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) {

        if (strlen(usr) > 50) {

        return USR_TOO_LONG;

        }

        char *auth = malloc(strlen("USER ")+strlen(usr)+2);
        char buf[1024]={'\0'};
        int n = 0;
                
        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';

        struct timeval tm; //tv_sec - tv_usec
        fd_set readfds;
        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;

}