/******************************************************************************

Copyright 1993, 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: Ralph Mor, X Consortium

******************************************************************************/

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <X11/ICE/ICElib.h>

#include "ICElibint.h"

#include <X11/ICE/ICEutil.h>

#include <time.h>

#define Time_t time_t

#ifdef HAVE_LIBBSD

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

#endif

static int was_called_state;

#ifndef HAVE_ARC4RANDOM_BUF

static void

emulate_getrandom_buf (

	char *auth,

	int len

)

{

    long    ldata[2];

    int	    seed;

    int	    value;

    int	    i;

#ifdef ITIMER_REAL

    {

	struct timeval  now;

	X_GETTIMEOFDAY (&now;;

	ldata[0] = now.tv_sec;

	ldata[1] = now.tv_usec;

    }

#else /* ITIMER_REAL */

    {

	long    time ();

	ldata[0] = time ((long *) 0);

	ldata[1] = getpid ();

    }

#endif /* ITIMER_REAL */

    seed = (ldata[0]) + (ldata[1] << 16);

    srand (seed);

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

    {

	value = rand ();

	auth[i] = value & 0xff;

    }

}

#ifndef HAVE_GETENTROPY

#include <sys/syscall.h>

#include <errno.h>

/* code taken from libressl, license: */

/*

 * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>

 * Copyright (c) 2014 Bob Beck <beck@obtuse.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 *

 * Emulation of getentropy(2) as documented at:

 * http://man.openbsd.org/getentropy.2

 */

#ifdef __NR_getrandom

static int

getentropy(void *buf, size_t len)

{

	int pre_errno = errno;

	int ret;

	if (len > 256)

		return (-1);

	do {

		ret = syscall(__NR_getrandom, buf, len, 0);

	} while (ret == -1 && errno == EINTR);

	if (ret != len)

		return (-1);

	errno = pre_errno;

	fprintf(stderr, "generating cookie with syscall\n");

	return (0);

}

#define HAVE_GETENTROPY 1

#endif /* __NR_getrandom */

#endif /* HAVE_GETENTROPY */

static void

arc4random_buf (

	char *auth,

	int len

)

{

    int	    ret;

#if HAVE_GETENTROPY

    /* weak emulation of arc4random through the entropy libc */

    ret = getentropy (auth, len);

    if (ret == 0)

	return;

#endif /* HAVE_GETENTROPY */

    emulate_getrandom_buf (auth, len);

}

#endif /* !defined(HAVE_ARC4RANDOM_BUF) */

/*

 * MIT-MAGIC-COOKIE-1 is a sample authentication method implemented by

 * the SI.  It is not part of standard ICElib.

 */

char *

IceGenerateMagicCookie (

	int len

)

{

    char    *auth;

    if ((auth = malloc (len + 1)) == NULL)

	return (NULL);

    arc4random_buf (auth, len);

    auth[len] = '\0';

    return (auth);

}

IcePoAuthStatus

_IcePoMagicCookie1Proc (

	IceConn		iceConn,

	IcePointer	*authStatePtr,

	Bool 		cleanUp,

	Bool		swap,

	int     	authDataLen,

	IcePointer	authData,

	int 		*replyDataLenRet,

	IcePointer	*replyDataRet,

	char    	**errorStringRet

)

{

    if (cleanUp)

    {

	/*

	 * We didn't allocate any state.  We're done.

	 */

	return (IcePoAuthDoneCleanup);

    }

    *errorStringRet = NULL;

    if (*authStatePtr == NULL)

    {

	/*

	 * This is the first time we're being called.  Search the

	 * authentication data for the first occurence of

	 * MIT-MAGIC-COOKIE-1 that matches iceConn->connection_string.

	 */

	unsigned short  length;

	char		*data;

	_IceGetPoAuthData ("ICE", iceConn->connection_string,

	    "MIT-MAGIC-COOKIE-1", &length, &data);

	if (!data)

	{

	    const char *tempstr =

		"Could not find correct MIT-MAGIC-COOKIE-1 authentication";

	    *errorStringRet = strdup(tempstr);

	    return (IcePoAuthFailed);

	}

	else

	{

	    *authStatePtr = (IcePointer) &was_called_state;

	    *replyDataLenRet = length;

	    *replyDataRet = data;

	    return (IcePoAuthHaveReply);

	}

    }

    else

    {

	/*

	 * We should never get here for MIT-MAGIC-COOKIE-1 since it is

	 * a single pass authentication method.

	 */

	const char *tempstr =

	    "MIT-MAGIC-COOKIE-1 authentication internal error";

	*errorStringRet = strdup(tempstr);

	return (IcePoAuthFailed);

    }

}

IcePoAuthProc	_IcePoAuthProcs[] = {_IcePoMagicCookie1Proc};

IcePaAuthStatus

_IcePaMagicCookie1Proc (

	IceConn		iceConn,

	IcePointer	*authStatePtr,

	Bool		swap,

	int     	authDataLen,

	IcePointer	authData,

	int 		*replyDataLenRet,

	IcePointer	*replyDataRet,

	char    	**errorStringRet

)

{

    *errorStringRet = NULL;

    *replyDataLenRet = 0;

    *replyDataRet = NULL;

    if (*authStatePtr == NULL)

    {

	/*

	 * This is the first time we're being called.  We don't have

	 * any data to pass to the other client.

	 */

	*authStatePtr = (IcePointer) &was_called_state;

	return (IcePaAuthContinue);

    }

    else

    {

	/*

	 * Search the authentication data for the first occurence of

	 * MIT-MAGIC-COOKIE-1 that matches iceConn->connection_string.

	 */

	unsigned short  length;

	char		*data;

	_IceGetPaAuthData ("ICE", iceConn->connection_string,

	    "MIT-MAGIC-COOKIE-1", &length, &data);

	if (data)

	{

	    IcePaAuthStatus stat;

	    if (authDataLen == length &&

	        memcmp (authData, data, authDataLen) == 0)

	    {

		stat = IcePaAuthAccepted;

	    }

	    else

	    {

		const char *tempstr

		    = "MIT-MAGIC-COOKIE-1 authentication rejected";

		*errorStringRet = strdup(tempstr);

		stat = IcePaAuthRejected;

	    }

	    free (data);

	    return (stat);

	}

	else

	{

	    /*

	     * We should never get here because in the ConnectionReply

	     * we should have passed all the valid methods.  So we should

	     * always find a valid entry.

	     */

	    const char *tempstr =

		"MIT-MAGIC-COOKIE-1 authentication internal error";

	    *errorStringRet = strdup(tempstr);

	    return (IcePaAuthFailed);

	}

    }

}

IcePaAuthProc	_IcePaAuthProcs[] = {_IcePaMagicCookie1Proc};