2.2 Message Syntax
PKCA MAY<3> support these variations based on an earlier draft of [RFC4556] for interoperability.
An earlier draft of [RFC4556] supported a different pre-authentication data identifier:
The algorithm identifier in Cryptographic Message Syntax (CMS) messages, as specified in [RFC2315] and [RFC3852], is md5WithRSAEncryption instead of md5 ([RFC3370] sections 3.2 and 2.2).<4> SHA-1WithRSAEncryption [RFC3370] SHOULD<5> be supported. ecdsa-with-Sha1, ecdsa-with-Sha256, ecdsa-with-Sha384, and ecdsa-with-Sha512 ([RFC5349] section 3) SHOULD<6> be supported.
ECPRGF256Random | groupP-256 | secp256r1
ECPRGF384Random | groupP-384 | secp384r1
ECPRGF521Random | groupP-521 | secp521r1