tags/REL-1.1/ftpauth.c

/*

    libftp 1.0 (stable): this is an FTP library to simplify the work to a Developer
    who want to work with FTP servers (RFC 959).
    Copyright (C) 2007/2008  omnipresent - omnipresent[at]email.it

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>

*/

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>

#include "ftp_main.h"

/* Global Variable used to store the password length */

int pwd_len = 0;

#define    USR_TOO_LONG     -2
#define    PWD_TOO_LONG     -2

/*** 
     ftp_connect:
     - char *host           => HostName/IP
     - int port             => Port to connect to
     - struct sockaddr_in * => pointer to sockaddr_in structure
     - int verbose          => Verbose?
     . 0 Do not Print
     . 1 Print
     - ret                  => Success?
     . sock Socket Descriptor Returned
     .-1 Error
***/


int ftp_auth(int sck, char *usr, char *pwd, int verbose)
{
    char *auth;
    char buf[1024]={'\0'};
    int n = 0;
    struct timeval tm; //tv_sec - tv_usec
    fd_set readfds;

    
    if (strlen(usr) > 50) {

        return USR_TOO_LONG;

    }

    auth = malloc(strlen("USER ")+strlen(usr)+2);
                
    sprintf(auth, "%s %s\n", "USER", usr);

    if (write(sck, auth, strlen(auth)) == -1) {

        if (verbose) {

            if (errno == EBADF) {

                fprintf(stderr, "Socket Descriptor Not Valid!\n");
                free(auth);
                return -1;
            } else if (errno == EIO) {

                fprintf(stderr, "I/O Error!\n");
                free(auth);
                
                return -1;
            } else if (errno == EINTR) {

                fprintf(stderr, "Signal Interrupted The write() Function\n");
                free(auth);
                return -1;
            }

        } else {

            if (errno == EBADF) {
                free(auth);
                return -1;
            } else if (errno == EIO) {
                free(auth);
                
                return -1;
            } else if (errno == EINTR) {
                free(auth);
                return -1;
            }

        }

        free(auth);
                
        return -1;

    }

    free(auth);

    buf[1023] = '\0';

    tm.tv_sec = 3;
    tm.tv_usec = 0;

    FD_ZERO(&readfds);
        
    FD_SET(sck, &readfds);
    sleep(1); //wait a little bit

    if (select(sck+1, &readfds, NULL, NULL, &tm) < 0 ) {
        if (verbose) {
            perror("select()");
        }
        return -1;
    } else {

        if (FD_ISSET(sck, &readfds)) {

            if ( (n = recv(sck, buf, 1022, 0)) < 0)  {
                if (verbose) {
                    perror("recv()");
                }
                return -1;
            }

            if (verbose)
                printf("[Server] %s\n", buf);
                        
        }
        else {
            if (verbose)
                printf("[-] Timeout\n");
                        
            return -1;
        }
    }

    buf[n] = '\0';

    if (ftp_login_handler(buf, 0) != 2) { //2? Yes.. Need a Password
        return -1;
    }

    memset(buf, 0x0, 1024);

    if (strlen(pwd) > 50) {

        return PWD_TOO_LONG;

    }

    auth = malloc(strlen("PASS ")+strlen(pwd)+2);

    sprintf(auth, "%s %s\n", "PASS", pwd);

    if (write(sck, auth, strlen(auth)) == -1) {

        if (verbose) {
            if (errno == EBADF) {
                fprintf(stderr, "Socket Descriptor Not Valid!\n");
                free(auth);
                
                return -1;

            } else if (errno == EIO) {

                fprintf(stderr, "I/O Error!\n");
                free(auth);
                
                return -1;

            } else if (errno == EINTR) {

                fprintf(stderr, "Signal Interrupted The write() Function\n");
                free(auth);
                
                return -1;
            }

        } else {

            if (errno == EBADF) {
                free(auth);
                
                return -1;

            } else if (errno == EIO) {
                free(auth);
                
                return -1;

            } else if (errno == EINTR) {
                free(auth);
                
                return -1;
            }

        }

        free(auth);
        
        return -1;

    }
                
    pwd_len = strlen(pwd) - 1;

    free(auth);


    FD_ZERO(&readfds);
        
    FD_SET(sck, &readfds);

    sleep(1);

    if (select(sck+1, &readfds, NULL, NULL, &tm) < 0 ) {
        if (verbose) {
            perror("select()");
        }
        return -1;
    } else {

        if (FD_ISSET(sck, &readfds)) {

            if ( (n= recv(sck, buf, 1022, 0)) < 0)  {
                if (verbose) {
                    perror("recv()");
                }
                return -1;
            }
            buf[n] = '\0';

            if (verbose)
                printf("[Server] %s\n", buf);
                        
        }
        else {
            if (verbose)
                printf("[-] Timeout\n");
                        
            return -1;
        }
    }

    if (ftp_login_handler(buf, 0) != 0) {
        
        return -1;
    }

    memset(buf, 0x0, 1024);

    return 0;

}