验证通过crypt存储的密码

Question

我使用此代码登录并且我已经通过crypt功能存储了我的密码，但是当我验证密码时，它说的密码不正确。 如何验证密码？

<?php

session_start();
include 'connect.php';

$hash = crypt('password');
$passErr = $nameErr = "";
$pass = $name = "";

if ($_SERVER["REQUEST_METHOD"] == "POST")
  {
  if (empty($_POST["username"]))
    {
    $nameErr = "Username is required";
    }

  if (empty($_POST["password"]))
    {
    $passErr = "Password is required";
    }

  if (empty($passErr) && empty($nameErr) && isset($_POST['username']))
    {
    $username = mysqli_real_escape_string($con, $_POST['username']);
    $password = mysqli_real_escape_string($con, $_POST['password']);
    $sql = "SELECT * FROM users WHERE username='$username' and password='$password' and activation='approved'";
    $result = mysqli_query($con, $sql);
    $count = mysqli_num_rows($result);

    if (password_verify($_POST['password'], $hash))
      {
      header('Location:test.php');
      }
      else
      {
      echo "Incorrect Username/Password";
      }
    }
  }

?>