Fake (or Anonymous) NetSend for Windows NT/2000/XP

/*
	Fake NetSend for Windows NT/2000/XP v1.01
	Written by me (Caio Proiete).
	mailto:caio@proiete.com.br

	Copyright (c) 2003.

	If you find any bugs, please notify me!

	You may use it, abuse it, redistribute it, in any way 
	you desire, but don't change the author credits ;)

	HISTORY

		2003-06-08 - First version. Bugs: Zero, I hope :)
		2003-06-11 - Version 1.01. Just improving the code.
*/

const char szAbout[] = \
		"Fake NetSend for Windows NT/2000/XP v1.01\n" \
		"by Caio Proiete (caio@proiete.com.br)\n";

const char szUsage[] = \
		"Usage: FakeSend [Sender] [Receiver] \"[Message]\"\n" \
		"Example: FakeSend James Kevin \"Hi Kevin this is James!\"\n";

const char szMailSlotPath[] = "\\\\%s\\MAILSLOT\\messngr";
const char szMsgFormat[] = "%s\r%s\r%s\r";

const unsigned char nTotalParam = 4;

bool NetSend(const char * szSender, const char * szReceiver, 
			 const char * szMessage);

// Exclude rarelly used Windows stuff
#define WIN32_LEAN_AND_MEAN

#include <stdio.h>
#include <windows.h>

int main(int argc, char **argv)
{
	///////////////////////////////////////////
	//  What do we expect in argv variable?  //
	///////////////////////////////////////////
	// argv[0] = Application PathName        //
	// argv[1] = Sender's Name               //
	// argv[2] = Receiver's Login or Machine //
	// argv[3] = Message                     //
	///////////////////////////////////////////

	// We have all needed parameters?
	if (argc == nTotalParam)
	{
		// Just showing a status
		printf("%s\n" \
				"Sending Fake Message:\n" \
				"Sender...: %s\n" \
				"Receiver.: %s\n" \
				"Message..: %s\n",
				szAbout,
				argv[1],
				argv[2],
				argv[3]);

		if (NetSend(argv[1], argv[2], argv[3]))
			printf("Message sent!\n");
		else
			printf("Error sending the message!\n");
	}
	else
		printf("%s\n%s", szAbout, szUsage); // Show About and Usage descriptions
	
	return 0;
}

/* 
	This function takes the Sender's and Receiver's Name, 
	the Message and then send the "Fake" message
*/
bool NetSend(const char * szSender, const char * szReceiver, 
			 const char * szMessage)
{
	// Our main variables
	char * pszMailSlot = NULL;
	unsigned char * pucMessage = NULL;
	unsigned int nMailSlotLen, nMsgFormatLen;

	HANDLE hHandle;
	DWORD dwBytesWritten;
	bool bRet = false;

	// Get the length of the strings
	nMailSlotLen  = strlen(szReceiver) + sizeof(szMailSlotPath);
	nMsgFormatLen = strlen(szSender) + strlen(szReceiver) + 
					strlen(szMessage) + sizeof(szMsgFormat);

	// Allocate necessary memory
	pszMailSlot = new char[nMailSlotLen];
	pucMessage  = new unsigned char[nMsgFormatLen];

	// Network path for <Receiver> MailSlot:
	// "\\Receiver\MAILSLOT\messngr"
	sprintf(pszMailSlot, szMailSlotPath, szReceiver);

	// Message Format:
	// "Sender\0Receiver\0Message\0"
	// sprintf doesn't work with \0 so here I'm using \r
	sprintf((char *)pucMessage, szMsgFormat, szSender, 
								szReceiver, szMessage);
	
	// Replace all '\r' characters with '\0'
	for (unsigned short i = 0; i < nMsgFormatLen; i++)
	{
		if (pucMessage[i] == '\r')
			pucMessage[i] = '\0';
		
		else if (pucMessage[i] == '\0')
			break;
	}
	
	// Create the file into Receiver's MailSlot and get a Handle to this file
	hHandle = CreateFile(pszMailSlot, GENERIC_WRITE, FILE_SHARE_READ, NULL, 
							OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

	// We have a valid handle?
	if (hHandle)
	{
		// Write the message to file
		bRet = (WriteFile(hHandle, pucMessage, (DWORD)nMsgFormatLen,
					&dwBytesWritten, NULL) == TRUE);

		// Free the handle
		CloseHandle(hHandle);
	}

	return bRet;
}