Stealth profile consistency (#269)

* feat(stealth): randomize browser profile per session

Add a pool of 8 realistic browser profiles (Win10/Win11/macOS, Chrome
143-146). One is picked randomly per BrowserContext instead of always
advertising Linux, which is a strong bot signal.

Each profile keeps navigator.platform, userAgentData.platform, and
userAgentData.platformVersion internally consistent with the UA string.

- profiles.rs: static PROFILES pool + random_profile() picker
- context.rs: pick profile on construction, store platform fields
- page.rs: call rt.set_platform() alongside rt.set_user_agent()
- runtime.rs: add set_platform() to inject __obscura_platform globals
- bootstrap.js: read platform/userAgentData from globals (default Win32)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* feat(stealth): match GPU renderer pool to OS profile

Windows profiles get ANGLE Direct3D11 renderers; macOS profiles get
ANGLE Metal renderers. Vendor strings updated to match (Google Inc. (Apple)
for Apple Silicon/Intel Mac, Google Inc. (NVIDIA/AMD/Intel) for Windows).

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* fix(stealth): navigator.webdriver returns false instead of undefined

Browsers set navigator.webdriver to false when automation is not active.
Returning undefined is a detectable bot signal — fingerprinting scripts
check typeof navigator.webdriver === 'boolean' as part of headless detection.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

* Make stealth profile stable by default, rotation opt-in

Picking a random profile per BrowserContext meant one address would cycle
through different browser identities, which is itself a bot signal, and the
rotated profile carries no matching TLS or timezone fingerprint. Default to a
single stable profile; opt into rotation with OBSCURA_ROTATE_PROFILE, or pin
one with OBSCURA_PROFILE=<index>.

Drive timezone from the process TZ so Intl.DateTimeFormat and Date report one
consistent zone. Default Europe/Berlin; override with OBSCURA_TIMEZONE.

Update navigator.webdriver test to expect false, matching real Chrome.

---------

Co-authored-by: SGavrl <[email protected]>

crates/obscura-browser/src/context.rs

@@ -8,6 +8,9 @@ pub struct BrowserContext {
     pub cookie_jar: Arc<CookieJar>,
     pub http_client: Arc<ObscuraHttpClient>,
     pub user_agent: String,
+    pub platform: String,
+    pub ua_platform: String,
+    pub ua_platform_version: String,
     pub proxy_url: Option<String>,
     pub robots_cache: Arc<RobotsCache>,
     pub obey_robots: bool,
@@ -103,9 +106,11 @@ impl BrowserContext {
         if stealth {
             client.block_trackers = true;
         }
-        let resolved_ua = user_agent.unwrap_or_else(|| {
+        let profile = crate::profiles::select_profile();
-            "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36".to_string()
+        let resolved_ua = user_agent.unwrap_or_else(|| profile.user_agent.to_string());
-        });
+        let platform = profile.platform.to_string();
+        let ua_platform = profile.ua_platform.to_string();
+        let ua_platform_version = profile.ua_platform_version.to_string();
         // Sync the http client's UA at construction so navigation requests pick it
         // up before any async setup runs. The lock has no other holders here, so
         // try_write always succeeds; we fall back silently if it ever fails.
@@ -118,6 +123,9 @@ impl BrowserContext {
             cookie_jar,
             http_client,
             user_agent: resolved_ua,
+            platform,
+            ua_platform,
+            ua_platform_version,
             proxy_url,
             robots_cache: Arc::new(RobotsCache::new()),
             obey_robots: false,

crates/obscura-browser/src/lib.rs

@@ -1,6 +1,7 @@
 pub mod page;
 pub mod context;
 pub mod lifecycle;
+pub mod profiles;
 
 pub use page::{NetworkEvent, Page, PageError};
 pub use context::BrowserContext;

crates/obscura-browser/src/page.rs

@@ -267,6 +267,11 @@ impl Page {
         if let Ok(ua) = self.http_client.user_agent.try_read() {
             rt.set_user_agent(&ua);
         }
+        rt.set_platform(
+            &self.context.platform,
+            &self.context.ua_platform,
+            &self.context.ua_platform_version,
+        );
 
