Config/Annotations: Add ssl-forbid-http and force-ssl-forbid-http

[gavinkflam]

What this PR does / why we need it:

API-only endpoints should disable HTTP altogether and only support encrypted connections. When that is not possible, API endpoints should fail requests made over unencrypted HTTP connections instead of redirecting them.

According to OWASP, the best practice for HTTPS API services is to disable HTTP or fail HTTP requests. Redirection is a common but insecure practice. Misconfigured clients would inadvertently expose sensitive information such as API keys without ever knowing about it.

In my opinion, this is an important security feature. Without this feature, the only way to implement such best practice is snippets. However, snippets are almost always disabled for good reasons - prevent arbitrary code injection.

I've added two config map items and two annotations. They allow enforcing HTTPS connections by rejecting unencrypted requests with a forbidden error. The core implementation is just a small twist of the existing SSL redirect annotations. The maintenance overhead is minimal and totally justify the benefits.

---

This article Your API Shouldn't Redirect HTTP to HTTPS offers an in-depth comparison between this practice and redirecting HTTP traffic to HTTPS.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

fixes #11391

How Has This Been Tested?

Automated unit and e2e tests.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added unit and/or e2e tests to cover my changes.
• All new and existing tests passed.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: gavinkflam / name: Gavin Lam (f1a96ee)

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[longwuyuan]

Please see this post from me #11391 (comment)

[strongjz]

/ok-to-test
/priority backlog
/triage accepted

[strongjz]

/kind feature

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[gavinkflam]

Discussed in community meeting today with @rikatz. We may want to make it the default since this is a security best practice. Concern is it will become a breaking change.

Open to any changes and suggestions.