This code is a PHP-based contact form processor that sends emails using the msmtp command. It validates and sanitizes user input, composes an email with the user’s input, and sends it to a hardcoded recipient email address. The code prioritizes security and includes error handling and debugging mechanisms. To use this code, you’ll need to have your own email account that can work with an msmtp configuration, as it relies on this setup to send emails. Overall, the code provides a solid foundation for a contact form processor, and with some customizations, it can become even more robust and feature-rich. Expansion opportunities include adding support for multiple recipient email addresses, implementing CAPTCHA or anti-spam measures, integrating with popular email services, and allowing file attachments.

HTML

<style>
    /* Set a max width for the form */<br />
    form {<br />
        width: 100%;<br />
        max-width: 600px;  /* Adjust the max-width as needed */<br />
        margin: 0 auto;  /* Center the form */<br />
        padding: 20px;<br />
        background-color: #f9f9f9;<br />
        border-radius: 8px;<br />
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);<br />
    }</p>
<p>    /* Style the labels */<br />
    label {<br />
        display: block;<br />
        margin-bottom: 8px;<br />
        font-weight: bold;<br />
    }</p>
<p>    /* Style the input fields */<br />
    input[type="text"],<br />
    input[type="email"] {<br />
        width: 100%;  /* Make input fields full width */<br />
        padding: 10px;<br />
        margin-bottom: 15px;<br />
        border: 1px solid #ccc;<br />
        border-radius: 4px;<br />
        box-sizing: border-box;  /* Include padding in the width calculation */<br />
    }</p>
<p>    /* Style the textarea */<br />
    textarea {<br />
        width: 100%;  /* Make the textarea full width */<br />
        height: 150px;  /* Increase the height of the message box */<br />
        padding: 10px;<br />
        margin-bottom: 15px;<br />
        border: 1px solid #ccc;<br />
        border-radius: 4px;<br />
        box-sizing: border-box;  /* Include padding in the width calculation */<br />
    }</p>
<p>    /* Style the submit button */<br />
    button {<br />
        padding: 12px 20px;<br />
        background-color: #4CAF50;  /* Green background */<br />
        color: white;<br />
        border: none;<br />
        border-radius: 4px;<br />
        cursor: pointer;<br />
        font-size: 16px;<br />
    }</p>
<p>    button:hover {<br />
        background-color: #45a049;  /* Slightly darker green on hover */<br />
    }</p>
<p>    /* Add small text for the message character limit */<br />
    .char-limit {<br />
        font-size: 14px;<br />
        color: #888;<br />
        margin-bottom: 10px;<br />
    }<br />
</style>
<form action="/contact-process-form.php" method="POST">
    <input type="hidden" name="nonce" value="<?php echo $nonce; ?>"></p>
<p>    <label for="name">Name:</label><br />
    <input type="text" id="name" name="name" required maxlength="100"></p>
<p>    <label for="email">Email:</label><br />
    <input type="email" id="email" name="email" required maxlength="100"></p>
<p>    <label for="subject">Subject:</label><br />
    <input type="text" id="subject" name="subject" required maxlength="100"></p>
<p>    <label for="message">Message:</label><br />
    <textarea id="message" name="message" required maxlength="6000"></textarea></p>
<p>    <!-- Add a character limit notice --><br />
    <small class="char-limit">Maximum characters allowed in message: 6000</small><br /> <!-- Added line break --></p>
<p>    <button type="submit">Send</button><br />
</form>

php contact-process-form.php in root folder of website.

