saltyrtc-client 0.7.0

/// The state of the entire signaling instance.
///
/// When establishing a connection with a SaltyRTC peer, the connection buildup
/// can be in one of three stages: Server handshake, peer handshake or task.
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum SignalingState {
    /// The server handshake is in progress.
    ServerHandshake,
    /// The server handshake is finished, the peer handshake is in progress.
    PeerHandshake,
    /// The peer handshake is finished, control has been handed over to a task.
    Task,
}

impl SignalingState {
    pub fn may_transition_to(self, new_state: Self) -> bool {
        match (self, new_state) {
            (SignalingState::ServerHandshake, SignalingState::PeerHandshake) => true,
            (SignalingState::PeerHandshake, SignalingState::Task) => true,
            _ => false,
        }
    }
}

/// The states when doing a handshake with the server.
///
/// The `ClientHello` state is only valid for the responder role, otherwise the
/// state will transition from `ServerHello` to `ClientAuth` directly.
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum ServerHandshakeState {
    /// Initial state.
    New,
    /// The client-hello (only responder) and client-auth messages have been sent.
    ClientInfoSent,
    /// The server-auth message has been received and processed.
    Done,
}

/// The states when doing a handshake with the initiator.
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum InitiatorHandshakeState {
    /// Initial state.
    New,
    /// A [`Key`](../messages/struct.Key.html) message and maybe a
    /// [`Token`](../messages/struct.Token.html) message have been sent.
    KeySent,
    /// A [`Key`](../messages/struct.Key.html) message has been received.
    KeyReceived,
    /// An [`Auth`](../messages/struct.Auth.html) message has been sent.
    AuthSent,
    /// An [`Auth`](../messages/struct.Auth.html) message has been received.
    AuthReceived,
}

/// The states when doing a handshake with the responder.
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum ResponderHandshakeState {
    /// Initial state.
    New,
    /// Either [`Token`](../messages/struct.Token.html) message has been received,
    /// or a trusted key is available.
    TokenReceived,
    /// A [`Key`](../messages/struct.Key.html) message has been received.
    KeyReceived,
    /// A [`Key`](../messages/struct.Key.html) message has been sent.
    KeySent,
    /// An [`Auth`](../messages/struct.Auth.html) message has been received.
    AuthReceived,
    /// An [`Auth`](../messages/struct.Auth.html) message has been sent.
    AuthSent,
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn signaling_handshake_validate_transitions() {
        let s = SignalingState::ServerHandshake;
        let p = SignalingState::PeerHandshake;
        let t = SignalingState::Task;

        assert!(!s.may_transition_to(s));
        assert!(s.may_transition_to(p));
        assert!(!s.may_transition_to(t));

        assert!(!p.may_transition_to(s));
        assert!(!p.may_transition_to(p));
        assert!(p.may_transition_to(t));

        assert!(!t.may_transition_to(s));
        assert!(!t.may_transition_to(p));
        assert!(!t.may_transition_to(t));
    }
}