30 0B 06 09 2A 85 03 07 01 02 05 01 01

const oSymAlgo = await cadesplugin.CreateObjectAsync("cadescom.symmetricalgorithm");

await oSymAlgo.GenerateKey();

const oSesKeyIV = await oSymAlgo.IV;
    
const data = Buffer.from(`${unencryptedMessage}`).toString('base64');

await oSymAlgo.SetMode(cadesplugin.CRYPT_MODE_CBCSTRICT);
await oSymAlgo.SetPadding(cadesplugin.ISO10126_PADDING);

const EncryptedData = await oSymAlgo.Encrypt(data, 1);

const dataBase64 = Buffer.from(`${oSesKeyIV.replace(/ /g, '')}${EncryptedData}`, 'hex').toString('base64');

const ExportedKey = await oSymAlgo.ExportKey(cadesCertificate);
const ExportedKeyArr = ExportedKey.replace(/ /g, '').split(':');

const publicKey = ExportedKeyArr[1].substr(-64 * 2);

const sessionKeyBlob = ExportedKeyArr[2];
// UKM
const sessionSV = sessionKeyBlob.substr(16 * 2, 8 * 2);
// sessionKey
const sessionKey = sessionKeyBlob.substr(24 * 2, 32 * 2);
// MAC сессионного ключа
const sessionMAC = sessionKeyBlob.substr(56 * 2, 4 * 2);

const
  T1 = '30 81 A9 30 28 04 20',
  T2 = '04 04',
  T3 = 'A0 7D 06 09 2A 85 03 07 01 02 05 01 01 A0 66 30 1F 06 08 2A 85 03 07 01 01 01 01 30 13 06 07 2A 85 03 02 02 24 00 ' +
       '06 08 2A 85 03 07 01 01 02 02 03 43 00 04 40',
  T4 = '04 08';

const keyTransport = (T1 + sessionKey + T2 + sessionMAC + T3 + publicKey + T4 + sessionSV)
  .replace(/ /g, '');

const keyTransportBase64 = Buffer.from(keyTransport, 'hex').toString('base64');