*	Sets the device into blocking or nonblocking mode.
 *	Can call Tcl_SetChannelError.
 *
 *-------------------------------------------------------------------
 */
static int EncryptBlockModeProc(ClientData clientData, int mode) {
    EncryptState *statePtr = (EncryptState *) clientData;

    dprintf("Called");

    if (mode == TCL_MODE_NONBLOCKING) {
	statePtr->flags |= TLS_TCL_ASYNC;
    } else {
	statePtr->flags &= ~(TLS_TCL_ASYNC);
    }
    return 0;

 * Side effects:
 *	Deletes stored state data.
 *
 *-------------------------------------------------------------------
 */
int EncryptCloseProc(ClientData clientData, Tcl_Interp *interp) {
    EncryptState *statePtr = (EncryptState *) clientData;

    dprintf("Called");

    /* Cancel active timer, if any */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = (Tcl_TimerToken) NULL;
    }

    return 0;
}

/*
 * Same as EncryptCloseProc but with individual read and write close control
 */
static int EncryptClose2Proc(ClientData instanceData, Tcl_Interp *interp, int flags) {
    dprintf("Called");

    if ((flags & (TCL_CLOSE_READ | TCL_CLOSE_WRITE)) == 0) {
	return EncryptCloseProc(instanceData, interp);
    }
    return EINVAL;
}

/*

    EncryptState *statePtr = (EncryptState *) clientData;
    Tcl_Channel parent;
    int out_len;
    Tcl_Size read;
    *errorCodePtr = 0;
    char *in_buf;
    
    dprintf("Called");

    /* Abort if nothing to process */
    if (toRead <= 0 || statePtr->self == (Tcl_Channel) NULL) {
	return 0;
    }

    /* Get bytes from underlying channel */
    in_buf = Tcl_Alloc((Tcl_Size) toRead);
    parent = Tcl_GetStackedChannel(statePtr->self);
    read = Tcl_ReadRaw(parent, in_buf, (Tcl_Size) toRead);

    /* Update function */
    if (read > 0) {
	/* Have data - Update function */
	if (EncryptUpdate(statePtr->interp, statePtr->type, statePtr->ctx, (unsigned char *) buf,
		&out_len, (unsigned char *) in_buf, read) == TCL_OK) {
	    /* If have data, put in buf, otherwise tell TCL to try again */
	    if (out_len > 0) {
		read = (Tcl_Size) out_len;
	    } else {
		*errorCodePtr = EAGAIN;
		read = -1;
	    }

 *----------------------------------------------------------------------
 */
 int EncryptOutputProc(ClientData clientData, const char *buf, int toWrite, int *errorCodePtr) {
    EncryptState *statePtr = (EncryptState *) clientData;
    int write = 0, out_len;
    *errorCodePtr = 0;
    char *out_buf;

    dprintf("Called");

    /* Abort if nothing to process */
    if (toWrite <= 0 || statePtr->self == (Tcl_Channel) NULL) {
	return 0;
    }

    out_buf = Tcl_Alloc((Tcl_Size) toWrite+EVP_MAX_BLOCK_LENGTH);

    /* Update function */
    if (EncryptUpdate(statePtr->interp, statePtr->type, statePtr->ctx, (unsigned char *) out_buf,
	    &out_len, (unsigned char *) buf, (Tcl_Size) toWrite) == TCL_OK) {
	/* If have data, output it, otherwise tell TCL to try again */
	if (out_len > 0) {
	    Tcl_Channel parent = Tcl_GetStackedChannel(statePtr->self);
	    write = (int) Tcl_WriteRaw(parent, (const char *) out_buf, (Tcl_Size) out_len);
	    write = toWrite;
	} else {
	    *errorCodePtr = EAGAIN;

 *----------------------------------------------------------------------
 */
static int EncryptSetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
	const char *optionValue) {
    EncryptState *statePtr = (EncryptState *) clientData;
    Tcl_Channel parent;
    Tcl_DriverSetOptionProc *setOptionProc;

    dprintf("Called");

    /* Abort if no channel */
    if (statePtr->self == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    /* Delegate options downstream */

 *----------------------------------------------------------------------
 */
static int EncryptGetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
	Tcl_DString *optionValue) {
    EncryptState *statePtr = (EncryptState *) clientData;
    Tcl_Channel parent;
    Tcl_DriverGetOptionProc *getOptionProc;

    dprintf("Called");

    /* Abort if no channel */
    if (statePtr->self == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    /* Delegate options downstream */

 * Side effects:
 *	May call Tcl_NotifyChannel
 *
 *----------------------------------------------------------------------
 */
static void EncryptTimerHandler(ClientData clientData) {
    EncryptState *statePtr = (EncryptState *) clientData;

    dprintf("Called");

    /* Abort if no channel */
    if (statePtr->self == (Tcl_Channel) NULL) {
	return;
    }

    /* Clear timer token */

 *
 *----------------------------------------------------------------------
 */
void EncryptWatchProc(ClientData clientData, int mask) {
    EncryptState *statePtr = (EncryptState *) clientData;
    Tcl_Channel parent;
    Tcl_DriverWatchProc *watchProc;

    dprintf("Called");

    /* Abort if no channel */
    if (statePtr->self == (Tcl_Channel) NULL) {
	return;
    }

    /* Store OR-ed combination of TCL_READABLE, TCL_WRITABLE and TCL_EXCEPTION */

 *	None
 *
 *----------------------------------------------------------------------
 */
int EncryptGetHandleProc(ClientData clientData, int direction, ClientData *handlePtr) {
    EncryptState *statePtr = (EncryptState *) clientData;
    Tcl_Channel parent;

    dprintf("Called");

    /* Abort if no channel */
    if (statePtr->self == (Tcl_Channel) NULL) {
	return TCL_ERROR;
    }

    parent = Tcl_GetStackedChannel(statePtr->self);

 * Side effects:
 *	Cancels any pending timer.
 *
 *----------------------------------------------------------------------
 */
int EncryptNotifyProc(ClientData clientData, int interestMask) {
    EncryptState *statePtr = (EncryptState *) clientData;

    dprintf("Called");

    /* Skip timer event as redundant */
    if (statePtr->timer != (Tcl_TimerToken) NULL) {
	Tcl_DeleteTimerHandler(statePtr->timer);
	statePtr->timer = (Tcl_TimerToken) NULL;
    }
    return interestMask;

 * Side effects:
 *	Destroys state info structure
 *
 *-------------------------------------------------------------------
 */
void EncryptCommandDeleteHandler(ClientData clientData) {
    EncryptState *statePtr = (EncryptState *) clientData;

    dprintf("Called");

    /* Clean-up */
    EncryptStateFree(statePtr);
}

/*
 *-------------------------------------------------------------------