aiohttp webhook for github

github_webhook.py

async def github_webhook(secret :str, request :web.Request) -> dict:
    assert request.content_length < 1000000, "Request content too fat" # 1M
    digest, signature = request.headers['X-HUB-SIGNATURE'].split("=", 1)
    assert digest == "sha1", "Digest must be sha1" # use a whitelist
    body = await request.content.read()
    h = hmac.HMAC(bytes(secret, "UTF8"), msg=body, digestmod=digest)
    assert h.hexdigest() == signature, "Bad signature"
    return json.loads(body.decode('UTF8'))