signin

backend.js

router.post("/signin", async (req, res) => {
  const username = req.body.username;
  const password = req.body.password;

  if (await isUserValid(username, password)) {
    await sendToken(res, username);
  } else {
    res.status(401).json({
      error: {
        message: "Username or password invalid",
      },
    });
  }
});

async function isUserValid(username?: string, password?: string): Promise<boolean> {
  if (
    username !== undefined &&
    username.trim().length > 0 &&
    password !== undefined &&
    password.trim().length > 0
  ) {
    const user = await database().ref(`accounts/${username}`).get();
    if (user.exists()) {
      const salt = user.exportVal().salt;
      const hash = user.exportVal().password;
      return scrypt.verify(password, salt, hash);
    }
  }
  return false;
}