsock.getInputStream());
DataOutputStream outstr = new DataOutputStream(connsock.getOutputStream());
System.out.println("Streams Instantiated!\n");
BufferedReader in = new BufferedReader(instr);
System.out.println("Server is up! Waiting for username\n\n");
username = in.readLine();
System.out.println("Username recieved: "+username+"\n\n");
while(true)
{
System.out.println("Waiting for message\n");
//message=in.readLine();
//int len = instr.readLine(encryptedmsg,0,300);
int len = in.read(buffer, 0,3000);
String strEnc = new String(buffer,0,len);
//message = in.readLine();
//System.out.println("len: "+len);
System.out.println("Encrypted msg received: "+strEnc);
/*for(int i=0; i<400; i++)
{
System.out.print((encryptedmsg[i]));
}*/
//String strEnc = new String(encryptedmsg);
//System.out.println(strEnc);
orgmsg=aes_run(strEnc,username,1);
System.out.println("Decrypting message : "+orgmsg+"\n");
//orgmsg=aes_run(encryptedmsg.toString(),username,1);
//System.out.println("Encrypted Message :"+asHex(message.getBytes())+"\nPlain text"+orgmsg+"\n");
//messagereturn = "\"You send me ->" +message.toUpperCase() + "\"\n";
//outstr.writeBytes(messagereturn);
}
}
}
客户代码
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
import java.net.*;
public class socket_client_simple {
public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
// You cannot create an array using a long type.
// It needs to be an int type.
// Before converting to an int type, check
// to ensure that file is not larger than Integer.MAX_VALUE.
if (length > Integer.MAX_VALUE) {
// File is too large
}
// Create the byte array to hold the data
byte[] bytes = new byte[(int)length];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}
public static String asHex (byte buf[]) {
StringBuffer strbuf = new StringBuffer(buf.length * 2);
int i;
for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10)
strbuf.append("0");
strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}
return strbuf.toString();
}
public static String aes_run(String message, String username, int mode) throws Exception
{
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(256); // 192 and 256 bits may not be available
// Generate the secret key specs.
SecretKey skey = kgen.generateKey();
String keyfilepath=new String(username+".key");
File keyfile = new File(keyfilepath);
byte[] raw = getBytesFromFile(keyfile);
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
System.out.println("Key file found\n\n");
// Instantiate the cipher
byte[] encdecres;
String encdecresstr= new String();
Cipher cipher = Cipher.getInstance("AES");
if(mode==0)
{
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
encdecres= cipher.doFinal(message.getBytes());
encdecresstr= new String(encdecres);
}
else if(mode==1)
{
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
encdecres = cipher.doFinal(message.getBytes());
encdecresstr= new String(encdecres);
}
return encdecresstr;
}
public static void main(String[] args) throws Exception
{
String message,encrypted;
String returnmessage;
String username=args[2];
BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in));
if(args.length<3)
{
System.out.println("Usage: java socket_client_simple <ip_address> <Port_num> <username>");
System.exit(1);
}
Socket mysock = new Socket("localhost",Integer.parseInt(args[1]));
System.out.println("Socket Instantiated\n\n");
DataOutputStream out = new DataOutputStream( mysock.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(mysock.getInputStream()));
out.writeBytes(username+"\n");
do
{
System.out.println("Enter Message: ");
message=keyboard.readLine();
System.out.println("Sending message\n");
//System.out.println(aes_run(message.getBytes(),username,0) + "\n");
encrypted = aes_run(message,username,0);
System.out.println("length: "+encrypted.length());
out.write(encrypted + "\n");
System.out.println("message sent: "+encrypted );
System.out.println("Waiting for reply\n\n");
returnmessage = in.readLine();
System.out.println("Server replied: " + aes_run(returnmessage,username,1));
}while(!message.equals("bye"));
mysock.close();
}
}
答案 0 :(得分：0)
原来问题在于将数据作为加密的字节流发送。我已经使用java中的Object流解决了这个问题并完成了我所需要的工作。
感谢您的帮助。