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pub(super) mod key;
pub mod rendezvous;
mod server_messages;
#[cfg(test)]
mod test;
mod wordlist;
use serde_derive::{Deserialize, Serialize};
use std::borrow::Cow;
use self::rendezvous::*;
pub(self) use self::server_messages::EncryptedMessage;
use crypto_secretbox as secretbox;
use log::*;
#[derive(Debug, thiserror::Error)]
#[non_exhaustive]
pub enum WormholeError {
/// Some deserialization went wrong, we probably got some garbage
#[error("Corrupt message received from peer")]
ProtocolJson(
#[from]
#[source]
serde_json::Error,
),
#[error("Error with the rendezvous server connection")]
ServerError(
#[from]
#[source]
rendezvous::RendezvousError,
),
/// A generic string message for "something went wrong", i.e.
/// the server sent some bullshit message order
#[error("Protocol error: {}", _0)]
Protocol(Box<str>),
#[error(
"Key confirmation failed. If you didn't mistype the code, \
this is a sign of an attacker guessing passwords. Please try \
again some time later."
)]
PakeFailed,
#[error("Cannot decrypt a received message")]
Crypto,
}
impl WormholeError {
/** Should we tell the server that we are "errory" or "scared"? */
pub fn is_scared(&self) -> bool {
matches!(self, Self::PakeFailed)
}
}
impl From<std::convert::Infallible> for WormholeError {
fn from(_: std::convert::Infallible) -> Self {
unreachable!()
}
}
/**
* The result of the client-server handshake
*/
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct WormholeWelcome {
/** A welcome message from the server (think of "message of the day"). Should be displayed to the user if present. */
pub welcome: Option<String>,
pub code: Code,
}
/**
* Establishing Wormhole connection
*
* You can send and receive arbitrary messages in form of byte slices over it, using [`Wormhole::send`] and [`Wormhole::receive`].
* Everything else (including encryption) will be handled for you.
*
* To create a wormhole, use the [`Wormhole::connect_without_code`], [`Wormhole::connect_with_code`] etc. methods, depending on
* which values you have. Typically, the sender side connects without a code (which will create one), and the receiver side
* has one (the user entered it, who got it from the sender).
*
* # Clean shutdown
*
* TODO
*/
/* TODO
* Maybe a better way to handle application level protocols is to create a trait for them and then
* to paramterize over them.
*/
#[derive(Debug)]
pub struct Wormhole {
server: RendezvousServer,
phase: u64,
key: key::Key<key::WormholeKey>,
appid: AppID,
/**
* If you're paranoid, let both sides check that they calculated the same verifier.
*
* PAKE hardens a standard key exchange with a password ("password authenticated") in order
* to mitigate potential man in the middle attacks that would otherwise be possible. Since
* the passwords usually are not of hight entropy, there is a low-probability possible of
* an attacker guessing the password correctly, enabling them to MitM the connection.
*
* Not only is that probability low, but they also have only one try per connection and a failed
* attempts will be noticed by both sides. Nevertheless, comparing the verifier mitigates that
* attack vector.
*/
pub verifier: Box<secretbox::Key>,
/**
* Our "app version" information that we sent. See the [`peer_version`] for more information.
*/
pub our_version: Box<dyn std::any::Any + Send + Sync>,
/**
* Protocol version information from the other side.
* This is bound by the [`AppID`]'s protocol and thus shall be handled on a higher level
* (e.g. by the file transfer API).
*/
pub peer_version: serde_json::Value,
}
impl Wormhole {
/**
* Generate a code and connect to the rendezvous server.
*
* # Returns
*
* A tuple with a [`WormholeWelcome`] and a [`std::future::Future`] that will
* do the rest of the client-client handshake and yield the [`Wormhole`] object
* on success.
