import { JWEInvalid, JOSENotSupported } from '../util/errors.js'; import isKeyObject from './is_key_object.js'; const checkCekLength = (enc, cek) => { let expected; switch (enc) { case 'A128CBC-HS256': case 'A192CBC-HS384': case 'A256CBC-HS512': expected = parseInt(enc.slice(-3), 10); break; case 'A128GCM': case 'A192GCM': case 'A256GCM': expected = parseInt(enc.slice(1, 4), 10); break; default: throw new JOSENotSupported(`Content Encryption Algorithm ${enc} is not supported either by JOSE or your javascript runtime`); } if (cek instanceof Uint8Array) { const actual = cek.byteLength << 3; if (actual !== expected) { throw new JWEInvalid(`Invalid Content Encryption Key length. Expected ${expected} bits, got ${actual} bits`); } return; } if (isKeyObject(cek) && cek.type === 'secret') { const actual = cek.symmetricKeySize << 3; if (actual !== expected) { throw new JWEInvalid(`Invalid Content Encryption Key length. Expected ${expected} bits, got ${actual} bits`); } return; } throw new TypeError('Invalid Content Encryption Key type'); }; export default checkCekLength;