linkerd check: trust anchors are using supported crypto algorithm fails with Invalid trustAnchors

[cconnert]

Hi,

we integrated cert-manager & linkerd. Unfortunately due to #7449 cloud not follow the suggestions in #7345. As we already got a preconfigured cluster issue we went ahead and used that one to sign linkerds control plane cert (https://linkerd.io/2.12/tasks/automatically-rotating-control-plane-tls-credentials/).
While doing a linkerd check we noticed that it fails with:

× trust anchors are using supported crypto algorithm
    Invalid trustAnchors:
        * Internal Root CA must use ECDSA for public key algorithm, instead RSA was used
    see https://linkerd.io/2.11/checks/#l5d-identity-trustAnchors-use-supported-crypto for hintsLinkerd extensions checks

According to https://linkerd.io/2.11/tasks/troubleshooting/#l5d-identity-trustAnchors-use-supported-crypto we have to ensure that all of your roots use ECDSA P-256 for their public key algorithm. But up until now we did not notice any further issues with linkerd.

So my questions are:

• Why does linkerd only allow one algorithm for it's root of turst
• What is the impact of ignoring this check result?

Thanks

[cconnert]

Issue got resolved in the latest stable version