Show why the extension failed to start

* Rename the Installer app to Firewall

* Name the app Strix Firewall

* Name the app StrixFirewall

core/src/main.rs

@@ -12,6 +12,10 @@ fn main() {
         firewall::init_logging("info");
         serve()
     }
+    if matches.subcommand_matches("uninstall").is_some() {
+        firewall::init_logging("info");
+        uninstall()
+    }
     let mut command = matches.get_many::<String>("COMMAND").unwrap().cloned();
     let program = command.next().unwrap();
     firewall::init_logging("warn");
@@ -40,6 +44,8 @@ fn options() -> Command {
             Command::new("serve")
                 .about("Serve a local registry for package managers configured to use it"),
         )
+        // Run as root by the macOS app's uninstall.
+        .subcommand(Command::new("uninstall").hide(true))
         .arg(
             Arg::new("COMMAND")
                 .help("A command to run with its package downloads screened")
@@ -69,6 +75,13 @@ fn serve() -> ! {
     }
 }
 
+fn uninstall() -> ! {
+    match firewall::os::uninstall() {
+        Ok(()) => exit(0),
+        Err(e) => fail("uninstall", &format!("could not uninstall: {e}")),
+    }
+}
+
 fn run(invocation: Invocation) -> ! {
     let command = &invocation.program;
     let port = match aliasing::spawn(0, load()) {

core/src/mitm/ca.rs

@@ -60,10 +60,12 @@ pub fn crl(hosts: &[&str], signer: &dyn SigningKey) -> Result<Vec<u8>, BoxError>
     Ok(list.signed_by(&Issuer::from_params(&ca, signer))?.der().to_vec())
 }
 
+pub const COMMON_NAME: &str = "Strix Firewall";
+
 /// Also used by the issuer, whose issuer name must match the CA's subject.
 pub fn params(hosts: &[&str]) -> CertificateParams {
     let mut name = DistinguishedName::new();
-    name.push(DnType::CommonName, "Strix Firewall");
+    name.push(DnType::CommonName, COMMON_NAME);
     name.push(DnType::OrganizationName, "Strix");
 
     let mut params = CertificateParams::default();

core/src/mitm/mod.rs

@@ -3,7 +3,7 @@ mod issuer;
 mod route;
 mod screen;
 
-pub use ca::{crl, CaSigner, CertificateAuthority};
+pub use ca::{crl, CaSigner, CertificateAuthority, COMMON_NAME};
 
 use crate::Firewall;
 use issuer::ConstrainedCertIssuer;

core/src/os/macos/mod.rs

@@ -2,6 +2,8 @@ mod enclave;
 mod install;
 mod uninstall;
 
+pub use uninstall::uninstall;
+
 use crate::config::FirewallConfig;
 use crate::{mitm, telemetry};
 use crate::Firewall;
@@ -49,15 +51,11 @@ impl TransparentProxyHandler for Handler {
         TransparentProxyConfig::new().with_rules(vec![tcp_rule(80), tcp_rule(443)])
     }
 
-    /// Setup requests from the installer. Never empty: Swift cannot tell that from no reply.
+    /// Setup requests from the app. Never empty: Swift cannot tell that from no reply.
     async fn handle_app_message(&self, _exec: Executor, message: Bytes) -> Option<Bytes> {
         let message = String::from_utf8_lossy(&message).into_owned();
         Some(Bytes::from(match message.as_str() {
             "ca" => self.ca.pem.clone(),
-            "uninstall" => match uninstall::certificate_authority(&self.ca) {
-                Ok(()) => "ok".to_owned(),
-                Err(error) => format!("error: {error}"),
-            },
             other => format!("error: unknown message {other}"),
         }))
     }

core/src/os/macos/uninstall.rs

@@ -1,26 +1,47 @@
 use super::enclave::EnclaveKey;
 use super::{CA_FILE, KEYCHAIN_ACCOUNT, KEYCHAIN_SERVICE};
-use crate::mitm::CertificateAuthority;
+use crate::mitm::COMMON_NAME;
 use rama::error::BoxError;
 use rama::net::apple::networkextension::system_keychain;
+use security_framework::item::{ItemClass, ItemSearchOptions, Limit};
+use security_framework::os::macos::keychain::SecKeychain;
+use security_framework_sys::base::errSecItemNotFound;
 use std::io::ErrorKind;
 use tracing::info;
 
