Stop rebuilding the menu bar menu on every block poll

A PyPI mirror serves its files from the index host, so the pypi registry
now names packages in /packages/ paths too, and checks their age.

core/Cargo.lock

@@ -711,6 +711,20 @@ version = "1.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "252afb9ae5eaa683babdc6a068b3f5726eb19e05070c731f9b2a23a7c3e8ed34"
 
+[[package]]
+name = "embed-resource"
+version = "3.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6168487b5e7eb2673e6efe1200b1848016e436a6ca0b8031bf04bd9d493a249f"
+dependencies = [
+ "cc",
+ "memchr",
+ "rustc_version",
+ "toml",
+ "vswhom",
+ "winreg",
+]
+
 [[package]]
 name = "encoding_rs"
 version = "0.8.42"
@@ -3243,6 +3257,15 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "serde_spanned"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e7523beb55eece201a2356bee0bbca0d1ab466c14c07703b2e0ee6d42cb0c2c"
+dependencies = [
+ "serde_core",
+]
+
 [[package]]
 name = "sha1"
 version = "0.11.0"
@@ -3370,11 +3393,12 @@ checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
 
 [[package]]
 name = "strix-firewall"
-version = "0.1.0-rc.1"
+version = "0.1.0-rc.2"
 dependencies = [
  "clap",
  "core-foundation 0.10.1",
  "directories",
+ "embed-resource",
  "muda",
  "percent-encoding",
  "png",
@@ -3671,10 +3695,25 @@ dependencies = [
 ]
 
 [[package]]
-name = "toml_datetime"
-version = "1.1.1+spec-1.1.0"
+name = "toml"
+version = "1.1.8+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3165f65f62e28e0115a00b2ebdd37eb6f3b641855f9d636d3cd4103767159ad7"
+checksum = "20489e00e4d8741d6be680764cc12e270655e375a20d1011e844a9c3379e678d"
+dependencies = [
+ "indexmap",
+ "serde_core",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_parser",
+ "toml_writer",
+ "winnow",
+]
+
+[[package]]
+name = "toml_datetime"
+version = "1.1.2+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b86d767906c6c42421dcba507eb9d203e779497710a47782a224bb871653053"
 dependencies = [
  "serde_core",
 ]
@@ -3693,13 +3732,19 @@ dependencies = [
 
 [[package]]
 name = "toml_parser"
-version = "1.1.3+spec-1.1.0"
+version = "1.1.5+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d38ac1cf9b95face32296c0a3ede1fdc270627c9d9c02a7274dd6d960dc4d56"
+checksum = "baa693a8032d7e1cada7d0041e96126df243179ff061456783ac7f12bda4744c"
 dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "toml_writer"
+version = "1.1.3+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06bdbd8cfc056b8d2e2e85f29b56a3bdbecb527cef81eb39e3e7b98af4652770"
+
 [[package]]
 name = "tower-layer"
 version = "0.3.3"
@@ -3909,6 +3954,26 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
+[[package]]
+name = "vswhom"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be979b7f07507105799e854203b470ff7c78a1639e330a58f183b5fea574608b"
+dependencies = [
+ "libc",
+ "vswhom-sys",
+]
+
+[[package]]
+name = "vswhom-sys"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb067e4cbd1ff067d1df46c9194b5de0e98efd2810bbc95c5d5e5f25a3231150"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "walkdir"
 version = "2.5.0"
@@ -4284,6 +4349,16 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "winreg"
+version = "0.56.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d6f32a0ff4a9f6f01231eb2059cc85479330739333e0e58cadf03b6af2cca10"
+dependencies = [
+ "cfg-if",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "wit-bindgen"
 version = "0.57.1"

core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "strix-firewall"
-version = "0.1.0-rc.1"
+version = "0.1.0-rc.2"
 edition = "2021"
 license = "Apache-2.0"
 authors = ["Strix"]
@@ -129,10 +129,14 @@ 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_Storage_FileSystem", "Win32_System_Com", "Win32_System_Console", "Win32_System_Environment", "Win32_System_JobObjects", "Win32_System_Pipes", "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_Storage_FileSystem", "Win32_System_Com", "Win32_System_Console", "Win32_System_Environment", "Win32_System_JobObjects", "Win32_System_LibraryLoader", "Win32_System_Pipes", "Win32_System_Registry", "Win32_System_Threading", "Win32_UI_Controls", "Win32_UI_Shell", "Win32_UI_WindowsAndMessaging"] }
 windows-registry = "0.6.1"
 windows-service = "0.8.0"
 
