This change adds a new authority option that allows to pass a callback
that returns the certificate chain and signer used to sign X.509
certificates.
This option will be used by Caddy, they renew the intermediate
certificate weekly and there's no other way to replace it without
re-creating the embedded CA.
Fixes#874
* use json.RawMessage to remote mapstructure in options
* use vault secretid structure to support multiple source aka string, file and env
* remove log prefix
* return raw cert on error on newline for cert and csr
* clean sans, commonName in createCertificate (bad copy/paste from StepCAS)
* verify authority fingerprint
* convert serial on revoke to bigint, bytes and vault dashed representation
CloudKMS keys signs data using an specific signature algorithm, in RSA keys,
this can be PKCS#1 RSA or RSA-PSS, if the later is used, x509.CreateCertificate
will fail unless the template SignatureCertificate is properly set.
On contrast, AWSKMS RSA keys, are just RSA keys, and can sign with PKCS#1 or
RSA-PSS schemes, so right now the way to enforce one or the other is to used
templates.
This change makes easier the configuration of cloudCAS as it does
not require to configure the root or intermediate certificate
in the ca.json. CloudCAS will get the root certificate using
the configured certificateAuthority.
