glibc/nss/nss_files/files-key.c

112 lines
3.0 KiB
C

/* Public key file parser in nss_files module.
Copyright (C) 1996-2020 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
<https://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;
}