qr-login: add a --image argument for providing an image to scan for the QR code (#381)

closes #380

Cargo.toml

@@ -55,7 +55,7 @@ uuid = { version = "0.8", features = ["v4"] }
 steamguard = { version = "^0.13.0", path = "./steamguard" }
 dirs = "3.0.2"
 aes = { version = "0.8.3", features = ["zeroize"] }
-thiserror = "1.0.26"
+thiserror = "1.0.61"
 crossterm = { version = "0.23.2", features = ["event-stream"] }
 qrcode = { version = "0.12.0", optional = true }
 gethostname = "0.4.3"
@@ -73,6 +73,8 @@ argon2 = { version = "0.5.0", features = ["std", "zeroize"] }
 pbkdf2 = { version = "0.12.1", features = ["parallel"] }
 sha1 = "0.10.5"
 rayon = "1.7.0"
+rqrr = "0.7.1"
+image = "0.25"
 
 [dev-dependencies]
 tempfile = "3"

src/accountmanager.rs

@@ -339,8 +339,9 @@ impl AccountManager {
 			debug!("Adding missing account names");
 			for i in 0..self.manifest.entries.len() {
 				let account = self.load_account_by_entry(&self.manifest.entries[i].clone())?;
-				self.manifest.entries[i].account_name =
-					account.lock().unwrap().account_name.clone();
+				self.manifest.entries[i]
+					.account_name
+					.clone_from(&account.lock().unwrap().account_name);
 			}
 			upgraded = true;
 		}

src/commands/qr_login.rs

@@ -1,6 +1,10 @@
-use std::sync::{Arc, Mutex};
+use std::{
+	path::{Path, PathBuf},
+	sync::{Arc, Mutex},
+};
 
 use log::*;
+use rqrr::PreparedImage;
 use steamguard::{QrApprover, QrApproverError};
 
 use crate::AccountManager;
@@ -10,11 +14,8 @@ use super::*;
 #[derive(Debug, Clone, Parser)]
 #[clap(about = "Log in to Steam on another device using the QR code that it's displaying.")]
 pub struct QrLoginCommand {
-	#[clap(
-		long,
-		help = "The URL that would normally open in the Steam app. This is the URL that the QR code is displaying. It should start with \"https://s.team/...\""
-	)]
-	pub url: String,
+	#[clap(flatten)]
+	login_url_source: LoginUrlSource,
 }
 
 impl<T> AccountCommand<T> for QrLoginCommand
@@ -32,6 +33,11 @@ where
 			accounts.len() == 1,
 			"You can only log in to one account at a time."
 		);
+		// FIXME: in clap v4, this constraint can be expressed as a arg group: https://stackoverflow.com/questions/76315540/how-do-i-require-one-of-the-two-clap-options
+		ensure!(
+			self.login_url_source.url.is_some() || self.login_url_source.image.is_some(),
+			"You must provide either a URL with --url or an image file with --image."
+		);
 
 		let mut account = accounts[0].lock().unwrap();
 
@@ -41,6 +47,8 @@ where
 			crate::do_login(transport.clone(), &mut account, args.password.clone())?;
 		}
 
+		let url = self.login_url_source.url()?;
+		debug!("Using login URL to approve: {}", url);
 		loop {
 			let Some(tokens) = account.tokens.as_ref() else {
 				error!(
@@ -51,7 +59,7 @@ where
 			};
 
 			let mut approver = QrApprover::new(transport.clone(), tokens);
-			match approver.approve(&account, &self.url) {
+			match approver.approve(&account, url.to_owned()) {
 				Ok(_) => {
 					info!("Login approved.");
 					break;
@@ -70,3 +78,55 @@ where
 		Ok(())
 	}
 }
+
+#[derive(Debug, Clone, clap::Args)]
+pub struct LoginUrlSource {
+	/// The URL that would normally open in the Steam app. This is the URL that the QR code is displaying. It should start with \"https://s.team/...\"
+	#[clap(long)]
+	url: Option<String>,
+	/// Path to an image file containing the QR code. The QR code will be scanned from this image.
+	#[clap(long)]
+	image: Option<PathBuf>,
+}
+
+impl LoginUrlSource {
+	fn url(&self) -> anyhow::Result<String> {
+		match self {
+			Self { url: Some(url), .. } => Ok(url.clone()),
+			Self {
+				image: Some(path), ..
+			} => read_qr_image(path),
+			_ => Err(anyhow!(
+				"You must provide either a URL with --url or an image file with --image."
+			)),
+		}
+	}
+}
+
+fn read_qr_image(path: &Path) -> anyhow::Result<String> {
+	use image::io::Reader as ImageReader;
+	let image = ImageReader::open(path)?.decode()?.to_luma8();
+	let mut img = PreparedImage::prepare(image);
+	let grids = img.detect_grids();
+	for grid in grids {
+		let (_meta, text) = grid.decode()?;
+		// a rough validation that the QR code is a Steam login code
+		if text.contains("s.team") {
+			return Ok(text);
+		}
+	}
+	Err(anyhow!("No Steam login url found in the QR code"))
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use std::path::Path;
+
+	#[test]
+	fn test_read_qr_image() {
+		let path = Path::new("src/fixtures/qr-codes/login-qr.png");
+		let url = read_qr_image(path).unwrap();
+		assert_eq!(url, "https://s.team/q/1/2372462679780599330");
+	}
+}