C / C++ / MFC

#include <stdio.h>
#include <httpext.h>
#include <httpfilt.h>
#include <string.h>

#define USERNAME "user"
#define PASSWORD "pass"
#define DOMAIN   "domainname"

/* This function is called when the filter is loaded by the web server */
BOOL WINAPI
GetFilterVersion( HTTP_FILTER_VERSION *pVer )
{
  /*  Set the filter version */
  pVer->dwFilterVersion = HTTP_FILTER_REVISION;

  /*  Set a description string for this filter */
  strncpy(pVer->lpszFilterDesc, "Basic Authentication Filter", SF_MAX_FILTER_DESC_LEN);

  /*  Ask to be notified at the authentication stage of every HTTP request */
  pVer->dwFlags = SF_NOTIFY_PREPROC_HEADERS;

  return TRUE;
}


/*  This function is called for every HTTP request */
DWORD WINAPI
HttpFilterProc( PHTTP_FILTER_CONTEXT pfc,
		DWORD notificationType,
		VOID *pvNotification )
{
  HTTP_FILTER_AUTHENT *auth = (HTTP_FILTER_AUTHENT *) pvNotification;
  char domain[256];
  char user[256];

 if( auth->pszUser[0] == '\0') {
    char domain[256];
    OutputDebugString("No user/password given");

    sprintf(domain, "WWW-Authenticate: Basic realm=\"%s\"\r\n", DOMAIN);
	pfc->ServerSupportFunction( pfc, SF_REQ_SEND_RESPONSE_HEADER,
			      (PVOID)   "401 Unauthorized",
			      (DWORD) domain,
			      (DWORD) NULL );

  	return SF_STATUS_REQ_FINISHED;
  }


OutputDebugString(USERNAME);
OutputDebugString(auth->pszUser);
OutputDebugString(auth->pszPassword);

if( strcmp( auth->pszUser, USERNAME ) && strcmp( auth->pszPassword, PASSWORD ) ) {
    char domain[256];
    OutputDebugString("Username or password wrong");
	sprintf(domain, "WWW-Authenticate: Basic realm=\"%s\"\r\n", DOMAIN);
	pfc->ServerSupportFunction( pfc, SF_REQ_SEND_RESPONSE_HEADER,
			      (PVOID)   "401 Unauthorized",
			      (DWORD) domain,
			      (DWORD) NULL );
    return SF_STATUS_REQ_FINISHED;
  }

   
  if( !strcmp( auth->pszUser, USERNAME ) && !strcmp( auth->pszPassword, PASSWORD ) ) {
  OutputDebugString("All conditions satisfied");
  sprintf(domain, "WWW-Authenticate: Basic realm=\"%s\"\r\n", DOMAIN);
  pfc->ServerSupportFunction( pfc, SF_REQ_SEND_RESPONSE_HEADER,
			      (PVOID)   "200 OK",
				  (DWORD) domain,
			      (DWORD) NULL );

  return SF_STATUS_REQ_HANDLED_NOTIFICATION;
}

 return SF_STATUS_REQ_HANDLED_NOTIFICATION;
}