oauth2: fix Max-Age attribute of Set-Cookie response header

[ggmoy]

Commit Message: oauth2: fix Max-Age attribute of Set-Cookie response header

Additional Description: The Max-Age attribute of Set-Cookie response header indicates the number of seconds until the cookie expires. Currently, we are assigning a value representing Seconds Since the Epoch to the Max-Age attribute. This is not correct and causes cookies to expire in ~53 years.

This PR updates the code to use the expires_in value received from the OAuth server response to set the Max-Age attribute.

Risk Level:
Testing: Adding unit tests for the fixed code and for the new runtime guard introduced by this PR
Docs Changes:
Release Notes:
Platform Specific Features:
Runtime guard: Adding envoy.reloadable_features.oauth_use_standard_max_age_value runtime guard
[Optional Fixes #Issue]
[Optional Fixes commit #PR or SHA]
[Optional Deprecated:]
[Optional API Considerations:]

[repokitteh-read-only]

Hi @ggmoy, welcome and thank you for your contribution.

We will try to review your Pull Request as quickly as possible.

In the meantime, please take a look at the contribution guidelines if you have not done so already.

🐱

Caused by: #26715 was opened by ggmoy.

see: more, trace.

[yanavlasov]

Looks like the original intention was to use the Expires cookie, instead of Max-Age. The fix looks good to me, however given that this is user visible change, it needs a runtime flag protection, in case someone was relying on old behavior.

Here is an example of using a runtime guard: #26326

/wait-any

[repokitteh-read-only]

CC @envoyproxy/runtime-guard-changes: FYI only for changes made to (source/common/runtime/runtime_features.cc).

🐱

Caused by: #26715 was synchronize by ggmoy.

see: more, trace.

[phlax]

@ggmoy probably best to merge main (other than the runtime guard issue that CI is flagging)

[phlax]

wait! - i just saw this is against release/v1.25

is this an issue only on 1.25- - otherwise lets fix on main and then backport - also wondering about older versions

[ggmoy]

wait! - i just saw this is against release/v1.25

is this an issue only on 1.25- - otherwise lets fix on main and then backport - also wondering about older versions

No, it is not only on release/v1.25. So, do I have to create a new PR againt main?

[phlax]

So, do I have to create a new PR againt main?

yeah, if you could, that would be great

[ggmoy]

So, do I have to create a new PR againt main?

yeah, if you could, that would be great

@phlax, I created a new one from main. Could you have a look, please?