Parse .cookie, .env, or environment variables for RPC auth details

Author: alecchendev

.gitignore

@@ -9,3 +9,6 @@ Cargo.lock
 # These are backup files generated by rustfmt
 **/*.rs.bk
 .ldk
+
+# RPC auth
+.env

src/args.rs

@@ -0,0 +1,371 @@
+use crate::cli::LdkUserInfo;
+use bitcoin::network::constants::Network;
+use lightning::ln::msgs::NetAddress;
+use std::collections::HashMap;
+use std::env;
+use std::fs;
+use std::net::IpAddr;
+use std::path::{Path, PathBuf};
+use std::str::FromStr;
+
+pub(crate) fn parse_startup_args() -> Result<LdkUserInfo, ()> {
+	if env::args().len() < 3 {
+		println!("ldk-tutorial-node requires 3 arguments: `cargo run [<bitcoind-rpc-username>:<bitcoind-rpc-password>@]<bitcoind-rpc-host>:<bitcoind-rpc-port> ldk_storage_directory_path [<ldk-incoming-peer-listening-port>] [bitcoin-network] [announced-node-name announced-listen-addr*]`");
+		return Err(());
+	}
+	let bitcoind_rpc_info = env::args().skip(1).next().unwrap();
+	let bitcoind_rpc_info_parts: Vec<&str> = bitcoind_rpc_info.rsplitn(2, "@").collect();
+
+	// Parse rpc auth after getting network for default .cookie location
+	let bitcoind_rpc_path: Vec<&str> = bitcoind_rpc_info_parts[0].split(":").collect();
+	if bitcoind_rpc_path.len() != 2 {
+		println!("ERROR: bad bitcoind RPC path provided");
+		return Err(());
+	}
+	let bitcoind_rpc_host = bitcoind_rpc_path[0].to_string();
+	let bitcoind_rpc_port = bitcoind_rpc_path[1].parse::<u16>().unwrap();
+
+	let ldk_storage_dir_path = env::args().skip(2).next().unwrap();
+
+	let mut ldk_peer_port_set = true;
+	let ldk_peer_listening_port: u16 = match env::args().skip(3).next().map(|p| p.parse()) {
+		Some(Ok(p)) => p,
+		Some(Err(_)) => {
+			ldk_peer_port_set = false;
+			9735
+		}
+		None => {
+			ldk_peer_port_set = false;
+			9735
+		}
+	};
+
+	let mut arg_idx = match ldk_peer_port_set {
+		true => 4,
+		false => 3,
+	};
+	let network: Network = match env::args().skip(arg_idx).next().as_ref().map(String::as_str) {
+		Some("testnet") => Network::Testnet,
+		Some("regtest") => Network::Regtest,
+		Some("signet") => Network::Signet,
+		Some(net) => {
+			panic!("Unsupported network provided. Options are: `regtest`, `testnet`, and `signet`. Got {}", net);
+		}
+		None => Network::Testnet,
+	};
+
+	let (bitcoind_rpc_username, bitcoind_rpc_password) = if bitcoind_rpc_info_parts.len() == 1 {
+		get_rpc_auth_from_cookie(None, Some(network), None)
+			.or(get_rpc_auth_from_env_file(None))
+			.or(get_rpc_auth_from_env_vars())
+			.or({
+				println!("ERROR: unable to get bitcoind RPC username and password");
+				print_rpc_auth_help();
+				Err(())
+			})?
+	} else if bitcoind_rpc_info_parts.len() == 2 {
+		parse_rpc_auth(bitcoind_rpc_info_parts[1])?
+	} else {
+		println!("ERROR: bad bitcoind RPC URL provided");
+		return Err(());
+	};
+
+	let ldk_announced_node_name = match env::args().skip(arg_idx + 1).next().as_ref() {
+		Some(s) => {
+			if s.len() > 32 {
+				panic!("Node Alias can not be longer than 32 bytes");
+			}
+			arg_idx += 1;
+			let mut bytes = [0; 32];
