iptvnator/docs/architecture/electron-security.md

Electron Security Contract

This document records the Electron runtime security contract for the desktop app.

BrowserWindow Defaults

The main window is created in apps/electron-backend/src/app/app.ts with an explicit hardened webPreferences object:

• contextIsolation: true
• nodeIntegration: false
• sandbox: !frameCopyExperiment — true by default; the opt-in Embedded MPV frame-copy experiment is the one path that disables the renderer sandbox (contextIsolation/nodeIntegration stay hardened regardless)
• webSecurity: true
• preload: apps/electron-backend/src/app/api/main.preload.ts

Renderer code must use the preload bridge exposed as window.electron. Do not re-enable direct Node.js access from Angular code. New desktop-only APIs should be added to the preload bridge and backed by an ipcMain.handle(...) owner in the Electron backend.

Preload API Type Contract

The canonical renderer bridge type is libs/shared/interfaces/src/lib/electron-api.interface.ts.

Keep these surfaces in sync when adding or changing a preload method:

1. ElectronBridgeApi in @iptvnator/shared/interfaces
2. apps/electron-backend/src/app/api/main.preload.ts
3. the owning ipcMain.handle(...) event module
4. renderer capability checks or runtime bridge services that consume the method

global.d.ts and apps/web/src/typings.d.ts should reference ElectronBridgeApi instead of redeclaring window.electron method lists. main.preload.ts is typed as ElectronBridgeApi, so missing or extra preload methods fail typecheck instead of silently drifting from renderer typings.

Navigation And External URLs

The main window owns three navigation gates:

• setWindowOpenHandler denies every new window. http: and https: targets are opened in the operating system browser through shell.openExternal.
• will-navigate allows only the trusted renderer URL. Development mode allows http://localhost:4200, http://127.0.0.1:4200, and http://[::1]:4200.
• will-redirect applies the same allow/deny rules so server-side redirects cannot move the app window to an untrusted origin.

Packaged mode allows only the app's resolved index.html renderer file, not arbitrary file: URLs. External web navigations are denied in the app window and opened in the operating system browser.

Do not add broad protocol allow-lists for renderer navigation. If a new desktop-only flow needs to open a URL outside IPTVnator, route it through the default browser unless the app window is deliberately meant to host that URL.

Desktop Auto Updates

Desktop application updates are owned by the Electron main process. Renderer code talks only through the typed preload bridge:

• window.electron.getAppUpdateStatus()
• window.electron.checkForAppUpdate()
• window.electron.downloadAppUpdate()
• window.electron.installAppUpdate()
• window.electron.getAppUpdateReleaseNotes(...)
• window.electron.onAppUpdateStatusChange(...)

The backend implementation lives in apps/electron-backend/src/app/services/app-update.service.ts and registers IPC handlers through apps/electron-backend/src/app/events/app-update.events.ts. The service uses electron-updater with autoDownload = false, so renderer actions explicitly ask to download and install. The main process starts one packaged startup check after IPC registration; it never downloads during that check. After a successful download, the renderer may show a restart/install action backed by quitAndInstall().

Self-update is supported only for packaged macOS builds, Windows NSIS builds, and Linux AppImage builds. Other Linux packages still point users to the latest GitHub Release through manualDownloadUrl because Snap, Flatpak, DEB, RPM, and Pacman installs have package-manager/store-specific update ownership. Packaged non-AppImage Linux builds may still check GitHub Releases for a newer stable version, but their update action remains a browser handoff to GitHub.

Release notes are also fetched by the main process from the public GitHub Releases API. The updater service caches release pages lazily and filters out draft/prerelease entries before returning Markdown to the renderer. The Angular dialog renders that Markdown with the local Markdown renderer and Angular HTML sanitization; do not bypass sanitizer for release body content.

Release CI must publish both installer artifacts and updater metadata generated by electron-builder (latest.yml, latest-mac.yml, latest-linux*.yml, and blockmap files when present). macOS must keep a signed/notarized app bundle, produce both dmg and zip targets, and publish a single merged latest-mac.yml containing both x64 and arm64 zip entries.

Content Security Policy

The Angular shell defines a baseline CSP in apps/web/src/index.html.

The policy keeps the application self-hosted for scripts, blocks object embedding (object-src 'none') while allowing frames only from https://www.youtube-nocookie.com (frame-src, used for TMDB trailers), limits forms to the app origin, and allows IPTV playback sources through media-src and connect-src for http:, https:, blob:, and data:. The policy keeps script-src self-hosted and currently keeps unsafe-inline for existing inline styles.

Angular production builds must not rely on inline event handlers for stylesheet activation. Keep web:build:production and web:build:pwa configured without critical CSS stylesheet deferral (optimization.styles.inlineCritical: false) unless the CSP is intentionally changed and runtime-validated in both Electron and the self-hosted PWA.

Before tightening either value, validate both Electron development startup and the PWA/electron build configurations. Playback-heavy changes should also check that HLS, MPEG-TS, thumbnails, and local file playback are still allowed by the policy.

Scoped Request Header Overrides

Inline playback can request temporary User-Agent, Referer, and Origin header overrides through window.electron.setUserAgent(userAgent, referer, scopeUrl).

