CDE/cde/programs/dtlogin/xdmauth.c

/*
 * CDE - Common Desktop Environment
 *
 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
 *
 * These libraries and programs are free software; you can
 * redistribute them and/or modify them under the terms of the GNU
 * Lesser General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * These libraries and programs are distributed in the hope that
 * they 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 these libraries and programs; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301 USA
 */
/* $TOG: xdmauth.c /main/4 1997/03/14 13:45:35 barstow $ */
/* (c) Copyright 1997 The Open Group */
/*                                                                      *
 * (c) Copyright 1993, 1994 Hewlett-Packard Company                     *
 * (c) Copyright 1993, 1994 International Business Machines Corp.       *
 * (c) Copyright 1993, 1994 Sun Microsystems, Inc.                      *
 * (c) Copyright 1993, 1994 Novell, Inc.                                *
 */

/*
 * @DEC_COPYRIGHT@
 */
/*
 * HISTORY
 * $Log$
 * Revision 1.1.2.3  1995/06/06  20:25:50  Chris_Beute
 * 	Code snapshot merge from March 15 and SIA changes
 * 	[1995/05/31  20:17:31  Chris_Beute]
 *
 * Revision 1.1.2.2  1995/04/21  13:05:43  Peter_Derr
 * 	dtlogin auth key fixes from deltacde
 * 	[1995/04/12  19:21:36  Peter_Derr]
 * 
 * 	xdm R6 version used to handle XDM-AUTHORIZATION-1
 * 	[1995/04/12  18:06:02  Peter_Derr]
 * 
 * $EndLog$
 */
/*

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.

*/

/*
 * xdm - display manager daemon
 * Author:  Keith Packard, MIT X Consortium
 *
 * xdmauth
 *
 * generate authorization data for XDM-AUTHORIZATION-1 as per XDMCP spec
 */

#include "dm.h"

#ifdef HASXDMAUTH

static char	auth_name[256];
static int	auth_name_len;

void GenerateAuthData(char *auth, int len); // genauth.c

void
XdmPrintDataHex(const char *s, const char *a, int l)
{
    int	i;

    Debug ("%s", s);
    for (i = 0; i < l; i++)
	Debug (" %02x", a[i] & 0xff);
    Debug ("\n");
}

#ifdef XDMCP
void
XdmPrintArray8Hex(const char *s, ARRAY8Ptr a)
{
    XdmPrintDataHex (s, (char *) a->data, a->length);
}
#endif

#if NeedWidePrototypes
void
XdmInitAuth (unsigned int name_len, char *name)
#else
void
XdmInitAuth (unsigned short name_len, char *name)
#endif /* NeedWidePrototypes */
{
    if (name_len > 256)
	name_len = 256;
    auth_name_len = name_len;
    memmove( auth_name, name, name_len);
}

/*
 * Generate authorization for XDM-AUTHORIZATION-1 
 *
 * When being used with XDMCP, 8 bytes are generated for the session key
 * (sigma), as the random number (rho) is already shared between xdm and
 * the server.  Otherwise, we'll prepend a random number to pass in the file
 * between xdm and the server (16 bytes total)
 */

Xauth *
XdmGetAuthHelper (unsigned short namelen, char *name, int includeRho)
{
    Xauth   *new;
    new = (Xauth *) malloc (sizeof (Xauth));

    if (!new)
	return (Xauth *) 0;
    new->family = FamilyWild;
    new->address_length = 0;
    new->address = 0;
    new->number_length = 0;
    new->number = 0;
    if (includeRho)
	new->data_length = 16;
    else
	new->data_length = 8;

    new->data = (char *) malloc (new->data_length);
    if (!new->data)
    {
	free ((char *) new);
	return (Xauth *) 0;
    }
    new->name = (char *) malloc (namelen);
    if (!new->name)
    {
	free ((char *) new->data);
	free ((char *) new);
	return (Xauth *) 0;
    }
    memmove( (char *)new->name, name, namelen);
    new->name_length = namelen;
    GenerateAuthData ((char *)new->data, new->data_length);
    /*
     * set the first byte of the session key to zero as it
     * is a DES key and only uses 56 bits
     */
    ((char *)new->data)[new->data_length - 8] = '\0';
    XdmPrintDataHex ("Local server auth", (char *)new->data, new->data_length);
    return new;
}

#if NeedWidePrototypes
Xauth *
XdmGetAuth (unsigned int namelen, char *name)
#else
Xauth *
XdmGetAuth (unsigned short namelen, char *name)
#endif /* NeedWidePrototypes */
{
    return XdmGetAuthHelper (namelen, name, TRUE);
}

