every.channel: sanitized baseline

third_party/iroh-org/iroh-gossip/examples/chat.rs

@@ -0,0 +1,319 @@
+use std::{
+    collections::HashMap,
+    fmt,
+    net::{Ipv4Addr, SocketAddrV4},
+    str::FromStr,
+};
+
+use bytes::Bytes;
+use clap::Parser;
+use futures_lite::StreamExt;
+use iroh::{
+    address_lookup::memory::MemoryLookup, Endpoint, EndpointAddr, PublicKey, RelayMode, RelayUrl,
+    SecretKey,
+};
+use iroh_gossip::{
+    api::{Event, GossipReceiver},
+    net::{Gossip, GOSSIP_ALPN},
+    proto::TopicId,
+};
+use n0_error::{bail_any, AnyError, Result, StdResultExt};
+use n0_future::task;
+use serde::{Deserialize, Serialize};
+use serde_byte_array::ByteArray;
+
+/// Chat over iroh-gossip
+///
+/// This broadcasts signed messages over iroh-gossip and verifies signatures
+/// on received messages.
+///
+/// By default a new endpoint id is created when starting the example. To reuse your identity,
+/// set the `--secret-key` flag with the secret key printed on a previous invocation.
+///
+/// By default, the relay server run by n0 is used. To use a local relay server, run
+///     cargo run --bin iroh-relay --features iroh-relay -- --dev
+/// in another terminal and then set the `-d http://localhost:3340` flag on this example.
+#[derive(Parser, Debug)]
+struct Args {
+    /// secret key to derive our endpoint id from.
+    #[clap(long)]
+    secret_key: Option<String>,
+    /// Set a custom relay server. By default, the relay server hosted by n0 will be used.
+    #[clap(short, long)]
+    relay: Option<RelayUrl>,
+    /// Disable relay completely.
+    #[clap(long)]
+    no_relay: bool,
+    /// Set your nickname.
+    #[clap(short, long)]
+    name: Option<String>,
+    /// Set the bind port for our socket. By default, a random port will be used.
+    #[clap(short, long, default_value = "0")]
+    bind_port: u16,
+    #[clap(subcommand)]
+    command: Command,
+}
+
+#[derive(Parser, Debug)]
+enum Command {
+    /// Open a chat room for a topic and print a ticket for others to join.
+    ///
+    /// If no topic is provided, a new topic will be created.
+    Open {
+        /// Optionally set the topic id (64 bytes, as hex string).
+        topic: Option<TopicId>,
+    },
+    /// Join a chat room from a ticket.
+    Join {
+        /// The ticket, as base32 string.
+        ticket: String,
+    },
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    tracing_subscriber::fmt::init();
+    let args = Args::parse();
+
+    // parse the cli command
+    let (topic, peers) = match &args.command {
+        Command::Open { topic } => {
+            let topic = topic.unwrap_or_else(|| TopicId::from_bytes(rand::random()));
+            println!("> opening chat room for topic {topic}");
+            (topic, vec![])
+        }
+        Command::Join { ticket } => {
+            let Ticket { topic, peers } = Ticket::from_str(ticket)?;
+            println!("> joining chat room for topic {topic}");
+            (topic, peers)
+        }
+    };
+
+    // parse or generate our secret key
+    let secret_key = match args.secret_key {
+        None => SecretKey::generate(&mut rand::rng()),
+        Some(key) => key.parse()?,
+    };
+    println!(
+        "> our secret key: {}",
+        data_encoding::HEXLOWER.encode(&secret_key.to_bytes())
+    );
+
+    // configure our relay map
+    let relay_mode = match (args.no_relay, args.relay) {
+        (false, None) => RelayMode::Default,
+        (false, Some(url)) => RelayMode::Custom(url.into()),
+        (true, None) => RelayMode::Disabled,
+        (true, Some(_)) => bail_any!("You cannot set --no-relay and --relay at the same time"),
+    };
+    println!("> using relay servers: {}", fmt_relay_mode(&relay_mode));
+
+    // create a memory lookup to pass in endpoint addresses to
+    let memory_lookup = MemoryLookup::new();
+
+    // build our magic endpoint
+    let endpoint = Endpoint::builder()
+        .secret_key(secret_key)
+        .address_lookup(memory_lookup.clone())
+        .relay_mode(relay_mode.clone())
+        .bind_addr(SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, args.bind_port))?
