# gnh1201/caterpillar
Caterpillar - The simple and parasitic web proxy with spam filter (formerly, php-httpproxy)

![title image](title.jfif)

## How it works

### Basic structure
```
You <-> Proxy client (Python) <-> Parasitized proxy server (Optional, PHP) <-> On the Web
```
For example, build a simple web debugging proxy on the shared servers.

### Spam filtering strategy
* [K-Anonymity](https://en.wikipedia.org/wiki/K-anonymity) test - Estimating whether the characters has been arranged by humans. (use [Have I Been Pwned](https://haveibeenpwned.com/Passwords))
* Not CAPTCHA - Image spam containing characters that look very similar to [CAPTCHA](https://en.wikipedia.org/wiki/CAPTCHA). (use [TrueCaptcha](https://truecaptcha.org/))
* VowelRatio10 - In characters arranged by humans, there is a high frequency of [vowels](https://en.wikipedia.org/wiki/Vowel) (aeiou) and [semivowels](https://en.wikipedia.org/wiki/Semivowel) (wy) included in strings that are 10 characters.
* Palindrome5 - Detect [palindromes](https://en.wikipedia.org/wiki/Palindrome) composed of 5 or more characters
* KnownWords5 - Detect [well-known words](https://github.com/dwyl/english-words) composed of 5 or more characters
* SSL decryption (MITM) when relaying to federated servers.

The strategies were implemented to respond to [the Fediverse Spam Attacks which started on the 15th of February](https://github.com/Mastodon-DE/blocklists/blob/main/spam%2F2024-02-15%2F2024-02-15-spam-mute-list.md).

## (Optional) Before to use
If you have an ***will be parasitize*** server that you want to proxy, you can install the `index.php` file.

## How to use
1. Write a file `.env`(Linux) or `settings.ini`(Windows). Like this:

```
[settings]
PORT=5555
SERVER_URL=http://example.org
CA_KEY=ca.key
CA_CERT=ca.crt
CERT_KEY=cert.key
CERT_DIR=certs/
OPENSSL_BINPATH=openssl
CLIENT_ENCODING=utf-8
LOCAL_DOMAIN=example.org
PROXY_PASS=http://127.0.0.1:3000
MASTODON_SERVER=
MASTODON_USER_TOKEN=
TRUECAPTCHA_USERID=
TRUECAPTCHA_APIKEY=
```

- (Optional) Install RootCA for SSL decryption ([Download CA Certificate](ca.crt))

```bash
sudo apt-get install -y ca-certificates
sudo cp ca.crt /usr/local/share/ca-certificates/caterpillar-ca.crt
sudo update-ca-certificates
```

2. Run `python3 server.py` and set HTTP(S) proxy in your web browser (e.g. Firefox)

3. Test [100MB](http://speed.hetzner.de/100MB.bin)/[SSL](https://speed.hetzner.de/100MB.bin), [1GB](http://speed.hetzner.de/1GB.bin)/[SSL](https://speed.hetzner.de/1GB.bin), [10GB](http://speed.hetzner.de/10GB.bin)/[SSL](http://speed.hetzner.de/10GB.bin) download and check the speed (e.g. https://speed.hetzner.de/1GB.bin)

3. Enjoy it

4. (Optional) With [Cloudflare](https://cloudflare.com), we can expect to accelerate the 4x speed and reduce the network stuck.

## (Optional) For Mastodon users

### In [Caterpillar installed directory]/settings.ini or .env
1. set `SERVER_URL` variable to `localhost` in `.env`  (e.g. `SERVER_URL=localhost`)
2. set `PROXY_PASS` variable to Mastodon backend URI (e.g. `http://127.0.0.1:3000`)
3. if you want use notification, set `MASTODON_SERVER`(server domain) and `MASTODON_USER_TOKEN`(access token) variables

### In [Mastodon installed directory]/env.production
1. set `http_proxy` variable to `http://localhost:5555` (e.g. `http_proxy=http://localhost:5555`)

### In NGINX configuration
1. Check your port number of Caterpillar (default: 5555)
1. In NGINX configuration (e.g. `/etc/nginx/conf.d/mastodon.conf`), edit the `proxy_pass` like a `proxy_pass http://localhost:5555`

## References
* https://github.com/anapeksha/python-proxy-server
* https://github.com/inaz2/proxy2

## Contact
* ActivityPub [@gnh1201@catswords.social](https://catswords.social/@gnh1201)
* abuse@catswords.net