C++ smtp serwer z tls/ssl z openssl i STARTTLS - BarracudaSMTP

// smtp server test
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// fork, read
#include <unistd.h>
// sockets
#include <sys/socket.h>
#include <netinet/in.h>
// pid kill
#include <signal.h>
#include <string>
#include <iostream>

using namespace std;

#define PORT 5555

bool Contain( std::string str, std::string search ) {
    std::size_t found = str.find( search );
    if( found != std::string::npos ) {
        return 1;
    }
    return 0;
}

int main( int argc, char const * argv[] )
{
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof( address );
    char buffer[ 1024 ] = { 0 };
   
   
    // Creating socket file descriptor
    if(( server_fd = socket( AF_INET, SOCK_STREAM, 0 ) ) == 0 )
    {
        perror( "socket failed" );
        exit( EXIT_FAILURE );
    }
   
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons( PORT );
   
    //set master socket to allow multiple connections
    if( setsockopt( server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT,( char * ) & opt, sizeof( opt ) ) < 0 )
    {
        perror( "setsockopt" );
        exit( EXIT_FAILURE );
    }
   
    // Forcefully attaching socket to the port 25
    if( bind( server_fd,( struct sockaddr * ) & address, sizeof( address ) ) < 0 )
    {
        perror( "bind failed" );
        exit( EXIT_FAILURE );
    }
    if( listen( server_fd, 100 ) < 0 )
    {
        perror( "listen" );
        exit( EXIT_FAILURE );
    }
   
    while( 1 ) {
        // fork pid
        pid_t pid;
        int currpid = 0;
       
        if(( new_socket = accept( server_fd,( struct sockaddr * ) & address,( socklen_t * ) & addrlen ) ) < 0 )
        {
            perror( "accept" );
            exit( EXIT_FAILURE );
        }
       
        // create child proccess with fork() for new client
        pid = fork();
       
        if( pid > 0 ) {
            currpid = pid;
            fprintf( stderr, "Mam mowego klienta, pid=%d\n", currpid );
            // continue;
        }
        if( new_socket < 0 ) {
            perror( "Unable to accept" );
            exit( EXIT_FAILURE );
        }
       
        char * welcome =( char * ) "220 Hello ESMTP\r\n";
        char * ehlo =( char * ) "250-bobo.pp at your service\r\n250-SIZE 157286400\r\n250 250-STARTTLS\r\n";
        char * ok =( char * ) "250 Ok\r\n";
        char * data =( char * ) "354 send data\r\n";
        char * end =( char * ) "250 email was send\r\n";
        char * bye =( char * ) "221 Bye...\r\n";
        char * tls =( char * ) "220 Ready to start TLS\r\n";
       
        // Clear buffer
        buffer[ 0 ] = '\0';
        memset( buffer, 0, sizeof( buffer ) );
       
        // socket helo1
        send( new_socket, welcome, strlen( welcome ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // ehlo
        valread = read( new_socket, buffer, 1024 );
        printf( "Client send %s\n", buffer );
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, ehlo, strlen( ehlo ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // mail from:
        valread = read( new_socket, buffer, 1024 );
        printf( "Client send %s\n", buffer );
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, ok, strlen( ok ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // rcpt to:
        valread = read( new_socket, buffer, 1024 );
        printf( "Client send %s\n", buffer );
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, ok, strlen( ok ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // DATA
        valread = read( new_socket, buffer, 1024 );
        printf( "Client send %s\n", buffer );
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, data, strlen( data ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // DATA CONTENT   
        while( 1 ) {
            valread = read( new_socket, buffer, 1024 );
            printf( "Client send %s\n", buffer );
            if( Contain( std::string( buffer ), ".\r\n" ) ) {
                break;
            }
        }
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, end, strlen( end ), 0 );
       
        // QUIT
        valread = read( new_socket, buffer, 1024 );
        printf( "Client send %s\n", buffer );
        memset( buffer, 0, sizeof( buffer ) );
        send( new_socket, bye, strlen( bye ), 0 );
        // printf("Hello message sent %s\n",hello1);
       
        // end connection
        close( new_socket );
        // kill(getpid(), SIGKILL);
        // kill(pid, SIGTERM);
    }
    // return 0;
}