src/RSAESOAEPParams.js

import * as asn1js from "asn1js";
import { getParametersValue, clearProps } from "pvutils";
import AlgorithmIdentifier from "./AlgorithmIdentifier.js";
//**************************************************************************************
/**
 * Class from RFC3447
 */
export default class RSAESOAEPParams
{
	//**********************************************************************************
	/**
	 * Constructor for RSAESOAEPParams class
	 * @param {Object} [parameters={}]
	 * @property {Object} [schema] asn1js parsed value
	 */
	constructor(parameters = {})
	{
		//region Internal properties of the object
		/**
		 * @type {AlgorithmIdentifier}
		 * @description hashAlgorithm
		 */
		this.hashAlgorithm = getParametersValue(parameters, "hashAlgorithm", RSAESOAEPParams.defaultValues("hashAlgorithm"));
		/**
		 * @type {AlgorithmIdentifier}
		 * @description maskGenAlgorithm
		 */
		this.maskGenAlgorithm = getParametersValue(parameters, "maskGenAlgorithm", RSAESOAEPParams.defaultValues("maskGenAlgorithm"));
		/**
		 * @type {AlgorithmIdentifier}
		 * @description pSourceAlgorithm
		 */
		this.pSourceAlgorithm = getParametersValue(parameters, "pSourceAlgorithm", RSAESOAEPParams.defaultValues("pSourceAlgorithm"));
		//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 "hashAlgorithm":
				return new AlgorithmIdentifier({
					algorithmId: "1.3.14.3.2.26", // SHA-1
					algorithmParams: new asn1js.Null()
				});
			case "maskGenAlgorithm":
				return new AlgorithmIdentifier({
					algorithmId: "1.2.840.113549.1.1.8", // MGF1
					algorithmParams: (new AlgorithmIdentifier({
						algorithmId: "1.3.14.3.2.26", // SHA-1
						algorithmParams: new asn1js.Null()
					})).toSchema()
				});
			case "pSourceAlgorithm":
				return new AlgorithmIdentifier({
					algorithmId: "1.2.840.113549.1.1.9", // id-pSpecified
					algorithmParams: new asn1js.OctetString({ valueHex: (new Uint8Array([0xda, 0x39, 0xa3, 0xee, 0x5e, 0x6b, 0x4b, 0x0d, 0x32, 0x55, 0xbf, 0xef, 0x95, 0x60, 0x18, 0x90, 0xaf, 0xd8, 0x07, 0x09])).buffer }) // SHA-1 hash of empty string
				});
			default:
				throw new Error(`Invalid member name for RSAESOAEPParams 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 = {})
	{
		//RSAES-OAEP-params ::= SEQUENCE {
		//    hashAlgorithm     [0] HashAlgorithm    DEFAULT sha1,
		//    maskGenAlgorithm  [1] MaskGenAlgorithm DEFAULT mgf1SHA1,
		//    pSourceAlgorithm  [2] PSourceAlgorithm DEFAULT pSpecifiedEmpty
		//}

		/**
		 * @type {Object}
		 * @property {string} [blockName]
		 * @property {string} [hashAlgorithm]
		 * @property {string} [maskGenAlgorithm]
		 * @property {string} [pSourceAlgorithm]
		 */
		const names = getParametersValue(parameters, "names", {});

		return (new asn1js.Sequence({
			name: (names.blockName || ""),
			value: [
				new asn1js.Constructed({
					idBlock: {
						tagClass: 3, // CONTEXT-SPECIFIC
						tagNumber: 0 // [0]
					},
					optional: true,
					value: [AlgorithmIdentifier.schema(names.hashAlgorithm || {})]
				}),
				new asn1js.Constructed({
					idBlock: {
						tagClass: 3, // CONTEXT-SPECIFIC
						tagNumber: 1 // [1]
					},
					optional: true,
					value: [AlgorithmIdentifier.schema(names.maskGenAlgorithm || {})]
				}),
				new asn1js.Constructed({
					idBlock: {
						tagClass: 3, // CONTEXT-SPECIFIC
						tagNumber: 2 // [2]
					},
					optional: true,
					value: [AlgorithmIdentifier.schema(names.pSourceAlgorithm || {})]
				})
			]
		}));
	}
	//**********************************************************************************
	/**
	 * Convert parsed asn1js object into current class
	 * @param {!Object} schema
	 */
	fromSchema(schema)
	{
		//region Clear input data first
		clearProps(schema, [
			"hashAlgorithm",
			"maskGenAlgorithm",
			"pSourceAlgorithm"
		]);
		//endregion
		
