feat: adding a bind shell example with more stuff

adding a bind shell that can allow for more practice with future
features such as multiple transports, encryption, transferring files,
and a more robust client interface

sparse-05/sparse-05-client/src/commands/connect/mod.rs

@@ -0,0 +1,27 @@
+use std::{net::SocketAddr, path::PathBuf, sync::Arc};
+
+use ed25519_dalek::{Keypair, Signer};
+use sparse_05_common::messages::CONNECT_MESSAGE;
+use tokio::{fs, net::UdpSocket};
+
+use crate::configs::ClientConfig;
+
+enum State {
+    Ready,
+    UploadingFile,
+    DownloadingFile,
+}
+
+pub async fn connect(config: PathBuf, ip: SocketAddr) -> anyhow::Result<()> {
+    let config = fs::read(&config).await?;
+    let config: ClientConfig = rmp_serde::from_slice(&config)?;
+
+    let remote = Arc::new(UdpSocket::bind("0.0.0.0:0").await?);
+
+    let connect_signature = config.keypair.sign(CONNECT_MESSAGE).to_bytes();
+    let connect_msg = &[&connect_signature, CONNECT_MESSAGE].concat();
+
+    remote.send_to(connect_msg, ip).await?;
+
+    Ok(())
+}

sparse-05/sparse-05-client/src/commands/generate.rs

@@ -0,0 +1,48 @@
+use std::{ffi::OsString, path::PathBuf};
+
+use ed25519_dalek::Keypair;
+use sparse_05_common::CONFIG_SEPARATOR;
+use tokio::{fs, io::AsyncWriteExt};
+
+use crate::configs::ClientConfig;
+
+#[cfg(debug_assertions)]
+pub const SPARSE_SERVER_BINARY: &'static [u8] =
+    include_bytes!("../../../../target/debug/sparse-05-server");
+#[cfg(not(debug_assertions))]
+pub const SPARSE_SERVER_BINARY: &'static [u8] =
+    include_bytes!("../../../../target/release/sparse-05-server");
+
+pub async fn generate(mut name: PathBuf, port: u16) -> anyhow::Result<()> {
+    let mut csprng = rand::thread_rng();
+    let keypair = Keypair::generate(&mut csprng);
+
+    let mut file = fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .mode(0o755)
+        .open(&name)
+        .await?;
+
+    file.write_all(SPARSE_SERVER_BINARY).await?;
+    file.write_all(CONFIG_SEPARATOR).await?;
+    file.write_all(&port.to_be_bytes()[..]).await?;
+    file.write_all(keypair.public.as_bytes()).await?;
+
+    let config = ClientConfig { keypair, port };
+
+    let mut file_part = name.file_name().unwrap().to_owned();
+    file_part.push(OsString::from(".conf"));
+    name.pop();
+    name.push(file_part);
+    let mut file = fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(&name)
+        .await?;
+
+    let config = rmp_serde::to_vec(&config)?;
+    file.write_all(&config).await?;
+
+    Ok(())
+}

sparse-05/sparse-05-client/src/commands/mod.rs

@@ -0,0 +1,2 @@
+pub mod connect;
+pub mod generate;

sparse-05/sparse-05-client/src/configs.rs

@@ -0,0 +1,8 @@
+use ed25519_dalek::Keypair;
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub struct ClientConfig {
+    pub keypair: Keypair,
+    pub port: u16,
+}

sparse-05/sparse-05-client/src/main.rs

@@ -0,0 +1,17 @@
+use structopt::StructOpt;
+
+mod commands;
+mod configs;
+mod options;
+
+use options::{Command, Options};
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let options = Options::from_args();
+
+    match options.command {
+        Command::Generate { name, port } => commands::generate::generate(name, port).await,
+        Command::Connect { config, ip } => commands::connect::connect(config, ip).await,
+    }
+}

sparse-05/sparse-05-client/src/options.rs

@@ -0,0 +1,43 @@
+use std::{
+    net::{Ipv4Addr, SocketAddr, ToSocketAddrs},
+    path::PathBuf,
+};
+
+use structopt::{self, StructOpt};
+
+fn to_socket_addr(src: &str) -> Result<SocketAddr, std::io::Error> {
+    use std::io::{Error, ErrorKind};
+
+    src.to_socket_addrs()?.next().ok_or(Error::new(
+        ErrorKind::Other,
+        "could not get a valid socket address",
+    ))
+}
+
+#[derive(StructOpt)]
+pub enum Command {
+    Generate {
+        #[structopt(parse(from_os_str))]
+        name: PathBuf,
+
+        #[structopt(default_value = "54248")]
+        port: u16,
+    },
+    Connect {
+        #[structopt(parse(from_os_str))]
+        config: PathBuf,
+
+        #[structopt(parse(try_from_str = to_socket_addr))]
+        ip: SocketAddr,
+    },
+}
+
+#[derive(StructOpt)]
+#[structopt(
+    name = "sparse-client",
+    about = "Client to and generator of sparse shells"
+)]
+pub struct Options {
+    #[structopt(subcommand)]
+    pub command: Command,
+}