nss/nss_files/files-key.c

   1 /* Public key file parser in nss_files module.
   2    Copyright (C) 1996-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <errno.h>
  21 #include <string.h>
  22 #include <netdb.h>
  23 #include <rpc/key_prot.h>
  24 #include <rpc/des_crypt.h>
  25 #include "nsswitch.h"
  26
  27 #define DATAFILE "/etc/publickey"
  28
  29
  30 static enum nss_status
  31 search (const char *netname, char *result, int *errnop, int secret)
  32 {
  33   FILE *stream = fopen (DATAFILE, "rce");
  34   if (stream == NULL)
  35     return errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
  36
  37   for (;;)
  38     {
  39       char buffer[HEXKEYBYTES * 2 + KEYCHECKSUMSIZE + MAXNETNAMELEN + 17];
  40       char *p;
  41       char *save_ptr;
  42
  43       buffer[sizeof (buffer) - 1] = '\xff';
  44       p = fgets_unlocked (buffer, sizeof (buffer), stream);
  45       if (p == NULL)
  46         {
  47           /* End of file or read error.  */
  48           *errnop = errno;
  49           fclose (stream);
  50           return NSS_STATUS_NOTFOUND;
  51         }
  52       else if (buffer[sizeof (buffer) - 1] != '\xff')
  53         {
  54           /* Invalid line in file?  Skip remainder of line.  */
  55           if (buffer[sizeof (buffer) - 2] != '\0')
  56             while (getc_unlocked (stream) != '\n')
  57               continue;
  58           continue;
  59         }
  60
  61       /* Parse line.  */
  62       p = __strtok_r (buffer, "# \t:\n", &save_ptr);
  63       if (p == NULL) /* Skip empty and comment lines.  */
  64         continue;
  65       if (strcmp (p, netname) != 0)
  66         continue;
  67
  68       /* A hit!  Find the field we want and return.  */
  69       p = __strtok_r (NULL, ":\n", &save_ptr);
  70       if (p == NULL)  /* malformed line? */
  71         continue;
  72       if (secret)
  73         p = __strtok_r (NULL, ":\n", &save_ptr);
  74       if (p == NULL)  /* malformed line? */
  75         continue;
  76       fclose (stream);
  77       strcpy (result, p);
  78       return NSS_STATUS_SUCCESS;
  79     }
  80 }
  81
  82 enum nss_status
  83 _nss_files_getpublickey (const char *netname, char *pkey, int *errnop)
  84 {
  85   return search (netname, pkey, errnop, 0);
  86 }
  87
  88 enum nss_status
  89 _nss_files_getsecretkey (const char *netname, char *skey, char *passwd,
  90                          int *errnop)
  91 {
  92   enum nss_status status;
  93   char buf[HEXKEYBYTES + KEYCHECKSUMSIZE + 16];
  94
  95   skey[0] = 0;
  96
  97   status = search (netname, buf, errnop, 1);
  98   if (status != NSS_STATUS_SUCCESS)
  99     return status;
 100
 101   if (!xdecrypt (buf, passwd))
 102     return NSS_STATUS_SUCCESS;
 103
 104   if (memcmp (buf, &(buf[HEXKEYBYTES]), KEYCHECKSUMSIZE) != 0)
 105     return NSS_STATUS_SUCCESS;
 106
 107   buf[HEXKEYBYTES] = 0;
 108   strcpy (skey, buf);
 109
 110   return NSS_STATUS_SUCCESS;
 111 }