pylint was pinned below 4.0 because pylint-django used to require it.
pylint-django 2.8.0 accepts pylint 4.
pylint 3.x kept too-many-lines pragma line numbers across modules: a C0302
disable in one file could make the check report on the wrong line
in another and fail depending on how files were spread across jobs.
pylint 4.1 resets them per module.
cf https://github.com/pylint-dev/pylint/pull/11191
Application token authentication currently uses Django's default
password hasher. On our production hardware, token requests take
at least ~500 ms. Authentication happens per user of each
application, so this cost accumulates across frequently used
integrations.
Password hashers deliberately make guessing expensive to protect
human-chosen passwords after a database leak. Our application
secrets are generated server-side using a cryptographically secure
random generator, with a default length of 128 alphanumeric
characters. Guessing these secrets is already computationally
infeasible, making password stretching an unnecessary CPU cost.
Use salted SHA-256 for application secrets while retaining
constant-time comparison, and keep user password hashing
unchanged. Existing secrets migrate after successful verification
without requiring key rotation. Conditional updates prevent
migration from overwriting a concurrent rotation.
Store the new hash in `client_secret_sha256` while preserving the
original Django hash in `client_secret`. New applications populate
both fields, allowing the previous release to authenticate both
existing and newly created applications if we need to roll back.
Once every application has migrated and the rollback window has
closed, complete the migration by removing the legacy verification
code and `client_secret` field.
This assumes securely generated, high-entropy secrets. Deployments
that reduce `APPLICATION_CLIENT_SECRET_LENGTH` or supply
predictable secrets lose the offline guessing protection that the
previous slow hasher provided.
We need to integrate with external applications. Objective: enable them to
securely generate room links with proper ownership attribution.
Proposed solution: Following the OAuth2 Machine-to-Machine specification,
we expose an endpoint allowing external applications to exchange a client_id
and client_secret pair for a JWT. This JWT is valid only within a well-scoped,
isolated external API, served through a dedicated viewset.
This commit introduces a model to persist application records in the database.
The main challenge lies in generating a secure client_secret and ensuring
it is properly stored.
The restframework-apikey dependency was discarded, as its approach diverges
significantly from OAuth2. Instead, inspiration was taken from oauthlib and
django-oauth-toolkit. However, their implementations proved either too heavy or
not entirely suitable for the intended use case. To avoid pulling in large
dependencies for minimal utility, the necessary components were selectively
copied, adapted, and improved.
A generic SecretField was introduced, designed for reuse and potentially
suitable for upstream contribution to Django.
Secrets are exposed only once at object creation time in the Django admin.
Once the object is saved, the secret is immediately hashed, ensuring it can
never be retrieved again.
One limitation remains: enforcing client_id and client_secret as read-only
during edits. At object creation, marking them read-only excluded them from
the Django form, which unintentionally regenerated new values.
This area requires further refinement.
The design prioritizes configurability while adhering to the principle of least
privilege. By default, new applications are created without any assigned scopes,
preventing them from performing actions on the API until explicitly configured.
If no domain is specified, domain delegation is not applied, allowing tokens
to be issued for any email domain.