Function deltachat::decrypt::validate_detached_signature

pub(crate) fn validate_detached_signature<'a, 'b>(
    mail: &'a ParsedMail<'b>,
    public_keyring_for_validate: &[SignedPublicKey],
) -> Option<(&'a ParsedMail<'b>, HashSet<Fingerprint>)>

Validates signatures of Multipart/Signed message part, as defined in RFC 1847.

Returns the signed part and the set of key fingerprints for which there is a valid signature.

Returns None if the message is not Multipart/Signed or doesn’t contain necessary parts.