#ifdef XDMCP

#if NeedWidePrototypes
void XdmGetXdmcpAuth (struct protoDisplay *pdpy, unsigned int authorizationNameLen, char *authorizationName)
#else
void XdmGetXdmcpAuth (struct protoDisplay *pdpy, unsigned short authorizationNameLen, char *authorizationName)
#endif /* NeedWidePrototypes */
{
    Xauth   *fileauth, *xdmcpauth;

    if (pdpy->fileAuthorization && pdpy->xdmcpAuthorization)
	return;
    xdmcpauth = XdmGetAuthHelper (authorizationNameLen, authorizationName, FALSE);
    if (!xdmcpauth)
	return;
    fileauth = (Xauth *) malloc (sizeof (Xauth));
    if (!fileauth)
    {
	XauDisposeAuth(xdmcpauth);
	return;
    }
    /* build the file auth from the XDMCP auth */
    *fileauth = *xdmcpauth;
    fileauth->name = malloc (xdmcpauth->name_length);
    fileauth->data = malloc (16);
    fileauth->data_length = 16;
    if (!fileauth->name || !fileauth->data)
    {
	XauDisposeAuth (xdmcpauth);
	if (fileauth->name)
	    free ((char *) fileauth->name);
	if (fileauth->data)
	    free ((char *) fileauth->data);
	free ((char *) fileauth);
	return;
    }
    /*
     * for the file authorization, prepend the random number (rho)
     * which is simply the number we've been passing back and
     * forth via XDMCP
     */
    memmove( fileauth->name, xdmcpauth->name, xdmcpauth->name_length);
    memmove( fileauth->data, pdpy->authenticationData.data, 8);
    memmove( fileauth->data + 8, xdmcpauth->data, 8);
    XdmPrintDataHex ("Accept packet auth", xdmcpauth->data, xdmcpauth->data_length);
    XdmPrintDataHex ("Auth file auth", fileauth->data, fileauth->data_length);
    /* encrypt the session key for its trip back to the server */
    XdmcpWrap (xdmcpauth->data, &pdpy->key, xdmcpauth->data, 8);
    pdpy->fileAuthorization = fileauth;
    pdpy->xdmcpAuthorization = xdmcpauth;
}

#define atox(c)	('0' <= c && c <= '9' ? c - '0' : \
		 'a' <= c && c <= 'f' ? c - 'a' + 10 : \
		 'A' <= c && c <= 'F' ? c - 'A' + 10 : -1)

static int
HexToBinary (char *key)
{
    char    *out, *in;
    int	    top, bottom;

    in = key + 2;
    out= key;
    while (in[0] && in[1])
    {
	top = atox(in[0]);
	if (top == -1)
	    return 0;
	bottom = atox(in[1]);
	if (bottom == -1)
	    return 0;
	*out++ = (top << 4) | bottom;
	in += 2;
    }
    if (in[0])
	return 0;
    *out++ = '\0';
    return 1;
}

/*
 * Search the Keys file for the entry matching this display.  This
 * routine accepts either plain ascii strings for keys, or hex-encoded numbers
 */

int XdmGetKey (struct protoDisplay *pdpy, ARRAY8Ptr displayID)
{
    FILE    *keys;
    char    line[1024], id[1024], key[1024];
    int	    keylen;

    Debug ("Lookup key for %*.*s\n", displayID->length, displayID->length, displayID->data);
    keys = fopen (keyFile, "r");
    if (!keys)
	return FALSE;
    while (fgets (line, sizeof (line) -  1, keys))
    {
	if (line[0] == '#' || sscanf (line, "%s %s", id, key) != 2)
	    continue;
	bzero(line, sizeof(line));
	Debug ("Key entry \"%s\" \"%s\"\n", id, key);
	if (strlen (id) == displayID->length &&
	    !strncmp (id, (char *)displayID->data, displayID->length))
	{
	    if (!strncmp (key, "0x", 2) || !strncmp (key, "0X", 2))
		if (!HexToBinary (key))
		    break;
	    keylen = strlen (key);
	    while (keylen < 7)
		key[keylen++] = '\0';
	    pdpy->key.data[0] = '\0';
	    memmove( pdpy->key.data + 1, key, 7);
	    bzero(key, sizeof(key));
	    fclose (keys);
	    return TRUE;
	}
    }
    bzero(line, sizeof(line));
    bzero(key, sizeof(key));
    fclose (keys);
    return FALSE;
}

/*ARGSUSED*/
int XdmCheckAuthentication (struct protoDisplay *pdpy, ARRAY8Ptr displayID,
                        ARRAY8Ptr authenticationName, ARRAY8Ptr authenticationData)
{
    XdmAuthKeyPtr   incoming;

    if (!XdmGetKey (pdpy, displayID))
	return FALSE;
    if (authenticationData->length != 8)
	return FALSE;
    XdmcpUnwrap (authenticationData->data, &pdpy->key,
		  authenticationData->data, 8);
    XdmPrintArray8Hex ("Request packet auth", authenticationData);
    if (!XdmcpCopyARRAY8(authenticationData, &pdpy->authenticationData))
	return FALSE;
    incoming = (XdmAuthKeyPtr) authenticationData->data;
    XdmcpIncrementKey (incoming);
    XdmcpWrap (authenticationData->data, &pdpy->key,
		  authenticationData->data, 8);
    return TRUE;
}

#endif /* XDMCP */
#endif /* HASXDMAUTH (covering the entire file) */