password.c

   1 /* usmb - mount SMB shares via FUSE and Samba
   2  * Copyright (C) 2006-2009 Geoff Johnstone
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 3 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include "config.h"
  18 #include <assert.h>
  19 #include <stdbool.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <termios.h>
  24 #include <unistd.h>
  25 #include "password.h"
  26 #include "utils.h"
  27
  28
  29 bool password_read (char **out)
  30 {
  31   struct termios attr, new;
  32
  33   assert (NULL != out);
  34   *out = NULL;
  35
  36   if (0 != tcgetattr (STDIN_FILENO, &attr))
  37   {
  38     perror ("tcgetattr");
  39     fputs ("Cannot configure terminal to read password securely.\n", stderr);
  40     return false;
  41   }
  42
  43   new = attr;
  44   new.c_lflag &= ~ECHO;
  45
  46   if (0 != tcsetattr (STDIN_FILENO, TCSAFLUSH, &new))
  47   {
  48     perror ("tcsetattr");
  49     fputs ("Cannot configure terminal to read password securely.\n", stderr);
  50     return false;
  51   }
  52
  53   char buff[1024];
  54
  55   fputs ("\nPassword: ", stdout);
  56   fflush (stdout);
  57   const bool ok = (buff == fgets (buff, sizeof (buff), stdin));
  58   fputc ('\n', stdout);
  59
  60   if (0 != tcsetattr (STDIN_FILENO, TCSAFLUSH, &attr))
  61   {
  62     perror ("tcsetattr");
  63     fputs ("Failed to reset terminal.\n", stderr);
  64   }
  65
  66   if (!ok)
  67   {
  68     return false;
  69   }
  70
  71   // strip a trailing '\n'.
  72   {
  73     size_t len = strlen (buff);
  74
  75     if ((0 < len) && ('\n' == buff[len - 1]))
  76       buff[len - 1] = '\0';
  77   }
  78
  79   *out = xstrdup (buff);
  80   memset (buff, 0, sizeof (buff));
  81
  82   DEBUG (fprintf (stderr, "Password: %s\n", *out));
  83
  84   return (NULL != *out);
  85 }
  86