Define Certificate message type for Kingdom internal services.

[SanjayVas]

This includes some fields denormalized from the X.509 certificate so they can be queried.

For issue #52.

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This change is 

[efoxepstein]

Reviewed 2 of 2 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

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src/main/proto/wfa/measurement/internal/kingdom/certificate.proto, line 43 at r1 (raw file):

  // RFC 5280 revocation state.
  enum RevocationState {
    REVOCATION_STATE_UNSPECIFIED = 0;

How are valid Certs represented? Using REVOCATION_STATE_UNSPECIFIED? Is it worthwhile to add a specific state for this?

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @efoxepstein)

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src/main/proto/wfa/measurement/internal/kingdom/certificate.proto, line 43 at r1 (raw file):

Previously, efoxepstein (Eli Fox-Epstein) wrote…

How are valid Certs represented? Using REVOCATION_STATE_UNSPECIFIED? Is it worthwhile to add a specific state for this?

A valid cert is one that has both no revocation state specified and the current time is within its validity period.

If this enum was representing the overall certificate state, we'd indeed want to require that a state value is specified and the _UNSPECIFIED value would be considered an error. This is instead something that provides details about revocation from RFC 5280.

[efoxepstein]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @SanjayVas)

[kungfucraig]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @corbantek, @oliver-amzn, @SanjayVas, and @zachcwc)

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src/main/proto/wfa/measurement/internal/kingdom/certificate.proto, line 25 at r1 (raw file):

message Certificate {
  oneof parent {

You'll move to strings later?

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @corbantek, @kungfucraig, @oliver-amzn, and @zachcwc)

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src/main/proto/wfa/measurement/internal/kingdom/certificate.proto, line 25 at r1 (raw file):

Previously, kungfucraig (Craig Wright) wrote…

You'll move to strings later?

You're thinking of the switch to resource names in the public API. This PR is for internal services where we don't need to be quite so generic.

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @corbantek, @kungfucraig, @oliver-amzn, and @zachcwc)

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src/main/proto/wfa/measurement/internal/kingdom/certificate.proto, line 25 at r1 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

You're thinking of the switch to resource names in the public API. This PR is for internal services where we don't need to be quite so generic.

For reference, the other change I mentioned is being handled in WIP PR world-federation-of-advertisers/cross-media-measurement-api#39.

[corbantek]

Reviewed 2 of 2 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @kungfucraig, @oliver-amzn, and @zachcwc)