<?php
// Load WordPress functions (adjust path if necessary)
require_once('/var/www/bashing.life/wp-load.php');

error_reporting(E_ALL);
ini_set('display_errors', 1);

// Log errors to a secure file instead of displaying
ini_set('log_errors', 1);
ini_set('error_log', '/var/log/php_errors.log');

// Define the path to msmtp (adjust according to where msmtp is installed)
$msmtp_path = '/usr/bin/msmtp';  // Replace with your msmtp path if it's different

// Define the path to the msmtp configuration file
$msmtp_config_file = '/etc/msmtprc';  // Replace with the correct path to the msmtp configuration file

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
// Sanitize and retrieve the form data
    $name = sanitize_text_field($_POST['name']);
    $email = sanitize_email($_POST['email']);
    $subject = sanitize_text_field($_POST['subject']);
    $message = wp_kses_post($_POST['message']);  // Sanitizing message further

    // Validate the email address
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        echo "Invalid email format.";
        exit;
    }

// Escape each variable to prevent command injection
    $safe_name = escapeshellarg($name);
    $safe_email = escapeshellarg($email);
    $safe_subject = escapeshellarg($subject);
    $safe_message = escapeshellarg($message);

    $hardcoded_subject = "New Contact Form Submission";

    $email_content = "You have received a new contact form submission:\n\n";
    $email_content .= "Name: $safe_name\n";
    $email_content .= "Email: $safe_email\n";
    $email_content .= "Subject (from form): $safe_subject\n\n";
    $email_content .= "Message:\n$safe_message\n";

 // Escape the full email content (to ensure no issues with newlines, quotes, etc.)
    $escaped_email_content = escapeshellarg($email_content);

    // Send the email using msmtp
    $recipient = 'example@example.com';  // Your recipient email address

    // Properly escape the command to avoid injection

    $command = "echo \"Subject:$hardcoded_subject\nContent-Type: text/plain; charset=UTF-8\n\n$email_content\" | $msmtp_path --file=$msmtp_config_file -a default example@example.com";


    // Execute the command and capture the output
    $output = shell_exec($command . ' 2>&1');  // Capture both stdout and stderr

    // Debugging: Check if output is captured and display it
    if ($output === null) {
        echo "Failed to send the message. No output received from msmtp.";
    } else {
        //echo "Message sent successfully!<br>"; //for future debugging
        //echo "<strong>Debugging Output from msmtp:</strong><br>"; //for future debugging
        //echo "<pre>$output</pre>";  // Debugging output from msmtp
        // Redirect to the thank-you page after success
        header("Location: thank-you");
        exit;
    }

} else {
    echo "Please fill in all fields.";
}
?>

The msmtprc system-wide configuration file must be in /etc

For openwrt devices exposed directly to the internet such as in a DMZ and need to have ssh access without compromising too much, we will have to follow these steps to achieve some basic security. Internet traffic is very much infested with bots trying to brute force into systems so this is a small but very useful step to harden your security and privacy. The main idea is to disable password authentication and use only a certificate with a custom ssh port.

First is to create a public and private key pair in the client from which we usually perform administrative tasks then we follow by copying the public key to our openwrt device. We continue by changing the standard ssh port 22 for a non standard port preferably in the range of dynamic or Private Ports (49152-65535) and we finish by creating a config file in .shh to manage the settings to log in with the certificate generated at the beginning and disabling password authentication.

In your local device (from where you intent to access your openwrt) generate the certificates. Go to your users .ssh directory (/home/[your_local_user]/.ssh) and type:

ssh-keygen -t ed25519 -a 100 -f .ssh/key-openwrt

This will generate key-openwrt (private) and key-openwrt.pub files. We will create a config file later to configure and use the connection for convenience.

Now its time to copy your public key to openwrt:

ssh-copy-id -i key-openwrt.pub root@ip_address

As you are trying to copy the pub key as root, the key will be associated to the root user. You will be prompted to provide your root password once. If the copy is successful lets try to log in without the password. The private key in your local machine will get verified against the public key you’ve just copied over to openwrt and if validation is successful you will log in as your openwrt’s root user.

ssh -i key-opewrt root@server_ip 

If login was successful we can now create a config file (named config) inside the .ssh directory. This file will manage your key based authentications but before doing that, let’s change the default port to put the new info in your config file:

Log in in the LUCI portal and click in Administration –> ssh-access:

Choose a non standard port for ssh and disable password authentication. Save and exit. Now lets create the config file in /home/[you_local_user]/.ssh:

nano config

host   openwrt
       Hostname [ip_address]
       User root
       port [example:49595]
       PreferredAuthentications publickey
       IdentityFile /home/[your_local_user]/.ssh/key-openwrt

Once the files has been saved and if everything went well you should be to log in without a password using your key pair. Try out the configuration:

ssh openwrt

Done!

