xref: /xsrc/external/mit/libXext/dist/src/XSecurity.c

/*

Copyright 1996, 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.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <X11/Xlibint.h>
#include <stdio.h>
#include <X11/extensions/Xext.h>
#include <X11/extensions/extutil.h>
#include <X11/extensions/securproto.h>
#include <X11/extensions/security.h>
#include <assert.h>

static XExtensionInfo _Security_info_data;
static XExtensionInfo *Security_info = &_Security_info_data;
static const char *Security_extension_name = SECURITY_EXTENSION_NAME;

#define SecurityCheckExtension(dpy,i,val) \
  XextCheckExtension (dpy, i, Security_extension_name, val)
#define SecuritySimpleCheckExtension(dpy,i) \
  XextSimpleCheckExtension (dpy, i, Security_extension_name)

#define SecurityGetReq(name,req,info) GetReq (name, req); \
        req->reqType = info->codes->major_opcode; \
        req->securityReqType = X_##name;

/*****************************************************************************
 *                                                                           *
 *			   private utility routines                          *
 *                                                                           *
 *****************************************************************************/

/*
 * find_display - locate the display info block
 */
static int close_display(Display *dpy, XExtCodes *codes);
static Bool wire_to_event(Display *dpy, XEvent *event, xEvent *wire);
static Status event_to_wire(Display *dpy, XEvent *event, xEvent *wire);
static char *error_string(Display *dpy, int code, XExtCodes *codes,
			  char *buf, int n);

static XExtensionHooks Security_extension_hooks = {
    NULL,                               /* create_gc */
    NULL,                               /* copy_gc */
    NULL,                               /* flush_gc */
    NULL,                               /* free_gc */
    NULL,                               /* create_font */
    NULL,                               /* free_font */
    close_display,                      /* close_display */
    wire_to_event,                      /* wire_to_event */
    event_to_wire,                      /* event_to_wire */
    NULL,                               /* error */
    error_string                        /* error_string */
};

static const char    *security_error_list[] = {
    "BadAuthorization",
    "BadAuthorizationProtocol"
};

static XEXT_GENERATE_FIND_DISPLAY (find_display, Security_info,
				   Security_extension_name,
				   &Security_extension_hooks,
				   XSecurityNumberEvents, NULL)

static XEXT_GENERATE_CLOSE_DISPLAY (close_display, Security_info)

static
XEXT_GENERATE_ERROR_STRING(error_string, Security_extension_name,
			   XSecurityNumberErrors, security_error_list)

static Bool
wire_to_event(Display *dpy, XEvent *event, xEvent *wire)
{
    XExtDisplayInfo *info = find_display(dpy);

    SecurityCheckExtension (dpy, info, False);

    switch ((wire->u.u.type & 0x7F) - info->codes->first_event)
    {
	case XSecurityAuthorizationRevoked:
	{
	    xSecurityAuthorizationRevokedEvent *rwire =
		(xSecurityAuthorizationRevokedEvent *)wire;
	    XSecurityAuthorizationRevokedEvent *revent =
		(XSecurityAuthorizationRevokedEvent *)event;

	  revent->type = rwire->type & 0x7F;
	  revent->serial = _XSetLastRequestRead(dpy,
						(xGenericReply *) wire);
	  revent->send_event = (rwire->type & 0x80) != 0;
	  revent->display = dpy;
	  revent->auth_id = rwire->authId;
	  return True;
	}
    }
    return False;
}

static Status
event_to_wire(Display *dpy, XEvent *event, xEvent *wire)
{
    XExtDisplayInfo *info = find_display(dpy);

    SecurityCheckExtension(dpy, info, False);

    switch ((event->type & 0x7F) - info->codes->first_event)
    {
	case XSecurityAuthorizationRevoked:
	{
	    xSecurityAuthorizationRevokedEvent *rwire =
		(xSecurityAuthorizationRevokedEvent *)wire;
	    XSecurityAuthorizationRevokedEvent *revent =
		(XSecurityAuthorizationRevokedEvent *)event;
	    rwire->type = revent->type | (revent->send_event ? 0x80 : 0);
	    rwire->sequenceNumber = revent->serial & 0xFFFF;
	    return True;
	}
    }
    return False;
}

/*****************************************************************************
 *                                                                           *
 *		       Security public interfaces                            *
 *                                                                           *
 *****************************************************************************/

Status XSecurityQueryExtension (
    Display *dpy,
    int *major_version_return,
    int *minor_version_return)
{
    XExtDisplayInfo *info = find_display (dpy);
    xSecurityQueryVersionReply rep;
    register xSecurityQueryVersionReq *req;

    if (!XextHasExtension (info))
        return (Status)0; /* failure */

    LockDisplay (dpy);
    SecurityGetReq (SecurityQueryVersion, req, info);
    req->majorVersion = SECURITY_MAJOR_VERSION;
    req->minorVersion = SECURITY_MINOR_VERSION;

    if (!_XReply (dpy, (xReply *) &rep, 0, xTrue)) {
	UnlockDisplay (dpy);
	SyncHandle ();
	return (Status)0; /* failure */
    }
    *major_version_return = rep.majorVersion;
    *minor_version_return = rep.minorVersion;
    UnlockDisplay (dpy);

