Tcl_Channel chan;
    DigestState *statePtr;

    dprintf("Called");

    /* Validate args */
    if (channel == (const char *) NULL) {
	Tcl_AppendResult(interp, "No channel", (char *) NULL);
	return TCL_ERROR;
    }

    /* Get channel Id */
    chan = Tcl_GetChannel(interp, channel, &mode);
    if (chan == (Tcl_Channel) NULL) {
	return TCL_ERROR;

    /* Clean-up */
    DigestStateFree(statePtr);
    return res;
}

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

static const char *command_opts [] = { "-bin", "-binary", "-hex", "-hexadecimal",
    "-chan", "-channel", "-cipher", "-command", "-data", "-digest", "-file", "-filename",
    "-hash", "-key", "-mac", NULL};

enum _command_opts {
    _opt_bin, _opt_binary, _opt_hex, _opt_hexadecimal, _opt_chan, _opt_channel, _opt_cipher,
    _opt_command, _opt_data, _opt_digest, _opt_file, _opt_filename, _opt_hash, _opt_key, _opt_mac
};

/*
 *-------------------------------------------------------------------
 *
 * DigestMain --
 *
 *	Return message digest or Message Authentication Code (MAC) of
 *	data using user specified hash function.
 *
 * Returns:
 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Sets result to message digest or error message
 *
 *-------------------------------------------------------------------
 */
static int DigestMain(int type, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
    int start = 1, format = HEX_FORMAT, res = TCL_OK, fn;
    Tcl_Obj *cipherObj = NULL, *cmdObj = NULL, *dataObj = NULL, *digestObj = NULL;
    Tcl_Obj *fileObj = NULL, *keyObj = NULL, *macObj = NULL;
    const char *channel = NULL, *opt;

    dprintf("Called");

    /* Clear interp result */
    Tcl_ResetResult(interp);

    /* Validate arg count */
    if (objc < 3 || objc > 12) {
	Tcl_WrongNumArgs(interp, 1, objv, "?-bin|-hex? ?-cipher name? ?-digest name? ?-key key? ?-mac name? [-channel chan | -command cmdName | -file filename | ?-data? data]");
	return TCL_ERROR;
    }

    /* Special case of first arg is digest, cipher, or mac */
    opt = Tcl_GetStringFromObj(objv[start], NULL);
    if (opt[0] != '-') {
	switch(type) {
	case TYPE_MD:
	case TYPE_HMAC:
	    digestObj = objv[start++];
	    break;
	case TYPE_CMAC:
	    cipherObj = objv[start++];
	    break;
	case TYPE_MAC:
	    macObj = objv[start++];
	    break;
	}
    }

    /* Get options */
    for (int idx = start; idx < objc; idx++) {
	/* Special case for when last arg is data */
	if (idx == objc - 1) {
	    opt = Tcl_GetStringFromObj(objv[idx], NULL);

	    if (opt[0] != '-' && dataObj == NULL) {
		dataObj = objv[idx];
		break;
	    }
	}

	/* Get option */
	if (Tcl_GetIndexFromObj(interp, objv[idx], command_opts, "option", 0, &fn) != TCL_OK) {
	    return TCL_ERROR;
	}

	/* Validate arg has value */
	if (fn > _opt_hexadecimal) {
	    if (++idx >= objc) {
		Tcl_AppendResult(interp, "No value for option \"", command_opts[fn], "\"", (char *) NULL);
		return TCL_ERROR;
	    }
	}

	switch(fn) {
	case _opt_bin:
	case _opt_binary:
	    format = BIN_FORMAT;
	    break;
	case _opt_hex:
	case _opt_hexadecimal:
	    format = HEX_FORMAT;
	    break;
	case _opt_chan:
	case _opt_channel:
    	    GET_OPT_STRING(objv[idx], channel, NULL);
	    break;
	case _opt_cipher:
	    cipherObj = objv[idx];
	    break;
	case _opt_command:
	    cmdObj = objv[idx];
	    break;
	case _opt_data:
	    dataObj = objv[idx];
	    break;
	case _opt_digest:
	case _opt_hash:
	    digestObj = objv[idx];
	    break;
	case _opt_file:
	case _opt_filename:
	    fileObj = objv[idx];
	    break;
	case _opt_key:
	    keyObj = objv[idx];
	    break;
	case _opt_mac:
	    macObj = objv[idx];

	    break;
	}




    }

    /* Check types */
    if (type == TYPE_MD) {
	 if (macObj != NULL) {
	    type = TYPE_MAC;
	} else if (cipherObj != NULL) {
	    type = TYPE_CMAC;
	} else if (keyObj != NULL) {
	    type = TYPE_HMAC;
	}
    }

    if (type == TYPE_MAC) {
	if (macObj != NULL) {
	    char *macName = Tcl_GetStringFromObj(macObj, NULL);
	    if (strcmp(macName,"cmac") == 0) {
		type = TYPE_CMAC;
	    } else if (strcmp(macName,"hmac") == 0) {
		type = TYPE_HMAC;
	    } else {
		Tcl_AppendResult(interp, "Invalid MAC \"", macName, "\"", NULL);
		return TCL_ERROR;
	    }
	} else {
	    Tcl_AppendResult(interp, "No MAC specified", NULL);
	    return TCL_ERROR;
	}
    }

    /* Calc digest on file, stacked channel, using instance command, or data blob */
    if (fileObj != NULL) {
	res = DigestFileHandler(interp, fileObj, digestObj, cipherObj, format | type, keyObj, macObj);
    } else if (channel != NULL) {
	res = DigestChannelHandler(interp, channel, digestObj, cipherObj, format | type, keyObj, macObj);

 *	TCL_OK or TCL_ERROR
 *
 * Side effects:
 *	Sets result to message digest or error message
 *
 *-------------------------------------------------------------------
 */
 int TemplateCmd(Tcl_Interp *interp, int objc, Tcl_Obj *const objv[], char *digestName, int format) {
    Tcl_Obj *dataObj, *digestObj;
    int res;

    if (objc == 2) {
	dataObj = objv[1];
    } else {
	Tcl_WrongNumArgs(interp, 1, objv, "data");
	return TCL_ERROR;
    }

    digestObj = Tcl_NewStringObj(digestName, -1);
    Tcl_IncrRefCount(digestObj);
    res = DigestDataHandler(interp, dataObj, digestObj, NULL, format, NULL, NULL);
    Tcl_DecrRefCount(digestObj);
    return res;
}
 
int MD4ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    return TemplateCmd(interp, objc, objv, "md4", HEX_FORMAT | TYPE_MD);
}

int MD5ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    return TemplateCmd(interp, objc, objv, "md5", HEX_FORMAT | TYPE_MD);
}

int SHA1ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    return TemplateCmd(interp, objc, objv, "sha1", HEX_FORMAT | TYPE_MD);
}

int SHA256ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    return TemplateCmd(interp, objc, objv, "sha256", HEX_FORMAT | TYPE_MD);
}

int SHA512ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {

    return TemplateCmd(interp, objc, objv, "sha512", HEX_FORMAT | TYPE_MD);
}

/*
 *-------------------------------------------------------------------
 *
 * Tls_DigestCommands --
 *