 /// Installed by the pkg.
 const ENV_AGENT: &str = "/Library/LaunchAgents/com.usestrix.firewall.env.plist";
 
-/// Removes what only root can: the CA, its enclave key and exported copy, and the env
+/// Removes what only root can: every CA the extension minted, its enclave key and exported
-/// agent. Trust settings need an authorization dialog, so the installer drops those itself.
+/// copy, and the env agent. Trust settings need an authorization dialog, so the app drops those.
-pub fn certificate_authority(ca: &CertificateAuthority) -> Result<(), BoxError> {
+pub fn uninstall() -> Result<(), BoxError> {
-    system_keychain::uninstall_system_ca(&ca.crt.to_der()?)?;
+    let deleted = ItemSearchOptions::new()
+        .class(ItemClass::certificate())
+        .keychains(&[SecKeychain::open("/Library/Keychains/System.keychain")?])
+        .label(COMMON_NAME)
+        .limit(Limit::All)
+        .delete();
+    let mut removed = match deleted {
+        Ok(()) => true,
+        Err(error) if error.code() == errSecItemNotFound => false,
+        Err(error) => return Err(error.into()),
+    };
+    if system_keychain::load_secret(KEYCHAIN_SERVICE, KEYCHAIN_ACCOUNT)?.is_some() {
         system_keychain::delete_secret(KEYCHAIN_SERVICE, KEYCHAIN_ACCOUNT)?;
+        removed = true;
+    }
     EnclaveKey::delete()?;
     for path in [CA_FILE, ENV_AGENT] {
         match std::fs::remove_file(path) {
-            Err(error) if error.kind() != ErrorKind::NotFound => return Err(error.into()),
+            Ok(()) => removed = true,
-            _ => {}
+            Err(error) if error.kind() == ErrorKind::NotFound => {}
+            Err(error) => return Err(error.into()),
         }
     }
+    if removed {
         info!("removed the CA from the system keychain");
+    } else {
+        info!("nothing to uninstall");
+    }
     Ok(())
 }

core/src/os/mod.rs

@@ -1,2 +1,11 @@
 #[cfg(target_os = "macos")]
 pub mod macos;
+
+#[cfg(target_os = "macos")]
+pub use macos::uninstall;
+
+/// Elsewhere nothing is installed system-wide.
+#[cfg(not(target_os = "macos"))]
+pub fn uninstall() -> Result<(), rama::error::BoxError> {
+    Ok(())
+}

macos/.gitignore

@@ -3,5 +3,5 @@ Firewall.xcodeproj
 .env
 Extension/Extension.entitlements
 Extension/Info.plist
-Installer/Installer.entitlements
+App/App.entitlements
-Installer/Info.plist
+App/Info.plist

macos/App/ContentView.swift

@@ -1,7 +1,7 @@
 import SwiftUI
 
 struct ContentView: View {
-    @ObservedObject var model: InstallerModel
+    @ObservedObject var model: FirewallModel
     @Environment(\.dismiss) private var dismiss
 
     var body: some View {

macos/App/FirewallApp.swift

@@ -1,8 +1,8 @@
 import SwiftUI
 
 @main
-struct InstallerApp: App {
+struct FirewallApp: App {
-    @StateObject private var model = InstallerModel()
+    @StateObject private var model = FirewallModel()
 
     var body: some Scene {
         MenuBarExtra {
@@ -31,7 +31,7 @@ enum SetupWindow {
 
 /// An accessory app restores no windows, so setup is raised from the label, the one view built at launch.
 private struct MenuBarLabel: View {
-    @ObservedObject var model: InstallerModel
+    @ObservedObject var model: FirewallModel
     @Environment(\.openWindow) private var openWindow
     @State private var raised = false
 

macos/App/FirewallModel.swift

@@ -23,22 +23,23 @@ enum StepStatus: Equatable {
     }
 }
 
-enum InstallerError: Error, LocalizedError {
+enum FirewallError: Error, LocalizedError {
     case extensionUnavailable
-    case extensionRefused(String)
     case screeningDidNotStart(NEVPNStatus)
+    case extensionStopped(String)
 
     var errorDescription: String? {
         switch self {
         case .extensionUnavailable: return "The extension is not running"
-        case let .extensionRefused(reply): return "The extension replied \(reply)"
         case let .screeningDidNotStart(status): return "Screening did not start (\(status.label))"
+        case let .extensionStopped(reason):
+            return "The extension stopped: \(reason). Its log: log show --last 5m --predicate 'subsystem BEGINSWITH \"\(FirewallIDs.appBundleID)\"'"
         }
     }
 }
 