+			bytes[..s.len()].copy_from_slice(s.as_bytes());
+			bytes
+		}
+		None => [0; 32],
+	};
+
+	let mut ldk_announced_listen_addr = Vec::new();
+	loop {
+		match env::args().skip(arg_idx + 1).next().as_ref() {
+			Some(s) => match IpAddr::from_str(s) {
+				Ok(IpAddr::V4(a)) => {
+					ldk_announced_listen_addr
+						.push(NetAddress::IPv4 { addr: a.octets(), port: ldk_peer_listening_port });
+					arg_idx += 1;
+				}
+				Ok(IpAddr::V6(a)) => {
+					ldk_announced_listen_addr
+						.push(NetAddress::IPv6 { addr: a.octets(), port: ldk_peer_listening_port });
+					arg_idx += 1;
+				}
+				Err(_) => panic!("Failed to parse announced-listen-addr into an IP address"),
+			},
+			None => break,
+		}
+	}
+
+	Ok(LdkUserInfo {
+		bitcoind_rpc_username,
+		bitcoind_rpc_password,
+		bitcoind_rpc_host,
+		bitcoind_rpc_port,
+		ldk_storage_dir_path,
+		ldk_peer_listening_port,
+		ldk_announced_listen_addr,
+		ldk_announced_node_name,
+		network,
+	})
+}
+
+// Default datadir relative to home directory
+#[cfg(target_os = "windows")]
+const DEFAULT_BITCOIN_DATADIR: &str = "AppData/Roaming/Bitcoin";
+#[cfg(target_os = "linux")]
+const DEFAULT_BITCOIN_DATADIR: &str = ".bitcoin";
+#[cfg(target_os = "macos")]
+const DEFAULT_BITCOIN_DATADIR: &str = "Library/Application Support/Bitcoin";
+
+// Environment variable/.env keys
+const BITCOIND_RPC_USER_KEY: &str = "RPC_USER";
+const BITCOIND_RPC_PASSWORD_KEY: &str = "RPC_PASSWORD";
+
+fn print_rpc_auth_help() {
+	// Get the default data directory
+	let home_dir = env::home_dir()
+		.as_ref()
+		.map(|ref p| p.to_str())
+		.flatten()
+		.unwrap_or("$HOME")
+		.replace("\\", "/");
+	let data_dir = format!("{}/{}", home_dir, DEFAULT_BITCOIN_DATADIR);
+	println!("To provide the bitcoind RPC username and password, you can either:");
+	println!(
+		"1. Provide the username and password as the first argument to this program in the format: \
+		<bitcoind-rpc-username>:<bitcoind-rpc-password>@<bitcoind-rpc-host>:<bitcoind-rpc-port>"
+	);
+	println!("2. Provide <bitcoind-rpc-username>:<bitcoind-rpc-password> in a .cookie file in the default \
+		bitcoind data directory (automatically created by bitcoind on startup): `{}`", data_dir);
+	println!(
+		"3. Set the {} and {} environment variables",
+		BITCOIND_RPC_USER_KEY, BITCOIND_RPC_PASSWORD_KEY
+	);
+	println!(
+		"4. Provide {} and {} fields in a .env file in the current directory",
+		BITCOIND_RPC_USER_KEY, BITCOIND_RPC_PASSWORD_KEY
+	);
+}
+
+fn parse_rpc_auth(rpc_auth: &str) -> Result<(String, String), ()> {
+	let rpc_auth_info: Vec<&str> = rpc_auth.split(':').collect();
+	if rpc_auth_info.len() != 2 {
+		println!("ERROR: bad bitcoind RPC username/password combo provided");
+		return Err(());
+	}
+	let rpc_username = rpc_auth_info[0].to_string();
+	let rpc_password = rpc_auth_info[1].to_string();
+	Ok((rpc_username, rpc_password))
+}
+
+fn get_cookie_path(
+	data_dir: Option<(&str, bool)>, network: Option<Network>, cookie_file_name: Option<&str>,
+) -> Result<PathBuf, ()> {
+	let data_dir_path = match data_dir {
