Function add_certificate 

pub fn add_certificate(
    raw_signer: &dyn RawSigningKey,
    flags: OpenPgpKeyUsageFlags,
    user_ids: &[OpenPgpUserId],
    created_at: Timestamp,
    version: OpenPgpVersion,
) -> Result<Vec<u8>, Error>

Generates an OpenPGP certificate for a RawSigningKey implementation.

The list of User IDs must not be empty. The first User ID is marked as primary.

Errors

Returns an error if

• conversion of the HSM public key to OpenPGP public key fails
• an empty list of user IDs is passed
• signing the certificate with the HSM key fails
• writing the resulting certificate to buffer fails