Restrict debug bundle log path and upload destinations

client/server/debug_gate.go

@@ -0,0 +1,98 @@
+//go:build !android && !ios
+
+package server
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/internal/debug"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+	"github.com/netbirdio/netbird/upload-server/types"
+)
+
+// uiLogFileName is the only file name the daemon accepts as a UI log path,
+// shared with the bundle collector so the two cannot drift. It must also stay in
+// sync with the name the desktop UI writes (client/ui/uilogpath.go).
+const uiLogFileName = debug.UILogFile
+
+// uiLogOpener opens the registered UI log, and its rotated siblings, on behalf
+// of the caller requesting the bundle: OpenOwnedFile then collects the log only
+// when that caller owns it (or is privileged). identified is false on a socket
+// that carries no caller identity, in which case nothing is opened.
+func uiLogOpener(id ipcauth.Identity, identified bool) debug.LogOpener {
+	return func(path string) (*os.File, error) {
+		if !identified {
+			return nil, fmt.Errorf("bundle requester has no verified identity")
+		}
+		return ipcauth.OpenOwnedFile(id, path)
+	}
+}
+
+// requirePrivilegeForUploadURL restricts where the daemon may send a debug
+// bundle. The bundle holds the daemon's own logs and state, and the daemon
+// fetches the upload URL itself, so an unrestricted endpoint turns the daemon
+// into both an exfiltration channel and a request forwarder that reaches
+// services only it can talk to.
+//
+// The upload service NetBird publishes is open to any caller, since that is what
+// the CLI and the desktop UI use. Any other endpoint, self-hosted upload servers
+// included, requires a privileged caller. Plaintext is refused for everyone: the
+// daemon fetches the URL and then PUTs the bundle to whatever that fetch returns,
+// so an http hop is a place to intercept the bundle or the redirect.
+//
+// insecure relaxes transport security (http, or an untrusted TLS certificate)
+// for a self-hosted server. It weakens a root-privileged upload, so it is
+// refused for an unprivileged caller regardless of the host.
+func requirePrivilegeForUploadURL(ctx context.Context, rawURL string, insecure bool) error {
+	if rawURL == "" {
+		return nil
+	}
+
+	parsed, err := url.Parse(rawURL)
+	if err != nil {
+		return gstatus.Errorf(codes.InvalidArgument, "parse upload URL: %v", err)
+	}
+
+	// --insecure relaxes https to http or an untrusted certificate; it does not
+	// widen the URL to arbitrary schemes, so a host and http/https are required
+	// before the insecure branch takes over.
+	if parsed.Host == "" || (parsed.Scheme != "https" && parsed.Scheme != "http") {
+		return gstatus.Errorf(codes.InvalidArgument, "upload URL must be http or https with a host")
+	}
+
+	if insecure {
+		return denyPrivileged(ctx,
+			"uploading a debug bundle without transport security (--upload-bundle-insecure)",
+			ipcauth.ElevatedCommand("netbird debug bundle -U --upload-bundle-insecure --upload-bundle-url <url>"))
+	}
+
+	if parsed.Scheme != "https" {
+		return gstatus.Errorf(codes.InvalidArgument, "upload URL must use https, got scheme %q", parsed.Scheme)
+	}
+
+	if isDefaultUploadService(parsed) {
+		return nil
+	}
+
+	return denyPrivileged(ctx,
+		"uploading a debug bundle to an upload service other than the default one",
+		ipcauth.ElevatedCommand("netbird debug bundle -U --upload-bundle-url <url>"))
+}
+
+// isDefaultUploadService reports whether the URL points at the upload service
+// NetBird runs. Only the host is compared: the service's path may differ between
+// releases, and the host is what decides who receives the bundle.
+func isDefaultUploadService(parsed *url.URL) bool {
+	defaultURL, err := url.Parse(types.DefaultBundleURL)
+	if err != nil {
+		return false
+	}
+	return parsed.Scheme == defaultURL.Scheme && strings.EqualFold(parsed.Host, defaultURL.Host)
+}