[PATCH] nss: Remove cryptographic key from nss_files

Florian Weimer fweimer@redhat.com
Tue Jun 30 15:52:01 GMT 2020


The interface has hard-coded buffer sizes and is therefore tied to
DES.  It also does not match current practice where different
services on the same host use different key material.

This change simplifies removal of the sunrpc code.

---
Tested on x86_64-linux-gnu (with the glibc test suite).

 NEWS                      |   3 ++
 nss/Makefile              |   3 +-
 nss/nss_files/files-key.c | 113 ----------------------------------------------
 3 files changed, 5 insertions(+), 114 deletions(-)

diff --git a/NEWS b/NEWS
index 1f70b73edd..ffb389161b 100644
--- a/NEWS
+++ b/NEWS
@@ -57,6 +57,9 @@ Deprecated and removed features, and other changes affecting compatibility:
 * ldconfig now defaults to the new format for ld.so.cache. glibc has
   already supported this format for almost 20 years.
 
+* The "files" NSS module can no longer process DES public or private
+  keys.  The contents of the /etc/publickey file is ignored.
+
 Changes to build and runtime requirements:
 
 * powerpc64le requires GCC 7.4 or newer.  This is required for supporting
diff --git a/nss/Makefile b/nss/Makefile
index 97bab5bb75..cbb70167a9 100644
--- a/nss/Makefile
+++ b/nss/Makefile
@@ -93,7 +93,8 @@ subdir-dirs = $(services:%=nss_%)
 vpath %.c $(subdir-dirs) ../locale/programs ../intl
 
 
-libnss_files-routines	:= $(addprefix files-,$(databases)) \
+libnss_files-routines	:= $(addprefix files-, \
+			     $(filter-out key, $(databases))) \
 			   files-initgroups files-init
 
 libnss_db-dbs		:= $(addprefix db-,\
diff --git a/nss/nss_files/files-key.c b/nss/nss_files/files-key.c
deleted file mode 100644
index cf0a7d9ad9..0000000000
--- a/nss/nss_files/files-key.c
+++ /dev/null
@@ -1,113 +0,0 @@
-/* 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"
-
-NSS_DECLARE_MODULE_FUNCTIONS (files)
-
-#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;
-}



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