Files
zulip/zerver/lib/camo.py
Aditya Bansal 079dfadf1a camo: Add endpoint to handle camo requests.
This endpoint serves requests which might originate from an image
preview link which had an http url and the message holding the image
link was rendered before we introduced thumbnailing. In that case
we would have used a camo proxy to proxy http content over https and
avoid mix content warnings.

In near future, we plan to drop use of camo and just rely on thumbor
to serve such images. This endpoint helps maintain backward
compatibility for links which were already rendered.
2019-01-04 10:27:04 -08:00

25 lines
940 B
Python

from django.conf import settings
import codecs
import hashlib
import hmac
def generate_camo_url(url: str) -> str:
encoded_url = url.encode("utf-8")
encoded_camo_key = settings.CAMO_KEY.encode("utf-8")
digest = hmac.new(encoded_camo_key, encoded_url, hashlib.sha1).hexdigest()
hex_encoded_url = codecs.encode(encoded_url, "hex") # type: ignore # https://github.com/python/typeshed/issues/300
return "%s/%s" % (digest, hex_encoded_url.decode("utf-8"))
# 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 "%s%s" % (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