cose-kit/dist/browser/cose/Sign1.js

This is an early prototype of a RFC8152 COSE library for node.js.

import verify from "#runtime/verify.js";
import { algsToValue, headers } from '../headers.js';
import sign from '#runtime/sign.js';
import { fromUTF8 } from '../lib/buffer_utils.js';
import { SignatureBase } from './SignatureBase.js';
import { encoder, addExtension } from '../cbor.js';
export class Sign1 extends SignatureBase {
    constructor(protectedHeaders, unprotectedHeaders, payload, signature) {
        super(protectedHeaders, unprotectedHeaders, signature);
        this.payload = payload;
    }
    getContentForEncoding() {
        return [
            this.encodedProtectedHeaders,
            this.unprotectedHeaders,
            this.payload,
            this.signature,
        ];
    }
    encode() {
        return encoder.encode(this);
    }
    static Signature1(protectedHeaders, applicationHeaders, payload) {
        return encoder.encode([
            'Signature1',
            protectedHeaders,
            applicationHeaders,
            payload,
        ]);
    }
    async verify(key, externalAAD = new Uint8Array()) {
        if (typeof key === 'function') {
            key = await key(this);
        }
        if (!key) {
            throw new Error('key not found');
        }
        const toBeSigned = Sign1.Signature1(this.encodedProtectedHeaders || new Uint8Array(), externalAAD, this.payload);
        if (!this.algName) {
            throw new Error('unknown algorithm: ' + this.alg);
        }
        return verify(this.algName, key, this.signature, toBeSigned);
    }
    async verifyX509(roots) {
        const { publicKey } = await this.verifyX509Chain(roots);
        return this.verify(publicKey);
    }
    static async sign(protectedHeaders, unprotectedHeaders, payload, key) {
        const { alg } = protectedHeaders;
        const encodedProtectedHeaders = encoder.encode(new Map(Object.entries(protectedHeaders).map(([k, v]) => {
            if (k === 'alg') {
                v = algsToValue.get(v);
            }
            else if (typeof v === 'string') {
                v = fromUTF8(v);
            }
            return [headers[k], v];
        })));
        const unprotectedHeadersMap = new Map(Object.entries(unprotectedHeaders || {}).map(([k, v]) => {
            if (typeof v === 'string') {
                v = fromUTF8(v);
            }
            return [headers[k], v];
        }));
        const toBeSigned = Sign1.Signature1(encodedProtectedHeaders, new Uint8Array(), payload);
        if (!alg) {
            throw new Error('The alg header must be set.');
        }
        const signature = await sign(alg, key, toBeSigned);
        return new Sign1(encodedProtectedHeaders, unprotectedHeadersMap, payload, signature);
    }
}
addExtension({
    Class: Sign1,
    tag: 18,
    encode(instance, encodeFn) {
        return encodeFn(instance.getContentForEncoding());
    },
    decode: (data) => {
        return new Sign1(data[0], data[1], data[2], data[3]);
    }
});