auth.c

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/* $XConsortium: auth.c /main/27 1996/12/02 10:22:41 lehors $ */
/*

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.

*/

/*
 * authorization hooks for the server
 * Author:  Keith Packard, MIT X Consortium
 */

#ifdef K5AUTH
# include   <krb5/krb5.h>
#endif
# include   "X.h"
# include   "Xauth.h"
# include   "misc.h"
# include   "dixstruct.h"
# include   <sys/types.h>
# include   <sys/stat.h>
#ifdef XCSECURITY
#define _SECURITY_SERVER
# include   "extensions/security.h"
#endif
#ifdef WIN32
#include "Xw32defs.h"
#endif

struct protocol {
    unsigned short   name_length;
    char    *name;
    int     (*Add)();	    /* new authorization data */
    XID	    (*Check)();	    /* verify client authorization data */
    int     (*Reset)();	    /* delete all authorization data entries */
    XID	    (*ToID)();	    /* convert cookie to ID */
    int	    (*FromID)();    /* convert ID to cookie */
    int	    (*Remove)();    /* remove a specific cookie */
#ifdef XCSECURITY
    XID     (*Generate)();
#endif
};

extern int  MitAddCookie ();
extern XID  MitCheckCookie ();
extern int  MitResetCookie ();
extern XID  MitToID ();
extern int  MitFromID (), MitRemoveCookie ();
extern XID  MitGenerateCookie();

#ifdef HASXDMAUTH
extern int  XdmAddCookie ();
extern XID  XdmCheckCookie ();
extern int  XdmResetCookie ();
extern XID  XdmToID ();
extern int  XdmFromID (), XdmRemoveCookie ();
#endif

#ifdef SECURE_RPC
extern int  SecureRPCAdd();
extern XID  SecureRPCCheck();
extern int  SecureRPCReset();
extern XID  SecureRPCToID();
extern int  SecureRPCFromID(), SecureRPCRemove();
#endif

#ifdef K5AUTH
extern int K5Add();
extern XID K5Check();
extern int K5Reset();
extern XID K5ToID();
extern int K5FromID(), K5Remove();
#endif

extern XID AuthSecurityCheck();

static struct protocol   protocols[] = {
{   (unsigned short) 18,    "MIT-MAGIC-COOKIE-1",
		MitAddCookie,	MitCheckCookie,	MitResetCookie,
		MitToID,	MitFromID,	MitRemoveCookie,
#ifdef XCSECURITY
		MitGenerateCookie
#endif
},
#ifdef HASXDMAUTH
{   (unsigned short) 19,    "XDM-AUTHORIZATION-1",
		XdmAddCookie,	XdmCheckCookie,	XdmResetCookie,
		XdmToID,	XdmFromID,	XdmRemoveCookie,
#ifdef XCSECURITY
		NULL
#endif
},
#endif
#ifdef SECURE_RPC
{   (unsigned short) 9,    "SUN-DES-1",
		SecureRPCAdd,	SecureRPCCheck,	SecureRPCReset,
		SecureRPCToID,	SecureRPCFromID,SecureRPCRemove,
#ifdef XCSECURITY
		NULL
#endif
},
#endif
#ifdef K5AUTH
{   (unsigned short) 14, "MIT-KERBEROS-5",
		K5Add, K5Check, K5Reset,
		K5ToID, K5FromID, K5Remove,
#ifdef XCSECURITY
		NULL
#endif
},
#endif
#ifdef XCSECURITY
{   (unsigned short) XSecurityAuthorizationNameLen,
	XSecurityAuthorizationName,
		NULL, AuthSecurityCheck, NULL,
		NULL, NULL, NULL,
		NULL
},
#endif
};

# define NUM_AUTHORIZATION  (sizeof (protocols) /\
			     sizeof (struct protocol))

/*
 * Initialize all classes of authorization by reading the
 * specified authorization file
 */

static char *authorization_file = (char *)NULL;

static Bool ShouldLoadAuth = TRUE;

void
InitAuthorization (file_name)
char	*file_name;
{
    authorization_file = file_name;
}

int
LoadAuthorization ()
{
    FILE    *f;
    Xauth   *auth;
    int	    i;
    int	    count = 0;

    ShouldLoadAuth = FALSE;
    if (!authorization_file)
	return 0;
    f = fopen (authorization_file, "r");
    if (!f)
	return 0;
    while (auth = XauReadAuth (f)) {
	for (i = 0; i < NUM_AUTHORIZATION; i++) {
	    if (protocols[i].name_length == auth->name_length &&
		memcmp (protocols[i].name, auth->name, (int) auth->name_length) == 0 &&
		protocols[i].Add)
	    {
		++count;
		(*protocols[i].Add) (auth->data_length, auth->data,
					 FakeClientID(0));
	    }
	}
	XauDisposeAuth (auth);
    }
    fclose (f);
    return count;
}

