Add a new 'user_principal_name' type to the downstream mTLS
match_subject_alt_names option. This corresponds to the 'OtherName' type
with type-id 1.3.6.1.4.1.311.20.2.3 and a UTF8String value.
Add support for UserPrincipalName SAN matching to the policy evaluator.
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.
Move the parseCRLs() method from package 'authorize/evaluator' to
'pkg/cryptutil', replacing the existing DecodeCRL() method. This method
will parse all CRLs found in the PEM input, rather than just the first.
(This removes our usage of the deprecated method x509.ParseDERCRL.)
Update this method to return an error if there is non-PEM data found in
the input, to satisfy the existing test that raw DER-encoded CRLs are
not permitted.
Delete the CRLFromBase64() and CRLFromFile() methods, as these are no
longer used.
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.
Move downstream mTLS settings to a nested config file object, under the
key 'downstream_mtls', and add a new DownstreamMTLSSettings struct for
these settings.
Deprecate the existing ClientCA and ClientCAFile fields in the Options
struct, but continue to honor them for now (log a warning if either is
populated).
Delete the ClientCRL and ClientCRLFile fields entirely (in current
releases these cannot be set without causing an Envoy error, so this
should not be a breaking change).
Update the Settings proto to mirror this nested structure.
