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      1 /*
      2 Copyright 1989, 1998  The Open Group
      3 
      4 Permission to use, copy, modify, distribute, and sell this software and its
      5 documentation for any purpose is hereby granted without fee, provided that
      6 the above copyright notice appear in all copies and that both that
      7 copyright notice and this permission notice appear in supporting
      8 documentation.
      9 
     10 The above copyright notice and this permission notice shall be included in
     11 all copies or substantial portions of the Software.
     12 
     13 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     14 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     15 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
     16 OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     17 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     18 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     19 
     20 Except as contained in this notice, the name of The Open Group shall not be
     21 used in advertising or otherwise to promote the sale, use or other dealings
     22 in 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  * Examine the XDMCP specification for the correct algorithm
     44  */
     45 
     46 #include "Wrap.h"
     47 
     48 void
     49 XdmcpWrap (
     50     unsigned char	*input,
     51     unsigned char	*wrapper,
     52     unsigned char	*output,
     53     int			bytes)
     54 {
     55     int			i, j;
     56     int			len;
     57     unsigned char	tmp[8];
     58     unsigned char	expand_wrapper[8];
     59     auth_wrapper_schedule	schedule;
     60 
     61     _XdmcpWrapperToOddParity (wrapper, expand_wrapper);
     62     _XdmcpAuthSetup (expand_wrapper, schedule);
     63     for (j = 0; j < bytes; j += 8)
     64     {
     65 	len = 8;
     66 	if (bytes - j < len)
     67 	    len = bytes - j;
     68 	/* block chaining */
     69 	for (i = 0; i < len; i++)
     70 	{
     71 	    if (j == 0)
     72 		tmp[i] = input[i];
     73 	    else
     74 		tmp[i] = input[j + i] ^ output[j - 8 + i];
     75 	}
     76 	for (; i < 8; i++)
     77 	{
     78 	    if (j == 0)
     79 		tmp[i] = 0;
     80 	    else
     81 		tmp[i] = 0 ^ output[j - 8 + i];
     82 	}
     83 	_XdmcpAuthDoIt (tmp, (output + j), schedule, 1);
     84     }
     85 }
     86 
     87 /*
     88  * Given a 56 bit wrapper in XDMCP format, create a 56
     89  * bit wrapper in 7-bits + odd parity format
     90  */
     91 
     92 static int
     93 OddParity (unsigned char c)
     94 {
     95     c = c ^ (c >> 4);
     96     c = c ^ (c >> 2);
     97     c = c ^ (c >> 1);
     98     return ~c & 0x1;
     99 }
    100 
    101 /*
    102  * Spread the 56 bit wrapper among 8 bytes, using the upper 7 bits
    103  * of each byte, and storing an odd parity bit in the low bit
    104  */
    105 
    106 void
    107 _XdmcpWrapperToOddParity (
    108     unsigned char   *in,
    109     unsigned char   *out)
    110 {
    111     int		    ashift, bshift;
    112     int		    i;
    113     unsigned char   c;
    114 
    115     ashift = 7;
    116     bshift = 1;
    117     for (i = 0; i < 7; i++)
    118     {
    119 	c = ((in[i] << ashift) | (in[i+1] >> bshift)) & 0x7f;
    120 	out[i] = (c << 1) | OddParity (c);
    121 	ashift--;
    122 	bshift++;
    123     }
    124     c = in[i];
    125     out[i] = (c << 1) | OddParity(c);
    126 }
    127 
    128 #endif
    129