#ifdef XDMCP
/*
 * XdmcpInit calls this function to discover all authorization
 * schemes supported by the display
 */
void
RegisterAuthorizations ()
{
    int	    i;

    for (i = 0; i < NUM_AUTHORIZATION; i++)
	XdmcpRegisterAuthorization (protocols[i].name,
				    (int)protocols[i].name_length);
}
#endif

XID
CheckAuthorization (name_length, name, data_length, data, client, reason)
    unsigned int name_length;
    char	*name;
    unsigned int data_length;
    char	*data;
    ClientPtr client;
    char	**reason;	/* failure message.  NULL for default msg */
{
    int	i;
    struct stat buf;
    static time_t lastmod = 0;

    if (!authorization_file || stat(authorization_file, &buf))
    {
	lastmod = 0;
	ShouldLoadAuth = TRUE;	/* stat lost, so force reload */
    }
    else if (buf.st_mtime > lastmod)
    {
	lastmod = buf.st_mtime;
	ShouldLoadAuth = TRUE;
    }
    if (ShouldLoadAuth)
    {
	if (LoadAuthorization())
	    DisableLocalHost(); /* got at least one */
	else
	    EnableLocalHost ();
    }
    if (name_length)
	for (i = 0; i < NUM_AUTHORIZATION; i++) {
	    if (protocols[i].name_length == name_length &&
		memcmp (protocols[i].name, name, (int) name_length) == 0)
	    {
		return (*protocols[i].Check) (data_length, data, client, reason);
	    }
	}
    return (XID) ~0L;
}

void
ResetAuthorization ()
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++)
	if (protocols[i].Reset)
	    (*protocols[i].Reset)();
    ShouldLoadAuth = TRUE;
}

XID
AuthorizationToID (name_length, name, data_length, data)
unsigned short	name_length;
char	*name;
unsigned short	data_length;
char	*data;
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++) {
    	if (protocols[i].name_length == name_length &&
	    memcmp (protocols[i].name, name, (int) name_length) == 0 &&
	    protocols[i].ToID)
    	{
	    return (*protocols[i].ToID) (data_length, data);
    	}
    }
    return (XID) ~0L;
}

int
AuthorizationFromID (id, name_lenp, namep, data_lenp, datap)
XID id;
unsigned short	*name_lenp;
char	**namep;
unsigned short	*data_lenp;
char	**datap;
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++) {
	if (protocols[i].FromID &&
	    (*protocols[i].FromID) (id, data_lenp, datap)) {
	    *name_lenp = protocols[i].name_length;
	    *namep = protocols[i].name;
	    return 1;
	}
    }
    return 0;
}

int
RemoveAuthorization (name_length, name, data_length, data)
unsigned short	name_length;
char	*name;
unsigned short	data_length;
char	*data;
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++) {
    	if (protocols[i].name_length == name_length &&
	    memcmp (protocols[i].name, name, (int) name_length) == 0 &&
	    protocols[i].Remove)
    	{
	    return (*protocols[i].Remove) (data_length, data);
    	}
    }
    return 0;
}

int
AddAuthorization (name_length, name, data_length, data)
unsigned int name_length;
char	*name;
unsigned int data_length;
char	*data;
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++) {
    	if (protocols[i].name_length == name_length &&
	    memcmp (protocols[i].name, name, (int) name_length) == 0 &&
	    protocols[i].Add)
    	{
	    return (*protocols[i].Add) (data_length, data, FakeClientID(0));
    	}
    }
    return 0;
}

#ifdef XCSECURITY

XID
GenerateAuthorization(name_length, name, data_length, data,
		      data_length_return, data_return)
unsigned int name_length;
char	*name;
unsigned int data_length;
char	*data;
unsigned int *data_length_return;
char	**data_return;
{
    int	i;

    for (i = 0; i < NUM_AUTHORIZATION; i++) {
    	if (protocols[i].name_length == name_length &&
	    memcmp (protocols[i].name, name, (int) name_length) == 0 &&
	    protocols[i].Generate)
    	{
	    return (*protocols[i].Generate) (data_length, data,
			FakeClientID(0), data_length_return, data_return);
    	}
    }
    return -1;
}

/* A random number generator that is more unpredictable
   than that shipped with some systems.
   This code is taken from the C standard. */

static unsigned long int next = 1;

static int
xdm_rand()
{
    next = next * 1103515245 + 12345;
    return (unsigned int)(next/65536) % 32768;
}

static void
xdm_srand(seed)
    unsigned int seed;
{
    next = seed;
}

void
GenerateRandomData (len, buf)
int	len;
char	*buf;
{
    static int seed;
    int value;
    int i;

    seed += GetTimeInMillis();
    xdm_srand (seed);
    for (i = 0; i < len; i++)
    {
	value = xdm_rand ();
	buf[i] ^= (value & 0xff00) >> 8;
    }

    /* XXX add getrusage, popen("ps -ale") */
}

#endif /* XCSECURITY */