+# Only on Windows hosts, where the tray and service are built.
+[target.'cfg(windows)'.build-dependencies]
+embed-resource = "3.0.12"
+
 [dev-dependencies]
 tokio = { version = "1.53.1", features = ["macros", "rt-multi-thread"] }
 

core/build.rs

@@ -0,0 +1,20 @@
+//! The tray's task dialogs exist only in version 6 of the common controls, which takes a manifest.
+//! Both machine-wide binaries also get the Strix icon.
+fn main() {
+    println!("cargo:rerun-if-changed=src/bin/firewall-tray.manifest");
+    let msvc = std::env::var("CARGO_CFG_TARGET_ENV").as_deref() == Ok("msvc");
+    if msvc && std::env::var_os("CARGO_FEATURE_MACHINE_WIDE").is_some() {
+        let manifest = concat!(env!("CARGO_MANIFEST_DIR"), "/src/bin/firewall-tray.manifest");
+        println!("cargo:rustc-link-arg-bin=firewall-tray=/MANIFEST:EMBED");
+        println!("cargo:rustc-link-arg-bin=firewall-tray=/MANIFESTINPUT:{manifest}");
+        #[cfg(windows)]
+        embed_resource::compile_for(
+            "src/bin/firewall.rc",
+            ["firewall-tray", "firewall-service"],
+            embed_resource::NONE,
+        )
+        // Fails the build, rather than ship without the icon.
+        .manifest_required()
+        .unwrap();
+    }
+}

core/src/aliasing/forward.rs

@@ -80,6 +80,7 @@ async fn handle(req: Request, firewall: &Firewall) -> Result<Response, Infallibl
         warn!(method = %req.method(), uri = %req.uri(), "unroutable, expected an absolute URL");
         return Ok(text(400, "firewall: expected an absolute URL\n"));
     };
+    let url = firewall.mirrored(url);
 
     let reason = policies::screen(&url, firewall).await;
     telemetry::screened(firewall, &url, reason.as_deref());
@@ -129,6 +130,9 @@ pub fn downgrade(firewall: &Firewall, body: Vec<u8>) -> Vec<u8> {
         Ok(text) => text,
         Err(raw) => return raw.into_bytes(),
     };
+    for (upstream, mirror) in firewall.mirrors() {
+        text = text.replace(mirror, upstream);
+    }
     for host in firewall.hosts() {
         text = text.replace(&format!("https://{host}"), &format!("http://{host}"));
     }

core/src/bin/firewall-tray.manifest

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0"
+        processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*"/>
+    </dependentAssembly>
+  </dependency>
+</assembly>

core/src/bin/firewall.rc

@@ -0,0 +1,2 @@
+// The icon Explorer, UAC and the tray's popups show.
+1 ICON "strix.ico"

core/src/firewall.rs

@@ -69,6 +69,28 @@ impl Firewall {
         self.registries.iter().any(|r| r.index && r.host() == host_of(url))
     }
 
+    /// The URL at the first mirror of the built-in registry it is on, if one is configured.
+    pub fn mirrored(&self, url: String) -> String {
+        for (upstream, mirror) in self.mirrors() {
+            if let Some(rest) = url.strip_prefix(upstream) {
+                return format!("{mirror}{rest}");
+            }
+        }
+        url
+    }
+
+    /// Each built-in upstream with a mirror, paired with its first one.
+    pub fn mirrors(&self) -> Vec<(&'static str, &str)> {
+        let mut mirrors = Vec::new();
+        for registry in BUILT_IN {
+            let first = self.config.registries.get(registry.name()).and_then(|m| m.first());
+            if let Some(mirror) = first {
+                mirrors.push((registry.upstream, mirror.as_str()));
+            }
+        }
+        mirrors
+    }
+
     pub fn resolve(&self, registry: &'static Registry, rest: &str) -> Resolved {
         resolve(registry, rest, &self.patterns[registry.prefix])
     }

core/src/os/windows/pipe.rs

@@ -1,5 +1,5 @@
-//! How the tray asks the service what it blocked, and allows a new package once, as the macOS
-//! app messages its extension.
+//! How the tray asks the service what it blocked, and allows a new package, as the macOS app
+//! messages its extension.
 
