/* $XConsortium: AuGetAddr.c,v 1.13 94/04/17 20:15:43 rws Exp $ */

/*

Copyright (c) 1988  X Consortium

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from the X Consortium.

*/

#include <X11/Xauth.h>
#include <X11/Xos.h>

static
binaryEqual (a, b, len)
register char	*a, *b;
register int	len;
{
    while (len--)
	if (*a++ != *b++)
	    return 0;
    return 1;
}

#if NeedFunctionPrototypes
Xauth *
XauGetAuthByAddr (
#if NeedWidePrototypes
unsigned int	family,
unsigned int	address_length,
#else
unsigned short	family,
unsigned short	address_length,
#endif
_Xconst char*	address,
#if NeedWidePrototypes
unsigned int	number_length,
#else
unsigned short	number_length,
#endif
_Xconst char*	number,
#if NeedWidePrototypes
unsigned int	name_length,
#else
unsigned short	name_length,
#endif
_Xconst char*	name)
#else
Xauth *
XauGetAuthByAddr (family, address_length, address,
			  number_length, number,
			  name_length, name)
unsigned short	family;
unsigned short	address_length;
char	*address;
unsigned short	number_length;
char	*number;
unsigned short	name_length;
char	*name;
#endif
{
    FILE    *auth_file;
    char    *auth_name;
    Xauth   *entry;

    auth_name = XauFileName ();
    if (!auth_name)
	return 0;
    if (access (auth_name, R_OK) != 0)		/* checks REAL id */
	return 0;
    auth_file = fopen (auth_name, "rb");
    if (!auth_file)
	return 0;
    for (;;) {
	entry = XauReadAuth (auth_file);
	if (!entry)
	    break;
	/*
	 * Match when:
	 *   either family or entry->family are FamilyWild or
	 *    family and entry->family are the same
	 *  and
	 *   either address or entry->address are empty or
	 *    address and entry->address are the same
	 *  and
	 *   either number or entry->number are empty or
	 *    number and entry->number are the same
	 *  and
	 *   either name or entry->name are empty or
	 *    name and entry->name are the same
	 */

	if ((family == FamilyWild || entry->family == FamilyWild ||
	     (entry->family == family &&
	      address_length == entry->address_length &&
	      binaryEqual (entry->address, address, (int)address_length))) &&
	    (number_length == 0 || entry->number_length == 0 ||
	     (number_length == entry->number_length &&
	      binaryEqual (entry->number, number, (int)number_length))) &&
	    (name_length == 0 || entry->name_length == 0 ||
	     (entry->name_length == name_length &&
 	      binaryEqual (entry->name, name, (int)name_length))))
	    break;
	XauDisposeAuth (entry);
    }
    (void) fclose (auth_file);
    return entry;
}