zulip/zerver/lib/camo.py

28 lines
811 B
Python

import hashlib
import hmac
from django.conf import settings
def generate_camo_url(url: str) -> str:
encoded_url = url.encode()
assert settings.CAMO_KEY is not None
encoded_camo_key = settings.CAMO_KEY.encode()
digest = hmac.new(encoded_camo_key, encoded_url, hashlib.sha1).hexdigest()
return f"{digest}/{encoded_url.hex()}"
# Encodes the provided URL using the same algorithm used by the camo
# caching https image proxy
def get_camo_url(url: str) -> str:
# Only encode the URL if Camo is enabled
if settings.CAMO_URI == "":
return url
return f"{settings.CAMO_URI}{generate_camo_url(url)}"
def is_camo_url_valid(digest: str, url: str) -> bool:
camo_url = generate_camo_url(url)
camo_url_digest = camo_url.split("/")[0]
return camo_url_digest == digest