Evaluate Security Risks and Implement Controls for `kms:CreateGrant` Permission in `Github OIDC` role

[sukeshreddyg]

User Story

As a Modernisation Platform engineer I want to investigate potential security risks associated with granting the kms:CreateGrant permission to the GitHub OIDC role. Additionally, I aim to explore the feasibility of adding conditions to restrict the usage of this permission to prevent unauthorized granting of keys to users and roles.

Value / Purpose

The purpose of this issue is to ensure security of our key management system by thoroughly assessing the risks introduced by granting the kms:CreateGrant permission. By implementing appropriate safeguards, we aim to mitigate the risk of unauthorized access to keys.

Useful Contacts

No response

Additional Information

This permission, kms:CreateGrant, is required for the purpose of copying snapshots

Proposal / Unknowns

Hypothesis If we... [do a thing] Then... [this will happ]

Proposal A proposal that is something testable, don't worry whether it works or not, it's a place for ideas.

Unknowns Potential pitfalls that could cause the story to expand beyond its original scope. Ideally this section will remain blank.

Definition of Done

• [x] Identify security risks associated with the newly added permission.
• [x] Document findings and recommendations in a comprehensive report.
• [x] Ensure that the implementation aligns with best practices and complies with security standards.
• [x] Another team member has reviewed
• [x] Tests are green

[github-actions[bot]]

This issue is stale because it has been open 90 days with no activity.

[Khatraf]

https://docs.google.com/document/d/16ZOZ0B29oo2hJ5yPZcxa2On4WDX23OHIjKuHQo1fAgY/edit

[richgreen-moj]

Ticket reviewed. The DoD is complete. Looks good to me - we now have stricter permissions on the use of kms:CreateGrant. Nice work @Khatraf 👍