import { wrap as aesKw } from '../runtime/aeskw.js'; import * as ECDH from '../runtime/ecdhes.js'; import { encrypt as pbes2Kw } from '../runtime/pbes2kw.js'; import { encrypt as rsaEs } from '../runtime/rsaes.js'; import { encode as base64url } from '../runtime/base64url.js'; import generateCek, { bitLength as cekLength } from '../lib/cek.js'; import { JOSENotSupported } from '../util/errors.js'; import { exportJWK } from '../key/export.js'; import checkKeyType from './check_key_type.js'; import { wrap as aesGcmKw } from './aesgcmkw.js'; async function encryptKeyManagement(alg, enc, key, providedCek, providedParameters = {}) { let encryptedKey; let parameters; let cek; checkKeyType(alg, key, 'encrypt'); switch (alg) { case 'dir': { cek = key; break; } case 'ECDH-ES': case 'ECDH-ES+A128KW': case 'ECDH-ES+A192KW': case 'ECDH-ES+A256KW': { if (!ECDH.ecdhAllowed(key)) { throw new JOSENotSupported('ECDH with the provided key is not allowed or not supported by your javascript runtime'); } const { apu, apv } = providedParameters; let { epk: ephemeralKey } = providedParameters; ephemeralKey || (ephemeralKey = (await ECDH.generateEpk(key)).privateKey); const { x, y, crv, kty } = await exportJWK(ephemeralKey); const sharedSecret = await ECDH.deriveKey(key, ephemeralKey, alg === 'ECDH-ES' ? enc : alg, alg === 'ECDH-ES' ? cekLength(enc) : parseInt(alg.slice(-5, -2), 10), apu, apv); parameters = { epk: { x, crv, kty } }; if (kty === 'EC') parameters.epk.y = y; if (apu) parameters.apu = base64url(apu); if (apv) parameters.apv = base64url(apv); if (alg === 'ECDH-ES') { cek = sharedSecret; break; } cek = providedCek || generateCek(enc); const kwAlg = alg.slice(-6); encryptedKey = await aesKw(kwAlg, sharedSecret, cek); break; } case 'RSA1_5': case 'RSA-OAEP': case 'RSA-OAEP-256': case 'RSA-OAEP-384': case 'RSA-OAEP-512': { cek = providedCek || generateCek(enc); encryptedKey = await rsaEs(alg, key, cek); break; } case 'PBES2-HS256+A128KW': case 'PBES2-HS384+A192KW': case 'PBES2-HS512+A256KW': { cek = providedCek || generateCek(enc); const { p2c, p2s } = providedParameters; ({ encryptedKey, ...parameters } = await pbes2Kw(alg, key, cek, p2c, p2s)); break; } case 'A128KW': case 'A192KW': case 'A256KW': { cek = providedCek || generateCek(enc); encryptedKey = await aesKw(alg, key, cek); break; } case 'A128GCMKW': case 'A192GCMKW': case 'A256GCMKW': { cek = providedCek || generateCek(enc); const { iv } = providedParameters; ({ encryptedKey, ...parameters } = await aesGcmKw(alg, key, cek, iv)); break; } default: { throw new JOSENotSupported('Invalid or unsupported "alg" (JWE Algorithm) header value'); } } return { cek, encryptedKey, parameters }; } export default encryptKeyManagement;