 @MainActor
-final class InstallerModel: NSObject, ObservableObject {
+final class FirewallModel: NSObject, ObservableObject {
     @Published private(set) var extensionStep = StepStatus.pending
     @Published private(set) var screeningStep = StepStatus.pending
     @Published private(set) var trustStep = StepStatus.pending
@@ -124,9 +125,9 @@ final class InstallerModel: NSObject, ObservableObject {
             log("Uninstall cancelled")
             return
         }
-        // The extension owns the private key, so ask it before tearing down the session that carries the request.
+        // Stop screening first so the extension cannot mint a fresh CA after it is removed.
-        let strandedKey = await removeStoredCA()
         await removeConfiguration()
+        let strandedKey = removeStoredCA()
         await deactivate()
         if let strandedKey { trustStep = .failed(strandedKey) }
 
@@ -167,7 +168,7 @@ final class InstallerModel: NSObject, ObservableObject {
         }
     }
 
-    private func stage(_ step: ReferenceWritableKeyPath<InstallerModel, StepStatus>,
+    private func stage(_ step: ReferenceWritableKeyPath<FirewallModel, StepStatus>,
                        running: String,
                        work: @MainActor () async throws -> String) async -> Bool {
         self[keyPath: step] = .running(running)
@@ -245,17 +246,18 @@ final class InstallerModel: NSObject, ObservableObject {
         return true
     }
 
-    /// Only root can delete the key, so the extension does it; returns what to report if it survived.
+    /// The extension wrote these as root, so the bundled CLI removes them behind an admin prompt; returns what to report if it failed.
-    private func removeStoredCA() async -> String? {
+    private func removeStoredCA() -> String? {
-        do {
+        let cli = Bundle.main.path(forAuxiliaryExecutable: "firewall") ?? ""
-            let reply = try await providerMessage("uninstall")
+        let script = "do shell script quoted form of \"\(cli)\" & \" uninstall\" with administrator privileges"
-            guard reply == "ok" else { throw InstallerError.extensionRefused(reply) }
+        var error: NSDictionary?
-            log("Removed the CA, its exported copy and the env agent")
+        NSAppleScript(source: script)?.executeAndReturnError(&error)
-            return nil
+        if let error {
-        } catch {
+            log("Could not remove the CA: \(error[NSAppleScript.errorMessage] ?? error)")
-            log("Could not remove the CA: \(error.localizedDescription)")
             return "The CA private key is still in the System keychain"
         }
+        log("Removed the CA, its exported copy and the env agent")
+        return nil
     }
 
     // MARK: - System extension
@@ -295,16 +297,22 @@ final class InstallerModel: NSObject, ObservableObject {
         try await manager.loadFromPreferences()
         watched = manager
 
+        screeningStep = .running("Starting the extension")
         try manager.connection.startVPNTunnel()
         guard try await wait(for: .connected, on: manager.connection) else {
-            throw InstallerError.screeningDidNotStart(manager.connection.status)
+            do {
+                try await manager.connection.fetchLastDisconnectError()
+            } catch {
+                throw FirewallError.extensionStopped(error.localizedDescription)
+            }
+            throw FirewallError.screeningDidNotStart(manager.connection.status)
         }
         return "Screening package downloads"
     }
 
     private func restartScreening() async throws -> String {
         guard let manager = try await loadManager() else {
-            throw InstallerError.extensionUnavailable
+            throw FirewallError.extensionUnavailable
         }
         manager.connection.stopVPNTunnel()
         _ = try await wait(for: .disconnected, on: manager.connection)
@@ -312,7 +320,7 @@ final class InstallerModel: NSObject, ObservableObject {
     }
 
     private func stopScreening() async throws -> String {
-        guard let manager = try await loadManager() else { throw InstallerError.extensionUnavailable }
+        guard let manager = try await loadManager() else { throw FirewallError.extensionUnavailable }
         manager.isEnabled = false
         try await manager.saveToPreferences()
         manager.connection.stopVPNTunnel()
@@ -320,9 +328,13 @@ final class InstallerModel: NSObject, ObservableObject {
         return "Screening disabled"
     }
 