+		Some((dir, true)) => env::home_dir().ok_or(())?.join(dir),
+		Some((dir, false)) => PathBuf::from(dir),
+		None => env::home_dir().ok_or(())?.join(DEFAULT_BITCOIN_DATADIR),
+	};
+
+	let data_dir_path_with_net = match network {
+		Some(Network::Testnet) => data_dir_path.join("testnet"),
+		Some(Network::Regtest) => data_dir_path.join("regtest"),
+		Some(Network::Signet) => data_dir_path.join("signet"),
+		_ => data_dir_path,
+	};
+
+	let cookie_path = data_dir_path_with_net.join(cookie_file_name.unwrap_or(".cookie"));
+
+	Ok(cookie_path)
+}
+
+fn get_rpc_auth_from_cookie(
+	data_dir: Option<(&str, bool)>, network: Option<Network>, cookie_file_name: Option<&str>,
+) -> Result<(String, String), ()> {
+	let cookie_path = get_cookie_path(data_dir, network, cookie_file_name)?;
+	let cookie_contents = fs::read_to_string(cookie_path).or(Err(()))?;
+	parse_rpc_auth(&cookie_contents)
+}
+
+fn get_rpc_auth_from_env_vars() -> Result<(String, String), ()> {
+	if let (Ok(username), Ok(password)) =
+		(env::var(BITCOIND_RPC_USER_KEY), env::var(BITCOIND_RPC_PASSWORD_KEY))
+	{
+		Ok((username, password))
+	} else {
+		Err(())
+	}
+}
+
+fn get_rpc_auth_from_env_file(env_file_name: Option<&str>) -> Result<(String, String), ()> {
+	let env_file_map = parse_env_file(env_file_name)?;
+	if let (Some(username), Some(password)) =
+		(env_file_map.get(BITCOIND_RPC_USER_KEY), env_file_map.get(BITCOIND_RPC_PASSWORD_KEY))
+	{
+		Ok((username.to_string(), password.to_string()))
+	} else {
+		Err(())
+	}
+}
+
+fn parse_env_file(env_file_name: Option<&str>) -> Result<HashMap<String, String>, ()> {
+	// Default .env file name is .env
+	let env_file_name = match env_file_name {
+		Some(filename) => filename,
+		None => ".env",
+	};
+
+	// Read .env file
+	let env_file_path = Path::new(env_file_name);
+	let env_file_contents = fs::read_to_string(env_file_path).or(Err(()))?;
+
+	// Collect key-value pairs from .env file into a map
+	let mut env_file_map: HashMap<String, String> = HashMap::new();
+	for line in env_file_contents.lines() {
+		let line_parts: Vec<&str> = line.splitn(2, '=').collect();
+		if line_parts.len() != 2 {
+			println!("ERROR: bad .env file format");
+			return Err(());
+		}
+		env_file_map.insert(line_parts[0].to_string(), line_parts[1].to_string());
+	}
+
+	Ok(env_file_map)
+}
+
+#[cfg(test)]
+mod rpc_auth_tests {
+	use super::*;
+
+	const TEST_ENV_FILE: &str = "test_data/test_env_file";
+	const TEST_ENV_FILE_BAD: &str = "test_data/test_env_file_bad";
+	const TEST_ABSENT_FILE: &str = "nonexistent_file";
+	const TEST_DATA_DIR: &str = "test_data";
+	const TEST_COOKIE: &str = "test_cookie";
+	const TEST_COOKIE_BAD: &str = "test_cookie_bad";
+	const EXPECTED_USER: &str = "testuser";
+	const EXPECTED_PASSWORD: &str = "testpassword";
+
+	#[test]
+	fn test_parse_rpc_auth_success() {
+		let (username, password) = parse_rpc_auth("testuser:testpassword").unwrap();
+		assert_eq!(username, EXPECTED_USER);
+		assert_eq!(password, EXPECTED_PASSWORD);
+	}
+
+	#[test]
+	fn test_parse_rpc_auth_fail() {
