PHP Change Password Script

Last modified on May 8th, 2018 by Vincy.

Change password feature in a web application is to let the user change their old password at some periodic interval. It makes the user protect the sensitive pages from hackers.

Some web application fixes some expiration period for user’s password. It forces the user to change the password once the expiration period is elapsed. For example, some banking applications force users to change the password for security.

We are going to see an example to change the password with Javascript validation by, accessing MySQL table.

php_change_password

HTML Code for Change Password Form

This HTML code shows the change password.

<html>
<head>
<title>Change Password</title>
<link rel="stylesheet" type="text/css" href="styles.css" />
</head>
<body>
<form name="frmChange" method="post" action="" onSubmit="return validatePassword()">
<div style="width:500px;">
<div class="message"><?php if(isset($message)) { echo $message; } ?></div>
<table border="0" cellpadding="10" cellspacing="0" width="500" align="center" class="tblSaveForm">
<tr class="tableheader">
<td colspan="2">Change Password</td>
</tr>
<tr>
<td width="40%"><label>Current Password</label></td>
<td width="60%"><input type="password" name="currentPassword" class="txtField"/><span id="currentPassword"  class="required"></span></td>
</tr>
<tr>
<td><label>New Password</label></td>
<td><input type="password" name="newPassword" class="txtField"/><span id="newPassword" class="required"></span></td>
</tr>
<td><label>Confirm Password</label></td>
<td><input type="password" name="confirmPassword" class="txtField"/><span id="confirmPassword" class="required"></span></td>
</tr>
<tr>
<td colspan="2"><input type="submit" name="submit" value="Submit" class="btnSubmit"></td>
</tr>
</table>
</div>
</form>
</body></html>

All the fields are mandatory and the newPassword and confirmPassword should be same. We are using Javascript validation. The validation function is,

<script>
function validatePassword() {
var currentPassword,newPassword,confirmPassword,output = true;

currentPassword = document.frmChange.currentPassword;
newPassword = document.frmChange.newPassword;
confirmPassword = document.frmChange.confirmPassword;

if(!currentPassword.value) {
currentPassword.focus();
document.getElementById("currentPassword").innerHTML = "required";
output = false;
}
else if(!newPassword.value) {
newPassword.focus();
document.getElementById("newPassword").innerHTML = "required";
output = false;
}
else if(!confirmPassword.value) {
confirmPassword.focus();
document.getElementById("confirmPassword").innerHTML = "required";
output = false;
}
if(newPassword.value != confirmPassword.value) {
newPassword.value="";
confirmPassword.value="";
newPassword.focus();
document.getElementById("confirmPassword").innerHTML = "not same";
output = false;
} 	
return output;
}
</script>

PHP Change Password Script

After successful form submits, the PHP code will access MySQL to get current password. If this database value is matched with the forms current password value, then the password will be changed. The PHP code is,

<?php
session_start();
$_SESSION["userId"] = "9";
$conn = mysqli_connect("localhost", "root", "test", "blog_samples") or die("Connection Error: " . mysqli_error($conn));

if (count($_POST) > 0) {
    $result = mysqli_query($conn, "SELECT *from users WHERE userId='" . $_SESSION["userId"] . "'");
    $row = mysqli_fetch_array($result);
    if ($_POST["currentPassword"] == $row["password"]) {
        mysqli_query($conn, "UPDATE users set password='" . $_POST["newPassword"] . "' WHERE userId='" . $_SESSION["userId"] . "'");
        $message = "Password Changed";
    } else
        $message = "Current Password is not correct";
}
?>

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This PHP code tutorial was published on September 15, 2013.

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