Blogpost Link

README.md

@@ -0,0 +1,93 @@
+# Strix's Dependency Firewall
+
+Stops malicious packages before they install. Built by [Strix](https://strix.ai/blog/firewall-announcement).
+
+Screening runs on your device: downloads go straight to the registry, never through a Strix server.
+Each package's name and version are looked up [Strix's malicious-package blocklist](https://github.com/usestrix/firewall-blocklist), so installs are blocked system-wide *before* reaching your machine.
+
+## Install
+
+**Machine-wide**, from the [latest release](https://github.com/usestrix/firewall/releases/latest):
+
+- macOS: open `Firewall.pkg`, then approve the extension when macOS asks.
+- Windows: run the `.msi` as an admin.
+
+**Prefix-mode**
+
+cargo:
+```sh
+cargo install strix-firewall
+```
+
+curl: 
+```sh
+curl -LsSf https://github.com/usestrix/firewall/releases/latest/download/strix-firewall-installer.sh | sh
+```
+
+Powershell:
+```powershell
+powershell -c "irm https://github.com/usestrix/firewall/releases/latest/download/strix-firewall-installer.ps1 | iex"
+```
+
+## Platforms
+
+| | Machine-wide | Command prefix |
+|---|---|---|
+| macOS 13+ | ✅ Apple silicon or T2 chip | ✅ |
+| Windows 10/11, x86-64 | ✅ with a TPM 2.0 | ✅ |
+| Linux (glibc 2.35+), x86-64 or arm64 | 🚧 Coming Soon | ✅ |
+
+## Supported registries
+
+| Registry | Package managers |
+|---|---|
+| npm | npm, pnpm, bun |
+| PyPI | pip, uv, pdm, pipenv |
+| crates.io | cargo |
+| Go module proxy | go |
+| RubyGems | gem |
+
+Mirrors of these, such as Artifactory or Nexus, can be added in via a config file.
+
+## Features
+
+- **Up-to-the-minute data:** Strix constantly monitors updates to top packages (covering 99% of installed packages) to scan for malware, and publishes the results. We also consult [OSSF's blocklist](https://github.com/ossf/malicious-packages) and [OSV](osv.dev), as well as other public reports. Updates take effect without any user action.
+- **Holds back new versions.** New packages are blocked by default, since malware is usually detected within a day. (Although this can be disabled, configured, and bypassed).
+- **Alerts you.** On macOS and Windows a popup names the blocked package and links its advisory.
+- **Two modes:**
+  - **Machine-wide:** screens downloads from every app, across your entire machine.
+  - **Command prefix:** e.g., `firewall npm install left-pad`, or create an alias with `alias npm='firewall npm`.
+
+## Configuration
+
+Settings are in a `config.json`:
+
+- Machine-wide: `/Library/Application Support/Firewall/` on macOS, `%ProgramData%\Strix Firewall\`
+  on Windows. Only an admin can edit it; restart from the menu bar or tray to apply.
+- Command prefix: `~/.config/firewall/` on Linux, `~/Library/Application Support/com.usestrix.firewall/`
+  on macOS, `%APPDATA%\usestrix\firewall\config\` on Windows.
+
+```json
+{
+  "min_age_hours": 48,
+  "allow": { "npm": [{ "name": "left-pad", "version": "1.3.0" }] },
+  "registries": {
+    "npm": ["https://npm.example.com/"],
+    "pypi": ["https://pypi.example.com/"]
+  },
+  "telemetry": false
+}
+```
+
+| Key | Default | |
+|---|---|---|
+| `min_age_hours` | `24` | How long new versions are held back. `0` turns this off. |
+| `allow` | none | Packages exempt from the hold, by ecosystem (`npm`, `pypi`, `cargo`, `gem`, `go`). Omit `version` for every version. Known malware is still blocked. |
+| `registries` | none | Mirrors, by the registry they copy (`npm`, `pypi`, `gem`, `go`, `cargo/index`). Both modes screen every mirror listed; command-prefix mode also downloads from the first one. |
+| `fail_open` | `true` | Allow a package when it can't be checked. |
+| `telemetry` | `true` | Log anonymized usage events to Strix. |
+| `port` | `8080` | Local port for command-prefix mode. |
+
+## License
+
+Apache 2.0. See [LICENSE](LICENSE).

core/Cargo.toml

@@ -38,17 +38,14 @@ path = "src/main.rs"
 [[bin]]
 name = "firewall-service"
 path = "src/bin/firewall-service.rs"
-required-features = ["machine-wide"]
 
 [[bin]]
 name = "firewall-tray"
 path = "src/bin/firewall-tray.rs"
-required-features = ["machine-wide"]
 
