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/src/config/mod.rs

@@ -1,10 +1,10 @@
 use crate::policies::registries::{Registry, BUILT_IN};
 use directories::ProjectDirs;
 use serde::Deserialize;
-use serde_json::{json, Map, Value};
+use serde_json::{Map, Value};
 use std::collections::HashMap;
 use std::io::{Error, ErrorKind};
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 pub const DEFAULT_PORT: u16 = 8080;
 
@@ -129,31 +129,3 @@ fn merge(base: &mut Map<String, Value>, top: Map<String, Value>) {
         }
     }
 }
-
-/// Adds an `allow` entry to the file, leaving the rest of it as written.
-pub fn allow(path: &Path, eco: &str, name: &str, version: Option<&str>) -> std::io::Result<()> {
-    let invalid = |e: String| Error::new(ErrorKind::InvalidData, format!("{}: {e}", path.display()));
-    let mut config = match std::fs::read_to_string(path) {
-        Ok(text) => serde_json::from_str(&text).map_err(|e| invalid(e.to_string()))?,
-        Err(e) if e.kind() == ErrorKind::NotFound => json!({}),
-        Err(e) => return Err(e),
-    };
-    if !config.is_object() {
-        return Err(invalid("not an object".into()));
-    }
-    let entry = json!({ "name": name, "version": version });
-    let entries = &mut config["allow"][eco];
-    if entries.is_null() {
-        *entries = Value::Array(Vec::new());
-    }
-    let Some(entries) = entries.as_array_mut() else {
-        return Err(invalid(format!("allow.{eco} is not a list")));
-    };
-    if !entries.contains(&entry) {
-        entries.push(entry);
-    }
-    if let Some(dir) = path.parent() {
-        std::fs::create_dir_all(dir)?;
-    }
-    std::fs::write(path, serde_json::to_string_pretty(&config)?)
-}

core/src/os/macos/mod.rs

@@ -4,7 +4,7 @@ mod uninstall;
 
 pub use uninstall::uninstall;
 
-use crate::config::{self, FirewallConfig};
+use crate::config::FirewallConfig;
 use crate::{blocks, mitm, telemetry};
 use crate::Firewall;
 use rama::bytes::Bytes;
@@ -22,7 +22,6 @@ use rama::net::apple::networkextension::{transparent_proxy_ffi, NwTcpStream, Tcp
 use rama::rt::Executor;
 use rama::telemetry::tracing::apple::oslog::{OsLogLayer, Privacy};
 use rama::{Layer, Service};
-use serde::Deserialize;
 use std::convert::Infallible;
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -60,11 +59,7 @@ impl TransparentProxyHandler for Handler {
         Some(Bytes::from(match message.as_str() {
             "ca" => self.ca.pem.clone(),
             "blocks" => serde_json::to_string(&blocks::take()).expect("blocks serialize"),
-            other => match other.strip_prefix("allow ").map(allow) {
-                Some(Ok(())) => "ok".to_owned(),
-                Some(Err(error)) => format!("error: {error}"),
-                None => format!("error: unknown message {other}"),
-            },
+            other => format!("error: unknown message {other}"),
         }))
     }
 
@@ -123,20 +118,6 @@ fn handler(exec: Executor) -> Result<Handler, BoxError> {
     Ok(Handler { ca, hosts, service })
 }
 
-#[derive(Deserialize)]
-struct AllowRequest {
-    eco: String,
-    name: String,
-    version: Option<String>,
-}
-
-/// Takes effect when the provider restarts, which rebuilds it from the config.
-fn allow(request: &str) -> Result<(), BoxError> {
-    let request: AllowRequest = serde_json::from_str(request)?;
-    config::allow(CONFIG_FILE.as_ref(), &request.eco, &request.name, request.version.as_deref())?;
-    Ok(())
-}
-
 /// stderr is invisible in a system extension, so events go to the unified log:
 /// `log stream --predicate 'subsystem == "com.usestrix.firewall"'`.
 fn init(_config: Option<&TransparentProxyInitConfig>) -> bool {

core/tests/config.rs

@@ -57,18 +57,3 @@ async fn failing_closed_blocks_what_could_not_be_checked() {
     let blocked = screen(url, &firewall).await.unwrap_or_default();
     assert!(blocked.contains("could not be checked"), "{blocked:?}");
 }
-
-#[test]
-fn allowing_keeps_the_rest_of_the_file() {
-    let path = std::env::temp_dir().join(format!("firewall-allow-{}.json", std::process::id()));
-    std::fs::write(&path, r#"{"fail_open": false}"#).expect("write");
-    for _ in 0..2 {
-        firewall::config::allow(&path, "npm", "left-pad", Some("1.3.0")).expect("allow");
-    }
-    let text = std::fs::read_to_string(&path).expect("read");
-    std::fs::remove_file(&path).ok();
-    let config: FirewallConfig = serde_json::from_str(&text).expect("parses");
-    assert!(!config.fail_open);
-    assert_eq!(config.allow["npm"].len(), 1);
-    assert_eq!(config.allow["npm"][0].version.as_deref(), Some("1.3.0"));
-}

macos/App/BlockAlerts.swift

@@ -1,5 +1,4 @@
 import AppKit
-import Security
 
 struct BlockedPackage: Codable, Hashable, Identifiable {
     let eco: String
@@ -12,46 +11,22 @@ struct BlockedPackage: Codable, Hashable, Identifiable {
     var label: String { version.map { "\(name) \($0)" } ?? name }
     /// The denylist and OSV only flag packages known to be malicious; the age check only holds back new ones.
     var malicious: Bool { filter != "age" }
-    /// Malware is never allowed, and a new package only by version.
-    var trustable: Bool { !malicious && version != nil }
 }
 
