* PKI: Add support for signature_bits param to the intermediate/generate api
- Mainly to work properly with GCP backed managed keys, we need to
issue signatures that would match the GCP key algorithm.
- At this time due to https://github.com/golang/go/issues/45990 we
can't issue PSS signed CSRs, as the libraries in Go always request
a PKCS1v15.
- Add an extra check in intermediate/generate that validates the CSR's
signature before providing it back to the client in case we generated
a bad signature such as if an end-user used a GCP backed managed key
with a RSA PSS algorithm.
- GCP ignores the requested signature type and always signs with the
key's algorithm which can lead to a CSR that says it is signed with
a PKCS1v15 algorithm but is actually a RSA PSS signature
* Add cl
* PR feedback
Steven Clark