The algorithm and size for the private key can now be specified in the certificate spec section to override the default algorithm `RSA` with key size 2048.
Supported algorithms are `RSA` and `ECDSA`. For `RSA` the allowed key sizes are `2048`, `3072`, and `4096` with `2048` as default is not specified explicitly. For `ECDSA` the allowed key sizes are `256` and `384` with `256` as default.
These algorithms and key sizes are supported by Let's Encrypt. For other ACME servers please check their documentation for information about supported combinations.
Release Notes: