/* $XConsortium: xdmauth.c,v 1.13 95/07/10 21:18:07 gildea 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.

*/

/*
 * 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;

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

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

#ifdef notdef			/* not used */
XdmPrintKey (s, k)
    char	    *s;
    XdmAuthKeyRec   *k;
{
    XdmPrintDataHex (s, (char *) k->data, 8);
}
#endif

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

XdmInitAuth (name_len, name)
    unsigned short  name_len;
    char	    *name;
{
    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 (namelen, name, includeRho)
    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;
}

Xauth *
XdmGetAuth (namelen, name)
    unsigned short  namelen;
    char	    *name;
{
    return XdmGetAuthHelper (namelen, name, TRUE);
}

#ifdef XDMCP

void
XdmGetXdmcpAuth (pdpy,authorizationNameLen, authorizationName)
    struct protoDisplay	*pdpy;
    unsigned short	authorizationNameLen;
    char		*authorizationName;
{
    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
HexToBinary (key)
    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
 */

XdmGetKey (pdpy, displayID)
    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 for \"%s\" %d bytes\n", id, strlen(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*/
XdmCheckAuthentication (pdpy, displayID, authenticationName, authenticationData)
    struct protoDisplay	*pdpy;
    ARRAY8Ptr		displayID, authenticationName, 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) */