Unwrap.c revision 44dda7b2 
1/*
2Copyright 1989, 1998  The Open Group
3
4Permission to use, copy, modify, distribute, and sell this software and its
5documentation for any purpose is hereby granted without fee, provided that
6the above copyright notice appear in all copies and that both that
7copyright notice and this permission notice appear in supporting
8documentation.
9
10The above copyright notice and this permission notice shall be included in
11all copies or substantial portions of the Software.
12
13THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
16OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
17AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
18CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
19
20Except as contained in this notice, the name of The Open Group shall not be
21used in advertising or otherwise to promote the sale, use or other dealings
22in this Software without prior written authorization from The Open Group.
23 * *
24 * Author:  Keith Packard, MIT X Consortium
25 */
26
27#ifdef HAVE_CONFIG_H
28#include <config.h>
29#endif
30#include <X11/Xos.h>
31#include <X11/X.h>
32#include <X11/Xmd.h>
33#include <X11/Xdmcp.h>
34
35#ifdef HASXDMAUTH
36
37/*
38 * The following function exists only to demonstrate the
39 * desired functional interface for this routine.  You will
40 * need to add the appropriate algorithm if you wish to
41 * use XDM-AUTHENTICATION-1/XDM-AUTHORIZATION-1.
42 *
43 * The interface for this routine is quite simple.  All three
44 * arguments are arrays of 8 unsigned characters, the first two
45 * are 64 bits of useful data, the last is 56 bits of useful
46 * data packed into 8 bytes, using the low 7 bits of each
47 * byte, filling the high bit with odd parity.
48 *
49 * Examine the XDMCP specification for the correct algorithm
50 */
51
52#include "Wrap.h"
53
54void
55XdmcpUnwrap (
56    unsigned char	*input,
57    unsigned char	*wrapper,
58    unsigned char	*output,
59    int			bytes)
60{
61    int			i, j, k;
62    unsigned char	tmp[8];
63    unsigned char	blocks[2][8];
64    unsigned char	expand_wrapper[8];
65    auth_wrapper_schedule	schedule;
66
67    _XdmcpWrapperToOddParity (wrapper, expand_wrapper);
68    _XdmcpAuthSetup (expand_wrapper, schedule);
69
70    k = 0;
71    for (j = 0; j < bytes; j += 8)
72    {
73	if (bytes - j < 8)
74	    return; /* bad input length */
75	for (i = 0; i < 8; i++)
76	    blocks[k][i] = input[j + i];
77	_XdmcpAuthDoIt ((unsigned char *) (input + j), (unsigned char *) tmp, schedule, 0);
78	/* block chaining */
79	k = (k == 0) ? 1 : 0;
80	for (i = 0; i < 8; i++)
81	{
82	    if (j == 0)
83		output[j + i] = tmp[i];
84	    else
85		output[j + i] = tmp[i] ^ blocks[k][i];
86	}
87    }
88}
89
90#endif /* HASXDMAUTH */
91