Function makeFirstMessage

src/cmap/auth/scram.ts:78–98

(
  cryptoMethod: CryptoMethod,
  credentials: MongoCredentials,
  nonce: Uint8Array
)

}

function makeFirstMessage(
  cryptoMethod: CryptoMethod,
  credentials: MongoCredentials,
  nonce: Uint8Array
) {
  const username = cleanUsername(credentials.username);
  const mechanism =
    cryptoMethod === 'sha1' ? AuthMechanism.MONGODB_SCRAM_SHA1 : AuthMechanism.MONGODB_SCRAM_SHA256;

  // NOTE: This is done b/c Javascript uses UTF-16, but the server is hashing in UTF-8.
  // Since the username is not sasl-prep-d, we need to do this here.
  return {
    saslStart: 1,
    mechanism,
    payload: new Binary(
      ByteUtils.concat([ByteUtils.fromUTF8('n,,'), clientFirstMessageBare(username, nonce)])
    ),
    autoAuthorize: 1,
    options: { skipEmptyExchange: true }
  };
}

async function executeScram(cryptoMethod: CryptoMethod, authContext: AuthContext): Promise<void> {
  const { connection, credentials } = authContext;