fix(desktop): allow self-signed remote HTTPS on Linux

Use WebKitGTK TLS exceptions for remote windows so Linux no longer depends on system CA installation or sudo-managed trust stores.

packages/tauri-app/src-tauri/src/linux_tls.rs

@@ -0,0 +1,88 @@
+use crate::AppState;
+use tauri::{AppHandle, Manager, WebviewWindow};
+use url::Url;
+use webkit2gtk::{WebContextExt, WebView, WebViewExt};
+
+pub fn should_bootstrap_tls_navigation(target_url: &Url, skip_tls_verify: bool) -> bool {
+    skip_tls_verify && target_url.scheme() == "https"
+}
+
+pub fn ensure_remote_window_tls_handler(
+    window: &WebviewWindow,
+    app_handle: &AppHandle,
+    window_label: &str,
+) -> Result<(), String> {
+    {
+        let state = app_handle.state::<AppState>();
+        let mut handlers = state
+            .remote_tls_handlers
+            .lock()
+            .map_err(|err| err.to_string())?;
+        if !handlers.insert(window_label.to_string()) {
+            return Ok(());
+        }
+    }
+
+    let app_handle = app_handle.clone();
+    let window_label = window_label.to_string();
+    window
+        .with_webview(move |platform_webview| {
+            let webview = platform_webview.inner();
+            let app_handle = app_handle.clone();
+            let window_label = window_label.clone();
+            webview.connect_load_failed_with_tls_errors(move |view, failing_uri, certificate, _| {
+                allow_remote_tls_certificate(
+                    &app_handle,
+                    &window_label,
+                    view,
+                    failing_uri,
+                    certificate,
+                )
+            });
+        })
+        .map_err(|err| err.to_string())
+}
+
+fn allow_remote_tls_certificate(
+    app_handle: &AppHandle,
+    window_label: &str,
+    view: &WebView,
+    failing_uri: &str,
+    certificate: &webkit2gtk::gio::TlsCertificate,
+) -> bool {
+    let Ok(parsed_uri) = Url::parse(failing_uri) else {
+        return false;
+    };
+    let Some(host) = parsed_uri.host_str() else {
+        return false;
+    };
+
+    let state = app_handle.state::<AppState>();
+    let skip_tls_verify = state
+        .remote_skip_tls_verify
+        .lock()
+        .ok()
+        .and_then(|values| values.get(window_label).copied())
+        .unwrap_or(false);
+    if !skip_tls_verify {
+        return false;
+    }
+
+    let expected_origin = state
+        .remote_origins
+        .lock()
+        .ok()
+        .and_then(|origins| origins.get(window_label).cloned());
+    let parsed_origin = parsed_uri.origin().ascii_serialization();
+    if expected_origin.as_deref() != Some(parsed_origin.as_str()) {
+        return false;
+    }
+
+    let Some(context) = view.context() else {
+        return false;
+    };
+
+    context.allow_tls_certificate_for_host(certificate, host);
+    view.load_uri(failing_uri);
+    true
+}