Member Avatar for leowdeo 
am trying to login to a server, say my gmail account by sending it my username and password in a typical POST request. to make my life simpler
i tested this code on www.campuser.net
i was able to see the pages http requests using a firefox addon called tamper data to analyse their requests
source code is attached

steps taken
----------------
1. connect to the server on port 80
2.send a simple GET request to see if stuff works well 
3.attempt a login by sending password and username

the good news
-------------------
1. connection was successful
2. GET / HTTP/1.1  request worked well

the bad news
-------------------
1. the post was not sucessful and i have totally failed to see why
#include<windows.h>
#include<winsock.h>

#include<fstream>
#include <stdio.h>
#include <string.h>
using namespace std;

//link the library -lwsock to the project in compiler->options





int main()
{


WSADATA WSAData;

struct hostent* HostEnt;

SOCKET Socket;

struct sockaddr_in ServerInfo;

WSAStartup(0x202, &WSAData);

HostEnt = gethostbyname("www.campuser.net");

if (HostEnt == NULL)
{
printf("Unable to get the host information.\n");

WSACleanup();
return -1;
}

Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

if (Socket == INVALID_SOCKET)
{
printf("Unable to create the socket.\n");
WSACleanup();
return -1;
}

memset(&ServerInfo, 0, sizeof(ServerInfo));
memcpy(&ServerInfo.sin_addr, HostEnt->h_addr, HostEnt->h_length);
ServerInfo.sin_family = HostEnt->h_addrtype; // Always AF_INET
ServerInfo.sin_port = htons(80);

if (connect(Socket, (struct sockaddr*) &ServerInfo, sizeof(ServerInfo)) == -1)
{
printf("Unable to connect to the server.\n");
WSACleanup();
return -1;
}

printf("Successfully connected to the server!\n");
closesocket(Socket);
WSACleanup();



char szSendBuffer[1024];
ZeroMemory(szSendBuffer, sizeof(szSendBuffer));
Strcat(szSendBuffer, GET / HTTP/1.1\r\n);
Strcat(szSendBuffer,"Host: campuser.net\r\n");
Strcat(szSendBuffer,"User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1  \r\n");                              
Strcat(szSendBuffer,"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n");
Strcat(szSendBuffer,"Accept-language: en-gb,en;q=0.5\r\n");
Strcat(szSendBuffer,"/r/n);//the terminating empty line

iRetVal = send(Socket, szSendBuffer, sizeof(szSendBuffer));
if (iRetVal != SOCKET_ERROR)
{
// Successfully sent the data here...
printf("sending successful\n");
}
else
{
printf("unable to send data\n");
// Handle error here...
}

//receiving data

int iBytesRecv = 0;
char szRecvBuffer[1024];
ZeroMemory(szRecvBuffer, sizeof(szRecvBuffer));//to empty a buffer
iBytesRecv = recv(Socket, szRecvBuffer, sizeof(szRecvBuffer), 0);
if (iBytesRecv <= 0)
{
// Nothing received, handle accordingly...
printf("nothing received.\n");
}
else
{
// received data, handle accordingly...
printf("receiving data......\n\n\n\n");
ofstream myfile("campuser.html","IOS::OUT");
myfile<<szRecvBuffer;//store data to file
myfile.close();//close the file to avoid data loss
printf("data successfully stored to file ..... campuser.html in the current folder\n\n");
}

//now trying a post request
printf("now attempting to post login information to campuser.net\n\n");


ZeroMemory(szSendBuffer, sizeof(szSendBuffer));//to clear the buffer
Strcat(szSendBuffer, POST http://campuser.net/scripts/login.php?from=index \r\n);
Strcat(szSendBuffer,"Host: campuser.net\r\n");
Strcat(szSendBuffer,"User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1  \r\n");                              
Strcat(szSendBuffer,"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n");
Strcat(szSendBuffer,"Accept-language: en-gb,en;q=0.5\r\n");

Strcat(szSendBuffer,"Referer: http://campuser.net/\r\n");
Strcat(szSendBuffer,"Content-Type: application/x-www-form-urlencoded\r\n");
Strcat(szSendBuffer,"Content-Length: 34\r\n");
Strcat(szSendBuffer,"/r/n);//the terminating empty line
Strcat(szSendBuffer,"username=mwesema&password=annette");//this is the post body or data

iRetVal = send(Socket, szSendBuffer, sizeof(szSendBuffer));
if (iRetVal != SOCKET_ERROR)
{
// Successfully sent the data here...
printf("sending successful\n");
}
else
{
printf("unable to send data\n");
// Handle error here...
}

//receiving data

int iBytesRecv = 0;
char szRecvBuffer[1024];
ZeroMemory(szRecvBuffer, sizeof(szRecvBuffer));//to empty a buffer
iBytesRecv = recv(Socket, szRecvBuffer, sizeof(szRecvBuffer), 0);
if (iBytesRecv <= 0)
{
// Nothing received, handle accordingly...
printf("nothing received.\n");
}
else
{
// received data, handle accordingly...
printf("receiving data......\n\n\n\n");
ofstream myfile("campuser.html","IOS::OUT");
myfile<<szRecvBuffer;//store data to file
myfile.close();//close the file to avoid data loss
printf("data stored to file ..... campuser.html in the current folder\n\n");
}




system("pause");
return 0;
}
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  • Latest Post Latest Post by Paul.Esson
Member Avatar for Paul.Esson

I don't know if this is the problem, but on the post request you have the terminating empty line after you have the post data.

Strcat(szSendBuffer,"/r/n);//the terminating empty line
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