*/
pub async fn connect_without_code(
config: AppConfig<impl serde::Serialize + Send + Sync + 'static>,
code_length: usize,
) -> Result<
(
WormholeWelcome,
impl std::future::Future<Output = Result<Self, WormholeError>>,
),
WormholeError,
> {
let AppConfig {
id: appid,
rendezvous_url,
app_version: versions,
} = config;
let (mut server, welcome) = RendezvousServer::connect(&appid, &rendezvous_url).await?;
let (nameplate, mailbox) = server.allocate_claim_open().await?;
log::debug!("Connected to mailbox {}", mailbox);
let code = Code::new(
&nameplate,
&wordlist::default_wordlist(code_length).choose_words(),
);
Ok((
WormholeWelcome {
welcome,
code: code.clone(),
},
Self::connect_custom(server, appid, code.0, versions),
))
}
/**
* Connect to a peer with a code.
*/
pub async fn connect_with_code(
config: AppConfig<impl serde::Serialize + Send + Sync + 'static>,
code: Code,
) -> Result<(WormholeWelcome, Self), WormholeError> {
let AppConfig {
id: appid,
rendezvous_url,
app_version: versions,
} = config;
let (mut server, welcome) = RendezvousServer::connect(&appid, &rendezvous_url).await?;
let nameplate = code.nameplate();
let mailbox = server.claim_open(nameplate).await?;
log::debug!("Connected to mailbox {}", mailbox);
Ok((
WormholeWelcome {
welcome,
code: code.clone(),
},
Self::connect_custom(server, appid, code.0, versions).await?,
))
}
/** TODO */
pub async fn connect_with_seed() {
todo!()
}
/// Do only the client-client part of the connection setup
///
/// The rendezvous server must already have an opened mailbox.
///
/// # Panics
///
/// If the [`RendezvousServer`] is not properly initialized, i.e. if the
/// mailbox is not open.
pub async fn connect_custom(
mut server: RendezvousServer,
appid: AppID,
password: String,
app_versions: impl serde::Serialize + Send + Sync + 'static,
) -> Result<Self, WormholeError> {
/* Send PAKE */
let (pake_state, pake_msg_ser) = key::make_pake(&password, &appid);
server.send_peer_message(Phase::PAKE, pake_msg_ser).await?;
/* Receive PAKE */
let peer_pake = key::extract_pake_msg(&server.next_peer_message_some().await?.body)?;
let key = pake_state
.finish(&peer_pake)
.map_err(|_| WormholeError::PakeFailed)
.map(|key| *secretbox::Key::from_slice(&key))?;
/* Send versions message */
let mut versions = key::VersionsMessage::new();
versions.set_app_versions(serde_json::to_value(&app_versions).unwrap());
let (version_phase, version_msg) = key::build_version_msg(server.side(), &key, &versions);
server.send_peer_message(version_phase, version_msg).await?;
let peer_version = server.next_peer_message_some().await?;
/* Handle received message */
let versions: key::VersionsMessage = peer_version
.decrypt(&key)
.ok_or(WormholeError::PakeFailed)
.and_then(|plaintext| {
serde_json::from_slice(&plaintext).map_err(WormholeError::ProtocolJson)
})?;
let peer_version = versions.app_versions;
if server.needs_nameplate_release() {
server.release_nameplate().await?;
}
log::info!("Found peer on the rendezvous server.");
/* We are now fully initialized! Up and running! :tada: */
Ok(Self {
server,
appid,
phase: 0,
key: key::Key::new(key.into()),
verifier: Box::new(key::derive_verifier(&key)),
our_version: Box::new(app_versions),
peer_version,
})
}
/** Send an encrypted message to peer */
pub async fn send(&mut self, plaintext: Vec<u8>) -> Result<(), WormholeError> {
let phase_string = Phase::numeric(self.phase);
self.phase += 1;
let data_key = key::derive_phase_key(self.server.side(), &self.key, &phase_string);
let (_nonce, encrypted) = key::encrypt_data(&data_key, &plaintext);
self.server
.send_peer_message(phase_string, encrypted)
.await?;
Ok(())
}
/**
* Serialize and send an encrypted message to peer
*
* This will serialize the message as `json` string, which is most commonly
* used by upper layer protocols. The serialization may not fail
*
* ## Panics
*
* If the serialization fails
*/
pub async fn send_json<T: serde::Serialize>(
&mut self,
message: &T,
) -> Result<(), WormholeError> {
self.send(serde_json::to_vec(message).unwrap()).await
}
/** Receive an encrypted message from peer */
pub async fn receive(&mut self) -> Result<Vec<u8>, WormholeError> {
loop {
let peer_message = match self.server.next_peer_message().await? {
Some(peer_message) => peer_message,
None => continue,
};
if peer_message.phase.to_num().is_none() {
// TODO: log and ignore, for future expansion
todo!("log and ignore, for future expansion");
}
// TODO maybe reorder incoming messages by phase numeral?
