src/MacData.js

import * as asn1js from "asn1js";
import { getParametersValue, clearProps } from "pvutils";
import DigestInfo from "./DigestInfo.js";
//**************************************************************************************
/**
 * Class from RFC7292
 */
export default class MacData 
{
	//**********************************************************************************
	/**
	 * Constructor for MacData class
	 * @param {Object} [parameters={}]
	 * @property {Object} [schema] asn1js parsed value
	 */
	constructor(parameters = {})
	{
		//region Internal properties of the object
		/**
		 * @type {DigestInfo}
		 * @description mac
		 */
		this.mac = getParametersValue(parameters, "mac", MacData.defaultValues("mac"));
		/**
		 * @type {OctetString}
		 * @description macSalt
		 */
		this.macSalt = getParametersValue(parameters, "macSalt", MacData.defaultValues("macSalt"));
		
		if("iterations" in parameters)
			/**
			 * @type {number}
			 * @description iterations
			 */
			this.iterations = getParametersValue(parameters, "iterations", MacData.defaultValues("iterations"));
		//endregion
		
		//region If input argument array contains "schema" for this object
		if("schema" in parameters)
			this.fromSchema(parameters.schema);
		//endregion
	}
	//**********************************************************************************
	/**
	 * Return default values for all class members
	 * @param {string} memberName String name for a class member
	 */
	static defaultValues(memberName)
	{
		switch(memberName)
		{
			case "mac":
				return new DigestInfo();
			case "macSalt":
				return new asn1js.OctetString();
			case "iterations":
				return 1;
			default:
				throw new Error(`Invalid member name for MacData class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Compare values with default values for all class members
	 * @param {string} memberName String name for a class member
	 * @param {*} memberValue Value to compare with default value
	 */
	static compareWithDefault(memberName, memberValue)
	{
		switch(memberName)
		{
			case "mac":
				return ((DigestInfo.compareWithDefault("digestAlgorithm", memberValue.digestAlgorithm)) &&
				(DigestInfo.compareWithDefault("digest", memberValue.digest)));
			case "macSalt":
				return (memberValue.isEqual(MacData.defaultValues(memberName)));
			case "iterations":
				return (memberValue === MacData.defaultValues(memberName));
			default:
				throw new Error(`Invalid member name for MacData class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Return value of asn1js schema for current class
	 * @param {Object} parameters Input parameters for the schema
	 * @returns {Object} asn1js schema object
	 */
	static schema(parameters = {})
	{
		//MacData ::= SEQUENCE {
		//    mac 		DigestInfo,
		//    macSalt       OCTET STRING,
		//    iterations	INTEGER DEFAULT 1
		//    -- Note: The default is for historical reasons and its use is
		//    -- deprecated. A higher value, like 1024 is recommended.
		//    }
		
		/**
		 * @type {Object}
		 * @property {string} [blockName]
		 * @property {string} [optional]
		 * @property {string} [mac]
		 * @property {string} [macSalt]
		 * @property {string} [iterations]
		 */
		const names = getParametersValue(parameters, "names", {});
		
		return (new asn1js.Sequence({
			name: (names.blockName || ""),
			optional: (names.optional || true),
			value: [
				DigestInfo.schema(names.mac || {
					names: {
						blockName: "mac"
					}
				}),
				new asn1js.OctetString({ name: (names.macSalt || "macSalt") }),
				new asn1js.Integer({
					optional: true,
					name: (names.iterations || "iterations")
				})
			]
		}));
	}
	//**********************************************************************************
	/**
	 * Convert parsed asn1js object into current class
	 * @param {!Object} schema
	 */
	fromSchema(schema)
	{
		//region Clear input data first
		clearProps(schema, [
			"mac",
			"macSalt",
			"iterations"
		]);
		//endregion
		
		//region Check the schema is valid
		const asn1 = asn1js.compareSchema(schema,
			schema,
			MacData.schema({
				names: {
					mac: {
						names: {
							blockName: "mac"
						}
					},
					macSalt: "macSalt",
					iterations: "iterations"
				}
			})
		);
		
		if(asn1.verified === false)
			throw new Error("Object's schema was not verified against input data for MacData");
		//endregion
		
		//region Get internal properties from parsed schema
		this.mac = new DigestInfo({ schema: asn1.result.mac });
		this.macSalt = asn1.result.macSalt;
		
		if("iterations" in asn1.result)
			this.iterations = asn1.result.iterations.valueBlock.valueDec;
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convert current object to asn1js object and set correct values
	 * @returns {Object} asn1js object
	 */
	toSchema()
	{
		//region Construct and return new ASN.1 schema for this object
		const outputArray = [
			this.mac.toSchema(),
			this.macSalt
		];
		
		if("iterations" in this)
			outputArray.push(new asn1js.Integer({ value: this.iterations }));
		
		return (new asn1js.Sequence({
			value: outputArray
		}));
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convertion for the class to JSON object
	 * @returns {Object}
	 */
	toJSON()
	{
		const output = {
			mac: this.mac.toJSON(),
			macSalt: this.macSalt.toJSON()
		};
		
		if("iterations" in this)
			output.iterations = this.iterations.toJSON();
		
		return output;
	}
	//**********************************************************************************
}
//**************************************************************************************