Cloudflare WARP linux client (using wg-quick for actual tunnel setup)

## wgcf.py
#!/usr/bin/env python3

import subprocess
import json
import os
from pathlib import Path

import requests
from requests.compat import urljoin


class CloudflareWarp():
    API_URL = "https://api.cloudflareclient.com/v0a774/"
    _session = None

    def __init__(self, account, token):
        self.id = account
        self.token = token

    def __repr__(self):
        return f"CloudflareWarp({self.id}, {self.token})"

    def _getsession(self):
        if self._session is None:
            self._session = requests.session()
            self._session.headers.update(
                    Authorization=f"Bearer {self.token}",
            )
        return self._session

    def getregurl(self):
        return urljoin(self.API_URL, f"reg/{self.id}")

    def getregstate(self):
        s = self._getsession()
        self.state = s.get(self.getregurl()).json()
        return self.state

    def patchreg(self, data):
        s = self._getsession()
        self.state = s.patch(self.getregurl(), json=data).json()
        return self.state

    def submit_key(self, key):
        return self.patchreg({"key": key})

    def deregister(self):
        s = self._getsession()
        s.delete(self.getregurl())

    @classmethod
    def register(cls, creds_path=None):
        url = urljoin(cls.API_URL, "reg")
        r = requests.post(url).json()
        print('Registered as', r['id'], 'with auth token', r['token'])
        if creds_path:
            with open(creds_path, "w") as outf:
                json.dump(r, outf)
        return cls(r['id'], r['token'])

    @classmethod
    def from_json(cls, path):
        with open(path) as inf:
            r = json.load(inf)
            return cls(r['id'], r['token'])


def wg_keypair():
    p = subprocess.run(
            ["wg", "genkey"],
            stdout=subprocess.PIPE,
            encoding="ascii",
    )
    private = p.stdout.strip()
    p = subprocess.run(
            ["wg", "pubkey"],
            stdout=subprocess.PIPE,
            encoding="ascii",
            input=private,
    )
    return (private, p.stdout.strip())


def wg_quick_conffile(privkey, cfconfig):
    return f"""[Interface]
PrivateKey = {privkey}
Address = {cfconfig['interface']['addresses']['v4']}
Address = {cfconfig['interface']['addresses']['v6']}
DNS = 1.1.1.1
MTU = 1400
# This fixes up IPv6 depreference due to the use of unique local addressing
Address = 2001:db8{cfconfig['interface']['addresses']['v6'][9:]}
PostUp = ip6tables -t nat -I POSTROUTING 1 -o %i -j SNAT --to-source {cfconfig['interface']['addresses']['v6']}
PreDown = ip6tables -t nat -D POSTROUTING 1

[Peer]
PublicKey = {cfconfig['peers'][0]['public_key']}
Endpoint = {cfconfig['peers'][0]['endpoint']['host']}
#Endpoint = {cfconfig['peers'][0]['endpoint']['v4']}
#Endpoint = {cfconfig['peers'][0]['endpoint']['v6']}
AllowedIPs = 0.0.0.0/0
AllowedIPs = ::/0
"""


def main():
    cfgpath = Path("~/.wgcf/").expanduser()
    credfile = cfgpath / "creds.json"
    wgfile = cfgpath / "wgcf.conf"
    os.makedirs(cfgpath, exist_ok=True)
    try:
        cf = CloudflareWarp.from_json(credfile)
    except (FileNotFoundError, json.decoder.JSONDecodeError):
        cf = CloudflareWarp.register(credfile)
    priv, pub = wg_keypair()
    c = cf.submit_key(pub)["config"]
    with open(wgfile, "w") as outf:
        outf.write(wg_quick_conffile(priv, c))
    print("To connect, run as root:")
    print("# wg-quick up", wgfile)


if __name__ == '__main__':
    main()

## wgcf.sh
#!/usr/bin/env bash
set -euo pipefail
shopt -s inherit_errexit 2>/dev/null || true

# this script will generate wg-quick(8) config file
# in order to connect to Cloudflare Warp using Wireguard on Linux
# note: this is *absolutely not* an official client from Cloudflare

# Copyright (C) 2019 Ondrej Caletka
# based heavily on macOS client by Jay Freeman (saurik)
# Original source: https://cache.saurik.com/twitter/wgcf.sh

# Zero Clause BSD license {{{
#
# Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
# }}}

if ! which jq >/dev/null || ! which wg >/dev/null; then
    echo "Please install jq and wireguard-tools"
    exit 0
fi

mkdir -p ~/.wgcf
chmod 700 ~/.wgcf
prv=~/.wgcf/private.key
usr=~/.wgcf/identity.cfg
cnf=~/.wgcf/wgcf.conf

pub=$({ cat "${prv}" 2>/dev/null || wg genkey | tee "${prv}"; } | wg pubkey)
test -n "${pub}"

api=https://api.cloudflareclient.com/v0i1909051800
ins() { vrb=$1; shift; curl -s -H 'user-agent:' -H 'content-type: application/json' -X "${vrb}" "${api}/$@"; }
sec() { ins "$@" -H 'authorization: Bearer '"${reg[1]}"''; }

cfgjson=$(if [[ -e "${usr}" ]]; then
    reg=($(cat "${usr}"))
    test "${#reg[@]}" -eq 2
    sec GET "reg/${reg[0]}"
else
    reg=($(ins POST "reg" -d '{"install_id":"","tos":"'"$(date -u +%FT%T.000Z)"'","key":"'"${pub}"'","fcm_token":"","type":"ios","locale":"en_US"}' |
        jq -r '.result|.id+" "+.token'))
    test "${#reg[@]}" -eq 2
    echo "${reg[@]}" >"${usr}"
    sec PATCH "reg/${reg[0]}" -d '{"warp_enabled":true}'
    fi)
# echo $cfgjson
cfg=($(echo $cfgjson| jq -r '.result.config|(.peers[0]|.public_key+" "+.endpoint.host)+" "+(.interface.addresses|.v4+" "+.v6)'))
test "${#cfg[@]}" -eq 4

cat >"$cnf" <<EOF
[Interface]
PrivateKey = $(cat "${prv}")
DNS = 1.1.1.1
Address = ${cfg[2]}
Address = ${cfg[3]}
MTU = 1400
# This fixes up IPv6 depreference due to the use of unique local addressing
Address = ${cfg[3]/#fd01:5ca1:/2001:db8:}
PostUp = ip6tables -t nat -I POSTROUTING 1 -o %i -j SNAT --to-source ${cfg[3]}
PreDown = ip6tables -t nat -D POSTROUTING 1

[Peer]
PublicKey = ${cfg[0]}
AllowedIPs = 0.0.0.0/0
AllowedIPs = ::/0
Endpoint = ${cfg[1]}
EOF

echo "To connect, run as root:"
echo "# wg-quick up ${cnf}"
echo ""
echo "To disconnect, run as root:"
echo "# wg-quick down ${cnf}"