let decrypted_message = peer_message
.decrypt(&self.key)
.ok_or(WormholeError::Crypto)?;
// Send to client
return Ok(decrypted_message);
}
}
/**
* Receive an encrypted message from peer
*
* This will deserialize the message as `json` string, which is most commonly
* used by upper layer protocols. We distinguish between the different layers
* on which a serialization error happened, hence the double `Result`.
*/
pub async fn receive_json<T>(&mut self) -> Result<Result<T, serde_json::Error>, WormholeError>
where
T: for<'a> serde::Deserialize<'a>,
{
self.receive().await.map(|data: Vec<u8>| {
serde_json::from_slice(&data).map_err(|e| {
log::error!(
"Received invalid data from peer: '{}'",
String::from_utf8_lossy(&data)
);
e
})
})
}
pub async fn close(self) -> Result<(), WormholeError> {
log::debug!("Closing Wormhole…");
self.server.shutdown(Mood::Happy).await.map_err(Into::into)
}
/**
* The `AppID` this wormhole is bound to.
* This determines the upper-layer protocol. Only wormholes with the same value can talk to each other.
*/
pub fn appid(&self) -> &AppID {
&self.appid
}
/**
* The symmetric encryption key used by this connection.
* Can be used to derive sub-keys for different purposes.
*/
pub fn key(&self) -> &key::Key<key::WormholeKey> {
&self.key
}
}
// the serialized forms of these variants are part of the wire protocol, so
// they must be spelled exactly as shown
#[derive(Debug, PartialEq, Copy, Clone, Deserialize, Serialize, derive_more::Display)]
pub enum Mood {
#[serde(rename = "happy")]
Happy,
#[serde(rename = "lonely")]
Lonely,
#[serde(rename = "errory")]
Errory,
#[serde(rename = "scary")]
Scared,
#[serde(rename = "unwelcome")]
Unwelcome,
}
/**
* Wormhole configuration corresponding to an uppler layer protocol
*
* There are multiple different protocols built on top of the core
* Wormhole protocol. They are identified by a unique URI-like ID string
* (`AppID`), an URL to find the rendezvous server (might be shared among
* multiple protocols), and client implementations also have a "version"
* data to do protocol negotiation.
*
* See [`crate::transfer::APP_CONFIG`], which entails
*/
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct AppConfig<V> {
pub id: AppID,
pub rendezvous_url: Cow<'static, str>,
pub app_version: V,
}
impl<V> AppConfig<V> {
pub fn id(mut self, id: AppID) -> Self {
self.id = id;
self
}
pub fn rendezvous_url(mut self, rendezvous_url: Cow<'static, str>) -> Self {
self.rendezvous_url = rendezvous_url;
self
}
}
impl<V: serde::Serialize> AppConfig<V> {
pub fn app_version(mut self, app_version: V) -> Self {
self.app_version = app_version;
self
}
}
/// Newtype wrapper for application IDs
///
/// The application ID is a string that scopes all commands
/// to that name, effectively separating different protocols
/// on the same rendezvous server.
