Crude solution to ban bots by their user-agent

Okay, this is a very crude way to block bots, spiders and crawlers by their user-agent, but so far, this has been very, very efficient.

Even when one chooses ” yes “, the question will be repeated. This is not a problem, because no one in their right mind is going to add “bot”, “spider” or “crawler” as their user-agent.

So here’s the PHP script that I rammed into a certain website to prevent it from being DDOSsed by (malicious) bots.

<?php

// Emergency bypass
// goto end;

/////////////////////////////////////////////////////////////
// (c) FoxSAIn 2023, Free to use.
/////////////////////////////////////////////////////////////

// Function to check if the user agent appears to be a bot or spider.
// Enter the bots you would like to block in a list as shown below.
function isBot()
{
    $user_agent = $_SERVER["HTTP_USER_AGENT"];
    $bot_keywords = [
        "bytespider",
        "amazonbot",
        "mj12bot",
        "YandexBot",
        "SemrushBot",
        "AhrefsBot"
    ];

    foreach ($bot_keywords as $keyword) {
        if (stripos($user_agent, $keyword) !== false) {
            return true;
        }
    }

    return false;
}

// Check if the visitor is a bot or spider
if (isBot()) {
    // This visitor appears to be a bot or spider, so display a choice.
    // Check if the choice form is submitted
    if (isset($_POST["submit"])) {
        // Check the choice made by the visitor
        $choice = isset($_POST["choice"]) ? $_POST["choice"] : "";

        if ($choice === "yes") {
            // User selected "Yes," block access
            echo "Access denied. If you believe this is an error, please contact us by writing the word support before the at sign, followed by 4-stroke.net";
        } elseif ($choice === "no") {
            // User selected "No," proceed to end
            goto end;
        }
    } else {
        // Output the message to the user and make the choice mandatory
        echo "Your user agent suggests you might be a bot, spider, or crawler. Are you one of these three?";

        // Output the radio button choices within a form
        echo '</p>
<form method="post" action="">';
        echo ' <label><input type="radio" name="choice" value="yes" required>Yes</label>';
        echo ' <label><input type="radio" name="choice" value="no">No</label>';
        echo ' <button type="submit" name="submit">Proceed</button>';
        echo "</form>
<p>";
    }

    // Exit to prevent further processing
    exit();
}
end:
// Original website code starts from here.
/////////////////////////////////////////////////////////////
?>

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CloudPanel website causing “Too many redirects”

I have installed CloudPanel and the new website caused a “Too many redirects” bug. This is because my SSL certificates are controlled by a proxy and this can cause some confusion between the systems. Also, because CloudPanel installs its own certificates.

This application can also install a Let’s Encrypt certificate, but this works only in more conventional systems. Mine is going through a DNS to a Proxy that listens to a certain IP address and that proxy redirects the request to a Virtual Machine on one of my servers.

So, here is my, probably unconventional method of disabling the SSL certificates on my CloudPanel installation:

  1. Open the CloudPanel controlpanel.
  2. Select the website you want to edit
  3. Choose the Vhost tab
  4. Change the following code into the new code:
server {
listen 80;
listen [::]:80;
listen 443 ssl http2;
listen [::]:443 ssl http2;
{{ssl_certificate_key}}
{{ssl_certificate}}
server_name subdomain.3xn.nl;
{{root}}

{{nginx_access_log}}
{{nginx_error_log}}

if ($scheme != "https") {
rewrite ^ https://$host$uri permanent;
}
server {
listen 80;
listen [::]:80;
# listen 443 ssl http2;
# listen [::]:443 ssl http2;
# {{ssl_certificate_key}}
# {{ssl_certificate}}
server_name subdomain.3xn.nl;
{{root}}

{{nginx_access_log}}
{{nginx_error_log}}

# if ($scheme != "https") {
# rewrite ^ https://$host$uri permanent;
# }

Done! Your website should now say “Hello world :-)”

You can see that I have disabled the listen to port 443, the certificate keys, the forced https and the path to the keys. I chose to switch off the forced HTTP, because my proxy is already taking care of that.

This post is subject to change, but this helps you along your way!

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Fixing a 0x800700df error

Possible reason: File transfer limit in Webclient Service

  1. Open regedit
  2. Go to: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ WebClient \ Parameters
  3. Find: FileSizeLimitInBytes and open it
  4. Select Decimal
  5. Enter the following number:
    4294967295
  6. Click op OK
  7. Hold windowskey + R
  8. Enter services.msc
  9. Find WebClient
  10. Right click the service and select restart.

Done.

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