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Instances from Programs must use the class javax.net.ssl.SSLSocket should be created instead of normal Sockets when transferring objects over communication channels. SSLSockets provide a layer of class rather than the java.net.Socket class when transferring sensitive data over insecure communication channels. The class SSLSocket provides security protocols such as SSL or TLSSecure Sockets Layer/Transport Layer Security (SSL/TLS) to ensure that the channel is not vulnerable to eavesdropping and malicious tampering.

The principal protections included in SSLSockets SSLSocket that are not provided by the Socket class are : Java [API 2014]:

Integrity Protection. : SSL protects against modification of messages by an active wiretapper.
Authentication. : In most modes, SSL provides peer authentication. Servers are usually authenticated, and clients may be authenticated as requested by servers.
Confidentiality (Privacy Protectionprivacy protection). : In most modes, SSL encrypts data being sent between client and server. This protects the confidentiality of data , so that passive wiretappers won't see sensitive data such as financial information or personal information of many kinds.

It is also important to use SSL for secure remote method invocation (RMI) communications because RMI depends on object serialization, and serialized data must be safeguarded in transit. Gong, Ellison, and Dageforde [Gong 2003] describe how to secure RMI communications using SSLSocket.

Note that this rule lacks any assumptions about the integrity of the data being sent down a socket. For information about ensuring data integrity, see SER02-J. Sign then seal objects before sending them outside a trust boundary.

Noncompliant Code Example

This noncompliant code example shows the use of regular sockets for a server application that does not fails to protect sensitive information in transit. Te The insecure code for the corresponding client application follows the server's code.

Code Block

bgColor	#FFCCCC


import java.net.ServerSocket;
import java.net.Socket;
import java.io.*; 

public   
// Exception handling has been omitted for the sake of brevity
class EchoServer { 
  public static void main(String[] args) throws IOException {
    ServerSocket serverSocket = null;
    try { 
      ServerSocket serverSocket = new ServerSocket(100079999); 
      Socket socket = serverSocket.accept();
			
      PrintWriter out = new PrintWriter( socket.getOutputStream(), true); 
      BufferedReader in = new BufferedReader(
          new InputStreamReader( socket.getInputStream())); 

      String inputLine; 

      while ((inputLine = in.readLine()) != null) { 
        System.out.println (inputLine); 
        out.println(inputLine); 
      }
 

   } finally {
      if out.close(); 
(serverSocket != null) {
        in.close(); 
try {
       socket   serverSocket.close();
  
    }
   } catch (ExceptionIOException ex) {
   
       /*/ Handle exception*/
error
        }
      }
    }
  }

{code:bgColor=#FFCCCC}
import java.io.*;
import java.net.*;

public class EchoClient {
  public static void main(String[] args) 
                          throws UnknownHostException, IOException {
    Socket socket = null;
    try {
      Socket socket = new Socket("localhost", 9999);
						
      PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
      BufferedReader in = new BufferedReader(
          new InputStreamReader(socket.getInputStream()));

      BufferedReader stdIn = new BufferedReader(
          new InputStreamReader(System.in));
			
      String userInput;

      while ((userInput = stdIn.readLine()) != null) {
        out.println(userInput);
	        System.out.println(in.readLine());
      } 

    }  out.close();
finally {
      if in.close();
(socket != null) {
         stdIn.close();
try {
          socket.close();
    }
    } catch (ExceptionIOException ex) {
 
         //*Handle exception*/
 Handle error
        }
      }
    }
  }
}

Note that the sockets are properly closed in accordance with ERR05-J. Do not let checked exceptions escape from a finally block.

Compliant

...

Solution

This compliant solution makes use of SSLSockets uses SSLSocket to protect packets using the SSL and /TLS security protocols.:

Code Block

bgColor	#CCCCFF


import javax.net.ssl.SSLServerSocket;
import javax.net.ssl.SSLServerSocketFactory;
import javax.net.ssl.SSLSocket;
import java.io.*;

public // Exception handling has been omitted for the sake of brevity
class EchoServer {
  public static void main(String[] args) throws IOException {
    SSLServerSocket sslServerSocket = null;
    try {
      SSLServerSocketFactory sslserversocketfactorysslServerSocketFactory =
          (SSLServerSocketFactory) SSLServerSocketFactory.getDefault();
      SSLServerSocket sslserversocketsslServerSocket = (SSLServerSocket) sslserversocketfactory.sslServerSocketFactory.
                        createServerSocket(9999);
      SSLSocket sslsocketsslSocket = (SSLSocket) sslserversocketsslServerSocket.accept();