 [[bin]]
 name = "firewall-uninstall"
 path = "src/bin/firewall-uninstall.rs"
-required-features = ["machine-wide"]
 
 [[example]]
 name = "proxy-test"
@@ -90,10 +87,6 @@ path = "tests/tpm.rs"
 name = "managers"
 path = "tests/managers.rs"
 
-[features]
-# Builds the machine-wide binaries: the Windows service and tray, and the macOS uninstaller.
-machine-wide = []
-
 [dependencies]
 clap = "4.6.6"
 directories = "6.0.0"
@@ -125,7 +118,7 @@ schannel = "0.1.29"
 tokio = { version = "1.53.1", features = ["net"] }
 tracing-appender = "0.2.5"
 tray-icon = { version = "0.26.1", default-features = false }
-windows = { version = "0.62", features = ["Win32_Foundation", "Win32_Security", "Win32_Security_Authorization", "Win32_Security_Cryptography", "Win32_System_Com", "Win32_System_Console", "Win32_System_Environment", "Win32_System_JobObjects", "Win32_System_Threading", "Win32_UI_Shell", "Win32_UI_WindowsAndMessaging"] }
+windows = { version = "0.62", features = ["Win32_Foundation", "Win32_Security", "Win32_Security_Authorization", "Win32_Security_Cryptography", "Win32_System_Com", "Win32_System_Environment", "Win32_System_Threading", "Win32_UI_Shell", "Win32_UI_WindowsAndMessaging"] }
 windows-registry = "0.6.1"
 windows-service = "0.8.0"
 

core/src/aliasing/mod.rs

@@ -1,7 +1,5 @@
 pub mod forward;
 pub mod managers;
-#[cfg(windows)]
-mod windows;
 
 pub use forward::spawn;
 pub use managers::*;
@@ -36,8 +34,7 @@ impl Invocation {
 
 pub fn run(port: u16, invocation: &Invocation, dir: Option<&Path>) -> std::io::Result<i32> {
     let proxy = crate::local_url(port, "");
-    let program = resolve(&invocation.program)?;
-    let mut command = Command::new(&program);
+    let mut command = Command::new(resolve(&invocation.program)?);
     command.args(invocation.arguments(&proxy));
     if let Some(dir) = dir {
         command.current_dir(dir);
@@ -45,12 +42,7 @@ pub fn run(port: u16, invocation: &Invocation, dir: Option<&Path>) -> std::io::R
     for (key, value) in managers::variables(&proxy) {
         command.env(key, value);
     }
-    #[cfg(windows)]
-    windows::prepare();
-    let status = command.status();
-    #[cfg(windows)]
-    let status = status.map_err(|error| windows::explain(error, &program));
-    Ok(status?.code().unwrap_or(1))
+    Ok(command.status()?.code().unwrap_or(1))
 }
 
 // Command::new only finds .exe on Windows; npm, pnpm and gem are .cmd shims found via PATHEXT.

core/src/aliasing/windows.rs

@@ -1,64 +0,0 @@
-use std::io::{Error, ErrorKind};
-use std::path::Path;
-use std::sync::Once;
-use tracing::debug;
-use windows::core::{BOOL, PCWSTR};
-use windows::Win32::System::Console::{SetConsoleCtrlHandler, CTRL_BREAK_EVENT, CTRL_C_EVENT};
-use windows::Win32::System::JobObjects::{
-    AssignProcessToJobObject, CreateJobObjectW, JobObjectExtendedLimitInformation,
-    SetInformationJobObject, JOBOBJECT_EXTENDED_LIMIT_INFORMATION,
-    JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE,
-};
-use windows::Win32::System::Threading::GetCurrentProcess;
-
-/// Called before spawning, so the manager behaves as it would run from the shell directly.
-/// Once per process: a caller may run several managers.
-pub fn prepare() {
-    static PREPARED: Once = Once::new();
-    PREPARED.call_once(|| {
-        // The console sends Ctrl+C to the manager too. Exiting first would hand the prompt back
-        // while a .cmd shim still asks "Terminate batch job (Y/N)?", so wait for its exit instead.
-        // A handler, unlike ignoring the signal outright, is not inherited by the manager.
-        let _ = unsafe { SetConsoleCtrlHandler(Some(ignore_interrupt), true) };
-        if let Err(error) = kill_children_on_exit() {
-            debug!(%error, "the manager may outlive the firewall");
-        }
-    });
-}
-
-unsafe extern "system" fn ignore_interrupt(event: u32) -> BOOL {
-    (event == CTRL_C_EVENT || event == CTRL_BREAK_EVENT).into()
-}
-
-/// Joins a job that kills what is left in it once the firewall exits, even if killed itself.
-/// The manager inherits the job when spawned, as do its own children.
-fn kill_children_on_exit() -> windows::core::Result<()> {
-    let mut limits = JOBOBJECT_EXTENDED_LIMIT_INFORMATION::default();
-    limits.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
-    // Never closed: the handle closing as the firewall exits is what kills the rest.
-    let job = unsafe { CreateJobObjectW(None, PCWSTR::null())? };
-    unsafe {
-        SetInformationJobObject(
-            job,
-            JobObjectExtendedLimitInformation,
-            (&raw const limits).cast(),
-            size_of_val(&limits) as u32,
-        )?
-    };
-    unsafe { AssignProcessToJobObject(job, GetCurrentProcess()) }
-}
-
-/// Rust refuses to pass a line break to a batch file, where it would cut the command short.
-pub fn explain(error: Error, program: &Path) -> Error {
-    let batch = program
-        .extension()
-        .is_some_and(|ext| ext.eq_ignore_ascii_case("cmd") || ext.eq_ignore_ascii_case("bat"));
-    if !batch || error.kind() != ErrorKind::InvalidInput {
-        return error;
-    }
-    let name = program.file_name().unwrap_or(program.as_os_str()).to_string_lossy();
-    Error::new(
-        ErrorKind::InvalidInput,
-        format!("{name} is a batch file, which cannot be passed an argument with a line break"),
-    )
-}