+		let result = parse_rpc_auth("testuser");
+		assert!(result.is_err());
+	}
+
+	#[test]
+	fn test_get_cookie_path_success() {
+		let test_cases = vec![
+			(
+				None,
+				None,
+				None,
+				env::home_dir().unwrap().join(DEFAULT_BITCOIN_DATADIR).join(".cookie"),
+			),
+			(
+				Some((TEST_DATA_DIR, true)),
+				Some(Network::Testnet),
+				None,
+				env::home_dir().unwrap().join(TEST_DATA_DIR).join("testnet").join(".cookie"),
+			),
+			(
+				Some((TEST_DATA_DIR, false)),
+				Some(Network::Regtest),
+				Some(TEST_COOKIE),
+				PathBuf::from(TEST_DATA_DIR).join("regtest").join(TEST_COOKIE),
+			),
+			(
+				Some((TEST_DATA_DIR, false)),
+				Some(Network::Signet),
+				None,
+				PathBuf::from(TEST_DATA_DIR).join("signet").join(".cookie"),
+			),
+			(
+				Some((TEST_DATA_DIR, false)),
+				Some(Network::Bitcoin),
+				None,
+				PathBuf::from(TEST_DATA_DIR).join(".cookie"),
+			),
+		];
+
+		for (data_dir, network, cookie_file, expected_path) in test_cases {
+			let path = get_cookie_path(data_dir, network, cookie_file).unwrap();
+			assert_eq!(path, expected_path);
+		}
+	}
+
+	#[test]
+	fn test_get_rpc_auth_from_cookie_success() {
+		let (username, password) = get_rpc_auth_from_cookie(
+			Some((TEST_DATA_DIR, false)),
+			Some(Network::Bitcoin),
+			Some(TEST_COOKIE),
+		)
+		.unwrap();
+		assert_eq!(username, EXPECTED_USER);
+		assert_eq!(password, EXPECTED_PASSWORD);
+	}
+
+	#[test]
+	fn test_get_rpc_auth_from_cookie_fail() {
+		let result = get_rpc_auth_from_cookie(
+			Some((TEST_DATA_DIR, false)),
+			Some(Network::Bitcoin),
+			Some(TEST_COOKIE_BAD),
+		);
+		assert!(result.is_err());
+	}
+
+	#[test]
+	fn test_parse_env_file_success() {
+		let env_file_map = parse_env_file(Some(TEST_ENV_FILE)).unwrap();
+		assert_eq!(env_file_map.get(BITCOIND_RPC_USER_KEY).unwrap(), EXPECTED_USER);
+		assert_eq!(env_file_map.get(BITCOIND_RPC_PASSWORD_KEY).unwrap(), EXPECTED_PASSWORD);
+	}
+
+	#[test]
+	fn test_parse_env_file_fail() {
+		let env_file_map = parse_env_file(Some(TEST_ENV_FILE_BAD));
+		assert!(env_file_map.is_err());
+
+		// Make sure the test file doesn't exist
+		assert!(!Path::new(TEST_ABSENT_FILE).exists());
+		let env_file_map = parse_env_file(Some(TEST_ABSENT_FILE));
+		assert!(env_file_map.is_err());
+	}
+
+	#[test]
+	fn test_get_rpc_auth_from_env_file_success() {
+		let (username, password) = get_rpc_auth_from_env_file(Some(TEST_ENV_FILE)).unwrap();
+		assert_eq!(username, EXPECTED_USER);
+		assert_eq!(password, EXPECTED_PASSWORD);
+	}
+
+	#[test]
+	fn test_get_rpc_auth_from_env_file_fail() {
+		let rpc_user_and_password = get_rpc_auth_from_env_file(Some(TEST_ABSENT_FILE));
+		assert!(rpc_user_and_password.is_err());
+	}
+
+	#[test]
+	fn test_get_rpc_auth_from_env_vars_success() {
+		env::set_var(BITCOIND_RPC_USER_KEY, EXPECTED_USER);
+		env::set_var(BITCOIND_RPC_PASSWORD_KEY, EXPECTED_PASSWORD);
+		let (username, password) = get_rpc_auth_from_env_vars().unwrap();
+		assert_eq!(username, EXPECTED_USER);
+		assert_eq!(password, EXPECTED_PASSWORD);
+	}
+}