GnuDIP2 can be used to update your ip address. The following configuration is going to be tailored to manage the free ddns service provided in ddns.freedombox.org or compatible ddns services.

Before starting you need to already have a gnudip account and install the curl package (sudo apt install curl).

Download the latest version of GnuDIP from the official site:
https://gnudip2.sourceforge.net/gnudip-www/latest/gnudip/html/clients.html

Direct link:
https://gnudip2.sourceforge.net/gnudip-www/latest/gnudip/html/client/UNIX/gnudip-latest-gdipc.tar.gz

Change to your root account: This is so that the gdipc script (necessary to update the ip address of your service) can be run at a regular basis without the need to log in with your personal user account. Just let the root user handle it and forget it…

Decompress and untar the file to /usr/local/

Now you need to add a new directory path to your $PATH so you can run the script at the location where the gdipc folder was placed. Recomended location /usr/local/

Edit the .bashrc file of your root account and add the following line at the end:

#DDNS GnuDIP update service
export PATH="$PATH:/usr/local/gdipc/bin"

Source the file to update your $PATH with:

source ~/.bashrc

Running gdipc.pl script to add a new entry. This entry will contain the necessary information so that GnuDIP2 logs in to your account and verify if it needs to update your ip address.

When you run gdipc.pl with the -c option, it allows you to configure the script through an interactive setup. This can help avoid manual editing of the script and ensure all necessary settings are entered correctly. Additionally, the information you enter will be saved in .GnuDIP2 in the same root home directory.

1. Run the Script with -c Option:To begin the configuration process, run the script with the -c flag: gdipc.pl -c
2. Follow the Prompts:The script will prompt you for the required configuration details. You will need to input the following:
   • Username: Your user account created in ddns.freedombox.org
   • Domain: Depending on the subdomain chosen at the time of registration like fbx.one or freedombox.rocks.
   • Connect by direct TCP (d) or web server (w) [d]:
   • GnuDIP Server – host[:port]: ddns.freedombox.org
   • Password: Your password provided at registration.
   • Cache File [/root/.GnuDIP2.cache..]: Location of the cache file.
   • Minimum Seconds Between Updates [0]: Leave as default
   • Maximum Seconds Between Updates [2073600]: Leave as default
3. Complete the Configuration:After entering all the necessary information, the script will configure itself with the values you’ve provided.
4. Verify the Configuration:Once you’ve configured the script, you can run it without the -c option to check if the DDNS update process works correctly:
   gdipc.pl The script should now update the DDNS service with your current IP address and domain.
5. Automate the Process :To ensure your IP is updated regularly, you can automate the execution of gdipc.pl using a cron job.
   • Here’s an example cron job that runs the script every 10 minutes:
   • crontab -e Add the following line to run the script every 10 minutes:
     • */10 * * * * /usr/local/gdipc/bin/gdipc.pl -q "curl -s ifconfig.me" >> /home/root/.GnuDIP2.log 2>&1
     • Note that “curl -s ifconfig.me” will retrieve you public ip address.
6. Executing and Logging: As you can see in the cron job configured, the script needs to be executed with the -q option. This is because if its run without it, it will use the local ip address of your network and not your public ip address to perform the update. Additionally, is configured standard and error output to a log file to keep track of the script work.

• With -q Option: You can specify a command to retrieve the IP address, and the script will execute that command.
• Without -q Option: The script tries to obtain the local machine’s IP address via getsockname() on a socket connection.
• With -g Option: If you’re behind a gateway, the script registers the external IP address that the GnuDIP server sees.