[cosigned] Webhook error when trying to verify an image signed with RSA key

[oliviergaumond]

Description

To reproduce:

• Sign an image with an RSA key
• Configure cosigned webhook with the RSA public key
• Try to run a pod with signed image

The admission webhook returns an error

The following is found in the webhook logs
http: panic serving 192.168.172.222:42498: interface conversion: interface {} is *rsa.PublicKey, not *ecdsa.PublicKey\n

Expected behavior
As cosign supports RSA key, cosigned should also support them

[hectorj2f]

Thanks for the issue @oliviergaumond. We’ ll check the weather

[dlorenc]

Yeah we probably missed a few refactors to support the genetic Verifier stuff.