TOR+Esplora example

Cargo.toml

@@ -109,6 +109,8 @@ env_logger = "0.7"
 electrsd = "0.21"
 # Move back to importing from rust-bitcoin once https://github.com/rust-bitcoin/rust-bitcoin/pull/1342 is released
 base64 = "^0.13"
+libtor = "47.8.0+0.4.7.x"
+ureq = {version = "*", features = ["json", "socks-proxy"]}
 
 [[example]]
 name = "compact_filters_balance"
@@ -146,13 +148,18 @@ required-features = ["electrum"]
 [[example]]
 name = "esplora_backend_synchronous"
 path = "examples/esplora_backend_synchronous.rs"
-required-features = ["use-esplora-ureq"]
+required-features = ["use-esplora-blocking"]
 
 [[example]]
 name = "esplora_backend_asynchronous"
 path = "examples/esplora_backend_asynchronous.rs"
 required-features = ["use-esplora-reqwest", "reqwest-default-tls", "async-interface"]
 
+[[example]]
+name = "esplora_backend_with_tor"
+path = "examples/esplora_backend_with_tor.rs"
+required-features = ["use-esplora-blocking"]
+
 [[example]]
 name = "mnemonic_to_descriptors"
 path = "examples/mnemonic_to_descriptors.rs"

examples/esplora_backend_with_tor.rs

@@ -0,0 +1,173 @@
+use std::fs::File;
+use std::io::Read;
+use std::str::FromStr;
+use std::time::Duration;
+use std::{env, thread};
+
+use bdk::blockchain::Blockchain;
+use bdk::{
+    blockchain::esplora::EsploraBlockchain,
+    database::MemoryDatabase,
+    template::Bip84,
+    wallet::{export::FullyNodedExport, AddressIndex},
+    KeychainKind, SyncOptions, Wallet,
+};
+use bitcoin::{
+    util::bip32::{self, ExtendedPrivKey},
+    Network,
+};
+use esplora_client::Builder;
+use libtor::{LogDestination, LogLevel, Tor, TorFlag};
+
+pub mod utils;
+
+use crate::utils::tx::build_signed_tx;
+
+/// This will create a wallet from an xpriv and get the balance by connecting to an Esplora server
+/// over Tor network, using blocking calls with `ureq`.
+/// If enough amount is available, this will send a transaction to an address.
+/// Otherwise, this will display a wallet address to receive funds.
+///
+/// This can be run with `cargo run --features=use-esplora-ureq --example esplora_backend_synchronous`
+/// in the root folder.
+fn main() {
+    let network = Network::Signet;
+
+    let xpriv = "tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy";
+
+    let esplora_url =
+        "http://explorerzydxu5ecjrkwceayqybizmpjjznk5izmitf2modhcusuqlid.onion/testnet/api";
+
+    run(&network, esplora_url, xpriv);
+}
+
+fn create_wallet(network: &Network, xpriv: &ExtendedPrivKey) -> Wallet<MemoryDatabase> {
+    Wallet::new(
+        Bip84(*xpriv, KeychainKind::External),
+        Some(Bip84(*xpriv, KeychainKind::Internal)),
+        *network,
+        MemoryDatabase::default(),
+    )
+    .unwrap()
+}
+
+fn run(network: &Network, esplora_url: &str, xpriv: &str) {
+    let xpriv = bip32::ExtendedPrivKey::from_str(xpriv).unwrap();
+
+    let socks_addr = start_tor();
+
+    let client = Builder::new(esplora_url)
+        .proxy(&format!("socks5://{}", socks_addr))
+        .timeout(120) // seconds
+        .build_blocking()
+        .expect("Should never fail with no proxy and timeout");
+
+    println!(
+        "Connecting to {} via SOCKS5 proxy {}",
+        &esplora_url, &socks_addr
+    );
+
+    let blockchain = EsploraBlockchain::from_client(client, 20);
+
+    let wallet = create_wallet(network, &xpriv);
+
+    wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+
+    let address = wallet.get_address(AddressIndex::New).unwrap().address;
+
+    println!("address: {}", address);
+
+    let balance = wallet.get_balance().unwrap();
+
+    println!("Available coins in BDK wallet : {} sats", balance);
+
+    if balance.confirmed > 10500 {
+        // the wallet sends the amount to itself.
+        let recipient_address = wallet
+            .get_address(AddressIndex::New)
+            .unwrap()
+            .address
+            .to_string();
+
+        let amount = 9359;
+
+        let tx = build_signed_tx(&wallet, &recipient_address, amount);
+
+        blockchain.broadcast(&tx).unwrap();
+
+        println!("tx id: {}", tx.txid());
+    } else {
+        println!("Insufficient Funds. Fund the wallet with the address above");
+    }
+
+    let export = FullyNodedExport::export_wallet(&wallet, "exported wallet", true)
+        .map_err(ToString::to_string)
+        .map_err(bdk::Error::Generic)
+        .unwrap();
+
+    println!("------\nWallet Backup: {}", export.to_string());
+}
+
+pub fn start_tor() -> String {
+    let socks_port = 19050;
+
+    let data_dir = format!("{}/{}", env::temp_dir().display(), "bdk-tor-example");
+    let log_file_name = format!("{}/{}", &data_dir, "log");
+
+    println!("Staring Tor in {}", &data_dir);
+
+    truncate_log(&log_file_name);
+
+    Tor::new()
+        .flag(TorFlag::DataDirectory(data_dir.into()))
+        .flag(TorFlag::LogTo(
+            LogLevel::Notice,
+            LogDestination::File(log_file_name.as_str().into()),
+        ))
+        .flag(TorFlag::SocksPort(socks_port))
+        .flag(TorFlag::Custom("ExitPolicy reject *:*".into()))
+        .flag(TorFlag::Custom("BridgeRelay 0".into()))
+        .start_background();
+
+    let mut started = false;
+    let mut tries = 0;
+    while !started {
+        tries += 1;
+        if tries > 120 {
+            panic!(
+                "It took too long to start Tor. See {} for details",
+                &log_file_name
+            );
+        }
+
+        thread::sleep(Duration::from_millis(1000));
+        started = find_string_in_log(&log_file_name, &"Bootstrapped 100%".into());
+    }
+
+    println!("Tor started");
+
+    format!("127.0.0.1:{}", socks_port)
+}
+
+fn truncate_log(filename: &String) {
+    let path = std::path::Path::new(filename);
+    if path.exists() {
+        let file = File::options()
+            .write(true)
+            .open(path)
+            .expect("no such file");
+        file.set_len(0).expect("cannot set size to 0");
+    }
+}
+
+fn find_string_in_log(filename: &String, str: &String) -> bool {
+    let path = std::path::Path::new(filename);
+    if path.exists() {
+        let mut file = File::open(path).expect("cannot open log file");
+        let mut buf = String::new();
+        file.read_to_string(&mut buf).expect("cannot read log file");
+        buf.contains(str)
+    } else {
+        false
+    }
+}