用户在使用哈希密码和盐之后如何更改密码？

Question

我正在尝试使用散列的密码和盐使网站安全。我成功实现了它。但是，如果用户想更改其密码，则变得困难。如何重新编码我拥有的更改密码，以支持刚刚实现的hashedpassword和salt？

这是我的changepassword表单-change_password.php

 <form  method="post" id="change_password" class="form-horizontal">
                                        <div class="control-group">
                                            <label class="control-label" for="inputEmail">Current Password</label>
                                            <div class="controls">
                                            <input type="hidden" id="password" name="password" value="<?php echo $row['password']; ?>"  placeholder="Current Password">
                                            <input type="password" id="current_password" name="current_password"  placeholder="Current Password">
                                            </div>
                                        </div>
                                        <div class="control-group">
                                            <label class="control-label" for="inputPassword">New Password</label>
                                            <div class="controls">
                                            <input type="password" id="new_password" name="new_password" placeholder="New Password">
                                            </div>
                                        </div>
                                        <div class="control-group">
                                            <label class="control-label" for="inputPassword">Re-type Password</label>
                                            <div class="controls">
                                            <input type="password" id="retype_password" name="retype_password" placeholder="Re-type Password">
                                            </div>
                                        </div>
                                        <div class="control-group">
                                            <div class="controls">
                                            <button type="submit" class="btn btn-info"><i class="icon-save"></i> Save</button>
                                            </div>
                                        </div>
                                    </form>

这是我的jQuery脚本

<script>
            jQuery(document).ready(function(){
            jQuery("#change_password").submit(function(e){
                    e.preventDefault();

                        var password = jQuery('#password').val();
                        var current_password = jQuery('#current_password').val();
                        var new_password = jQuery('#new_password').val();
                        var retype_password = jQuery('#retype_password').val();
                        if (password != current_password)
                        {
                        $.jGrowl("Password does not match with your current password  ", { header: 'Change Password Failed' });
                        }else if  (new_password != retype_password){
                        $.jGrowl("Password does not match with your new password  ", { header: 'Change Password Failed' });
                        }else if ((password == current_password) && (new_password == retype_password)){
                    var formData = jQuery(this).serialize();
                    $.ajax({
                        type: "POST",
                        url: "update_password.php",
                        data: formData,
                        success: function(html){

                        $.jGrowl("Your password is successfully change", { header: 'Change Password Success' });
                        var delay = 2000;
                            setTimeout(function(){ window.location = 'dashboard_teacher.php'  }, delay);  

                        }


                    });

                    }
                });
            });
            </script>

这是我的update_password.php

<?php
 include('dbcon.php');
 include('session.php');
 $new_password  = $_POST['new_password'];
 mysql_query("update admins set password = '$new_password' where admins_id = '$session_id'")or die(mysql_error());
 ?>

这是我的login.php

$query = "select * from admins where username = '$usernameVal';";

     $resultSet = mysqli_query($conn,$query);

                           if(@mysqli_num_rows($resultSet) > 0){
                           //check noraml user salt and pass
                           //echo "noraml";

 $saltQuery = "select salt from admins where username = '$usernameVal';";
$result = mysqli_query($conn,$saltQuery);
$row = mysqli_fetch_assoc($result);
$salt = $row['salt'];

$saltedPW =  $escapedPW . $salt;

$hashedPW = hash('sha256', $saltedPW);

 $query = "select * from admins where username = '$usernameVal' 
and password = '$hashedPW' ";

                            $resultSet = mysqli_query($conn,$query);

                           if(@mysqli_num_rows($resultSet) > 0){
                               $row = mysqli_fetch_assoc($resultSet);
                               echo "your username and  password is correct";
                               session_start();
                               $_SESSION["id"]=$row["admins_id"];

header("location:group/dashboard_teacher.php");
}
else
{
echo "your username or password is incorrect";
}

}

}
?>