#[derive(
PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display, derive_more::Deref,
)]
#[deref(forward)]
pub struct AppID(#[deref] pub Cow<'static, str>);
impl AppID {
pub fn new(id: impl Into<Cow<'static, str>>) -> Self {
AppID(id.into())
}
}
impl From<String> for AppID {
fn from(s: String) -> Self {
Self::new(s)
}
}
// MySide is used for the String that we send in all our outbound messages
#[derive(
PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display, derive_more::Deref,
)]
#[serde(transparent)]
#[display(fmt = "MySide({})", "&*_0")]
pub struct MySide(EitherSide);
impl MySide {
pub fn generate() -> MySide {
use rand::{rngs::OsRng, RngCore};
let mut bytes: [u8; 5] = [0; 5];
OsRng.fill_bytes(&mut bytes);
MySide(EitherSide(hex::encode(bytes)))
}
// It's a minor type system feature that converting an arbitrary string into MySide is hard.
// This prevents it from getting swapped around with TheirSide.
#[cfg(test)]
pub fn unchecked_from_string(s: String) -> MySide {
MySide(EitherSide(s))
}
}
// TheirSide is used for the string that arrives inside inbound messages
#[derive(
PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display, derive_more::Deref,
)]
#[serde(transparent)]
#[display(fmt = "TheirSide({})", "&*_0")]
pub struct TheirSide(EitherSide);
impl<S: Into<String>> From<S> for TheirSide {
fn from(s: S) -> TheirSide {
TheirSide(EitherSide(s.into()))
}
}
#[derive(
PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display, derive_more::Deref,
)]
#[serde(transparent)]
#[deref(forward)]
#[display(fmt = "{}", "&*_0")]
pub struct EitherSide(pub String);
impl<S: Into<String>> From<S> for EitherSide {
fn from(s: S) -> EitherSide {
EitherSide(s.into())
}
}
#[derive(PartialEq, Eq, Clone, Debug, Hash, Deserialize, Serialize, derive_more::Display)]
#[serde(transparent)]
pub struct Phase(pub Cow<'static, str>);
impl Phase {
pub const VERSION: Self = Phase(Cow::Borrowed("version"));
pub const PAKE: Self = Phase(Cow::Borrowed("pake"));
pub fn numeric(phase: u64) -> Self {
Phase(phase.to_string().into())
}
pub fn is_version(&self) -> bool {
self == &Self::VERSION
}
pub fn is_pake(&self) -> bool {
self == &Self::PAKE
}
pub fn to_num(&self) -> Option<u64> {
self.0.parse().ok()
}
}
#[derive(PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display)]
#[serde(transparent)]
pub struct Mailbox(pub String);
#[derive(
PartialEq, Eq, Clone, Debug, Deserialize, Serialize, derive_more::Display, derive_more::Deref,
)]
#[serde(transparent)]
#[deref(forward)]
#[display(fmt = "{}", _0)]
pub struct Nameplate(pub String);
impl Nameplate {
pub fn new(n: &str) -> Self {
Nameplate(String::from(n))
}
}
impl Into<String> for Nameplate {
fn into(self) -> String {
self.0
}
}
/** A wormhole code à la 15-foo-bar
*
* The part until the first dash is called the "nameplate" and is purely numeric.
* The rest is the password and may be arbitrary, although dash-joining words from
* a wordlist is a common convention.
*/
#[derive(PartialEq, Eq, Clone, Debug, derive_more::Display, derive_more::Deref)]
#[display(fmt = "{}", _0)]
pub struct Code(pub String);
impl Code {
pub fn new(nameplate: &Nameplate, password: &str) -> Self {
Code(format!("{}-{}", nameplate, password))
}
pub fn split(&self) -> (Nameplate, String) {
let mut iter = self.0.splitn(2, '-');
let nameplate = Nameplate::new(iter.next().unwrap());
let password = iter.next().unwrap();
(nameplate, password.to_string())
}
pub fn nameplate(&self) -> Nameplate {
Nameplate::new(self.0.splitn(2, '-').next().unwrap())
}
}