--- a/cagou/core/platform_/base.py	Sat Jan 04 16:24:57 2020 +0100
+++ b/cagou/core/platform_/base.py	Sat Jan 04 16:24:57 2020 +0100
@@ -16,7 +16,17 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import webbrowser
+from pathlib import Path
+from urllib.parse import urlparse
 from kivy.config import Config as KivyConfig
+from sat.core.log import getLogger
+from sat.tools.common import files_utils
+from sat_frontends.quick_frontend.quick_widgets import QuickWidget
+from cagou import G
+
+
+log = getLogger(__name__)
 
 
 class Platform:
@@ -46,3 +56,33 @@
 
     def on_stop(self):
         pass
+
+    def open_url(self, url, wid=None):
+        """Open an URL in the way appropriate for the platform
+
+        @param url(str): URL to open
+        @param wid(CagouWidget, None): widget requesting the opening
+            it may influence the way the URL is opened
+        """
+        parsed_url = urlparse(url)
+        if parsed_url.scheme == "aesgcm" and wid is not None:
+            # aesgcm files need to be decrypted first
+            # so we download them before opening
+            name = Path(parsed_url.path).name.strip() or "unnamed_file"
+            log.info(f"downloading/decrypting file {name!r}")
+            dest_path = files_utils.get_unique_name(Path(G.host.downloads_dir)/name)
+            quick_widget = G.host.getAncestorWidget(wid, QuickWidget)
+            if quick_widget is None:
+                log.error("Can't find ancestor QuickWidget")
+                return
+            profile = quick_widget.profile
+            G.host.bridge.fileDownloadComplete(
+                url,
+                str(dest_path),
+                '',
+                profile,
+                callback=webbrowser.open,
+                errback=G.host.errback
+            )
+        else:
+            webbrowser.open(url)