         rt.set_cookie_jar(self.context.cookie_jar.clone());
         rt.set_http_client(self.http_client.clone());

crates/obscura-browser/src/profiles.rs

@@ -0,0 +1,103 @@
+pub struct BrowserProfile {
+    pub user_agent: &'static str,
+    pub platform: &'static str,
+    pub ua_platform: &'static str,
+    pub ua_platform_version: &'static str,
+}
+
+pub static PROFILES: &[BrowserProfile] = &[
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36",
+        platform: "Win32",
+        ua_platform: "Windows",
+        ua_platform_version: "10.0.0",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36",
+        platform: "Win32",
+        ua_platform: "Windows",
+        ua_platform_version: "10.0.0",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36",
+        platform: "Win32",
+        ua_platform: "Windows",
+        ua_platform_version: "15.0.0",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36",
+        platform: "Win32",
+        ua_platform: "Windows",
+        ua_platform_version: "15.0.0",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36",
+        platform: "MacIntel",
+        ua_platform: "macOS",
+        ua_platform_version: "13.6.7",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36",
+        platform: "MacIntel",
+        ua_platform: "macOS",
+        ua_platform_version: "14.4.1",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36",
+        platform: "MacIntel",
+        ua_platform: "macOS",
+        ua_platform_version: "14.5.0",
+    },
+    BrowserProfile {
+        user_agent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36",
+        platform: "MacIntel",
+        ua_platform: "macOS",
+        ua_platform_version: "14.6.0",
+    },
+];
+
+pub fn random_profile() -> &'static BrowserProfile {
+    let idx = (std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap_or_default()
+        .subsec_nanos() as usize)
+        % PROFILES.len();
+    &PROFILES[idx]
+}
+
+/// Pick the profile for a new browser context.
+///
+/// The default is a single stable profile. Cycling through different browser
+/// identities from one address is itself a bot signal (a real address maps to a
+/// stable device), and the rotated profile does not yet carry a matching TLS or
+/// timezone fingerprint, so rotation is opt-in:
+///   OBSCURA_PROFILE=<index>   pin a specific profile from PROFILES
+///   OBSCURA_ROTATE_PROFILE=1  pick a random profile per context
+pub fn select_profile() -> &'static BrowserProfile {
+    if let Some(idx) = std::env::var("OBSCURA_PROFILE")
+        .ok()
+        .as_deref()
+        .map(str::trim)
+        .and_then(|s| s.parse::<usize>().ok())
+    {
+        if idx < PROFILES.len() {
+            return &PROFILES[idx];
+        }
+    }
+    if env_enabled("OBSCURA_ROTATE_PROFILE") {
+        return random_profile();
+    }
+    &PROFILES[0]
+}
+
+fn env_enabled(key: &str) -> bool {
+    matches!(
+        std::env::var(key)
+            .ok()
+            .as_deref()
+            .map(str::trim)
+            .map(str::to_ascii_lowercase)
+            .as_deref(),
+        Some("1") | Some("true") | Some("yes") | Some("on")
+    )
+}

crates/obscura-cli/src/main.rs

@@ -269,6 +269,20 @@ fn effective_v8_flags(user: Option<&str>) -> String {
 async fn main() -> anyhow::Result<()> {
     let args = Args::parse();
 
+    // Pin the process timezone before V8/ICU reads it. V8 sources the zone for
+    // both Date (getTimezoneOffset, toString) and Intl.DateTimeFormat from TZ; left
+    // unset it defaults to UTC for Date while the page layer advertised a different
+    // zone, a cross-surface mismatch fingerprinting scripts flag. Default to
+    // Europe/Berlin; set OBSCURA_TIMEZONE to match the exit IP's region. An existing
+    // TZ from the host is respected.
+    // SAFETY: runs before any V8 isolate or worker thread starts, so the env is
+    // effectively single threaded here.
+    if let Some(tz) = std::env::var("OBSCURA_TIMEZONE").ok().filter(|s| !s.trim().is_empty()) {
+        unsafe { std::env::set_var("TZ", tz); }
+    } else if std::env::var_os("TZ").is_none() {
+        unsafe { std::env::set_var("TZ", "Europe/Berlin"); }
+    }
+
     let quiet = is_quiet_command(&args.command);
     let filter = select_log_filter(args.verbose, quiet);
     tracing_subscriber::fmt()

