/// <summary>
/// The handler for HTTP GET requests.
/// </summary>
/// <param name="processor">The HTTP processor.</param>
public void HttpGetHandler(HttpProcessor processor)
{
processor.WriteSuccess();
Cryptkeeper myCrypt = new Cryptkeeper(this.passphrase);
DerivedValue derived = new DerivedValue(this.passphrase);
string result = derived.GetString(3, 10);
// No result? No handshake. Done.
if (processor.RequestURL.IndexOf(result) == -1) return;
// Parse out the host name and fetch the next page.
string hostname = string.Empty;
string absolutePath = processor.RequestURL;
string[] values = absolutePath.Split(new string[] { result }, StringSplitOptions.RemoveEmptyEntries);
absolutePath = values[0].Trim();
string hostBase64 = values[1].Trim();
byte[] hostBytes = System.Convert.FromBase64String(hostBase64);
hostname = Encoding.ASCII.GetString(hostBytes);
Uri link = new Uri(string.Concat("http://", hostname, absolutePath));
try
{
WebClient web = new WebClient();
byte[] page = web.DownloadData(link);
web.Dispose();
WebPageSteganography stegopage = new WebPageSteganography(page, this.passphrase);
string message = string.Empty;
if (this.MessageQueue.Count > 0)
{
message = (string)this.MessageQueue.Dequeue();
}
stegopage.WriteValue(message);
page = stegopage.GetBytes();
processor.StreamOutput.Write(page);
processor.StreamOutput.Flush();
processor.WriteSuccess();
}
catch (Exception ex)
{
processor.StreamOutput.Write("<html><p>Ping! Something odd happened while retrieving ... " + link.ToString() + "</p><p>" + ex.ToString() + "</p></html>");
}
}
/// <summary>
/// Provides a one-time, preprocessing functionality for the cmdlet.
/// </summary>
protected override void BeginProcessing()
{
// Initialize parameters and base Incog cmdlet components
this.InitializeComponent();
// Verify the browser history file path
this.BrowserHistoryFile = ConsoleTools.ExpandAndVerifyPath(this, this.BrowserHistoryFile);
StreamReader history = new StreamReader(this.BrowserHistoryFile.FullName);
string text = history.ReadToEnd();
string[] lines = text.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
this.links = new Uri[lines.Length];
for (int i = 0; i < this.links.Length; i++)
{
this.links[i] = new Uri(lines[i]);
this.WriteVerbose(string.Format("Loading ... {0}", this.links[i].ToString()));
}
// Invoke Interative Mode if selected
if (this.Interactive) this.InteractiveMode();
// Set the default TCP port
if (this.TCP == 0) this.TCP = 80;
// Get a derived value to indicate where the path and host split
DerivedValue derived = new DerivedValue(this.Passphrase);
string split = derived.GetString(3, 10);
int linkIndex = 0;
do
{
// Get the host and path of the next URL
string host = this.links[linkIndex].Host;
string absolutePath = this.links[linkIndex].AbsolutePath;
// Get the host as a base64 encoded string
byte[] hostBytes = System.Text.Encoding.ASCII.GetBytes(host);
string hostBase64 = System.Convert.ToBase64String(hostBytes);
// Get the resulting link -- absolute path and host in base 64
Uri resultingLink = new Uri(string.Concat(
"http://",
this.RemoteAddress.ToString(),
":",
this.TCP.ToString(),
absolutePath,
split,
hostBase64));
try
{
// Create a request for the URL and set the timeout
WebRequest request = WebRequest.Create(resultingLink);
request.Timeout = request.Timeout * 2;
// Get the response
WebResponse response = request.GetResponse();
// Display the status
this.WriteVerbose(resultingLink.ToString());
this.WriteVerbose(((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server
Stream dataStream = response.GetResponseStream();
// Read in the stream into a buffer
int growBufferBy = 1024;
byte[] buffer = new byte[10240];
byte[] page;
int index = 0;
do
{
int i = dataStream.ReadByte();
if (i == -1)
{
page = new byte[index];
Array.Copy(buffer, page, index);
break;
}
buffer[index] = Convert.ToByte(i);
index++;
if (index == buffer.Length)
{
byte[] temp = new byte[buffer.Length + growBufferBy];
Array.Copy(buffer, temp, buffer.Length);
buffer = new byte[temp.Length];
Array.Copy(temp, buffer, temp.Length);
}
}
while (true);
response.Close();
// Feed the bytes into a stego page and test
WebPageSteganography stegoPage = new WebPageSteganography(page, this.Passphrase);
string message = stegoPage.ReadValue();
// Break on exit
if (message.Trim().ToLower() == "exit") break;
if (message != string.Empty)
{
if (this.Interactive)
{
Console.WriteLine("{0} > {1}", this.RemoteAddress.ToString(), message);
}
else
{
this.WriteObject(message);
}
}
}
catch (System.Net.Sockets.SocketException ex)
{
this.WriteVerbose(ex.InnerException.ToString());
break;
}
catch (Exception ex)
{
if (ex.InnerException != null)
{
if (ex.InnerException.GetType() == typeof(System.Net.Sockets.SocketException))
{
this.WriteWarning(ex.InnerException.Message);
break;
}
}
this.WriteWarning(ex.ToString());
}
linkIndex++;
if (linkIndex == this.links.Length) linkIndex = 0;
System.Threading.Thread.Sleep(500);
}
while (true);
}
/// <summary>
/// Interactive Mode allows the user to key in message after message, and have the message sent over the covert channel.
