Method prepare

src/cmap/auth/scram.ts:25–48

(
    handshakeDoc: HandshakeDocument,
    authContext: AuthContext
  )

  }

  override async prepare(
    handshakeDoc: HandshakeDocument,
    authContext: AuthContext
  ): Promise<HandshakeDocument> {
    const cryptoMethod = this.cryptoMethod;
    const credentials = authContext.credentials;
    if (!credentials) {
      throw new MongoMissingCredentialsError('AuthContext must provide credentials.');
    }

    const nonce = await randomBytes(24);
    // store the nonce for later use
    authContext.nonce = nonce;

    const request = {
      ...handshakeDoc,
      speculativeAuthenticate: {
        ...makeFirstMessage(cryptoMethod, credentials, nonce),
        db: credentials.source
      }
    };

    return request;
  }

  override async auth(authContext: AuthContext) {
    const { reauthenticating, response } = authContext;