/*

Copyright 1989, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its

documentation for any purpose is hereby granted without fee, provided that

the above copyright notice appear in all copies and that both that

copyright notice and this permission notice appear in supporting

documentation.

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

OPEN GROUP 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 Open Group 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 Open Group.

 *

 * Author:  Keith Packard, MIT X Consortium

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <X11/Xos.h>

#include <X11/X.h>

#include <X11/Xmd.h>

#include <X11/Xdmcp.h>

#ifdef HAVE_LIBBSD

#include <bsd/stdlib.h> /* for arc4random_buf() */

#endif

#ifndef HAVE_ARC4RANDOM_BUF

static void

getbits (long data, unsigned char *dst)

{

    dst[0] = (data      ) & 0xff;

    dst[1] = (data >>  8) & 0xff;

    dst[2] = (data >> 16) & 0xff;

    dst[3] = (data >> 24) & 0xff;

}

#endif

#define Time_t time_t

#include <stdlib.h>

#if defined(HAVE_LRAND48) && defined(HAVE_SRAND48)

#define srandom srand48

#define random lrand48

#endif

#ifdef WIN32

#include <process.h>

#define srandom srand

#define random rand

#define getpid(x) _getpid(x)

#endif

#ifndef HAVE_ARC4RANDOM_BUF

static void

insecure_getrandom_buf (unsigned char *auth, int len)

{

    long    lowbits, highbits;

    srandom ((int)getpid() ^ time((Time_t *)0));

    lowbits = random ();

    highbits = random ();

    getbits (lowbits, auth);

    getbits (highbits, auth + 4);

}

static void

arc4random_buf (void *auth, int len)

{

    int	    ret;

#if HAVE_GETENTROPY

    /* weak emulation of arc4random through the getentropy libc call */

    ret = getentropy (auth, len);

    if (ret == 0)

	return;

#endif /* HAVE_GETENTROPY */

    insecure_getrandom_buf (auth, len);

}

#endif /* !defined(HAVE_ARC4RANDOM_BUF) */

void

XdmcpGenerateKey (XdmAuthKeyPtr key)

{

    arc4random_buf(key->data, 8);

}

int

XdmcpCompareKeys (const XdmAuthKeyPtr a, const XdmAuthKeyPtr b)

{

    int	i;

    for (i = 0; i < 8; i++)

	if (a->data[i] != b->data[i])

	    return FALSE;

    return TRUE;

}

void

XdmcpIncrementKey (XdmAuthKeyPtr key)

{

    int	i;

    i = 7;

    while (++key->data[i] == 0)

	if (--i < 0)

	    break;

}

void

XdmcpDecrementKey (XdmAuthKeyPtr key)

{

    int	i;

    i = 7;

    while (key->data[i]-- == 0)

	if (--i < 0)

	    break;

}