我以字节数组格式发送多个命令，并根据在典型客户端/服务器通信中发送的命令接收响应。我的Java应用程序是在Windows 7上运行的客户端，我知道要发送什么命令以及我希望在响应中收到什么。但是，我没有任何控制权或对服务器源代码有任何了解。
我遇到的问题是，在我发送的第二个命令或之后的任何命令中，数组的第一个字节被删除。当我发送第一个命令时，我得到了正确的响应，因为没有丢弃第一个字节。当发送下一个命令或之后的任何命令时，第一个字节被丢弃，服务器没有响应，因为命令的格式不正确，服务器无法识别。
我通过Java SSLSocket DataOutputStream发送这些命令，当然我在DataInputStream上接收响应。我首先与服务器进行握手，并在握手成功后继续。此时是我发送第一个命令并以十六进制显示此处显示的响应：
Sending: 01 03 03
Receive: 01 0e fd 85 02 09 01 01 04 01 06
发送下一个命令：
Sending: 01 48 65 6c 6c 6f
但这是我没有收到服务器响应的地方。
当打印出javax.net.debug输出时，我可以看到第一个字节＆＃39; 01＆＃39;以某种方式丢失或失踪。
Padded plaintext before ENCRYPTION: len = 32
0000: 48 65 6C 6C 6F FE 57 F9 4A 29 13 8F 2B AB 71 A3 Hello.W.J)..+.q.
0010: 16 12 29 FF D5 DE 12 48 8B 06 06 06 06 06 06 06 ..)....H........
main, WRITE: TLSv1 Application Data, length = 32
[Raw write]: length = 37
0000: 17 03 01 00 20 34 42 ED 88 FC 41 2D 13 1A FD BA .... 4B...A-....
0010: 64 0E 9D C7 FE 11 76 96 48 09 A6 BC B2 BC 0E FA d.....v.H.......
0020: C8 5B 79 4B 82 .[yK.
以下是我的源代码：
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.HandshakeCompletedEvent;
import javax.net.ssl.HandshakeCompletedListener;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.X509TrustManager;
import javax.net.ssl.TrustManager;
import java.security.KeyStore;
public class SSLSocketTest
{
private SSLSocket sslSocket = null;
private SSLSocketFactory sslSocketFactory = null;
private String ipAddress = "192.168.100.99";
private int port = 9999;
DataOutputStream dataOS = null;
DataInputStream dataIS = null;
private boolean handshakeSuccessful = false;
public static void main(String[] args)
{
SSLSocketTest sslSocketTest = new SSLSocketTest();
sslSocketTest.sslSocketConnect();
}
SSLSocketTest()
{
System.setProperty("javax.net.debug", "all");
try{
File certFile = new File("cacerts");
KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
char[] certPassword = "changeit".toCharArray();
InputStream fileIS = new FileInputStream(certFile);
keyStore.load(fileIS, certPassword);
fileIS.close();
SSLContext sslContext = SSLContext.getInstance("TLSv1");
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
trustManagerFactory.init(keyStore);
X509TrustManager defaultTrustManager = (X509TrustManager)trustManagerFactory.getTrustManagers()[0];
sslContext.init(null, new TrustManager[] {defaultTrustManager}, null);
sslSocketFactory = sslContext.getSocketFactory();
}catch(Exception e){
e.printStackTrace();
}
}
public void sslSocketConnect()
{
try{
sslSocket = (SSLSocket) sslSocketFactory.createSocket(ipAddress, port);
dataOS = new DataOutputStream(sslSocket.getOutputStream());
dataIS = new DataInputStream(sslSocket.getInputStream());
sslSocket.setSoTimeout(15000);
//Handshake
sslSocket.addHandshakeCompletedListener(new MyHandshakeListener());
sslSocket.startHandshake();
while(!handshakeSuccessful)
{
Thread.sleep(100);
}
//Sending commands
byte[] firstCommand = new byte[]{(byte)0x01, (byte)0x03, (byte)0x03};
String[] firstCommandResponse = processCommand(firstCommand);
byte[] secondCommand = new byte[]{(byte)0x01, (byte)0x48, (byte)0x65, (byte)0x6C, (byte)0x6C, (byte)0x6F};
String[] secondCommandResponse = processCommand(secondCommand);
disconnect();
}catch(Exception e){
e.printStackTrace();
}
}
public void disconnect()
{
try{
byte[] endConnection = new byte[]{(byte)0x01, (byte)0x01, (byte)0x02, (byte)0x03};
processCommand(endConnection);
dataOS.close();
dataIS.close();
sslSocket.close();
}catch (Exception e){
e.printStackTrace();
}
}
public String[] processCommand(byte[] command)
{
String[] returnResponse = null;
byte[] commandResponse = new byte[120];
byte[] trimCommandResponse;
try{
int commandResponseLength = -1;
int errorCount = 0;
while(commandResponseLength == -1)
{
StringBuilder cmdStr = new StringBuilder();
cmdStr.append("Sending: ");
for(int i=0; i<command.length; i++)
{
cmdStr.append(fixHexStringData(Integer.toHexString(command[i])) + " ");
}
System.out.println(cmdStr.toString());
dataOS.write(command, 0, command.length);
dataOS.flush();
commandResponseLength = dataIS.read(commandResponse);
errorCount++;
if(errorCount == 3)
{
throw new Exception();
}
}
returnResponse = new String[commandResponseLength];
trimCommandResponse = new byte[commandResponseLength];
//Getting Reponse Data
for(int i=0; i<commandResponseLength; i++)
{
returnResponse[i] = fixHexStringData(Integer.toHexString(commandResponse[i]));
trimCommandResponse[i] = commandResponse[i];
}
StringBuilder rcvStr = new StringBuilder();
rcvStr.append("Receive: ");
for(int i=0; i<returnResponse.length; i++)
{
rcvStr.append(returnResponse[i] + " ");
}
System.out.println(rcvStr.toString());
}catch(Exception e){
e.printStackTrace();
}
return returnResponse;
}
private String fixHexStringData(String dataByte)
{
if(dataByte.length() < 2)
{
dataByte = "0" + dataByte;
}
else if(dataByte.length() > 2)
{
dataByte = dataByte.substring(dataByte.length()-2);
}
return dataByte;
}
class MyHandshakeListener implements HandshakeCompletedListener
{
public void handshakeCompleted(HandshakeCompletedEvent e)
{
System.out.println("Handshake succesful!");
handshakeSuccessful = true;
}
}
}
我的问题是：
答案 0 :(得分：0)
看起来这实际上是JSSE实现的一个功能，它在两个数据包之间分割数据。第一个字节在一个数据包中，其余的在下一个数据包中。更多细节见this answer
您应该可以通过添加
来覆盖此功能System.setProperty("jsse.enableCBCProtection", "false");