tor-browser

Signature.ts (6654B)

---

import * as asn1js from "asn1js";
import * as pvutils from "pvutils";
import { AlgorithmIdentifier, AlgorithmIdentifierJson, AlgorithmIdentifierSchema } from "./AlgorithmIdentifier";
import { Certificate, CertificateJson } from "./Certificate";
import { EMPTY_STRING } from "./constants";
import { AsnError } from "./errors";
import { PkiObject, PkiObjectParameters } from "./PkiObject";
import * as Schema from "./Schema";

const SIGNATURE_ALGORITHM = "signatureAlgorithm";
const SIGNATURE = "signature";
const CERTS = "certs";

export interface ISignature {
 signatureAlgorithm: AlgorithmIdentifier;
 signature: asn1js.BitString;
 certs?: Certificate[];
}

export interface SignatureJson {
 signatureAlgorithm: AlgorithmIdentifierJson;
 signature: asn1js.BitStringJson;
 certs?: CertificateJson[];
}

export type SignatureParameters = PkiObjectParameters & Partial<ISignature>;

export type SignatureSchema = Schema.SchemaParameters<{
 signatureAlgorithm?: AlgorithmIdentifierSchema;
 signature?: string;
 certs?: string;
}>;

/**
* Represents the Signature structure described in [RFC6960](https://datatracker.ietf.org/doc/html/rfc6960)
*/
export class Signature extends PkiObject implements ISignature {

 public static override CLASS_NAME = "Signature";

 public signatureAlgorithm!: AlgorithmIdentifier;
 public signature!: asn1js.BitString;
 public certs?: Certificate[];

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

   this.signatureAlgorithm = pvutils.getParametersValue(parameters, SIGNATURE_ALGORITHM, Signature.defaultValues(SIGNATURE_ALGORITHM));
   this.signature = pvutils.getParametersValue(parameters, SIGNATURE, Signature.defaultValues(SIGNATURE));
   if (CERTS in parameters) {
     this.certs = pvutils.getParametersValue(parameters, CERTS, Signature.defaultValues(CERTS));
   }
   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 SIGNATURE_ALGORITHM): AlgorithmIdentifier;
 public static override defaultValues(memberName: typeof SIGNATURE): asn1js.BitString;
 public static override defaultValues(memberName: typeof CERTS): Certificate[];
 public static override defaultValues(memberName: string): any {
   switch (memberName) {
     case SIGNATURE_ALGORITHM:
       return new AlgorithmIdentifier();
     case SIGNATURE:
       return new asn1js.BitString();
     case CERTS:
       return [];
     default:
       return super.defaultValues(memberName);
   }
 }

 /**
  * Compare values with default values for all class members
  * @param memberName String name for a class member
  * @param memberValue Value to compare with default value
  */
 public static compareWithDefault(memberName: string, memberValue: any): boolean {
   switch (memberName) {
     case SIGNATURE_ALGORITHM:
       return ((memberValue.algorithmId === EMPTY_STRING) && (("algorithmParams" in memberValue) === false));
     case SIGNATURE:
       return (memberValue.isEqual(Signature.defaultValues(memberName)));
     case CERTS:
       return (memberValue.length === 0);
     default:
       return super.defaultValues(memberName);
   }
 }

 /**
  * @inheritdoc
  * @asn ASN.1 schema
  * ```asn
  * Signature ::= SEQUENCE {
  *    signatureAlgorithm      AlgorithmIdentifier,
  *    signature               BIT STRING,
  *    certs               [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
  *```
  */
 public static override schema(parameters: SignatureSchema = {}): Schema.SchemaType {
   const names = pvutils.getParametersValue<NonNullable<typeof parameters.names>>(parameters, "names", {});

   return (new asn1js.Sequence({
     name: (names.blockName || EMPTY_STRING),
     value: [
       AlgorithmIdentifier.schema(names.signatureAlgorithm || {}),
       new asn1js.BitString({ name: (names.signature || EMPTY_STRING) }),
       new asn1js.Constructed({
         optional: true,
         idBlock: {
           tagClass: 3, // CONTEXT-SPECIFIC
           tagNumber: 0 // [0]
         },
         value: [
           new asn1js.Sequence({
             value: [new asn1js.Repeated({
               name: (names.certs || EMPTY_STRING),
               // TODO Double check
               // value: Certificate.schema(names.certs || {})
               value: Certificate.schema({})
             })]
           })
         ]
       })
     ]
   }));
 }

 public fromSchema(schema: Schema.SchemaType): void {
   // Clear input data first
   pvutils.clearProps(schema, [
     SIGNATURE_ALGORITHM,
     SIGNATURE,
     CERTS
   ]);

   // Check the schema is valid
   const asn1 = asn1js.compareSchema(schema,
     schema,
     Signature.schema({
       names: {
         signatureAlgorithm: {
           names: {
             blockName: SIGNATURE_ALGORITHM
           }
         },
         signature: SIGNATURE,
         certs: CERTS
       }
     })
   );
   AsnError.assertSchema(asn1, this.className);

   // Get internal properties from parsed schema
   this.signatureAlgorithm = new AlgorithmIdentifier({ schema: asn1.result.signatureAlgorithm });
   this.signature = asn1.result.signature;
   if (CERTS in asn1.result)
     this.certs = Array.from(asn1.result.certs, element => new Certificate({ schema: element }));
 }

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

   outputArray.push(this.signatureAlgorithm.toSchema());
   outputArray.push(this.signature);

   if (this.certs) {
     outputArray.push(new asn1js.Constructed({
       optional: true,
       idBlock: {
         tagClass: 3, // CONTEXT-SPECIFIC
         tagNumber: 0 // [0]
       },
       value: [
         new asn1js.Sequence({
           value: Array.from(this.certs, o => o.toSchema())
         })
       ]
     }));
   }
   //#endregion

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

 public toJSON(): SignatureJson {
   const res: SignatureJson = {
     signatureAlgorithm: this.signatureAlgorithm.toJSON(),
     signature: this.signature.toJSON(),
   };

   if (this.certs) {
     res.certs = Array.from(this.certs, o => o.toJSON());
   }

   return res;
 }

}