add --offline flag for generating codes, closes #155

src/cli.rs

@@ -32,6 +32,12 @@ pub(crate) struct Args {
 	#[clap(short, long, arg_enum, default_value_t=Verbosity::Info, help = "Set the log level. Be warned, trace is capable of printing sensitive data.")]
 	pub verbosity: Verbosity,
 
+	#[clap(
+		long,
+		help = "Assume the computer's time is correct. Don't ask Steam for the time when generating codes."
+	)]
+	pub offline: bool,
+
 	#[clap(subcommand)]
 	pub sub: Option<Subcommands>,
 }
@@ -143,3 +149,23 @@ pub(crate) struct ArgsEncrypt;
 #[derive(Debug, Clone, Parser)]
 #[clap(about = "Decrypt all maFiles")]
 pub(crate) struct ArgsDecrypt;
+
+#[derive(Debug, Clone, Parser)]
+#[clap(about = "Generate 2FA codes")]
+pub(crate) struct ArgsCode {
+	#[clap(
+		long,
+		help = "Assume the computer's time is correct. Don't ask Steam for the time when generating codes."
+	)]
+	pub offline: bool,
+}
+
+// HACK: the derive API doesn't support default subcommands, so we are going to make it so that it'll be easier to switch over when it's implemented.
+// See: https://github.com/clap-rs/clap/issues/3857
+impl From<Args> for ArgsCode {
+	fn from(args: Args) -> Self {
+		ArgsCode {
+			offline: args.offline,
+		}
+	}
+}

src/main.rs

@@ -1,6 +1,7 @@
 extern crate rpassword;
 use clap::{IntoApp, Parser};
 use log::*;
+use std::time::{SystemTime, UNIX_EPOCH};
 use std::{
 	io::{stdout, Write},
 	path::Path,
@@ -180,7 +181,7 @@ fn run() -> anyhow::Result<()> {
 		}
 		_ => {
 			debug!("No subcommand given, assuming user wants a 2fa code");
-			return do_subcmd_code(selected_accounts);
+			return do_subcmd_code(args.into(), selected_accounts);
 		}
 	}
 }
@@ -662,8 +663,15 @@ fn do_subcmd_decrypt(
 	return Ok(());
 }
 
-fn do_subcmd_code(selected_accounts: Vec<Arc<Mutex<SteamGuardAccount>>>) -> anyhow::Result<()> {
-	let server_time = steamapi::get_server_time()?.server_time;
+fn do_subcmd_code(
+	args: cli::ArgsCode,
+	selected_accounts: Vec<Arc<Mutex<SteamGuardAccount>>>,
+) -> anyhow::Result<()> {
+	let server_time = if args.offline {
+		SystemTime::now().duration_since(UNIX_EPOCH)?.as_secs()
+	} else {
+		steamapi::get_server_time()?.server_time
+	};
 	debug!("Time used to generate codes: {}", server_time);
 	for account in selected_accounts {
 		info!(