 use super::{config_file, security_descriptor};
 use crate::{blocks, Firewall};
@@ -11,8 +11,8 @@ use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader};
 use tokio::net::windows::named_pipe::{NamedPipeServer, ServerOptions};
 use windows::core::{Owned, PWSTR};
 use windows::Win32::Foundation::HANDLE;
-use windows::Win32::Security::SECURITY_ATTRIBUTES;
-use windows::Win32::System::Pipes::GetNamedPipeClientProcessId;
+use windows::Win32::Security::*;
+use windows::Win32::System::Pipes::{GetNamedPipeClientProcessId, ImpersonateNamedPipeClient};
 use windows::Win32::System::Threading::*;
 
 pub(super) const PIPE: &str = r"\\.\pipe\StrixFirewall";
@@ -56,8 +56,7 @@ async fn answer(client: NamedPipeServer, firewall: &Firewall) -> Result<(), BoxE
     // Only the app can message the macOS extension; here any program could connect.
     let reply = if !client_is_tray(client.get_ref())? {
         "error: only the tray can ask".to_owned()
-    } else if request.starts_with("allow ") {
-        // Trusting writes the config for every user, so it is left to an administrator.
+    } else if request.starts_with("allow ") && !client_is_admin(client.get_ref())? {
         "error: trusting a package takes an administrator".to_owned()
     } else {
         blocks::answer(firewall, &config_file(), request)
@@ -81,3 +80,20 @@ fn client_is_tray(client: &NamedPipeServer) -> Result<bool, BoxError> {
     // Windows paths ignore case.
     Ok(path.to_lowercase() == tray.to_string_lossy().to_lowercase())
 }
+
+/// Elevated, as only an elevated token has the Administrators group enabled.
+fn client_is_admin(client: &NamedPipeServer) -> windows::core::Result<bool> {
+    let mut sid = [0u32; SECURITY_MAX_SID_SIZE as usize / 4];
+    let admins = PSID(sid.as_mut_ptr().cast());
+    let mut size = SECURITY_MAX_SID_SIZE;
+    unsafe { CreateWellKnownSid(WinBuiltinAdministratorsSid, None, Some(admins), &mut size)? };
+    unsafe { ImpersonateNamedPipeClient(HANDLE(client.as_raw_handle()))? };
+    let mut member = false.into();
+    let checked = unsafe { CheckTokenMembership(None, admins, &mut member) };
+    // Carrying on as the client would be worse than stopping.
+    if unsafe { RevertToSelf() }.is_err() {
+        std::process::abort();
+    }
+    checked?;
+    Ok(member.as_bool())
+}

core/src/os/windows/tray.rs

@@ -9,10 +9,12 @@ use std::os::windows::io::AsRawHandle;
 use std::sync::mpsc::{channel, Receiver, Sender};
 use std::time::Duration;
 use tray_icon::{Icon, MouseButtonState, TrayIcon, TrayIconBuilder, TrayIconEvent};
-use windows::core::{w, PCWSTR};
+use windows::core::{w, HRESULT, PCWSTR};
 use windows::Win32::Foundation::*;
+use windows::Win32::System::LibraryLoader::GetModuleHandleW;
 use windows::Win32::System::Pipes::GetNamedPipeServerProcessId;
-use windows::Win32::System::Threading::CreateMutexW;
+use windows::Win32::System::Threading::*;
+use windows::Win32::UI::Controls::*;
 use windows::Win32::UI::Shell::*;
 use windows::Win32::UI::WindowsAndMessaging::*;
 use windows_registry::CURRENT_USER;
@@ -23,7 +25,8 @@ const MENU_PAUSE: &str = "pause";
 const MENU_RESTART: &str = "restart";
 const MENU_LOG: &str = "log";
 const MENU_QUIT: &str = "quit";
-/// Also the service's request.
+/// Also the service's requests, and `allow` the elevated `firewall-tray` command.
+const ALLOW: &str = "allow";
 const ALLOW_ONCE: &str = "allow-once";
 const LOGO: &[u8] = include_bytes!("tray.png");
 /// Where blocked packages are listed, below Open logs.
@@ -32,6 +35,19 @@ const BLOCKED_KEPT: usize = 10;
 
