Function sign 

pub fn sign(
    raw_signer: &dyn RawSigningKey,
    message: &[u8],
) -> Result<Vec<u8>, Error>

Generates an OpenPGP signature using a RawSigningKey implementation.

Signs the message message using the RawSigningKey and returns a binary OpenPGP data signature.

Errors

Returns an Error if creating an OpenPGP signature for the hasher state fails:

• the certificate for a given key has not been generated or is invalid
• subpacket lengths exceed maximum values
• hashing signed data fails
• signature creation using a RawSigningKey implementation fails
• constructing OpenPGP signature from parts fails
• writing the signature to vector fails