Add a new match_subject_alt_names option to the downstream_mtls settings
group. This setting can be used to further constrain the allowed client
certificates by requiring that certificates contain a Subject
Alternative Name of a particular type, matching a particular regex.
When set, populate the corresponding match_typed_subject_alt_names
setting within Envoy, and also implement a corresponding check in the
authorize service.
Add a new max_verify_depth option to the downstream_mtls settings group,
with a default value of 1 (to match the behavior of current Pomerium
releases).
Populate the corresponding setting within Envoy, and also implement a
depth check within isValidClientCertificate() in the authorize service.
Add an "enforcement" option to the new downstream mTLS configuration
settings group.
When not set, or when set to "policy_default_deny", keep the current
behavior of adding an invalid_client_certificate rule to all policies.
When the enforcement mode is set to just "policy", remove the default
invalid_client_certificate rule that would be normally added.
When the enforcement mode is set to "reject_connection", configure the
Envoy listener with the require_client_certificate setting and remove
the ACCEPT_UNTRUSTED option.
Add a corresponding field to the Settings proto.
Update isValidClientCertificate() to also consult the configured
certificate revocation lists. Update existing test cases and add a new
unit test to exercise the revocation support. Restore the skipped
integration test case.
Generate new test certificates and CRLs using a new `go run`-able source
file.