 /// Runs until Quit, once per session.
 pub fn run() -> Result<(), BoxError> {
+    let args: Vec<String> = std::env::args().skip(1).collect();
+    if let [verb, id, label @ ..] = &args[..] {
+        if verb == ALLOW {
+            // Run by `run_elevated`, so the service can tell an admin asked.
+            let trusted = ask_service(&format!("{ALLOW} {id}"))
+                .and_then(|reply| answered(&format!("Trusted {}", label.join(" ")), &reply));
+            if let Err(error) = trusted {
+                show_error(error);
+                std::process::exit(1);
+            }
+            return Ok(());
+        }
+    }
     // Held until we exit.
     let _mutex = unsafe { CreateMutexW(None, false, w!(r"Local\StrixFirewallTray"))? };
     if unsafe { GetLastError() } == ERROR_ALREADY_EXISTS {
@@ -199,8 +215,8 @@ impl Tray {
         let allowed = self.allowed.0.clone();
         std::thread::spawn(move || {
             for package in new {
-                if alert(&package) {
-                    allow_once(package, &allowed);
+                if let Some(trust) = alert(&package) {
+                    allow(package, trust, &allowed);
                 }
             }
         });
@@ -219,9 +235,13 @@ impl Tray {
                 package.reason.clone()
             };
             let reason = MenuItem::new(reason, false, None);
-            let once = MenuItem::with_id(format!("{ALLOW_ONCE}:{i}"), "Allow Once", true, None);
+            let trustable = package.trustable();
+            let once =
+                MenuItem::with_id(format!("{ALLOW_ONCE}:{i}"), "Allow Once", trustable, None);
+            let always =
+                MenuItem::with_id(format!("{ALLOW}:{i}"), "Trust this version", trustable, None);
             let items: &[&dyn IsMenuItem] =
-                if package.trustable() { &[&reason, &once] } else { &[&reason] };
+                if package.malicious() { &[&reason] } else { &[&reason, &once, &always] };
             let label = format!("{verb} {}", package.label());
             if let Ok(item) = Submenu::with_items(label, true, items) {
                 let _ = self.menu.insert(&item, BLOCKED_AT + 1 + i);
@@ -230,11 +250,12 @@ impl Tray {
     }
 
     fn on_menu(&self, id: &str) {
-        if let Some(i) = id.strip_prefix(ALLOW_ONCE).and_then(|i| i.strip_prefix(':')) {
+        if let Some((verb @ (ALLOW | ALLOW_ONCE), i)) = id.split_once(':') {
+            let trust = verb == ALLOW;
             let package = i.parse().ok().and_then(|i: usize| self.blocked.get(i));
             if let Some(package) = package.cloned() {
                 let allowed = self.allowed.0.clone();
-                std::thread::spawn(move || allow_once(package, &allowed));
+                std::thread::spawn(move || allow(package, trust, &allowed));
             }
             return;
         }
@@ -263,42 +284,154 @@ impl Tray {
     }
 }
 
