- This PR adds two fields to CertificateSpec:
- `keyAlgorithm`, denotes which algorithm to use when generating
a private key. Can be either `rsa` or `ecdsa`. When not set, the
default algorithm used `rsa`.
- `keySize`, denotes the key size of the private key being generated.
For `rsa`, minimum key size is 2048 and maximum is 8192.
For `ecdsa`, sizes 224, 256, 384 & 521 are supported.
See https://golang.org/pkg/crypto/elliptic
- `keySize` can be set without being explicit about `keyAlgorithm`.
- If `keySize` is specified and `keyAlgorithm` is not provided, `rsa` will
be used as the key algorithm.
- `keyAlgorithm` can be set without being explicit about `keySize`.
- If `keyAlgorithm` is specified and `keySize` is not provided, key size
key size of `256` will be used for `ecdsa` key algorithm and
key size of `2048` will be used for `rsa` key algorithm.
- helper functions in `pki` package now return crypto.PrivateKey