 @MainActor
 enum BlockAlert {
-    /// Returns whether the user chose to trust the package.
-    static func show(_ package: BlockedPackage) -> Bool {
+    static func show(_ package: BlockedPackage) {
         let alert = NSAlert()
         alert.addButton(withTitle: "OK")
         if package.malicious {
             alert.alertStyle = .critical
-            alert.messageText = "Blocked malware: \(package.label) (\(package.eco))"
-            alert.informativeText = "\(package.label) \(package.reason).\n\n"
-                + "It was not installed. Don't install it from another source. "
-                + "If you didn't expect this package, a dependency may be compromised; tell your security team."
+            alert.messageText = "Blocked a malicious package"
+            alert.informativeText = "\(package.label) (\(package.eco)) \(package.reason). Do not install it."
         } else {
             alert.messageText = "Held back a new package"
             alert.informativeText = "\(package.label) (\(package.eco)) \(package.reason)."
-            if package.trustable { alert.addButton(withTitle: "Trust this version") }
         }
         NSApp.activate(ignoringOtherApps: true)
-        return alert.runModal() == .alertSecondButtonReturn
-    }
-}
-
-enum AdminAuthorization {
-    /// The allowlist applies to every user of the Mac, so changing it takes an admin, as `sudo` would.
-    static func confirm() -> Bool {
-        var authorization: AuthorizationRef?
-        guard AuthorizationCreate(nil, nil, [], &authorization) == errAuthorizationSuccess,
-              let authorization else { return false }
-        defer { AuthorizationFree(authorization, []) }
-        return "system.preferences".withCString { name in
-            var item = AuthorizationItem(name: name, valueLength: 0, value: nil, flags: 0)
-            return withUnsafeMutablePointer(to: &item) { item in
-                var rights = AuthorizationRights(count: 1, items: item)
-                let flags: AuthorizationFlags = [.interactionAllowed, .extendRights]
-                return AuthorizationCopyRights(authorization, &rights, nil, flags, nil) == errAuthorizationSuccess
-            }
-        }
+        alert.runModal()
     }
 }

macos/App/FirewallModel.swift

@@ -29,13 +29,11 @@ enum FirewallError: Error, LocalizedError {
     case extensionUnavailable
     case screeningDidNotStart(NEVPNStatus)
     case extensionStopped(String)
-    case extensionRefused(String)
 
     var errorDescription: String? {
         switch self {
         case .extensionUnavailable: return "The extension is not running"
         case let .screeningDidNotStart(status): return "Screening did not start (\(status.label))"
-        case let .extensionRefused(reply): return "The extension replied \(reply)"
         case let .extensionStopped(reason):
             return "The extension stopped: \(reason). Its log: log show --last 5m --predicate 'subsystem BEGINSWITH \"\(FirewallIDs.appBundleID)\"'"
         }
@@ -203,28 +201,6 @@ final class FirewallModel: NSObject, ObservableObject {
         if let url = URL(string: pane) { NSWorkspace.shared.open(url) }
     }
 
-    /// Allowing a version writes it into the extension's config, which a restart then loads.
-    func trust(_ package: BlockedPackage) async {
-        guard package.trustable else { return }
-        guard AdminAuthorization.confirm() else {
-            log("Trust cancelled for \(package.label)")
-            return
-        }
-        do {
-            var request = ["eco": package.eco, "name": package.name]
-            request["version"] = package.version
-            let json = String(decoding: try JSONSerialization.data(withJSONObject: request), as: UTF8.self)
-            let reply = try await providerMessage("allow \(json)")
-            guard reply == "ok" else { throw FirewallError.extensionRefused(reply) }
-            blocked.removeAll { $0 == package }
-            log("Trusted \(package.label) (\(package.eco))")
-        } catch {
-            log("Could not trust \(package.label): \(error.localizedDescription)")
-            return
-        }
-        await restart()
-    }
-
     /// The extension cannot message the app, so the app asks it for blocks.
     private func watchBlocks() async {
         while true {
@@ -232,7 +208,7 @@ final class FirewallModel: NSObject, ObservableObject {
                let packages = try? JSONDecoder().decode([BlockedPackage].self, from: Data(reply.utf8)) {
                 for package in packages where !blocked.contains(package) {
                     blocked.append(package)
-                    if BlockAlert.show(package) { await trust(package) }
+                    BlockAlert.show(package)
                 }
                 blocked = Array(blocked.suffix(10))
             }

macos/App/MenuBarView.swift

@@ -29,10 +29,6 @@ struct MenuBarView: View {
                 if !package.malicious {
                     Menu("Held back \(package.label) (\(package.eco))") {
                         Text(package.reason)
-                        Button("Trust this version") {
-                            Task { await model.trust(package) }
-                        }
-                        .disabled(model.busy || !package.trustable)
                     }
                 } else {
                     Menu("Blocked \(package.label) (\(package.eco))") {