-/// Whether the user chose to allow it once.
-fn alert(package: &BlockedPackage) -> bool {
+const ALLOW_ONCE_BUTTON: i32 = 100;
+const TRUST_BUTTON: i32 = 101;
+/// `firewall.rc`'s icon, embedded by `build.rs`.
+const STRIX_ICON: PCWSTR = PCWSTR(1 as _);
+
+/// `Some(true)` if the user chose to trust it, `Some(false)` to allow it once.
+/// A task dialog, as a message box can't have both buttons.
+fn alert(package: &BlockedPackage) -> Option<bool> {
     let text = format!("{} {}.", package.label(), package.reason);
-    let (title, text, style) = if package.malicious() {
+    let (title, text, icon) = if package.malicious() {
         let title = format!("Blocked malware: {}", package.label());
         let text = text
             + "\n\nIt 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.";
-        (title, text, MB_ICONERROR)
-    } else if !package.trustable() {
-        ("Held back a new package".to_owned(), text, MB_ICONINFORMATION)
+        (title, text, TD_ERROR_ICON)
     } else {
-        let text = text + "\n\nAllow it once?";
-        ("Held back a new package".to_owned(), text, MB_YESNO | MB_ICONINFORMATION)
+        ("Held back a new package".to_owned(), text, STRIX_ICON)
     };
-    let (title, text) = (HSTRING::from(title), HSTRING::from(text));
-    unsafe { MessageBoxW(None, &text, &title, style | MB_SETFOREGROUND) == IDYES }
+    let button = |id, text| TASKDIALOG_BUTTON { nButtonID: id, pszButtonText: text };
+    let allow = [
+        button(ALLOW_ONCE_BUTTON, w!("Allow Once")),
+        button(TRUST_BUTTON, w!("Trust this version")),
+    ];
+    let buttons: &[_] = if package.trustable() { &allow } else { &[] };
+    let (title, text) = (HSTRING::from(title), HSTRING::from(linked(&text)));
+    let dialog = TASKDIALOGCONFIG {
+        cbSize: size_of::<TASKDIALOGCONFIG>() as u32,
+        dwFlags: TDF_ENABLE_HYPERLINKS,
+        // Where `STRIX_ICON` is loaded from; the `TD_` icons are Windows'.
+        hInstance: unsafe { GetModuleHandleW(None) }.ok()?.into(),
+        dwCommonButtons: TDCBF_CLOSE_BUTTON,
+        pszWindowTitle: w!("Strix Firewall"),
+        Anonymous1: TASKDIALOGCONFIG_0 { pszMainIcon: icon },
+        pszMainInstruction: PCWSTR(title.as_ptr()),
+        pszContent: PCWSTR(text.as_ptr()),
+        cButtons: buttons.len() as u32,
+        pButtons: buttons.as_ptr(),
+        pfCallback: Some(on_dialog),
+        ..Default::default()
+    };
+    let mut chosen = 0;
+    unsafe { TaskDialogIndirect(&dialog, Some(&raw mut chosen), None, None) }.ok()?;
+    match chosen {
+        ALLOW_ONCE_BUTTON => Some(false),
+        TRUST_BUTTON => Some(true),
+        _ => None,
+    }
 }
 