/// </summary>
private void InteractiveMode()
{
// Update the screen with the parameters of the chat session
this.PrintInteractiveMode(ChannelTools.CommunicationMode.Alice);
// Wait for the client connection
this.WriteVerbose("Waiting for client connect . . .");
NamedPipeServerStream pipeServer = new NamedPipeServerStream(
this.CmdletGuid,
PipeDirection.InOut);
DerivedValue derived = new DerivedValue(this.Passphrase);
string handshake = derived.GetString(3, 12);
this.WriteVerbose(string.Format("Handshaking with {0}.", handshake));
pipeServer.WaitForConnection();
this.WriteVerbose("Connected. Ready to send chat messages.");
try
{
// Read the request from the client
IncogStream stream = new IncogStream(pipeServer, this.Passphrase, this.TargetEntropy);
// Verify our identity to the connected client using a handshake string
stream.WriteString(handshake);
do
{
Console.Write("{0}> ", this.CmdletName);
string line = Console.ReadLine();
if (line == string.Empty) continue;
stream.WriteString(line);
if (line.ToLower() == "exit") break;
}
while (true);
}
catch (System.IO.IOException e)
{
// Catch the IOException that is raised if the pipe is broken or disconnected.
this.WriteWarning(e.Message);
}
pipeServer.Close();
}
/// <summary>
/// Provides a one-time, preprocessing functionality for the cmdlet.
/// </summary>
protected override void BeginProcessing()
{
// Initialize parameters and base Incog cmdlet components
this.InitializeComponent();
// Invoke Interative Mode if selected
if (this.Interactive) this.InteractiveMode();
// Start the connection
this.WriteVerbose("Connecting to server . . .");
NamedPipeClientStream pipeClient = new NamedPipeClientStream(
this.RemoteAddress.ToString(),
this.CmdletGuid,
PipeDirection.InOut,
PipeOptions.None,
System.Security.Principal.TokenImpersonationLevel.Impersonation);
DerivedValue derived = new DerivedValue(this.Passphrase);
string handshake = derived.GetString(3, 12);
this.WriteVerbose(string.Format("Handshaking with {0}.", handshake));
pipeClient.Connect();
IncogStream stream = new IncogStream(pipeClient, this.Passphrase);
// Validate the server's signature string
if (stream.ReadString() == handshake)
{
// The client security token is sent with the first write.
// Print the file to the screen.
this.WriteVerbose("Connected. Incoming chat messages.");
do
{
string message = stream.ReadString();
if (message == string.Empty)
{
Thread.Sleep(250);
continue;
}
if (message.Trim().ToLower() == "exit")
{
break;
}
if (this.Interactive)
{
Console.WriteLine("{0} > {1}", this.RemoteAddress.ToString(), message);
}
else
{
this.WriteObject(message);
}
}
while (true);
}
else
{
this.WriteVerbose("The connected failed because of an invalid server handshake.");
}
pipeClient.Close();
// Give the client process some time to display results before exiting.
Thread.Sleep(2000);
}
