/* Public key file parser in nss_files module.

   Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <netdb.h>

#include <rpc/key_prot.h>

#include <rpc/des_crypt.h>

#include "nsswitch.h"

#define DATAFILE "/etc/publickey"

static enum nss_status

search (const char *netname, char *result, int *errnop, int secret)

{

  FILE *stream = fopen (DATAFILE, "rce");

  if (stream == NULL)

    return errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

  for (;;)

    {

      char buffer[HEXKEYBYTES * 2 + KEYCHECKSUMSIZE + MAXNETNAMELEN + 17];

      char *p;

      char *save_ptr;

      buffer[sizeof (buffer) - 1] = '\xff';

      p = fgets_unlocked (buffer, sizeof (buffer), stream);

      if (p == NULL)

	{

	  /* End of file or read error.  */

	  *errnop = errno;

	  fclose (stream);

	  return NSS_STATUS_NOTFOUND;

	}

      else if (buffer[sizeof (buffer) - 1] != '\xff')

	{

	  /* Invalid line in file?  Skip remainder of line.  */

	  if (buffer[sizeof (buffer) - 2] != '\0')

	    while (getc_unlocked (stream) != '\n')

	      continue;

	  continue;

	}

      /* Parse line.  */

      p = __strtok_r (buffer, "# \t:\n", &save_ptr);

      if (p == NULL) /* Skip empty and comment lines.  */

	continue;

      if (strcmp (p, netname) != 0)

	continue;

      /* A hit!  Find the field we want and return.  */

      p = __strtok_r (NULL, ":\n", &save_ptr);

      if (p == NULL)  /* malformed line? */

	continue;

      if (secret)

	p = __strtok_r (NULL, ":\n", &save_ptr);

      if (p == NULL)  /* malformed line? */

	continue;

      fclose (stream);

      strcpy (result, p);

      return NSS_STATUS_SUCCESS;

    }

}

enum nss_status

_nss_files_getpublickey (const char *netname, char *pkey, int *errnop)

{

  return search (netname, pkey, errnop, 0);

}

enum nss_status

_nss_files_getsecretkey (const char *netname, char *skey, char *passwd,

			 int *errnop)

{

  enum nss_status status;

  char buf[HEXKEYBYTES + KEYCHECKSUMSIZE + 16];

  skey[0] = 0;

  status = search (netname, buf, errnop, 1);

  if (status != NSS_STATUS_SUCCESS)

    return status;

  if (!xdecrypt (buf, passwd))

    return NSS_STATUS_SUCCESS;

  if (memcmp (buf, &(buf[HEXKEYBYTES]), KEYCHECKSUMSIZE) != 0)

    return NSS_STATUS_SUCCESS;

  buf[HEXKEYBYTES] = 0;

  strcpy (skey, buf);

  return NSS_STATUS_SUCCESS;

}