-/// Tells the user when the install had already stopped waiting.
-fn allow_once(package: BlockedPackage, allowed: &Sender<BlockedPackage>) {
-    let reply = match ask_service(&format!("{ALLOW_ONCE} {}", package.id)) {
-        Ok(reply) => reply,
-        Err(error) => return show_error(error),
+/// Asks for the foreground, as `MB_SETFOREGROUND` did; Windows may still leave it behind.
+/// Opens the links `linked` made, in the browser.
+unsafe extern "system" fn on_dialog(
+    window: HWND,
+    event: TASKDIALOG_NOTIFICATIONS,
+    _: WPARAM,
+    link: LPARAM,
+    _: isize,
+) -> HRESULT {
+    if event == TDN_CREATED {
+        let _ = unsafe { SetForegroundWindow(window) };
+    } else if event == TDN_HYPERLINK_CLICKED {
+        let link = PCWSTR(link.0 as *const u16);
+        // Only web pages, whatever a block's reason contains.
+        let web = unsafe { link.to_string() }
+            .is_ok_and(|link| link.starts_with("https://") || link.starts_with("http://"));
+        if web {
+            let none = PCWSTR::null();
+            unsafe { ShellExecuteW(None, w!("open"), link, none, none, SW_SHOWNORMAL) };
+        }
+    }
+    S_OK
+}
+
+/// A task dialog's markup for the text, with each URL a link.
+fn linked(text: &str) -> String {
+    let mut marked = String::new();
+    let mut rest = text;
+    while let Some(start) =
+        ["https://", "http://"].iter().filter_map(|scheme| rest.find(scheme)).min()
+    {
+        let end = rest[start..].find(|c: char| c.is_whitespace() || c == ',' || c == ')');
+        let url = rest[start..end.map_or(rest.len(), |end| start + end)].trim_end_matches('.');
+        marked += &rest[..start];
+        marked += &format!("<a href=\"{url}\">{url}</a>");
+        rest = &rest[start + url.len()..];
+    }
+    marked + rest
+}
+
+/// Trusting writes the config for every user, so it goes through a UAC prompt.
+/// The elevated process shows its own errors and late replies.
+fn allow(package: BlockedPackage, trust: bool, allowed: &Sender<BlockedPackage>) {
+    let allowed_it = if trust {
+        run_elevated(&[ALLOW, &package.id.to_string(), &package.label()])
+            .map(|code| code == Some(0))
+    } else {
+        let title = format!("Allowed {} for the next minute", package.label());
+        ask_service(&format!("{ALLOW_ONCE} {}", package.id))
+            .and_then(|reply| answered(&title, &reply))
+            .map(|()| true)
     };
-    match reply.as_str() {
-        "ok" => {}
+    match allowed_it {
+        Ok(true) => {
+            let _ = allowed.send(package);
+        }
+        Ok(false) => {}
+        Err(error) => show_error(error),
+    }
+}
+
+/// Tells the user, under `title`, when the install had already stopped waiting.
+fn answered(title: &str, reply: &str) -> Result<(), BoxError> {
+    match reply {
+        "ok" => Ok(()),
         "late" => {
-            let title = format!("Allowed {} for the next minute", package.label());
             let text = "The install had already stopped waiting for it. Run it again to finish.";
             let (title, text) = (HSTRING::from(title), HSTRING::from(text));
             unsafe { MessageBoxW(None, &text, &title, MB_ICONINFORMATION | MB_SETFOREGROUND) };
+            Ok(())
         }
-        other => return show_error(other.into()),
+        other => Err(other.into()),
     }
-    let _ = allowed.send(package);
+}
+
+/// This program as an admin, waiting for its exit code; `None` if the user said no.
+fn run_elevated(args: &[&str]) -> Result<Option<u32>, BoxError> {
+    let exe = HSTRING::from(std::env::current_exe()?.as_path());
+    let parameters = HSTRING::from(args.join(" "));
+    let mut info = SHELLEXECUTEINFOW {
+        cbSize: size_of::<SHELLEXECUTEINFOW>() as u32,
+        fMask: SEE_MASK_NOCLOSEPROCESS,
+        lpVerb: w!("runas"),
+        lpFile: PCWSTR(exe.as_ptr()),
+        lpParameters: PCWSTR(parameters.as_ptr()),
+        nShow: SW_HIDE.0,
+        ..Default::default()
+    };
+    if let Err(error) = unsafe { ShellExecuteExW(&mut info) } {
+        if error.code() == ERROR_CANCELLED.to_hresult() {
+            return Ok(None);
+        }
+        return Err(error.into());
+    }
+    let process = unsafe { Owned::new(info.hProcess) };
+    unsafe { WaitForSingleObject(*process, INFINITE) };
+    let mut code = 1;
+    unsafe { GetExitCodeProcess(*process, &mut code)? };
+    Ok(Some(code))
 }
 
 /// One request per connection, as the service answers.

core/src/policies/registries/pypi.rs

@@ -11,9 +11,12 @@ pub static PYPI: Registry = Registry {
     normalize: Some(pep503),
     patterns: &[
         Pattern { re: r"^simple/(?<name>[^/]+)", rewrite: Some(FILES) },
+        // A mirror serves the files from its index host.
+        WHEEL,
+        SDIST,
         Pattern { re: "", rewrite: Some(FILES) },
     ],
-    published: None,
+    published: PUBLISHED,
 };
 
