Trait Api 

pub trait Api: Client {
    // Required methods
    fn fetch_message_ids<R: RngCore + CryptoRng>(
        &self,
        _rng: &mut R,
    ) -> MessageChallengeFetchRequest;
    fn solve_fetch_challenges(
        &self,
        challenges: &[FetchResponse],
    ) -> Result<Vec<Uuid>, Error>
       where Self: Sized + UserSecret;
    fn fetch_message(&self, message_id: Uuid) -> Option<MessageFetchRequest>;
    fn submit_message<R, S, P>(
        &self,
        rng: &mut R,
        message: &[u8],
        sender: &S,
        recipient: &P,
    ) -> Result<Envelope, Error>
       where R: RngCore + CryptoRng,
             S: UserSecret,
             P: UserPublic;
    fn handle_welcome(
        &mut self,
        welcome: &WelcomeBundle,
        fpf_verifying_key: &VerifyingKey,
    ) -> Result<(), Error>;
    fn verify_long_term(
        &self,
        journalist: &JournalistLongTermView,
        newsroom_verifying_key: &VerifyingKey,
    ) -> Result<(), Error>;
    fn verify_ephemeral(
        &self,
        long_term: &JournalistLongTermView,
        ephemeral: &SignedKeyBundlePublic,
    ) -> Result<JournalistPublicView, Error>;
}

Common API shared by sources and journalists. Api users must provide a Client implementation (local storage abstraction). All users use the same API, but hax does not support default trait implementations (cryspen/hax/issues/888) so the trait is defined separately.

Required Methods

fn fetch_message_ids<R: RngCore + CryptoRng>( &self, _rng: &mut R, ) -> MessageChallengeFetchRequest

Creates a request to fetch encrypted message IDs from the server.

Corresponds to step 7 in the protocol spec. The server returns a fixed-size set of challenges (encrypted message IDs) that the client must solve using solve_fetch_challenges.

fn solve_fetch_challenges( &self, challenges: &[FetchResponse], ) -> Result<Vec<Uuid>, Error>

where Self: Sized + UserSecret,

Solves the encrypted message-ID challenges returned by the server.

Each FetchResponse contains an encrypted message ID and a per-request DH share. The client uses its fetch keypair to recover message IDs that were addressed to it, discarding the rest.

Returns the set of Uuids for messages belonging to this client.

fn fetch_message(&self, message_id: Uuid) -> Option<MessageFetchRequest>

Creates a request to fetch a specific message by its ID.

Corresponds to steps 8 and 10 in the protocol spec. Returns None if the request cannot be constructed (the default implementation always returns Some).

fn submit_message<R, S, P>( &self, rng: &mut R, message: &[u8], sender: &S, recipient: &P, ) -> Result<Envelope, Error>

where R: RngCore + CryptoRng, S: UserSecret, P: UserPublic,

Encrypts and submits a message from sender to recipient.

Handles padding, plaintext construction (including sender reply keys), and hybrid encryption. This covers step 6 (source submissions) and step 9 (journalist replies) in the protocol spec.

Errors

Returns an error if encryption fails.

fn handle_welcome( &mut self, welcome: &WelcomeBundle, fpf_verifying_key: &VerifyingKey, ) -> Result<(), Error>

Verifies a newsroom WelcomeBundle and stores the newsroom key (step 5).

We check the FPF signature using the newsroom verifying key, then for every journalist in the roster we verify:

• the newsroom’s signature over the journalist’s verifying key
• the journalist’s signature over their long term keys

On success the newsroom key is stored, and the long term views can be cached and reused.

Errors

Returns an error if the FPF signature or any journalist signature is invalid.

fn verify_long_term( &self, journalist: &JournalistLongTermView, newsroom_verifying_key: &VerifyingKey, ) -> Result<(), Error>

Verifies one journalist’s long-term view against a trusted newsroom verifying key, the newsroom’s signature over the journalist’s verifying key, and the journalist’s signature over their long term keys.

Errors

Returns an error if either signature is invalid.

fn verify_ephemeral( &self, long_term: &JournalistLongTermView, ephemeral: &SignedKeyBundlePublic, ) -> Result<JournalistPublicView, Error>

Verifies a journalist’s one-time bundle against their already verified long-term view and assembles a JournalistPublicView for encryption.

Errors

Returns an error if the signature on the one-time bundle is invalid.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> Api for T

where T: Client,