US
RFC 8551: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Message Specification
https://www.rfc-editor.org/rfc/rfc8551
…256 and SHA-256. - MUST support EdDSA with curve25519 using PureEdDSA mode [ RFC8419 ]. - MUST- support RSA PKCS #1 v1.5 with SHA-256. - SHOULD support the RSA Probabilistic Signature Scheme (RSASSA-PSS) with SHA-256. Schaad, et al. Standards Track [Page 12] RFC 8551 S/MIME 4.0 M…