* feat(lib): ensure that clients store cookies
If a client is misconfigured and does not store cookies, then they can
get into a proof of work death spiral with Anubis. This fixes the
problem by setting a test cookie whenever the user gets hit with a
challenge page. If the test cookie is not there at challenge pass time,
then they are blocked. Administrators will also get a log message
explaining that the user intentionally broke cookie support and that this
behavior is not an Anubis bug.
Additionally, this ensures that clients being shown a challenge support
gzip-compressed responses by showing the challenge page at gzip level 1.
This level is intentionally chosen in order to minimize system impacts.
The ClearCookie function is made more generic to account for cookie
names as an argument. A correlating SetCookie function was also added to
make it easier to set cookies.
* chore(lib): clean up test code
Signed-off-by: Xe Iaso <me@xeiaso.net>
---------
Signed-off-by: Xe Iaso <me@xeiaso.net>
* feat(lib/policy): add support for CEL checkers
This adds the ability for administrators to use Common Expression
Language[0] (CEL) for more advanced check logic than Anubis previously
offered.
These can be as simple as:
```yaml
- name: allow-api-routes
action: ALLOW
expression:
and:
- '!(method == "HEAD" || method == "GET")'
- path.startsWith("/api/")
```
or get as complicated as:
```yaml
- name: allow-git-clients
action: ALLOW
expression:
and:
- userAgent.startsWith("git/") || userAgent.contains("libgit") || userAgent.startsWith("go-git") || userAgent.startsWith("JGit/") || userAgent.startsWith("JGit-")
- >
"Git-Protocol" in headers && headers["Git-Protocol"] == "version=2"
```
Internally these are compiled and evaluated with cel-go[1]. This also
leaves room for extensibility should that be desired in the future. This
will intersect with #338 and eventually intersect with TLS fingerprints
as in #337.
[0]: https://cel.dev/
[1]: https://github.com/google/cel-go
Signed-off-by: Xe Iaso <me@xeiaso.net>
* feat(data/apps): add API route allow rule for non-HEAD/GET
Signed-off-by: Xe Iaso <me@xeiaso.net>
* docs: document expression syntax
Signed-off-by: Xe Iaso <me@xeiaso.net>
* fix: fixes in review
Signed-off-by: Xe Iaso <me@xeiaso.net>
---------
Signed-off-by: Xe Iaso <me@xeiaso.net>
