如何在 php 中将我的 md5 更改为散列密码

Question

My teacher wants to change my md5 password that was already made to a hashed one. I tried to use hashed but I cant login. I'm new with coding and I'm really confused on why I can't login.

This is my Sign Up page:

<?php
if(isset($_POST['btnCreate'])){
    $Aboutme = "This portion is about what can baby sitter tell about themselves to attract Parents/Guardian.";
    $txtName = trim($_POST['txtName']);
    $cboType = trim($_POST['cboType']);
    $txtUser = trim($_POST['txtUser']);
    $pwPass = $_POST['pwPass'];
    $pass = password_hash($pwPass, PASSWORD_DEFAULT);

    $exist = DB::query("SELECT * FROM user WHERE u_username=?",array($txtUser),"READ");

    if (count($exist)>0){
        error('Username already exist!');
    } else {

        if($cboType == "Sitter"){
            DB::query("INSERT INTO user(u_type, u_name, u_aboutme, u_username, u_password, u_hires) VALUES(?,?,?,?,?,?)",array($cboType, $txtName, $Aboutme, $txtUser, $pass,0),"CREATE");
        }
        else {
            DB::query("INSERT INTO user(u_type, u_name, u_username, u_password, u_hires) VALUES(?,?,?,?,?)",array($cboType, $txtName, $txtUser, $pass,0),"CREATE");
        }

        $exist_id = DB::query("SELECT * FROM user WHERE u_username=?",array($txtUser),"READ");

        if (count($exist_id)>0){
            $exist_id = $exist_id[0];

            DB::query("INSERT INTO subs(u_id) VALUES(?)",array($exist_id['u_id']),"CREATE");
        }

        success('Successfully created an account!');

This is my login page:

$txtUser = "";
$pwPass = "";
loginUser('btnLogin', 'txtUser', 'pwPass');
?>
        <label>Username</label>
        <input type="text" name="txtUser" required>

        <label>Password</label>
        <input type="password" name="pwPass" required>
        <button type="submit" name="btnLogin">Log In</button>
        <a href="create.php">Create</a>
    </form>
</div>
<div class="a-div">
    <a href="forgotpass.php">Forgot Password?</a>
</div>

Answer 1

you cannot login with the old password since it uses different hashing algorithme and it is impossible to decrypt, you can only compare it against a plain text password.

there are two things to bare in mind:

• You need to trim passwords too $pwPass = trim($_POST['pwPass']);
• you should use password_verify($password, $hashedpassword); in your loginUser.