网站登录系统

我正在开发一个网站，我想允许用户能够登录该网站。我是一个自学成才的开发人员，所以我不确定最佳实践是什么。我之前在我的 Java 应用程序中使用过 bcrypt，并在下面的密码 php 文件中实现了它（只有真正重要的行在类后的末尾）。

到目前为止，我现在对登录系统的唯一担忧是我使用的 ajax 是可见的，并显示正在运行的用于检查密码的脚本。这一切还安全吗？如果不是，应该如何做到这一点。

最后，在我的密码.php脚本中，我假设我应该制作一个cookie，以允许网站知道哪个帐户已成功登录，但是我如何使此cookie安全？

我的代码在下面，只是想知道这是否是一种危险的做事方式以及如何使cookie安全，谢谢你的任何答案

阿贾克斯检查器

<script type="text/javascript" src="jquery-1.7.1.min.js"/></script>
<script type="text/javascript">
function passWord(){
    var user = document.login.user.value;
    var pass = document.login.pass.value;
    $.ajax({
        url: "Password.php",
        type: "POST",
        data: {'user':user, 'pass':pass},
        success: function (response) {
            if(response!=1){
                //Wrong Password
                $('#divResults').html("The password or username you entered is incorrect.");
            }
        }
    });
    return false;
}
</script>

网页表单

<form name="login" onsubmit="return passWord()" method="get">
<font color="black"><br>Username or e-mail address:
<br><input type="text" size="40%" name="user" />
<br>You may login with either your assigned username or your e-mail address.
<br><br>Password:<br><input type="password" size="40%" name="pass" />
<br>The password field is case sensitive.<br><br></font>
<input type="submit" value="Log In" />
</form>

密码检查器

<?PHP
  class Bcrypt {
  private $rounds;
  public function __construct($rounds = 12) {
    if(CRYPT_BLOWFISH != 1) {
      throw new Exception("bcrypt not supported in this installation. See http://php.net/crypt");
    }
    $this->rounds = $rounds;
  }
  public function hash($input) {
    $hash = crypt($input, $this->getSalt());
    if(strlen($hash) > 13)
      return $hash;
    return false;
  }
  public function verify($input, $existingHash) {
    $hash = crypt($input, $existingHash);
    return $hash === $existingHash;
  }
  private function getSalt() {
    $salt = sprintf('$2a$%02d$', $this->rounds);
    $bytes = $this->getRandomBytes(16);
    $salt .= $this->encodeBytes($bytes);
    return $salt;
  }
  private $randomState;
  private function getRandomBytes($count) {
    $bytes = '';
    if(function_exists('openssl_random_pseudo_bytes') &&
        (strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN')) { // OpenSSL slow on Win
      $bytes = openssl_random_pseudo_bytes($count);
    }
    if($bytes === '' && is_readable('/dev/urandom') &&
       ($hRand = @fopen('/dev/urandom', 'rb')) !== FALSE) {
      $bytes = fread($hRand, $count);
      fclose($hRand);
    }
    if(strlen($bytes) < $count) {
      $bytes = '';
      if($this->randomState === null) {
        $this->randomState = microtime();
        if(function_exists('getmypid')) {
          $this->randomState .= getmypid();
        }
      }
      for($i = 0; $i < $count; $i += 16) {
        $this->randomState = md5(microtime() . $this->randomState);
        if (PHP_VERSION >= '5') {
          $bytes .= md5($this->randomState, true);
        } else {
          $bytes .= pack('H*', md5($this->randomState));
        }
      }
      $bytes = substr($bytes, 0, $count);
    }
    return $bytes;
  }
  private function encodeBytes($input) {
    // The following is code from the PHP Password Hashing Framework
    $itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    $output = '';
    $i = 0;
    do {
      $c1 = ord($input[$i++]);
      $output .= $itoa64[$c1 >> 2];
      $c1 = ($c1 & 0x03) << 4;
      if ($i >= 16) {
        $output .= $itoa64[$c1];
        break;
      }
      $c2 = ord($input[$i++]);
      $c1 |= $c2 >> 4;
      $output .= $itoa64[$c1];
      $c1 = ($c2 & 0x0f) << 2;
      $c2 = ord($input[$i++]);
      $c1 |= $c2 >> 6;
      $output .= $itoa64[$c1];
      $output .= $itoa64[$c2 & 0x3f];
    } while (1);
    return $output;
  }
}
$user = $_REQUEST['user'];
$pass = $_REQUEST['pass'];
$link = mysql_connect('localhost', 'root', 'root');
mysql_select_db("Colleges");
$result = mysql_query("SELECT `Password` FROM `Users` WHERE `Username`=UPPER('" . $user . "')");
$resultV = mysql_fetch_array($result);
$bcrypt = new Bcrypt(10);
$isGood = $bcrypt->verify($pass, $resultV['Password']);
die($isGood);
?>