crates/obscura-js/js/bootstrap.js

@@ -72,7 +72,15 @@ function _fpNoise(x, y, channel) {
 var _fpCache = null;
 function _getFp() {
   if (_fpCache) return _fpCache;
-  const gpuPool = [
+  const isMac = (globalThis.__obscura_ua_platform || 'Windows') === 'macOS';
+  const gpuPool = isMac ? [
+    'ANGLE (Apple, ANGLE Metal Renderer: Apple M1, Unspecified Version)',
+    'ANGLE (Apple, ANGLE Metal Renderer: Apple M1 Pro, Unspecified Version)',
+    'ANGLE (Apple, ANGLE Metal Renderer: Apple M2, Unspecified Version)',
+    'ANGLE (Apple, ANGLE Metal Renderer: Apple M2 Pro, Unspecified Version)',
+    'ANGLE (Apple, ANGLE Metal Renderer: Apple M3, Unspecified Version)',
+    'ANGLE (Intel Inc., ANGLE Metal Renderer: Intel(R) Iris(TM) Plus Graphics, Unspecified Version)',
+  ] : [
     'ANGLE (NVIDIA, NVIDIA GeForce RTX 3060 Direct3D11 vs_5_0 ps_5_0, D3D11)',
     'ANGLE (NVIDIA, NVIDIA GeForce GTX 1660 SUPER Direct3D11 vs_5_0 ps_5_0, D3D11)',
     'ANGLE (NVIDIA, NVIDIA GeForce RTX 2070 SUPER Direct3D11 vs_5_0 ps_5_0, D3D11)',
@@ -86,7 +94,11 @@ function _getFp() {
     'ANGLE (AMD, AMD Radeon RX 5700 XT Direct3D11 vs_5_0 ps_5_0, D3D11)',
     'ANGLE (NVIDIA, NVIDIA GeForce RTX 3080 Direct3D11 vs_5_0 ps_5_0, D3D11)',
   ];
-  const gpuVendorPool = [
+  const gpuVendorPool = isMac ? [
+    'Google Inc. (Apple)','Google Inc. (Apple)','Google Inc. (Apple)',
+    'Google Inc. (Apple)','Google Inc. (Apple)',
+    'Google Inc. (Intel Inc.)',
+  ] : [
     'Google Inc. (NVIDIA)','Google Inc. (NVIDIA)','Google Inc. (NVIDIA)',
     'Google Inc. (Intel)','Google Inc. (Intel)',
     'Google Inc. (AMD)','Google Inc. (AMD)',
@@ -2354,14 +2366,14 @@ function _registerIframe(iframeEl) {
 globalThis.navigator = {
   get userAgent() { return globalThis.__obscura_ua || "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36"; },
   get appVersion() { return this.userAgent.replace('Mozilla/', ''); },
-  language: "en-US", languages: ["en-US","en"], platform: "Linux x86_64",
+  language: "en-US", languages: ["en-US","en"], get platform() { return globalThis.__obscura_platform || "Win32"; },
   onLine: true, cookieEnabled: true, hardwareConcurrency: 8,
   maxTouchPoints: 0,
   vendor: "Google Inc.", product: "Gecko", productSub: "20030107",
   doNotTrack: null,
   deviceMemory: 8,
   connection: { effectiveType: "4g", rtt: 50, downlink: 10, saveData: false },
-  get webdriver() { return undefined; },
+  get webdriver() { return false; },
   pdfViewerEnabled: true,
   get plugins() {
     const p = [
@@ -2393,7 +2405,7 @@ globalThis.navigator = {
       {brand: "Not=A?Brand", version: "24"},
     ],
     mobile: false,
-    platform: "Linux",
+    get platform() { return globalThis.__obscura_ua_platform || "Windows"; },
     getHighEntropyValues(hints) {
       return Promise.resolve({
         architecture: "x86",
@@ -2402,8 +2414,8 @@ globalThis.navigator = {
         fullVersionList: [{brand:"Google Chrome",version:"145.0.0.0"},{brand:"Chromium",version:"145.0.0.0"},{brand:"Not=A?Brand",version:"24.0.0.0"}],
         mobile: false,
         model: "",
-        platform: "Linux",
+        platform: globalThis.__obscura_ua_platform || "Windows",
-        platformVersion: "6.8.0",
+        platformVersion: globalThis.__obscura_ua_platform_version || "15.0.0",
         uaFullVersion: "145.0.0.0",
       });
     },
@@ -5509,21 +5521,10 @@ _markNative(SpeechSynthesisUtterance);
 _markNative(MediaStream); _markNative(MediaStreamTrack);
 _markNative(RTCPeerConnection); _markNative(RTCSessionDescription); _markNative(RTCIceCandidate);
 
