Arbitrary group length restriction in chkname.c

Hi there,

[ See also https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=56850 ]

The code in libmisc/chkname.c has this for validating group names:

int
check_group_name(const char *name)
{
         /*
          * Arbitrary limit for group names - max 16
          * characters (same as on HP-UX 10).
          */
         if (strlen(name) > 16)
                 return 0;
[...]

Whereas the code for validating user names is:

int
check_user_name(const char *name)
{
#if HAVE_UTMPX_H
         struct utmpx ut;
#else
         struct utmp ut;
#endif

         /*
          * User names are limited by whatever utmp can
          * handle (usually max 8 characters).
          */
         if (strlen(name) > sizeof(ut.ut_user))
                 return 0;

[...]

Where (on RH7.3):

struct utmpx
{
...
   char ut_user[__UT_NAMESIZE];  /* Username.  */
...
};

and

#define __UT_NAMESIZE   32

The patch below changes the the group code to use the same length
as for users. It seems to work nicely for me on RH 7.3 and I can
happily add both users and groups up to 32 characters.

Is there a good reason to have the constant 16, or could that
be conditional for HP-UX?

Thanks,

Gordon
--
  Gordon Rowell [email protected]  http://www.gormand.com.au
  Gormand Pty Ltd  PO Box 239 St Pauls NSW 2031 Australia
   "The test of our progress is not whether we add more to the abundance
   of those who have much; it is whether we provide enough for those who
   have too little." Franklin D Roosevelt, Second Inaugural Address, 1937

---CUT HERE------CUT HERE------CUT HERE------CUT HERE------CUT HERE---
diff -rNu shadow-20000902.orig/libmisc/chkname.c 
shadow-20000902/libmisc/chkname.c
--- shadow-20000902.orig/libmisc/chkname.c	Thu Apr 16 15:57:43 1998
+++ shadow-20000902/libmisc/chkname.c	Thu Oct 14 06:32:30 2004
@@ -62,11 +62,17 @@
  int
  check_group_name(const char *name)
  {
+#if HAVE_UTMPX_H
+        struct utmpx ut;
+#else
+        struct utmp ut;
+#endif
+
  	/*
  	 * Arbitrary limit for group names - max 16
  	 * characters (same as on HP-UX 10).
  	 */
-	if (strlen(name) > 16)
+	if (strlen(name) > sizeof(ut.ut_user))
  		return 0;

  	return good_name(name);