+        .bind()
+        .await?;
+    println!("> our endpoint id: {}", endpoint.id());
+
+    // create the gossip protocol
+    let gossip = Gossip::builder().spawn(endpoint.clone());
+
+    // print a ticket that includes our own endpoint id and endpoint addresses
+    if !matches!(relay_mode, RelayMode::Disabled) {
+        // if we are expecting a relay, wait until we get a home relay
+        // before moving on
+        endpoint.online().await;
+    }
+    let ticket = {
+        let me = endpoint.addr();
+        let peers = peers.iter().cloned().chain([me]).collect();
+        Ticket { topic, peers }
+    };
+    println!("> ticket to join us: {ticket}");
+
+    // setup router
+    let router = iroh::protocol::Router::builder(endpoint.clone())
+        .accept(GOSSIP_ALPN, gossip.clone())
+        .spawn();
+
+    // join the gossip topic by connecting to known peers, if any
+    let peer_ids = peers.iter().map(|p| p.id).collect();
+    if peers.is_empty() {
+        println!("> waiting for peers to join us...");
+    } else {
+        println!("> trying to connect to {} peers...", peers.len());
+        // add the peer addrs from the ticket to our endpoint's addressbook so that they can be dialed
+        for peer in peers.into_iter() {
+            memory_lookup.add_endpoint_info(peer);
+        }
+    };
+    let (sender, receiver) = gossip.subscribe_and_join(topic, peer_ids).await?.split();
+    println!("> connected!");
+
+    // broadcast our name, if set
+    if let Some(name) = args.name {
+        let message = Message::AboutMe { name };
+        let encoded_message = SignedMessage::sign_and_encode(endpoint.secret_key(), &message)?;
+        sender.broadcast(encoded_message).await?;
+    }
+
+    // subscribe and print loop
+    task::spawn(subscribe_loop(receiver));
+
+    // spawn an input thread that reads stdin
+    // not using tokio here because they recommend this for "technical reasons"
+    let (line_tx, mut line_rx) = tokio::sync::mpsc::channel(1);
+    std::thread::spawn(move || input_loop(line_tx));
+
+    // broadcast each line we type
+    println!("> type a message and hit enter to broadcast...");
+    while let Some(text) = line_rx.recv().await {
+        let message = Message::Message { text: text.clone() };
+        let encoded_message = SignedMessage::sign_and_encode(endpoint.secret_key(), &message)?;
+        sender.broadcast(encoded_message).await?;
+        println!("> sent: {text}");
+    }
+
+    // shutdown
+    router.shutdown().await.anyerr()?;
+
+    Ok(())
+}
+
+async fn subscribe_loop(mut receiver: GossipReceiver) -> Result<()> {
+    // init a peerid -> name hashmap
+    let mut names = HashMap::new();
+    while let Some(event) = receiver.try_next().await? {
+        if let Event::Received(msg) = event {
+            let (from, message) = SignedMessage::verify_and_decode(&msg.content)?;
+            match message {
+                Message::AboutMe { name } => {
+                    names.insert(from, name.clone());
+                    println!("> {} is now known as {}", from.fmt_short(), name);
+                }
+                Message::Message { text } => {
+                    let name = names
+                        .get(&from)
+                        .map_or_else(|| from.fmt_short().to_string(), String::to_string);
+                    println!("{name}: {text}");
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+fn input_loop(line_tx: tokio::sync::mpsc::Sender<String>) -> Result<()> {
+    let mut buffer = String::new();
+    let stdin = std::io::stdin(); // We get `Stdin` here.
+    loop {
+        stdin.read_line(&mut buffer).anyerr()?;
+        line_tx.blocking_send(buffer.clone()).anyerr()?;
+        buffer.clear();
+    }
+}
+
+const SIGNATURE_LENGTH: usize = iroh::Signature::LENGTH;
+type Signature = ByteArray<SIGNATURE_LENGTH>;
+
+#[derive(Debug, Serialize, Deserialize)]
+struct SignedMessage {
+    from: PublicKey,
+    data: Bytes,
+    signature: Signature,
+}
+
+impl SignedMessage {
+    pub fn verify_and_decode(bytes: &[u8]) -> Result<(PublicKey, Message)> {
+        let signed_message: Self =
+            postcard::from_bytes(bytes).std_context("decode signed message")?;
+        let key: PublicKey = signed_message.from;
+        key.verify(
+            &signed_message.data,
+            &iroh::Signature::from_bytes(&signed_message.signature),
+        )
+        .std_context("verify signature")?;
+        let message: Message =
+            postcard::from_bytes(&signed_message.data).std_context("decode message")?;
+        Ok((signed_message.from, message))
+    }
+
+    pub fn sign_and_encode(secret_key: &SecretKey, message: &Message) -> Result<Bytes> {
+        let data: Bytes = postcard::to_stdvec(&message)
+            .std_context("encode message")?
+            .into();
+        let signature = secret_key.sign(&data);
+        let from: PublicKey = secret_key.public();
+        let signed_message = Self {
+            from,
+            data,
+            signature: ByteArray::new(signature.to_bytes()),
+        };
+        let encoded = postcard::to_stdvec(&signed_message).std_context("encode signed message")?;
+        Ok(encoded.into())
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+enum Message {
+    AboutMe { name: String },
+    Message { text: String },
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Ticket {
+    topic: TopicId,
+    peers: Vec<EndpointAddr>,
+}
+impl Ticket {
+    /// Deserializes from bytes.
+    fn from_bytes(bytes: &[u8]) -> Result<Self> {
+        postcard::from_bytes(bytes).std_context("decode ticket")
+    }
+    /// Serializes to bytes.
+    pub fn to_bytes(&self) -> Vec<u8> {
+        postcard::to_stdvec(self).expect("postcard::to_stdvec is infallible")
+    }
+}
+
+/// Serializes to base32.
+impl fmt::Display for Ticket {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut text = data_encoding::BASE32_NOPAD.encode(&self.to_bytes()[..]);
+        text.make_ascii_lowercase();
+        write!(f, "{text}")
+    }
+}
+
+/// Deserializes from base32.
+impl FromStr for Ticket {
+    type Err = AnyError;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let bytes = data_encoding::BASE32_NOPAD
+            .decode(s.to_ascii_uppercase().as_bytes())
+            .std_context("decode ticket base32")?;
+        Self::from_bytes(&bytes)
+    }
+}
+
+// helpers
+
+fn fmt_relay_mode(relay_mode: &RelayMode) -> String {
+    match relay_mode {
+        RelayMode::Disabled => "None".to_string(),
+        RelayMode::Default => "Default Relay (production) servers".to_string(),
+        RelayMode::Staging => "Default Relay (staging) servers".to_string(),
+        RelayMode::Custom(map) => map
+            .urls::<Vec<_>>()
+            .into_iter()
+            .map(|url| url.to_string())
+            .collect::<Vec<_>>()
+            .join(", "),
+    }
+}