How to Configure GCP for a WAF to Use Appdome MobileBOT™ Defense

Last updated July 24, 2024 by Appdome

Introduction

Web Application Firewalls (WAFs) play a crucial role in protecting web applications from a wide range of cyber threats. When combined with Appdome’s MobileBOT™ Defense solution, businesses can achieve an unparalleled level of protection for their mobile applications. This article will guide you on configuring Google Cloud Platform to connect to a WAF so it can work seamlessly with Appdome MobileBOT™ Defense.

Before delving into the steps, let’s understand some of the terms used:

MTLS (Mutual Transport Layer Security): Mutual TLS (mTLS) is a method for mutual authentication in which both parties in a network connection validate the SSL certificates presented by each other against a trusted root Certificate Authority (CA) certificate.

Client Certificate: In cryptography, a client certificate is a type of digital certificate that is used by client systems to make authenticated requests to a remote server.

Safe Session: Represents sessions that are determined to be safe or not at risk of any threat.

At Risk Session: Represents sessions that are potentially under threat or have detected anomalies.

Header Payload: The data transferred in the header of HTTP requests or responses. Protecting this data ensures that it cannot be tampered with during transit.

Prerequisites For Using GCP & Appdome Docker Image

In order to use the GCP Virtual Server in conjunction with Appdome, you’ll need:

  • A GCP account with admin permissions
  • A GCP server
  • An Android or iOS app secured by Appdome MobileBOT™ Defense
  • An Appdome MobileBOT™ Defense License

Getting Started with GCP Setup and Configuration

Set up a Linux Server on GCP

  1. Create a Project
    • Navigate to the GCP Console.
    • Click on the project drop-down and create a new project.
  2. Enable Compute Engine API

    • In the GCP Console, navigate to “APIs & Services” > “Dashboard
    • Click on “+ ENABLE APIS AND SERVICES” and search for “Compute Engine API” Enable it for your project.
  3. Create a Virtual Machine (VM)

    • In the GCP Console, navigate to “Compute Engine” > “VM instances
    • Click on “Create Instance
    • Configure your VM instance, including selecting the Linux distribution you prefer (e.g., Ubuntu, CentOS).
      Note: Make sure to allow HTTP/HTTPS traffic when configuring the firewall rules.

Connect SSH to your VM

gcloud compute ssh YOUR_VM_NAME

Running a Docker Container on GCP

To learn more, see the installation instructions for Installing Docker Engine on Ubuntu

Configure Appdome’s Docker Image

Appdome’s Docker Image is a custom solution to secure apps built on the Appdome platform with the Anti-Bot service enabled. This service functions within a Docker container based on Nginx. To facilitate its operation, users must supply an SSL certificate, config files and keys, and designated environment variables.

Prerequisites: Familiarity with Docker and UNIX-based machines is beneficial.

How Does It Work?

Based on Nginx and Lua, the service employs the Lua module to decrypt the payload and validate the signature, then it proxies the request to the target route as specified in the config file.

The module can be used with either the built-in LRU cache or with Redis, but it is recommended to use the built-in LRU to reduce the overhead of making the calls to Redis and ease the setup. If working in a cluster, it is necessary to use Redis to share storage across multiple instances.

Setup

The following environment variables are required to set up the service.

Environment Variable Name Required Description
REDIS Optional Only provide AD_REDIS_HOST if you intend to use it.
LOG_LEVEL Optional The default setting is warn. Available options include: debug, info, notice, warn, error, crit, alert, emerg. All logs are output to the stdout.
RESOLVER Mandatory Provide the resolver DNS server to use for discovering upstream servers.
PASSTHROUGH Optional A key that logs only headers but does not validate them.
USE_DEFAULT Optional If default.json config file was passed in the configs folder, and this variable passed as true , only the default config will be used. This is meant for testing purposes without constantly updating the config file.
Note: For a Kubernetes server, the default DNS server IP is 192.168.0.10. For a pure Docker configuration, the default server IP is 127.0.0.11

1. Receive the JSON config file

  • Obtain the JSON config file from our Appdome support team. The files will be named after the taskID of that build. There may be multiple files, each corresponding to different tasks.

