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: true
• 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.

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 and frame embedding, 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. Cross-origin redirects must not forward Authorization, Cookie, Proxy-Authorization, Axios params, or request bodies.

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 can opt in for that run with IPTVNATOR_ALLOW_PRIVATE_NETWORK_URLS=1. Directly configured Xtream, Stalker, and playlist providers retain private-network support, but still require HTTP(S), reject embedded credentials, and validate redirects.

Remote playlist TLS certificates are validated by default. The IPTVNATOR_ALLOW_INSECURE_TLS=1 escape hatch is only for explicitly trusted providers with invalid or self-signed certificates.

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.