 /// The directories are hash shards, but the filename names the distribution.
@@ -24,25 +27,28 @@ pub static PYPI_FILES: Registry = Registry {
     upstream: "https://files.pythonhosted.org/",
     index: false,
     normalize: Some(pep503),
-    patterns: &[
-        // A wheel escapes - _ and . to _, so the first two fields are exactly name and version.
-        Pattern {
-            re: r"^packages/.+/(?<name>[^-/]+)-(?<version>[^-/]+)-[^/]+\.whl(?:\.metadata)?$",
-            rewrite: None,
-        },
-        // An sdist keeps the name's hyphens, so the version is the last field starting with a digit.
-        Pattern {
-            re: r"^packages/.+/(?<name>.+)-(?<version>\d[^-/]*)\.(?:tar\.gz|zip|tar\.bz2)$",
-            rewrite: None,
-        },
-    ],
-    published: Some(Published {
-        url: "https://pypi.org/pypi/{name}/{version}/json",
-        pointer: "/urls/0/upload_time_iso_8601",
-        escape: None,
-    }),
+    patterns: &[WHEEL, SDIST],
+    published: PUBLISHED,
 };
 
+// A wheel escapes - _ and . to _, so the first two fields are exactly name and version.
+const WHEEL: Pattern = Pattern {
+    re: r"^packages/.+/(?<name>[^-/]+)-(?<version>[^-/]+)-[^/]+\.whl(?:\.metadata)?$",
+    rewrite: None,
+};
+
+// An sdist keeps the name's hyphens, so the version is the last field starting with a digit.
+const SDIST: Pattern = Pattern {
+    re: r"^packages/.+/(?<name>.+)-(?<version>\d[^-/]*)\.(?:tar\.gz|zip|tar\.bz2)$",
+    rewrite: None,
+};
+
+const PUBLISHED: Option<Published> = Some(Published {
+    url: "https://pypi.org/pypi/{name}/{version}/json",
+    pointer: "/urls/0/upload_time_iso_8601",
+    escape: None,
+});
+
 /// PEP 503: runs of - _ and . collapse to one -, lowercased, which also un-escapes a wheel.
 fn pep503(name: &str) -> String {
     let mut out = String::with_capacity(name.len());

core/tests/config.rs

@@ -84,6 +84,15 @@ async fn a_mirror_is_screened_like_the_registry_it_copies() {
     assert!(loaded.is_err());
 }
 
+#[tokio::test]
+async fn a_pypi_mirror_screens_the_files_it_serves() {
+    let config = r#"{"registries": {"pypi": ["https://art.example.com/pypi/"]}}"#;
+    let firewall = Firewall::new(serde_json::from_str(config).expect("parses"));
+    let url = "https://art.example.com/pypi/packages/ab/cd/six-1.16.0-py2.py3-none-any.whl";
+    let (registry, rest) = firewall.match_on(url, |r| r.upstream).expect("the mirror");
+    assert_eq!(firewall.resolve(registry, rest).pkg.map(|p| p.label()), Some("[email protected]".into()));
+}
+
 #[tokio::test]
 async fn an_allowed_version_is_still_checked_for_malware() {
     // The unreachable denylist shows that it still runs.

core/tests/forward.rs

@@ -65,3 +65,16 @@ async fn downgrade_touches_known_hosts_in_text_only() {
     let binary = vec![0x1f, 0x8b, 0xff, 0xfe];
     assert_eq!(downgrade(&firewall, binary.clone()), binary);
 }
+
+#[tokio::test]
+async fn a_mirror_stands_in_for_its_registry() {
+    let mut config = FirewallConfig::default();
+    config.registries.insert("pypi".into(), vec!["https://art.example.com/pypi/".into()]);
+    let firewall = Firewall::new(config);
+    let mirrored = firewall.mirrored("https://pypi.org/simple/six/".into());
+    assert_eq!(mirrored, "https://art.example.com/pypi/simple/six/");
+    let npm = "https://registry.npmjs.org/left-pad";
+    assert_eq!(firewall.mirrored(npm.into()), npm);
+    let links = b"https://art.example.com/pypi/packages/six.whl".to_vec();
+    assert_eq!(downgrade(&firewall, links), b"http://pypi.org/packages/six.whl".to_vec());
+}

macos/App/FirewallModel.swift

@@ -230,7 +230,7 @@ final class FirewallModel: NSObject, ObservableObject {
                     blocked.append(package)
                     if let allowance = BlockAlert.show(package) { await allow(package, allowance) }
                 }
-                blocked = Array(blocked.suffix(10))
+                if blocked.count > 10 { blocked.removeFirst(blocked.count - 10) }
             }
             try? await Task.sleep(nanoseconds: 500_000_000)
         }