core/src/config/mod.rs

@@ -17,7 +17,7 @@ pub struct FirewallConfig {
     /// 0 turns the age check off.
     pub min_age_hours: u64,
     pub denylist: DenylistSource,
-    /// Packages exempt from the age check, by ecosystem: `{"npm": [{"name": "left-pad"}]}`.
+    /// Packages never screened, by ecosystem: `{"npm": [{"name": "left-pad"}]}`.
     pub allow: HashMap<String, Vec<AllowedPackage>>,
     pub telemetry: bool,
     /// Not describable in the file yet, so this is always the built-in table.

core/src/os/windows/service.rs

@@ -26,7 +26,6 @@ use std::net::{IpAddr, Ipv4Addr};
 use std::sync::Arc;
 use std::time::Duration;
 use tracing_appender::rolling::{RollingFileAppender, Rotation};
-use windows::Win32::Foundation::ERROR_GEN_FAILURE;
 use windows_service::service::*;
 use windows_service::service_control_handler::{
     self, ServiceControlHandlerResult, ServiceStatusHandle,
@@ -74,12 +73,8 @@ fn run_until_stopped() -> Result<(), BoxError> {
         | ServiceControl::Shutdown
         | ServiceControl::Pause
         | ServiceControl::Continue => {
-            // Answered once handled, so a failed pause fails the caller's ControlService.
-            let (reply, handled) = tokio::sync::oneshot::channel();
-            let _ = control_sender.send((control, reply));
-            handled
-                .blocking_recv()
-                .unwrap_or(ServiceControlHandlerResult::NoError)
+            let _ = control_sender.send(control);
+            ServiceControlHandlerResult::NoError
         }
         ServiceControl::Interrogate => ServiceControlHandlerResult::NoError,
         _ => ServiceControlHandlerResult::NotImplemented,
@@ -94,26 +89,16 @@ fn run_until_stopped() -> Result<(), BoxError> {
             }
         };
         // Only pausing removes our hosts entries; a stop or crash keeps them, failing closed.
-        while let Some((control, reply)) = control_receiver.recv().await {
+        while let Some(control) = control_receiver.recv().await {
             let (hosts, state) = match control {
                 ServiceControl::Pause => (&[][..], ServiceState::Paused),
                 ServiceControl::Continue => (&hosts[..], ServiceState::Running),
                 _ => break,
             };
-            let result = match write_hosts_entries(hosts) {
-                Ok(()) => {
-                    set_status(&status, state, false)?;
-                    ServiceControlHandlerResult::NoError
-                }
-                Err(error) => {
-                    tracing::error!(%error, "could not rewrite the hosts file");
-                    let code = error
-                        .raw_os_error()
-                        .map_or(ERROR_GEN_FAILURE.0, |code| code as u32);
-                    ServiceControlHandlerResult::Other(code)
-                }
-            };
-            let _ = reply.send(result);
+            match write_hosts_entries(hosts) {
+                Ok(()) => set_status(&status, state, false)?,
+                Err(error) => tracing::error!(%error, "could not rewrite the hosts file"),
+            }
         }
         Ok::<_, BoxError>(())
     });
@@ -162,7 +147,7 @@ async fn start_screening(status: &ServiceStatusHandle) -> Result<Vec<&'static st
                 resolver: resolver.clone(),
                 service: service.clone(),
             };
-            let upstream = ConsumeErrLayer::trace_as_warning().into_layer(upstream);
+            let upstream = ConsumeErrLayer::trace_as_debug().into_layer(upstream);
             tokio::spawn(listen_on(address, port, &exec)?.serve(upstream));
         }
     }

