tor-browser

Extension.ts (6125B)

---

import * as asn1js from "asn1js";
import * as pvutils from "pvutils";
import * as Schema from "./Schema";
import { ExtensionParsedValue, ExtensionValueFactory } from "./ExtensionValueFactory";
import { PkiObject, PkiObjectParameters } from "./PkiObject";
import { AsnError } from "./errors";
import { EMPTY_STRING } from "./constants";

const EXTN_ID = "extnID";
const CRITICAL = "critical";
const EXTN_VALUE = "extnValue";
const PARSED_VALUE = "parsedValue";
const CLEAR_PROPS = [
 EXTN_ID,
 CRITICAL,
 EXTN_VALUE
];

export interface IExtension {
 extnID: string;
 critical: boolean;
 extnValue: asn1js.OctetString;
 parsedValue?: ExtensionParsedValue;
}

export interface ExtensionConstructorParameters {
 extnID?: string;
 critical?: boolean;
 extnValue?: ArrayBuffer;
 parsedValue?: ExtensionParsedValue;
}

export type ExtensionParameters = PkiObjectParameters & ExtensionConstructorParameters;

export type ExtensionSchema = Schema.SchemaParameters<{
 extnID?: string;
 critical?: string;
 extnValue?: string;
}>;

export interface ExtensionJson {
 extnID: string;
 extnValue: asn1js.OctetStringJson;
 critical?: boolean;
 parsedValue?: any;
}

/**
* Represents the Extension structure described in [RFC5280](https://datatracker.ietf.org/doc/html/rfc5280)
*/
export class Extension extends PkiObject implements IExtension {

 public static override CLASS_NAME = "Extension";

 public extnID!: string;
 public critical!: boolean;
 public extnValue!: asn1js.OctetString;

 private _parsedValue?: ExtensionParsedValue | null;
 public get parsedValue(): ExtensionParsedValue | undefined {
   if (this._parsedValue === undefined) {
     // Get PARSED_VALUE for well-known extensions
     const parsedValue = ExtensionValueFactory.fromBER(this.extnID, this.extnValue.valueBlock.valueHexView as BufferSource);
     this._parsedValue = parsedValue;
   }

   return this._parsedValue || undefined;
 }
 public set parsedValue(value: ExtensionParsedValue | undefined) {
   this._parsedValue = value;
 }

 /**
  * Initializes a new instance of the {@link Extension} class
  * @param parameters Initialization parameters
  */
 constructor(parameters: ExtensionParameters = {}) {
   super();

   this.extnID = pvutils.getParametersValue(parameters, EXTN_ID, Extension.defaultValues(EXTN_ID));
   this.critical = pvutils.getParametersValue(parameters, CRITICAL, Extension.defaultValues(CRITICAL));
   if (EXTN_VALUE in parameters) {
     this.extnValue = new asn1js.OctetString({ valueHex: parameters.extnValue });
   } else {
     this.extnValue = Extension.defaultValues(EXTN_VALUE);
   }
   if (PARSED_VALUE in parameters) {
     this.parsedValue = pvutils.getParametersValue(parameters, PARSED_VALUE, Extension.defaultValues(PARSED_VALUE));
   }

   if (parameters.schema) {
     this.fromSchema(parameters.schema);
   }
 }

 /**
  * Returns default values for all class members
  * @param memberName String name for a class member
  * @returns Default value
  */
 public static override defaultValues(memberName: typeof EXTN_ID): string;
 public static override defaultValues(memberName: typeof CRITICAL): boolean;
 public static override defaultValues(memberName: typeof EXTN_VALUE): asn1js.OctetString;
 public static override defaultValues(memberName: typeof PARSED_VALUE): ExtensionParsedValue;
 public static override defaultValues(memberName: string): any {
   switch (memberName) {
     case EXTN_ID:
       return EMPTY_STRING;
     case CRITICAL:
       return false;
     case EXTN_VALUE:
       return new asn1js.OctetString();
     case PARSED_VALUE:
       return {};
     default:
       return super.defaultValues(memberName);
   }
 }

 /**
  * @inheritdoc
  * @asn ASN.1 schema
  * ```asn
  * Extension ::= SEQUENCE  {
  *    extnID      OBJECT IDENTIFIER,
  *    critical    BOOLEAN DEFAULT FALSE,
  *    extnValue   OCTET STRING
  * }
  *```
  */
 public static override schema(parameters: ExtensionSchema = {}): Schema.SchemaType {
   const names = pvutils.getParametersValue<NonNullable<typeof parameters.names>>(parameters, "names", {});

   return (new asn1js.Sequence({
     name: (names.blockName || EMPTY_STRING),
     value: [
       new asn1js.ObjectIdentifier({ name: (names.extnID || EMPTY_STRING) }),
       new asn1js.Boolean({
         name: (names.critical || EMPTY_STRING),
         optional: true
       }),
       new asn1js.OctetString({ name: (names.extnValue || EMPTY_STRING) })
     ]
   }));
 }

 public fromSchema(schema: Schema.SchemaType): void {
   // Clear input data first
   pvutils.clearProps(schema, CLEAR_PROPS);

   // Check the schema is valid
   const asn1 = asn1js.compareSchema(schema,
     schema,
     Extension.schema({
       names: {
         extnID: EXTN_ID,
         critical: CRITICAL,
         extnValue: EXTN_VALUE
       }
     })
   );
   AsnError.assertSchema(asn1, this.className);

   // Get internal properties from parsed schema
   this.extnID = asn1.result.extnID.valueBlock.toString();
   if (CRITICAL in asn1.result) {
     this.critical = asn1.result.critical.valueBlock.value;
   }
   this.extnValue = asn1.result.extnValue;
 }

 public toSchema(): asn1js.Sequence {
   // Create array for output sequence
   const outputArray = [];

   outputArray.push(new asn1js.ObjectIdentifier({ value: this.extnID }));

   if (this.critical !== Extension.defaultValues(CRITICAL)) {
     outputArray.push(new asn1js.Boolean({ value: this.critical }));
   }

   outputArray.push(this.extnValue);

   // Construct and return new ASN.1 schema for this object
   return (new asn1js.Sequence({
     value: outputArray
   }));
 }

 public toJSON(): ExtensionJson {
   const object: ExtensionJson = {
     extnID: this.extnID,
     extnValue: this.extnValue.toJSON(),
   };

   if (this.critical !== Extension.defaultValues(CRITICAL)) {
     object.critical = this.critical;
   }
   if (this.parsedValue && this.parsedValue.toJSON) {
     object.parsedValue = this.parsedValue.toJSON();
   }

   return object;
 }

}