Certificate Requested as ECDSA-256 but receiving 384

[Evesy]

I am requesting a certificate using cert-manager with a requested key algorithm of ECDSA and size of 256.

For those familiar:

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: meves-test
spec:
  commonName: ""
  dnsNames:
  - 'meves-test.testing.k8.atcloud.io'
  issuerRef:
    kind: ClusterIssuer
    name: letsencrypt-prod
  privateKey:
    rotationPolicy: Always
    algorithm: ECDSA
    size: 256
  secretName: meves-test

I can see in the resultant CSR that is created and used these requested properties are seemingly set correctly as the CSR includes: Signature Algorithm: ecdsa-with-SHA256

However the resultant certificate that's issued has Signature Algorithm: ecdsa-with-SHA384

[rg305]

The signatures are separate to the size of the cert.
The cert itself is 256 bits:

            Public Key Algorithm: id-ecPublicKey
                Public-Key: (256 bit)
                pub:
                    04:65:04:18:75:ab:f2:7c:17:28:c7:f8:0a:2a:7c:
                    7c:1b:a1:76:e1:46:5c:48:4b:c8:f1:d2:3f:fa:03:
                    1e:30:d7:a7:67:53:f8:71:a5:0b:a8:23:80:1e:b8:
                    5c:76:0e:aa:d6:52:5e:99:64:3a:2f:47:32:c2:ef:
                    fb:46:4e:49:60

[petercooperjr]

Your key is P-256. Let's Encrypt has signed it with a P-384 intermediate. You control what key you're using, and Let's Encrypt controls what key they're using.

Other than it being a little confusing, is it causing any actual problems for you?

[Evesy]

Thanks both, complete misunderstanding on my part. What you've said makes complete sense.