microblog.pub/app/webfinger.py
2022-06-22 20:11:22 +02:00

79 lines
2.3 KiB
Python

from typing import Any
from urllib.parse import urlparse
import httpx
from loguru import logger
from app import activitypub as ap
def webfinger(
resource: str,
) -> dict[str, Any] | None: # noqa: C901
"""Mastodon-like WebFinger resolution to retrieve the activity stream Actor URL."""
logger.info(f"performing webfinger resolution for {resource}")
protos = ["https", "http"]
if resource.startswith("http://"):
protos.reverse()
host = urlparse(resource).netloc
elif resource.startswith("https://"):
host = urlparse(resource).netloc
else:
if resource.startswith("acct:"):
resource = resource[5:]
if resource.startswith("@"):
resource = resource[1:]
_, host = resource.split("@", 1)
resource = "acct:" + resource
is_404 = False
for i, proto in enumerate(protos):
try:
url = f"{proto}://{host}/.well-known/webfinger"
resp = ap.get(url, params={"resource": resource})
break
except httpx.HTTPStatusError as http_error:
logger.exception("HTTP error")
if http_error.response.status_code in [403, 404, 410]:
is_404 = True
continue
raise
except httpx.HTTPError:
logger.exception("req failed")
# If we tried https first and the domain is "http only"
if i == 0:
continue
break
if is_404:
return None
return resp
def get_remote_follow_template(resource: str) -> str | None:
data = webfinger(resource)
if data is None:
return None
for link in data["links"]:
if link.get("rel") == "http://ostatus.org/schema/1.0/subscribe":
return link.get("template")
return None
def get_actor_url(resource: str) -> str | None:
"""Mastodon-like WebFinger resolution to retrieve the activity stream Actor URL.
Returns:
the Actor URL or None if the resolution failed.
"""
data = webfinger(resource)
if data is None:
return None
for link in data["links"]:
if (
link.get("rel") == "self"
and link.get("type") == "application/activity+json"
):
return link.get("href")
return None