feat(osr): report the real screen — removes a headless fingerprint#23
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… fingerprint An OSR browser whose GetScreenInfo reports screen == its own viewport is a textbook headless/embedded fingerprint: window.screen.width == innerWidth, screen.colorDepth == 0, and (with no GetRootScreenRect) window.outerHeight == innerHeight and screenX/screenY == 0. Bot-detection engines (reCAPTCHA, DataDome, Cloudflare) key on exactly these. Measured on a live tile before this change: outerHeight == innerHeight == 530, colorDepth 0, screenX/Y 0. Report the truth instead of the tell — this is NOT spoofing: - GetScreenInfo.rect / available_rect = the REAL NSScreen frame / visibleFrame (the actual monitor the app is on), with depth 24 / 8-bit components. - GetRootScreenRect (added) = a plausible window frame at a non-zero offset, taller than the view by typical browser chrome, so outerHeight > innerHeight. - GetViewRect (the render size) stays tile-sized — exactly like a real browser window is smaller than its screen. device_scale_factor (Retina) is preserved. - Falls back to a plausible 14"-class frame when there's no display (headless CI). Popups (<select>) and IME composite into our own surface from VIEW-relative coords, and GetScreenPoint is left at its default, so the screen/root-window change doesn't move them; a bigger screen rect only widens the popup clamp area. Measured after (same tile): outerHeight 617 > innerHeight 530, screen 1496x935 (the real display, not 800x560), colorDepth 24, screenX/Y 100/80. Page still renders, DOM still interactive. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Why
An OSR browser whose
GetScreenInforeports screen == its own viewport is a textbook headless/embedded fingerprint. Bot-detection engines (reCAPTCHA v3, DataDome, Cloudflare) key on exactly this. Measured on a live cefWebview tile before this change:outerHeightvsinnerHeightscreen.width × heightscreen.colorDepthscreenX/screenYWhat
Report the truth, not the tell — this is not spoofing:
GetScreenInfo.rect/available_rect= the realNSScreenframe/visibleFrame(the actual monitor), withdepth 24/ 8-bit components.GetRootScreenRect(added) = a plausible window frame at a non-zero offset, taller than the view by typical browser chrome, soouterHeight > innerHeight.GetViewRect(the render size) stays tile-sized — exactly as a real browser window is smaller than its screen.device_scale_factor(Retina) preserved.Popups (
<select>) and IME composite into our own surface from view-relative coords, andGetScreenPointis left at default, so the screen/root-window change doesn't move them; a larger screen rect only widens the popup clamp area.Validation (live)
Measured after on the same tile:
outerHeight/innerHeightscreen.width × heightcolorDepthscreenX/screenYPage still renders (example.org), DOM still interactive,
<select>+ input inject fine. No wire-protocol change.Context
One of several fingerprint tells for Campus's embedded webview. Note the honest ceiling: this removes a headless geometry signal, but captcha scoring is dominated by IP/account reputation, and Google's embedded-framework sign-in block is a separate deterministic policy neither this nor any fingerprint change clears.
🤖 Generated with Claude Code