+    /// Gives up early once a start has failed, which shows as connecting then disconnected.
     private func wait(for status: NEVPNStatus, on connection: NEVPNConnection) async throws -> Bool {
+        var connecting = false
         for _ in 0 ..< 60 {
             if connection.status == status { return true }
+            if connection.status == .connecting { connecting = true }
+            if connecting && connection.status == .disconnected { return false }
             try await Task.sleep(nanoseconds: 250_000_000)
         }
         return false
@@ -358,13 +370,13 @@ final class InstallerModel: NSObject, ObservableObject {
 
     private func providerMessage(_ message: String) async throws -> String {
         guard let session = watched?.connection as? NETunnelProviderSession else {
-            throw InstallerError.extensionUnavailable
+            throw FirewallError.extensionUnavailable
         }
         return try await withCheckedThrowingContinuation { continuation in
             do {
                 try session.sendProviderMessage(Data(message.utf8)) { response in
                     guard let response, let reply = String(data: response, encoding: .utf8) else {
-                        continuation.resume(throwing: InstallerError.extensionUnavailable)
+                        continuation.resume(throwing: FirewallError.extensionUnavailable)
                         return
                     }
                     continuation.resume(returning: reply)
@@ -381,7 +393,7 @@ final class InstallerModel: NSObject, ObservableObject {
     }
 }
 
-extension InstallerModel: OSSystemExtensionRequestDelegate {
+extension FirewallModel: OSSystemExtensionRequestDelegate {
     nonisolated func request(_ request: OSSystemExtensionRequest,
                              actionForReplacingExtension existing: OSSystemExtensionProperties,
                              withExtension replacement: OSSystemExtensionProperties) -> OSSystemExtensionRequest.ReplacementAction {

macos/App/MenuBarView.swift

@@ -1,7 +1,7 @@
 import SwiftUI
 
 struct MenuBarView: View {
-    @ObservedObject var model: InstallerModel
+    @ObservedObject var model: FirewallModel
     @Environment(\.openWindow) private var openWindow
 
     var body: some View {
@@ -9,7 +9,7 @@ struct MenuBarView: View {
 
         Divider()
 
-        Button("Installer") {
+        Button("Setup") {
             SetupWindow.open(openWindow)
         }
 

macos/build.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-# Builds and signs Firewall.app, installs it to /Applications, and packages it as build/Firewall.pkg.
+# Builds and signs StrixFirewall.app, installs it to /Applications, and packages it as build/Firewall.pkg.
 # The package is notarized with the notarytool keychain profile in NOTARY_PROFILE; `build.sh debug`
 # makes a Debug build and skips notarization.
 #
@@ -32,7 +32,7 @@ VERSION=0.1
 INSTALLER_IDENTITY=${INSTALLER_IDENTITY:-Developer ID Installer}
 PROFILES="$HOME/Library/Developer/Xcode/UserData/Provisioning Profiles"
 
-APP=build/Build/Products/$CONFIGURATION/Installer.app
+APP=build/Build/Products/$CONFIGURATION/StrixFirewall.app
 EXT=$APP/Contents/Library/SystemExtensions/$EXT_ID.systemextension
 PKG_ROOT=build/pkg-root
 
@@ -47,7 +47,7 @@ main() {
 build() {
   echo "==> Building"
   xcodegen generate >/dev/null
-  xcodebuild -project Firewall.xcodeproj -scheme Installer -configuration $CONFIGURATION \
+  xcodebuild -project Firewall.xcodeproj -scheme StrixFirewall -configuration $CONFIGURATION \
     -derivedDataPath build CODE_SIGNING_ALLOWED=NO CODE_SIGNING_REQUIRED=NO \
     CODE_SIGN_IDENTITY="" CODE_SIGN_ENTITLEMENTS="" build >/dev/null
 }
@@ -56,18 +56,19 @@ sign() {
   echo "==> Signing with $IDENTITY"
   cp "$(profile_for $APP_ID)" "$APP/Contents/embedded.provisionprofile"
   cp "$(profile_for $EXT_ID)" "$EXT/Contents/embedded.provisionprofile"
+  codesign --force --options runtime --timestamp -s "$IDENTITY" "$APP/Contents/MacOS/firewall"
   codesign --force --options runtime --timestamp \
     --entitlements Extension/Extension.entitlements -s "$IDENTITY" "$EXT"
   codesign --force --options runtime --timestamp \
-    --entitlements Installer/Installer.entitlements -s "$IDENTITY" "$APP"
+    --entitlements App/App.entitlements -s "$IDENTITY" "$APP"
   codesign --verify --deep --strict "$APP"
 }
 