      PrintWriter out = new PrintWriter( sslsocketsslSocket.getOutputStream(),true);
      BufferedReader in = new BufferedReader(new InputStreamReader( sslsocket.getInputStream()));
            new InputStreamReader(sslSocket.getInputStream()));
      String inputLine; 
            
      while ((inputLine = in.readLine()) != null) { 
        System.out.println (inputLine); 
	        out.println(inputLine); 
      } 
			
    } finally {
      if out.close(); 
(sslServerSocket != null) {
        in.close(); 
try {
        sslsocket  sslServerSocket.close(); 
    } 
   } catch (ExceptionIOException ex) {
    
      /*/ Handle exception*/
error
        }
 
     }
    }

import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import java.io.*;

public  }
}

class EchoClient {
  public static void main(String[] args) throws IOException {
    SSLSocket sslSocket = null;
    try {
      SSLSocketFactory sslsocketfactorysslSocketFactory =
          (SSLSocketFactory) SSLSocketFactory.getDefault();
      sslSocket = 
       SSLSocket sslsocket = (SSLSocket) sslsocketfactorysslSocketFactory.createSocket("localhost", 9999);

      PrintWriter out = new PrintWriter(sslsocketsslSocket.getOutputStream(), true);
      BufferedReader in = new BufferedReader(
          new InputStreamReader(sslsocketsslSocket.getInputStream()));
			
      BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
            new InputStreamReader(System.in));
      String userInput;

      while ((userInput = stdIn.readLine()) != null) {
        out.println(userInput);
	        System.out.println(in.readLine());
      }

    }  out.close();
finally {
      if in.close();(sslSocket != null) {
      stdIn.close();
  try {
          sslsocketsslSocket.close();		
    } 
   } catch (ExceptionIOException ex) {
  
        /*Handle exception*// Handle error
        }
      }
    }
  }
}

Note that a program Programs that makes use of SSLSockets SSLSocket will hang if it tries block indefinitely if they attempt to connect to a port that is not using SSL and, similarly. Similarly, a program that does not use SSLSockets SSLSocket will hang block when trying attempting to establish a connection through a port that uses SSL.

...

does use SSL.

Note that SSLSocket does not validate host names, so providing an arbitrary host name to an SSLSocket is still vulnerable to a man-in-the-middle attack. Host names should be validated separately. The HttpsURLConnection class validates host names and is a suitable solution for secure web sockets.

Exceptions

MSC00-J-EX0: Because of the mechanisms that SSLSocket provides to ensure the secure transfer of packets, significant performance overhead may result. Regular sockets are sufficient under the following circumstances:

The data being sent over the socket is not sensitive.
The data is sensitive but properly encrypted (see SER02-J. Sign then seal objects before sending them outside a trust boundary for more information).
The network path of the socket never crosses a trust boundary. This could happen when, for example, the two endpoints of the socket are within the same local network and the entire network is trusted.

Risk Assessment

Use of plain sockets fails to provide any guarantee of the confidentiality and integrity of data transmitted over those sockets.

Rule	Severity	Likelihood	Remediation Cost	Priority	Level

SEC09

MSC00-J

medium

Medium

likely

Likely

high

High

P6

L2

Automated Detection

TODO

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

Exceptions

SEC36-EX1: Because of all the mechanisms that SSLSockets provide to ensure the secure transfer of packets, significant performance overhead can be incurred. If no sensitive information is being transmitted, or the channel used is not prone to attacks, the implementation of regular Sockets is sufficient.

References

The general case of automated detection appears to be infeasible because determining which specific data may be passed through the socket is not statically computable. An approach that introduces a custom API for passing sensitive data via secure sockets may be feasible. User tagging of sensitive data is a necessary requirement for such an approach.

Tool

Version

Checker

Description

Parasoft Jtest

Include Page

	Parasoft_V
	Parasoft_V

SECURITY.WSC.USC

Use the SSL-enabled version of classes when possible

Related Guidelines

MITRE CWE

CWE-311, Failure to Encrypt Sensitive Data

Bibliography

[API 2014]	Class `Socket`
[Gong 2003]	Section 11.3.3, "Securing RMI Communications"
[Ware 2008]

...

Image Added Image Added Image Added Wiki Markup\[[API 06|AA. Java References#API 06]\] \[[Ware 08|AA. Java References#Ware 08]\]

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Key

Noncompliant Code Example

Compliant

Solution

Exceptions

Risk Assessment

Automated Detection

Related Vulnerabilities

Exceptions

References

Related Guidelines

Bibliography