This initial work adds a pair of settings to configure specific CSP
directives for enforcing or reporting policy violations, a new
`django.middleware.csp.ContentSecurityPolicyMiddleware` to apply the
appropriate headers to responses, and a context processor to support CSP
nonces in templates for safely inlining assets.
Relevant documentation has been added for the 6.0 release notes,
security overview, a new how-to page, and a dedicated reference section.
Thanks to the multiple reviewers for their precise and valuable feedback.
Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>
This change preserves backwards-compatibility for a very common misuse
of render_to_response which even occurred in the official documentation.
It fixes that misuse wherever it happened in the code base and docs.
Context.__init__ is documented as accepting a dict and nothing else.
Since Context is dict-like, Context(Context({})) could work to some
extent. However, things get complicated with RequestContext and that
gets in the way of refactoring the template engine. This is the real
rationale for this change.