src/cli.rs

@@ -21,7 +21,7 @@ use lightning_invoice::{utils, Currency, Invoice};
 use std::env;
 use std::io;
 use std::io::Write;
-use std::net::{IpAddr, SocketAddr, ToSocketAddrs};
+use std::net::{SocketAddr, ToSocketAddrs};
 use std::ops::Deref;
 use std::path::Path;
 use std::str::FromStr;
@@ -40,107 +40,6 @@ pub(crate) struct LdkUserInfo {
 	pub(crate) network: Network,
 }
 
-pub(crate) fn parse_startup_args() -> Result<LdkUserInfo, ()> {
-	if env::args().len() < 3 {
-		println!("ldk-tutorial-node requires 3 arguments: `cargo run <bitcoind-rpc-username>:<bitcoind-rpc-password>@<bitcoind-rpc-host>:<bitcoind-rpc-port> ldk_storage_directory_path [<ldk-incoming-peer-listening-port>] [bitcoin-network] [announced-node-name announced-listen-addr*]`");
-		return Err(());
-	}
-	let bitcoind_rpc_info = env::args().skip(1).next().unwrap();
-	let bitcoind_rpc_info_parts: Vec<&str> = bitcoind_rpc_info.rsplitn(2, "@").collect();
-	if bitcoind_rpc_info_parts.len() != 2 {
-		println!("ERROR: bad bitcoind RPC URL provided");
-		return Err(());
-	}
-	let rpc_user_and_password: Vec<&str> = bitcoind_rpc_info_parts[1].split(":").collect();
-	if rpc_user_and_password.len() != 2 {
-		println!("ERROR: bad bitcoind RPC username/password combo provided");
-		return Err(());
-	}
-	let bitcoind_rpc_username = rpc_user_and_password[0].to_string();
-	let bitcoind_rpc_password = rpc_user_and_password[1].to_string();
-	let bitcoind_rpc_path: Vec<&str> = bitcoind_rpc_info_parts[0].split(":").collect();
-	if bitcoind_rpc_path.len() != 2 {
-		println!("ERROR: bad bitcoind RPC path provided");
-		return Err(());
-	}
-	let bitcoind_rpc_host = bitcoind_rpc_path[0].to_string();
-	let bitcoind_rpc_port = bitcoind_rpc_path[1].parse::<u16>().unwrap();
-
-	let ldk_storage_dir_path = env::args().skip(2).next().unwrap();
-
-	let mut ldk_peer_port_set = true;
-	let ldk_peer_listening_port: u16 = match env::args().skip(3).next().map(|p| p.parse()) {
-		Some(Ok(p)) => p,
-		Some(Err(_)) => {
-			ldk_peer_port_set = false;
-			9735
-		}
-		None => {
-			ldk_peer_port_set = false;
-			9735
-		}
-	};
-
-	let mut arg_idx = match ldk_peer_port_set {
-		true => 4,
-		false => 3,
-	};
-	let network: Network = match env::args().skip(arg_idx).next().as_ref().map(String::as_str) {
-		Some("testnet") => Network::Testnet,
-		Some("regtest") => Network::Regtest,
-		Some("signet") => Network::Signet,
-		Some(net) => {
-			panic!("Unsupported network provided. Options are: `regtest`, `testnet`, and `signet`. Got {}", net);
-		}
-		None => Network::Testnet,
-	};
-
-	let ldk_announced_node_name = match env::args().skip(arg_idx + 1).next().as_ref() {
-		Some(s) => {
-			if s.len() > 32 {
-				panic!("Node Alias can not be longer than 32 bytes");
-			}
-			arg_idx += 1;
-			let mut bytes = [0; 32];
-			bytes[..s.len()].copy_from_slice(s.as_bytes());
-			bytes
-		}
-		None => [0; 32],
-	};
-
-	let mut ldk_announced_listen_addr = Vec::new();
-	loop {
-		match env::args().skip(arg_idx + 1).next().as_ref() {
-			Some(s) => match IpAddr::from_str(s) {
-				Ok(IpAddr::V4(a)) => {
-					ldk_announced_listen_addr
-						.push(NetAddress::IPv4 { addr: a.octets(), port: ldk_peer_listening_port });
-					arg_idx += 1;
-				}
-				Ok(IpAddr::V6(a)) => {
-					ldk_announced_listen_addr
-						.push(NetAddress::IPv6 { addr: a.octets(), port: ldk_peer_listening_port });
-					arg_idx += 1;
-				}
-				Err(_) => panic!("Failed to parse announced-listen-addr into an IP address"),
-			},
-			None => break,
-		}
-	}
-
-	Ok(LdkUserInfo {
-		bitcoind_rpc_username,
-		bitcoind_rpc_password,
-		bitcoind_rpc_host,
-		bitcoind_rpc_port,
-		ldk_storage_dir_path,
-		ldk_peer_listening_port,
-		ldk_announced_listen_addr,
-		ldk_announced_node_name,
-		network,
-	})
-}
-
 struct UserOnionMessageContents {
 	tlv_type: u64,
 	data: Vec<u8>,

src/main.rs

@@ -1,3 +1,4 @@
+mod args;
 pub mod bitcoind_client;
 mod cli;
 mod convert;
@@ -358,7 +359,7 @@ async fn handle_ldk_events(
 }
 
 async fn start_ldk() {
-	let args = match cli::parse_startup_args() {
+	let args = match args::parse_startup_args() {
 		Ok(user_args) => user_args,
 		Err(()) => return,
 	};

test_data/test_cookie

@@ -0,0 +1 @@
+testuser:testpassword

test_data/test_cookie_bad

@@ -0,0 +1 @@
+testuser

test_data/test_env_file

@@ -0,0 +1,2 @@
+RPC_USER=testuser
+RPC_PASSWORD=testpassword

test_data/test_env_file_bad

@@ -0,0 +1,2 @@
+RPC_USER=testuser
+RPC_PASSWORD