Function get_secure_join_step

src/securejoin.rs:376–404

Parses message headers to find out which Secure-Join step the message represents. Returns `None` if the message is not a Secure-Join message.

(mime_message: &MimeMessage)

///
/// Returns `None` if the message is not a Secure-Join message.
pub(crate) fn get_secure_join_step(mime_message: &MimeMessage) -> Option<SecureJoinStep> {
    if let Some(invitenumber) = mime_message.get_header(HeaderDef::SecureJoinInvitenumber) {
        // We do not care about presence of `Secure-Join: vc-request` or `Secure-Join: vg-request` header.
        // This allows us to always treat `Secure-Join` header as protected and ignore it
        // in the unencrypted part even though it is sent there for backwards compatibility.
        Some(SecureJoinStep::Request {
            invitenumber: invitenumber.to_string(),
        })
    } else if let Some(step) = mime_message.get_header(HeaderDef::SecureJoin) {
        match step {
            "vc-request-pubkey" => Some(SecureJoinStep::RequestPubkey),
            "vc-pubkey" => Some(SecureJoinStep::Pubkey),
            "vg-auth-required" | "vc-auth-required" => Some(SecureJoinStep::AuthRequired),
            "vg-request-with-auth" | "vc-request-with-auth" => {
                Some(SecureJoinStep::RequestWithAuth)
            }
            "vc-contact-confirm" => Some(SecureJoinStep::ContactConfirm),
            "vg-member-added" => Some(SecureJoinStep::MemberAdded),
            "vg-member-added-received" | "vc-contact-confirm-received" => {
                Some(SecureJoinStep::Deprecated)
            }
            step => Some(SecureJoinStep::Unknown {
                step: step.to_string(),
            }),
        }
    } else {
        None
    }
}

/// Handle incoming secure-join handshake.
///