 # The extension can only be activated from /Applications.
 install_app() {
-  echo "==> Installing /Applications/Firewall.app"
+  echo "==> Installing /Applications/StrixFirewall.app"
-  rm -rf /Applications/Firewall.app
+  rm -rf /Applications/StrixFirewall.app
-  cp -R "$APP" /Applications/Firewall.app
+  cp -R "$APP" /Applications/StrixFirewall.app
 }
 
 # Marked non-relocatable so the installer never updates another copy with the same bundle id.
@@ -75,7 +76,7 @@ package() {
   echo "==> Packaging build/Firewall.pkg"
   rm -rf "$PKG_ROOT"
   mkdir -p "$PKG_ROOT/Applications" "$PKG_ROOT/Library/LaunchAgents"
-  cp -R "$APP" "$PKG_ROOT/Applications/Firewall.app"
+  cp -R "$APP" "$PKG_ROOT/Applications/StrixFirewall.app"
   cp LaunchAgents/com.usestrix.firewall.env.plist "$PKG_ROOT/Library/LaunchAgents/"
 
   pkgbuild --analyze --root "$PKG_ROOT" build/components.plist >/dev/null

macos/pkg/postinstall

@@ -6,5 +6,5 @@ uid=$(id -u "$user")
 agent=/Library/LaunchAgents/com.usestrix.firewall.env.plist
 launchctl bootout "gui/$uid" "$agent" 2>/dev/null
 launchctl bootstrap "gui/$uid" "$agent"
-launchctl asuser "$uid" sudo -u "$user" open -a /Applications/Firewall.app --args --install
+launchctl asuser "$uid" sudo -u "$user" open -a /Applications/StrixFirewall.app --args --install
 exit 0

macos/project.yml

@@ -87,25 +87,25 @@ targets:
               $([ "$CONFIGURATION" = Debug ] || echo --release)
           done
 
-  Installer:
+  StrixFirewall:
     type: application
     platform: macOS
     sources:
-      - Installer
+      - App
       - path: ../assets/logo-transparent.png
         buildPhase: resources
     settings:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: com.usestrix.firewall
     info:
-      path: Installer/Info.plist
+      path: App/Info.plist
       properties:
         CFBundleShortVersionString: "0.1"
         LSMinimumSystemVersion: $(MACOSX_DEPLOYMENT_TARGET)
         NSSystemExtensionUsageDescription: Firewall uses a network extension to screen package downloads before they install.
         LSUIElement: true
     entitlements:
-      path: Installer/Installer.entitlements
+      path: App/App.entitlements
       properties:
         com.apple.application-identifier: ${TEAM}.com.usestrix.firewall
         com.apple.developer.team-identifier: ${TEAM}
@@ -117,3 +117,14 @@ targets:
       - target: Extension
         embed: true
         codeSign: true
+    # Uninstall runs the CLI as root to remove what the extension left.
+    postBuildScripts:
+      - name: Embed the CLI
+        basedOnDependencyAnalysis: false
+        script: |
+          export PATH="$HOME/.cargo/bin:$PATH"
+          unset CC CXX CFLAGS CXXFLAGS
+          export SDKROOT="$(xcrun --sdk macosx --show-sdk-path)"
+          cd "$SRCROOT/../core"
+          cargo build --bin firewall --target aarch64-apple-darwin $([ "$CONFIGURATION" = Debug ] || echo --release)
+          cp "target/aarch64-apple-darwin/$CARGO_PROFILE/firewall" "$TARGET_BUILD_DIR/$EXECUTABLE_FOLDER_PATH/"