Re: How hard is socket programming?

From:

Hector Santos <sant9442@nospam.gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 17 Mar 2010 13:59:06 -0400

Message-ID:

<#OsdMufxKHA.4752@TK2MSFTNGP04.phx.gbl>

Peter Olcott wrote:

It looks like the mongoose approach may be simpler:
http://code.google.com/p/mongoose/wiki/EmbeddingMongoose

Simply bind the webserver and the application into a single
executable that now has web server capability.
It has HTTPS too, the only other thing that I need is
cookies. I don't know if it has cookies.

If you are have a separate service, you don't need this or don't have
to worry about FASTCGI. Use any web server with an embedded language
or CGI. I'm telling ya, you are making this more complex than it is.

Do you know a way that I can authenticate once, and then
have several (possibly many) ten cent financial transactions
that decrement the account balance very quickly? Since HTTP
is a stateless protocol, I was wondering how I could best
maintain this state. Could I use a cookie for this?

AUTHENTICATION comes in two flavors:

   1) IETF HTTP AUTH standard BASIC and DIGEST, where BASIC is
      a requirement and DIGEST (more secure) is optional.
      However, most, if not all browsers today support DIGEST.
      Most "branded" WEB Servers support DIGEST too.

      The BROWSER handles BASIC/DIGEST, its the POPUP window
      you see. Not a FORM based HTML login.

   2) NON-STANDARD COOKIE-BASED FORM AUTHENTICATION

      It is non-standard because the COOKIE information is not
      a standard. (Except for OpenID and OpenAuth which are
      "cookie based" proposed standard).

      The user most allow the browser to support cookies and
      javascript (for hashing the cookies perhaps). If its
      off, its breaks your authentication, so you will have
      to enforce it on users for your site.

      COOKIES are passed as a HTTP header in the HTTP request.

As far the financial port, that is implementation detail that either
the CGI or OCR server will handle per request.

Our WINSERVER package gives you everything you need here, including
establishing subscription for your authenticated customers. The only
thing you need to write is the OCR server and the embedded script or
CGI that talks to it.

Here is example c/c++ CGI that interfaces with our server:

// File: cgitest.cpp

#include <stdio.h>
#include <afx.h>
#include <wctype.h>
#include <wcserver.h>

#pragma comment(lib,"wcsrv2.lib")

#define CGITEST_VERSION "v2.0"

//---------------------------------------------------------------------
// Global Variable (Single Thread Process)
TUser User = {0};
//---------------------------------------------------------------------

CString HtmlToText(const char *s)
{
    CString result = s;
    result.Replace("<","&lt");
    result.Replace(">","&gt");
    return result;
}

void penv(const char *s)
{
    CString sTemp = HtmlToText(getenv(s));
    printf("%s=<font color=\"red\"><b>%s</b></font>\n",s,sTemp);
}

void Dump(char argc, char *argv[])
{
    printf("<h2>CGI Environment</h2>");
    printf("<hr>\n");
    printf("<pre>\n");
    {
       for (int i=0; i < argc; i++) {
          printf("p%d [%s]\n",i,argv[i]);
       }
    }

    penv("AUTH_TYPE");
    penv("CONTENT_LENGTH");
    penv("CONTENT_TYPE");
    penv("DOCUMENT_ROOT");
    penv("GATEWAY_INTERFACE");
    penv("PATH_INFO");
    penv("PATH_TRANSLATED");
    penv("NOPUBLIC");
    penv("QUERY_STRING");
    penv("REMOTE_ADDR");
    penv("REMOTE_HOST");
    penv("REMOTE_IDENT");
    penv("REMOTE_USER");
    penv("REQUEST_METHOD");
    penv("SCRIPT_FILENAME");
    penv("SCRIPT_NAME");
    penv("SERVER_NAME");
    penv("SERVER_PORT");
    penv("SERVER_PROTOCOL");
    penv("SERVER_SOFTWARE");
    penv("WILDCATCONTEXT");
    penv("WILDCATSERVER");
    penv("WILDCATSERVERCONTEXT");
    printf("</pre>\n");
}

void DumpEnv()
{
    LPTSTR lpszVariable;
    LPVOID lpvEnv;

    // Get a pointer to the environment block.

    lpvEnv = GetEnvironmentStrings();

    printf("<hr>\n");
    // Variable strings are separated by NULL byte, and the block is
    // terminated by a NULL byte.

    for (lpszVariable = (LPTSTR) lpvEnv; *lpszVariable; lpszVariable++)
    {
       while (*lpszVariable)
          putchar(*lpszVariable++);
       putchar('\n');
    }
    printf("<hr>\n");
}

//---------------------------------------------------------------------

int DoMain1(char argc, char *argv[])
{
     printf("Content-Type: text/html\n\n");

     printf("<html>\n");
     printf("<head>\n");
     printf("<title>hello! version %s!</title>\n", CGITEST_VERSION);
     printf("</head>\n");
     printf("<body>\n");
     printf("<h2>hello! %s</h2>\n", User.Info.Name);
     printf("<pre>\n");

     //WriteResultToHtml();
     Dump(argc, argv);
     //DumpEnv();

     printf("</pre>\n");
     printf("</body>\n");
     printf("</html>\n");

     return 0;

}

int DoCGI(char argc, char *argv[])
{

    // Reestablish User Session

    const char *chall = getenv("WILDCATCONTEXT");
    if (chall) {
       if (!WildcatServerCreateContextFromChallenge(chall))
       {
           printf("Content-Type: text/plain\n\n");
           printf("! Error %08X - session context\n",GetLastError());
           return 1;
       }
    }

    __try {
      WildcatLoggedIn(&User);
      return DoMain1(argc,argv);
    } __finally {
      WildcatServerDeleteContext();
    }
    return 0;
}

int main(char argc, char *argv[])
{
   // connect to application server
   if (!WildcatServerConnect(NULL)) return 1;

   DoCGI(argc,argv);

   return 0;
}

Once it runs, you connect to your OCR server, do your thing, then
update the user record subtraction some subscription value.

The alternative is to connect to some SQL databases to manage your users.

--
HLS