OptionalcurveEC curve.
During key generation when importPkcs8 is absent, the default is "P-256". During key import when importPkcs8 is specified, this is auto-detected from SPKI.
OptionalimportImport PKCS#8 private key and SPKI public key instead of generating.
If curve is also specified, it must match the SPKI public key.
OptionalimportImport SEC#1 private key and SPKI public key instead of generating.
If curve is also specified, it must match the SPKI public key. If importPkcs8 is also specified, this field is ignored.
Key generation parameters.