core/src/os/windows/tray.rs

@@ -144,11 +144,7 @@ impl Tray {
 }
 
 fn show_error(error: BoxError) {
-    let text = match error.source() {
-        Some(source) => format!("{error}: {source}"),
-        None => error.to_string(),
-    };
-    let text = HSTRING::from(text);
+    let text = HSTRING::from(error.to_string());
     unsafe { MessageBoxW(None, &text, w!("Strix Firewall"), MB_ICONERROR) };
 }
 

core/src/policies/filters/mod.rs

@@ -25,18 +25,16 @@ pub trait Filter: Send + Sync {
 }
 
 /// Asks every filter. A `Deny` wins; failing that, the first filter that could not tell.
-/// An allowed package skips only the age check, so malware is never let through.
 pub async fn consult(
     firewall: &Firewall,
     registry: &'static Registry,
     pkg: &Package,
 ) -> Option<(&'static str, Verdict)> {
-    let allowed = allowed(firewall, registry, pkg);
+    if allowed(firewall, registry, pkg) {
+        return None;
+    }
     let mut unsure = None;
     for filter in firewall.filters() {
-        if allowed && filter.name() == "age" {
-            continue;
-        }
         match filter.check(registry, pkg).await {
             Verdict::Allow => continue,
             Verdict::Deny(reason) => return Some((filter.name(), Verdict::Deny(reason))),

core/tests/config.rs

@@ -39,14 +39,14 @@ fn a_later_file_wins_and_allow_lists_add_up() {
 }
 
 #[tokio::test]
-async fn an_allowed_version_is_still_checked_for_malware() {
-    // The unreachable denylist shows that it still runs.
+async fn an_allowed_version_skips_the_filters() {
+    // An unreachable denylist would otherwise leave the package unchecked.
     let config = r#"{"allow": {"go": [{"name": "golang.org/x/net", "version": "v0.20.0"}]}, "denylist": {"base": "http://127.0.0.1:1"}}"#;
     let firewall = Firewall::new(serde_json::from_str(config).expect("parses"));
     let (registry, _) = firewall.match_on("/go/golang.org/x/net/@v/list", |r| r.prefix).expect("go");
-    let pkg = Package { name: "golang.org/x/net".into(), version: Some("0.20.0".into()) };
-    let verdict = consult(&firewall, registry, &pkg).await;
-    assert_eq!(verdict.map(|(filter, _)| filter), Some("denylist"));
+    let pkg = |version: &str| Package { name: "golang.org/x/net".into(), version: Some(version.into()) };
+    assert!(consult(&firewall, registry, &pkg("0.20.0")).await.is_none());
+    assert!(consult(&firewall, registry, &pkg("0.21.0")).await.is_some());
 }
 
 #[tokio::test]

dist-workspace.toml

@@ -7,7 +7,6 @@ ci = "github"
 installers = ["shell", "powershell", "homebrew", "msi"]
 # core/wix/main.wxs is edited to install the service.
 allow-dirty = ["msi"]
-features = ["machine-wide"]
 tap = "usestrix/homebrew-tap"
 publish-jobs = ["homebrew", "./publish-crates"]
 targets = ["aarch64-apple-darwin", "x86_64-apple-darwin", "aarch64-unknown-linux-gnu", "x86_64-unknown-linux-gnu", "x86_64-pc-windows-msvc"]

macos/project.yml

@@ -133,7 +133,7 @@ targets:
               arm64|arm64e) triple=aarch64-apple-darwin ;;
               x86_64)       triple=x86_64-apple-darwin ;;
             esac
-            cargo build --bin firewall-uninstall --features machine-wide --target $triple $([ "$CONFIGURATION" = Debug ] || echo --release)
+            cargo build --bin firewall-uninstall --target $triple $([ "$CONFIGURATION" = Debug ] || echo --release)
             bins="$bins target/$triple/$CARGO_PROFILE/firewall-uninstall"
           done
           lipo -create $bins -output "$TARGET_BUILD_DIR/$EXECUTABLE_FOLDER_PATH/firewall-uninstall"