2. Modify the JSON config file

  • Add the following fields:
    • key: The filename of the key that is relative to the /home folder in your docker container used for validation.
    • target: The endpoint to which requests are forwarded. Make sure your DNS resolver resolves this address.
    • heartbeat_validity (optional): Time in seconds for how long the heartbeat remains valid.

Example

[{

"key": "keys/your_key_file.key",

"target": "http://target_address",

"heartbeat_validity": 60

...

}]

3. Prepare the Docker Container:
– Ensure your Docker container has the necessary directories (`/home/configs` and `/home/keys`).

  • Configs Directory: This directory will store JSON files containing mobile anti-bot configurations provided by Appdome.
  • Keys Directory: This directory will store private keys used to validate the headers sent by Appdome.

Note: Ensure Key Matches. Verify that the key specified in the JSON config file correctly points to a key file located in the `/home/keys` directory within the Docker container.

Note: If you want to use only one config file for multiple task_ids for testing, rename the config file to default.json file and set the environment variable USE_DEFAULT=true. This setup is useful for initial testing but is not recommended for production if you regularly change the Anti-bot configuration.

4. Mount the JSON config file to the Docker Container

  • Use the `docker run` command with the `-v` option to bind mount the host directories to the container directories.

By following these steps, you’ll be able to correctly set up and mount the JSON config file to your Appdome Docker container.

Optional: How to Configure SSL & mTLS

If you want the Appdome Docker Image to handle SSL and mTLS, additional configuration is required. This includes passing environment variables and mounting certificates to the service.
Environment Variable Name Description
SSL_ON In order to enable the reverse proxy to handle SSL connections, you need to mark the SSL_ON=true. Make sure to mount SSL certificates to the container under /etc/nginx/certs/{ssl.crt, key.key}.
MTLS_ON=true In order to enable the reverse proxy to handle mTLS, you need to set both SSL_ON and MTLS_ON=true.
Make sure to mount the CA certificate that will be used for the mTLS under /etc/nginx/certs/ca.crt.
FINGERPRINTS If MTLS_ON=true the certificate fingerprints can be passed to allow only specific certificates identified by a SHA1 fingerprint. The value format should include a string of comma-separated values with a space following each comma as follows: asd, zxc, qwe

How to run Appdome Docker Image

Connect to your VM, and run the following commands:

    • Pull the docker image from our public repository:
      docker pull public.ecr.aws/n2i7f1e2/appdome-waf:1.0.6
    • Run the docker image with the following command:
      docker run -p 443:443 -p 80:80 -d \
      -v "$(pwd)"/certs:/etc/nginx/certs \
      -v "$(pwd)"/keys:/home/keys \
      -v "$(pwd)"/configs:/home/configs \
      -e AD_REDIS_HOST=<redis address> \
      -e PASSTHROUGH=false \
      -e RESOLVER=<resolver address> \
      -e SSL_ON=true \
      -e MTLS_ON=true \
      -e FINGERPRINTS=asd, zxc, qwe \
      -e LOG_LEVEL=debug \
      --restart unless-stopped \
      public.ecr.aws/n2i7f1e2/appdome-waf:1.0.6

At this point, you have a machine that will run the Appdome Docker Image. Make sure that your application traffic is routing correctly to the Appdome Docker Image and that the Appdome Docker Image is passing the traffic correctly to the target.

Monitoring Docker Health

To ensure your Docker container is operational, it is important to configure a health check endpoint within your system’s monitoring tools. Set up an endpoint in your health monitoring system to regularly check the /_health endpoint of the Docker container. This setup helps confirm that the Docker container is running correctly and is responsive. You can use any system that supports health checks, ensuring it aligns with your deployment environment and monitoring needs.

Note: The health check only verifies that the docker is up and running, but it does not verify that the target is accessible. If you want to make sure that the connectivity between the reverse proxy and the target is working as expected, configure an additional health check that monitors the target connectivity.

Conclusion

Integrating GCP Virtual Server with Appdome provides robust protection for mobile apps. By understanding and applying the configurations above, businesses can ensure that their mobile app traffic is both secure and optimized.

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How Do I Learn More?

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app defense easy. We hope we’re living up to the mission with your project. If you don’t already have an account, you can sign up for free

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