I was wondering if is it possible to generate EC private key:
openssl ecparam -name sect571r1 -out ecparam.pem
openssl ecparam -in ecparam.pem -genkey -noout -out eckey.pem
then generate CSR, which would tell CA to sign it normally as RSA:
openssl req -new -sha512 -key eckey.pem -nodes -out csr.csr
and give it to CA, which will sign it and make RSA certificate. Is there any way to do this? If not, is there at least some EC curve that can produce a key of 2048 bits or more? The longest I know is sect571r1.