cose-kit/dist/node/esm/cose/Encrypt.js

**DEPRECATED:** Use [@auth0/cose](https://www.npmjs.com/package/@auth0/cose).

import { addExtension, encoder } from '../cbor.js';
import { COSEBase } from './COSEBase.js';
import * as errors from "../util/errors.js";
import validateAlgorithms from "../lib/validate_algorithms.js";
import { EncryptProtectedHeaders, EncryptionAlgorithmNames, Headers, UnprotectedHeaders } from '../headers.js';
import { decode } from "./decode.js";
import decrypt from '#runtime/decrypt.js';
import { COSEKeyParam } from '../key/index.js';
import { COSEKey } from "../key/COSEKey.js";
import { concat } from '../lib/buffer_utils.js';
import generateIv from '../lib/iv.js';
import encrypt from '#runtime/encrypt.js';
export class Encrypt extends COSEBase {
    constructor(protectedHeaders, unprotectedHeaders, ciphertext, recipients) {
        super(protectedHeaders, unprotectedHeaders);
        this.ciphertext = ciphertext;
        this.recipients = recipients;
    }
    static createAAD(protectedHeaders, externalAAD) {
        return encoder.encode([
            'Encrypt',
            protectedHeaders,
            externalAAD
        ]);
    }
    getContentForEncoding() {
        const mapRecipient = (r) => {
            var _a;
            const result = [
                r.protectedHeaders,
                r.unprotectedHeaders,
                (_a = r.ciphertext) !== null && _a !== void 0 ? _a : new Uint8Array(),
            ];
            if (r.recipients && Array.isArray(r.recipients)) {
                result.push(r.recipients.map(mapRecipient));
            }
            return result;
        };
        return [
            this.encodedProtectedHeaders,
            this.unprotectedHeaders,
            this.ciphertext,
            this.recipients.map(mapRecipient),
        ];
    }
    static decode(cose) {
        return decode(cose, Encrypt);
    }
    async decrypt(key, options) {
        var _a, _b, _c;
        if (this.recipients.length > 1 || this.recipients.some(r => r.unprotectedHeaders.get(Headers.Algorithm) !== -6)) {
            throw new Error('Multiple recipients or recipient with non-direct algorithm not supported');
        }
        const ciphertextWithTag = (_a = options === null || options === void 0 ? void 0 : options.detachedPayload) !== null && _a !== void 0 ? _a : this.ciphertext;
        const aad = Encrypt.createAAD((_b = this.encodedProtectedHeaders) !== null && _b !== void 0 ? _b : new Uint8Array(), (_c = options === null || options === void 0 ? void 0 : options.externalAAD) !== null && _c !== void 0 ? _c : new Uint8Array());
        if (!this.alg || !this.algName || !EncryptionAlgorithmNames.has(this.alg)) {
            throw new errors.COSEInvalid(`Unsupported encryption algorithm ${this.alg}`);
        }
        const algorithms = options && validateAlgorithms('algorithms', options.algorithms);
        if (algorithms && !algorithms.has(this.alg)) {
            throw new errors.COSEAlgNotAllowed(`[${Headers.Algorithm}] (algorithm) Header Parameter not allowed`);
        }
        let iv;
        if (this.unprotectedHeaders.has(Headers.IV) && this.unprotectedHeaders.has(Headers.PartialIV)) {
            throw new errors.COSEInvalid('IV and Partial IV must not both be present in the COSE message.');
        }
        else if (this.unprotectedHeaders.has(Headers.PartialIV)) {
            if (!(key instanceof COSEKey) || !key.has(COSEKeyParam.BaseIV)) {
                throw new errors.COSEInvalid('Key must be a COSEKey instance with Base IV to use Partial IV');
            }
            iv = concat(key.get(COSEKeyParam.BaseIV), this.unprotectedHeaders.get(Headers.PartialIV));
        }
        else if (this.unprotectedHeaders.has(Headers.IV)) {
            iv = this.unprotectedHeaders.get(Headers.IV);
        }
        else {
            throw new errors.COSEInvalid('IV or Partial IV must be present in the COSE message.');
        }
        const tag = ciphertextWithTag.slice(-16);
        const ciphertext = ciphertextWithTag.slice(0, -16);
        const decryptKey = key instanceof COSEKey ? (await key.toKeyLike()) : key;
        return decrypt(this.algName, decryptKey, ciphertext, iv, tag, aad);
    }
    get alg() {
        return this.protectedHeaders.get(Headers.Algorithm) ||
            this.unprotectedHeaders.get(Headers.Algorithm);
    }
    get algName() {
        return this.alg ? EncryptionAlgorithmNames.get(this.alg) : undefined;
    }
    hasSupportedAlg() {
        return !!this.algName;
    }
    static async encrypt(protectedHeaders, unprotectedHeaders, content, key, externalAAD = new Uint8Array(), recipients) {
        if (recipients.length > 1 || recipients.some(r => r.unprotectedHeaders.get(Headers.Algorithm) !== -6)) {
            throw new Error('Multiple recipients or recipient with non-direct algorithm not supported');
        }
        const wProtectedHeaders = EncryptProtectedHeaders.wrap(protectedHeaders);
        const alg = EncryptionAlgorithmNames.get(wProtectedHeaders.get(Headers.Algorithm));
        if (!alg) {
            throw new Error(`The protected header [${Headers.Algorithm}] (Algorithm) must be valid.`);
        }
        const wUnprotectedHeaders = UnprotectedHeaders.wrap([...(unprotectedHeaders || [])]);
        let iv = wUnprotectedHeaders.get(Headers.IV);
        if (!iv) {
            const partialIV = wUnprotectedHeaders.get(Headers.PartialIV);
            if (partialIV) {
                if (!(key instanceof COSEKey) || !key.has(COSEKeyParam.BaseIV)) {
                    throw new errors.COSEInvalid('Key must be a COSEKey instance with Base IV to use Partial IV');
                }
                iv = concat(key.get(COSEKeyParam.BaseIV), partialIV);
            }
            else {
                iv = generateIv(alg);
                wUnprotectedHeaders.set(Headers.IV, iv);
            }
        }
        const aad = Encrypt.createAAD(encoder.encode(wProtectedHeaders.esMap), externalAAD);
        const encryptKey = key instanceof COSEKey ? (await key.toKeyLike()) : key;
        const { ciphertext, tag } = await encrypt(alg, content, encryptKey, iv, aad);
        const r = concat(ciphertext, tag);
        return new Encrypt(wProtectedHeaders.esMap, wUnprotectedHeaders.esMap, r, recipients);
    }
}
Encrypt.tag = 96;
export class Recipient extends COSEBase {
    constructor(protectedHeaders, unprotectedHeaders, ciphertext, recipients) {
        super(protectedHeaders, unprotectedHeaders);
        this.ciphertext = ciphertext;
        this.recipients = recipients;
    }
    static create(protectedHeaders, unprotectedHeaders) {
        const wProtectedHeaders = EncryptProtectedHeaders.wrap(protectedHeaders);
        const wUnprotectedHeaders = UnprotectedHeaders.wrap(unprotectedHeaders);
        return new Recipient(wProtectedHeaders.esMap, wUnprotectedHeaders.esMap);
    }
    get alg() {
        return this.protectedHeaders.get(Headers.Algorithm) ||
            this.unprotectedHeaders.get(Headers.Algorithm);
    }
    get algName() {
        return this.alg && this.alg !== -6 ? EncryptionAlgorithmNames.get(this.alg) : undefined;
    }
    hasSupportedAlg() {
        return !!this.algName;
    }
}
addExtension({
    Class: Encrypt,
    tag: Encrypt.tag,
    encode(instance, encodeFn) {
        return encodeFn(instance.getContentForEncoding());
    },
    decode: (data) => {
        const recipients = data[3].map(rec => new Recipient(rec[0], rec[1], rec[2], rec[3]));
        return new Encrypt(data[0], data[1], data[2], recipients);
    }
});