		//region Check the schema is valid
		const asn1 = asn1js.compareSchema(schema,
			schema,
			RSAESOAEPParams.schema({
				names: {
					hashAlgorithm: {
						names: {
							blockName: "hashAlgorithm"
						}
					},
					maskGenAlgorithm: {
						names: {
							blockName: "maskGenAlgorithm"
						}
					},
					pSourceAlgorithm: {
						names: {
							blockName: "pSourceAlgorithm"
						}
					}
				}
			})
		);

		if(asn1.verified === false)
			throw new Error("Object's schema was not verified against input data for RSAESOAEPParams");
		//endregion

		//region Get internal properties from parsed schema
		if("hashAlgorithm" in asn1.result)
			this.hashAlgorithm = new AlgorithmIdentifier({ schema: asn1.result.hashAlgorithm });

		if("maskGenAlgorithm" in asn1.result)
			this.maskGenAlgorithm = new AlgorithmIdentifier({ schema: asn1.result.maskGenAlgorithm });

		if("pSourceAlgorithm" in asn1.result)
			this.pSourceAlgorithm = new AlgorithmIdentifier({ schema: asn1.result.pSourceAlgorithm });
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convert current object to asn1js object and set correct values
	 * @returns {Object} asn1js object
	 */
	toSchema()
	{
		//region Create array for output sequence
		const outputArray = [];
		
		if(!this.hashAlgorithm.isEqual(RSAESOAEPParams.defaultValues("hashAlgorithm")))
		{
			outputArray.push(new asn1js.Constructed({
				idBlock: {
					tagClass: 3, // CONTEXT-SPECIFIC
					tagNumber: 0 // [0]
				},
				value: [this.hashAlgorithm.toSchema()]
			}));
		}
		
		if(!this.maskGenAlgorithm.isEqual(RSAESOAEPParams.defaultValues("maskGenAlgorithm")))
		{
			outputArray.push(new asn1js.Constructed({
				idBlock: {
					tagClass: 3, // CONTEXT-SPECIFIC
					tagNumber: 1 // [1]
				},
				value: [this.maskGenAlgorithm.toSchema()]
			}));
		}

		if(!this.pSourceAlgorithm.isEqual(RSAESOAEPParams.defaultValues("pSourceAlgorithm")))
		{
			outputArray.push(new asn1js.Constructed({
				idBlock: {
					tagClass: 3, // CONTEXT-SPECIFIC
					tagNumber: 2 // [2]
				},
				value: [this.pSourceAlgorithm.toSchema()]
			}));
		}
		//endregion
		
		//region Construct and return new ASN.1 schema for this object
		return (new asn1js.Sequence({
			value: outputArray
		}));
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convertion for the class to JSON object
	 * @returns {Object}
	 */
	toJSON()
	{
		const object = {};

		if(!this.hashAlgorithm.isEqual(RSAESOAEPParams.defaultValues("hashAlgorithm")))
			object.hashAlgorithm = this.hashAlgorithm.toJSON();

		if(!this.maskGenAlgorithm.isEqual(RSAESOAEPParams.defaultValues("maskGenAlgorithm")))
			object.maskGenAlgorithm = this.maskGenAlgorithm.toJSON();

		if(!this.pSourceAlgorithm.isEqual(RSAESOAEPParams.defaultValues("pSourceAlgorithm")))
			object.pSourceAlgorithm = this.pSourceAlgorithm.toJSON();

		return object;
	}
	//**********************************************************************************
}
//**************************************************************************************