-const _OrigDateTimeFormat = Intl.DateTimeFormat;
+// Timezone is driven by the process TZ (set by the CLI, default Europe/Berlin),
-const _defaultTZ = 'Europe/Berlin';
+// so native Intl.DateTimeFormat and Date report the same zone. No JS override:
-Intl.DateTimeFormat = function(locales, options) {
+// forcing a fixed zone here only on Intl left Date on UTC, which is the exact
-  if (!options) options = {};
+// cross-surface mismatch a fingerprinting script looks for.
-  if (!options.timeZone) options.timeZone = _defaultTZ;
-  return new _OrigDateTimeFormat(locales, options);
-};
-Intl.DateTimeFormat.prototype = _OrigDateTimeFormat.prototype;
-Intl.DateTimeFormat.supportedLocalesOf = _OrigDateTimeFormat.supportedLocalesOf;
-const _origResolved = _OrigDateTimeFormat.prototype.resolvedOptions;
-_OrigDateTimeFormat.prototype.resolvedOptions = function() {
-  const r = _origResolved.call(this);
-  if (r.timeZone === 'UTC') r.timeZone = _defaultTZ;
-  return r;
-};
 
 if (typeof PointerEvent === 'undefined') {
   globalThis.PointerEvent = class PointerEvent extends MouseEvent {

crates/obscura-js/src/runtime.rs

@@ -206,6 +206,19 @@ impl ObscuraJsRuntime {
             format!("globalThis.__obscura_ua = '{}';", escaped),
         );
     }
+
+    pub fn set_platform(&mut self, platform: &str, ua_platform: &str, ua_platform_version: &str) {
+        let p = platform.replace('\'', "\\'");
+        let uap = ua_platform.replace('\'', "\\'");
+        let uapv = ua_platform_version.replace('\'', "\\'");
+        let _ = self.runtime.execute_script(
+            "<set-platform>",
+            format!(
+                "globalThis.__obscura_platform='{}';globalThis.__obscura_ua_platform='{}';globalThis.__obscura_ua_platform_version='{}';",
+                p, uap, uapv
+            ),
+        );
+    }
     pub fn evaluate(&mut self, expression: &str) -> Result<serde_json::Value, String> {
         let wrapped = Self::wrap_expression(expression);
         let result = self
@@ -1511,7 +1524,7 @@ mod tests {
         let ua = rt.evaluate("navigator.userAgent").unwrap();
         assert!(ua.as_str().unwrap().contains("Chrome"), "UA should contain Chrome: {}", ua);
         let wd = rt.evaluate("navigator.webdriver").unwrap();
-        assert_eq!(wd, serde_json::Value::Null);
+        assert_eq!(wd, serde_json::json!(false));
         let plugins = rt.evaluate("navigator.plugins.length").unwrap();
         assert!(plugins.as_f64().unwrap() > 0.0, "Should have plugins");
         let chrome = rt.evaluate("typeof window.chrome").unwrap();