/*

 *  Unix SMB/CIFS implementation.

 *

 *  getpass.c - platform independent getpass function.

 *

 *  Copyright (c) 2010-2012 Andreas Schneider <asn@samba.org>

 *

 *  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 "includes.h"

#include "system/filesys.h"

#include "system/terminal.h"

#if !defined(SMB_MALLOC)

#undef malloc

#define SMB_MALLOC(s) malloc((s))

#endif

/**

 * @internal

 *

 * @brief Get the password from the console.

 *

 * @param[in]  prompt   The prompt to display.

 *

 * @param[in]  buf      The buffer to fill.

 *

 * @param[in]  len      The length of the buffer.

 *

 * @param[in]  verify   Should the password be verified?

 *

 * @return              1 on success, 0 on error.

 */

static int samba_gets(const char *prompt, char *buf, size_t len, bool verify)

{

  char *tmp;

  char *ptr = NULL;

  int ok = 0;

  tmp = SMB_MALLOC(len);

  if (tmp == NULL) {

    return 0;

  }

  memset(tmp,'\0',len);

  /* read the password */

  while (!ok) {

    if (buf[0] != '\0') {

      fprintf(stdout, "%s[%s] ", prompt, buf);

    } else {

      fprintf(stdout, "%s", prompt);

    }

    fflush(stdout);

    if (fgets(tmp, len, stdin) == NULL) {

      free(tmp);

      return 0;

    }

    if ((ptr = strchr(tmp, '\n'))) {

      *ptr = '\0';

    }

    fprintf(stdout, "\n");

    if (*tmp) {

      strncpy(buf, tmp, len);

    }

    if (verify) {

      char *key_string;

      key_string = SMB_MALLOC(len);

      if (key_string == NULL) {

        break;

      }

      memset(key_string, '\0', len);

      fprintf(stdout, "\nVerifying, please re-enter. %s", prompt);

      fflush(stdout);

      if (! fgets(key_string, len, stdin)) {

        memset(key_string, '\0', len);

        SAFE_FREE(key_string);

        clearerr(stdin);

        continue;

      }

      if ((ptr = strchr(key_string, '\n'))) {

        *ptr = '\0';

      }

      fprintf(stdout, "\n");

      if (strcmp(buf, key_string)) {

        printf("\n\07\07Mismatch - try again\n");

        memset(key_string, '\0', len);

        SAFE_FREE(key_string);

        fflush(stdout);

        continue;

      }

      memset(key_string, '\0', len);

      SAFE_FREE(key_string);

    }

    ok = 1;

  }

  memset(tmp, '\0', len);

  free(tmp);

  return ok;

}

/**

 * @brief Get a password from the console.

 *

 * You should make sure that the buffer is an empty string!

 *

 * You can also use this function to ask for a username. Then you can fill the

 * buffer with the username and it is shows to the users. If the users just

 * presses enter the buffer will be untouched.

 *

 * @code

 *   char username[128];

 *

 *   snprintf(username, sizeof(username), "john");

 *

 *   samba_getpass("Username:", username, sizeof(username), 1, 0);

 * @endcode

 *

 * The prompt will look like this:

 *

 *   Username: [john]

 *

 * If you press enter then john is used as the username, or you can type it in

 * to change it.

 *

 * @param[in]  prompt   The prompt to show to ask for the password.

 *

 * @param[out] buf    The buffer the password should be stored. It NEEDS to be

 *                      empty or filled out.

 *

 * @param[in]  len      The length of the buffer.

 *

 * @param[in]  echo     Should we echo what you type.

 *

 * @param[in]  verify   Should we ask for the password twice.

 *

 * @return              0 on success, -1 on error.

 */

int samba_getpass(const char *prompt,

      char *buf,

      size_t len,

      bool echo,

      bool verify)

{

  struct termios attr;

  struct termios old_attr;

  int ok = 0;

  int fd = -1;

  /* fgets needs at least len - 1 */

  if (prompt == NULL || buf == NULL || len < 2) {

    return -1;

  }

  if (isatty (STDIN_FILENO)) {

    ZERO_STRUCT(attr);

    ZERO_STRUCT(old_attr);

    /* get local terminal attributes */

    if (tcgetattr(STDIN_FILENO, &attr) < 0) {

      perror("tcgetattr");

      return -1;

    }

    /* save terminal attributes */

    memcpy(&old_attr, &attr, sizeof(attr));

    if((fd = fcntl(0, F_GETFL, 0)) < 0) {

      perror("fcntl");

      return -1;

    }

    /* disable echo */

    if (!echo) {

      attr.c_lflag &= ~(ECHO);

    }

    /* write attributes to terminal */

    if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &attr) < 0) {

      perror("tcsetattr");

      return -1;

    }

  }

  /* disable nonblocking I/O */

  if (fd & O_NDELAY) {

    fcntl(0, F_SETFL, fd & ~O_NDELAY);

  }

  ok = samba_gets(prompt, buf, len, verify);

  if (isatty (STDIN_FILENO)) {

    /* reset terminal */

    tcsetattr(STDIN_FILENO, TCSANOW, &old_attr);

  }

  /* close fd */

  if (fd & O_NDELAY) {

    fcntl(0, F_SETFL, fd);

  }

  if (!ok) {

    memset (buf, '\0', len);

    return -1;

  }

  /* force termination */

  buf[len - 1] = '\0';

  return 0;

}