    SyncHandle ();

    if (*major_version_return != SECURITY_MAJOR_VERSION)
        return (Status)0; /* failure */
    else
        return (Status)1; /* success */
}

Xauth *
XSecurityAllocXauth(void)
{
    return Xcalloc(1, sizeof(Xauth));
}

void
XSecurityFreeXauth(Xauth *auth)
{
    XFree(auth);
}

#ifdef HAVE___BUILTIN_POPCOUNTL
# define Ones __builtin_popcountl
#else
/*
 * Count the number of bits set to 1 in a 32-bit word.
 * Algorithm from MIT AI Lab Memo 239: "HAKMEM", ITEM 169.
 * http://dspace.mit.edu/handle/1721.1/6086
 */
static inline int
Ones(Mask mask)
{
    register Mask y;

    y = (mask >> 1) & 033333333333;
    y = mask - y - ((y >>1) & 033333333333);
    return (((y + (y >> 3)) & 030707070707) % 077);
}
#endif

Xauth *
XSecurityGenerateAuthorization(
    Display *dpy,
    Xauth *auth_in,
    unsigned long valuemask,
    XSecurityAuthorizationAttributes *attributes,
    XSecurityAuthorization *auth_id_return)
{
    XExtDisplayInfo *info = find_display (dpy);
    register xSecurityGenerateAuthorizationReq *req;
    xSecurityGenerateAuthorizationReply rep;
    Xauth *auth_return;
    unsigned long values[4];
    unsigned long *value = values;
    unsigned int nvalues;

    /* values array must have a slot for each possible valuemask value */
    assert(Ones(XSecurityAllAuthorizationAttributes)
           == (sizeof(values) / sizeof(values[0])));

    *auth_id_return = 0;  /* in case we fail */

    /* make sure extension is available */

    SecurityCheckExtension (dpy, info, (Xauth *)NULL);

    LockDisplay(dpy);
    SecurityGetReq(SecurityGenerateAuthorization, req, info);

    req->nbytesAuthProto = auth_in->name_length;
    req->nbytesAuthData  = auth_in->data_length;

    /* adjust length to account for auth name and data */
    req->length += (auth_in->name_length + (unsigned)3) >> 2;
    req->length += (auth_in->data_length + (unsigned)3) >> 2;

    /* adjust length to account for list of values */
    req->valueMask = valuemask & XSecurityAllAuthorizationAttributes;
    nvalues = Ones(req->valueMask);
    req->length += nvalues;

    /* send auth name and data */
    Data(dpy, auth_in->name, auth_in->name_length);
    Data(dpy, auth_in->data, auth_in->data_length);

    /* send values */
    if (valuemask & XSecurityTimeout)	 *value++ = attributes->timeout;
    if (valuemask & XSecurityTrustLevel) *value++ = attributes->trust_level;
    if (valuemask & XSecurityGroup)	 *value++ = attributes->group;
    if (valuemask & XSecurityEventMask)	 *value++ = attributes->event_mask;

    nvalues <<= 2;
    Data32(dpy, (long *)values, (long)nvalues);

    if (!_XReply (dpy, (xReply *) &rep, 0, xFalse)) {
	UnlockDisplay (dpy);
	SyncHandle ();
	return (Xauth *)NULL;
    }

    *auth_id_return = rep.authId;

    /* Allocate space for the Xauth struct and the auth name and data all
     * in one hunk.  This lets XSecurityFreeXauth not have to care
     * about whether the auth was allocated here or in
     * XSecurityAllocXauth; in both cases, you just free one pointer.
     */

    if ((auth_return = Xcalloc(1,
		(sizeof(Xauth) + auth_in->name_length + rep.dataLength))))
    {
	auth_return->data_length = rep.dataLength;
	auth_return->data = (char *)&auth_return[1];
	_XReadPad(dpy, auth_return->data, (long)rep.dataLength);

	auth_return->name_length = auth_in->name_length;
	auth_return->name = auth_return->data + auth_return->data_length;
	memcpy(auth_return->name, auth_in->name, auth_return->name_length);
    }
    else
    {
	_XEatDataWords(dpy, rep.length);
    }

    UnlockDisplay (dpy);
    SyncHandle ();
    return auth_return;

} /* XSecurityGenerateAuthorization */

Status
XSecurityRevokeAuthorization(
    Display *dpy,
    XSecurityAuthorization auth_id)
{
    XExtDisplayInfo *info = find_display (dpy);
    xSecurityRevokeAuthorizationReq *req;

    SecurityCheckExtension (dpy, info, 0);
    LockDisplay(dpy);
    SecurityGetReq(SecurityRevokeAuthorization, req, info);
    req->authId = auth_id;
    UnlockDisplay (dpy);
    SyncHandle ();
    return 1;
} /* XSecurityRevokeAuthorization */