The Electron backend handles that IPC in apps/electron-backend/src/app/events/shared.events.ts and delegates to apps/electron-backend/src/app/services/request-header-overrides.service.ts. The service registers one session.defaultSession.webRequest.onBeforeSendHeaders listener and updates layered in-memory overrides instead of stacking a new listener for every channel change.

Rules:

• empty playlist-level userAgent and referer clear all active overrides
• empty channel-level userAgent and referer with a scopeUrl clear only the scoped channel override, preserving playlist-level defaults
• channel playback should pass the stream URL as scopeUrl
• scoped overrides apply only to the active stream origin and referer origin
• playlist-level user agents and referrers may call the bridge without a scopeUrl; that is intentionally broader because playlist settings apply to the whole M3U playlist
• header names are replaced case-insensitively before canonical User-Agent, Referer, and Origin names are written

When changing this flow, keep stale header cleanup covered. Switching from a channel or playlist with custom headers to one without custom headers must clear the previous override.

Main-Process Remote Requests

Renderer-triggered HTTP requests must pass through the URL policy in apps/electron-backend/src/app/events/url-safety.ts. The policy rejects non-HTTP(S) URLs and embedded credentials, and strict callers also reject loopback, private, reserved, and DNS-resolved private addresses. IPv4-mapped IPv6 literals are decoded before classification, including hexadecimal forms such as ::ffff:7f00:1, so alternate IPv6 spelling cannot bypass IPv4 rules.

Remote request callers must use the validated Axios redirect helper so every redirect target is checked before the main process follows it. Under the strict policy, the helper pins the socket lookup to the IP addresses that passed validation while retaining the original hostname for TLS SNI, certificate validation, and virtual hosting. This prevents DNS rebinding between validation and connection. Callers with custom TLS policy provide a typed agent factory; the validated request layer supplies the pinned lookup instead of copying private Node Agent.options state. Credential stripping is scoped to the host rather than the origin, with one transport-security carve-out: same-hostname redirects that upgrade the scheme (http→https) or move ports keep Authorization, Cookie, basic auth, params, and request bodies, because IPTV portals routinely answer with such redirects and losing the session cookie/token there breaks the portal outright (#1158) while disclosing nothing to a third party. Redirects that change the host or downgrade https→http must not forward any of those — the former would hand provider credentials to a third party, the latter would replay a TLS-obtained session in cleartext.

EPG URLs are strict by default because an M3U playlist can supply them through url-tvg. Operators who intentionally use a LAN-hosted EPG source should prefer the renderer's source-scoped “Allow source” action, which persists the exact EPG URL in settings and retries that source only. The IPTVNATOR_ALLOW_PRIVATE_NETWORK_URLS=1 environment flag remains an emergency/development process-wide override for strict EPG fetches. Directly configured Xtream, Stalker, and playlist providers retain private-network support, but still require HTTP(S), reject embedded credentials, and validate redirects.

Callers that allow private-network provider URLs but only need redirects within the same provider origin should pass both allowPrivateNetworkRedirects: false and pinAllowedPrivateNetworkHosts: true to the validated Axios helper. This keeps same-origin LAN redirects working, reuses the initially resolved addresses for same-origin redirect hops, and requires cross-origin redirects to resolve to public addresses. A provider-controlled URL cannot bounce the Electron main process to another private or loopback host or rebind the same hostname between redirect hops.

Remote playlist TLS certificates are validated by default. The renderer can persist a host-scoped invalid-certificate trust decision for a playlist or EPG source host. The IPTVNATOR_ALLOW_INSECURE_TLS=1 escape hatch is only for explicitly trusted providers with invalid or self-signed certificates when the host-scoped UI path is not available.

Sensitive Diagnostic Logging

Settings, portal requests/responses, IPC trace payloads, and remote-request errors can contain provider credentials. Code at those boundaries must pass structured values through redactSensitiveData from @iptvnator/shared/logging, or through the portal createLogger/portal-debug helpers that apply it. Do not send a raw settings object, request params, response, or Error directly to console.*.

The redactor preserves non-sensitive diagnostic fields while replacing credential fields case-insensitively, including usernames, passwords, tokens, API keys, authorization/cookie headers, and MAC addresses. It also sanitizes URL query parameters, serialized JSON, nested query values, errors, arrays, and cyclic objects without mutating the original value. Depth, collection, object-key, and string limits keep opt-in debug traces bounded.

When adding a new logging boundary, extend the closest regression test with a synthetic secret and assert that the exact value is absent from captured log output. Never use a real provider credential to validate logging.

Filesystem Capabilities

Renderer IPC payloads are not filesystem authorization.

• write-file accepts only a path returned to the same renderer by the native save dialog. The capability is single-use and is consumed before the write, including when the filesystem operation fails.
• Download folders are owned by the Electron main process. The OS downloads directory is always allowed; a custom directory is accepted only after the native folder dialog selects it.
• The selected download directory is persisted under Electron userData and returned by DOWNLOADS_GET_DEFAULT_FOLDER, so renderer-managed settings cannot substitute an arbitrary host path.
• Downloads do not overwrite an existing destination file.
• Reveal and playback handlers accept only file paths recorded in IPTVnator's downloads database.