1 files changed, 60 insertions, 0 deletions
diff --git a/cloud_mdir_sync/oauth.py b/cloud_mdir_sync/oauth.py
new file mode 100644
index 0000000..449d16c
--- /dev/null
+++ b/cloud_mdir_sync/oauth.py
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: GPL-2.0+
+import asyncio
+
+import aiohttp
+import aiohttp.web
+
+
+class WebServer(object):
+    """A small web server is used to manage oauth requests. The user should point a browser
+    window at localhost. The program will generate redirects for the browser to point at
+    OAUTH servers when interactive authentication is required."""
+    url = "http://localhost:8080/"
+    runner = None
+
+    def __init__(self):
+        self.auth_redirs = {}
+        self.web_app = aiohttp.web.Application()
+        self.web_app.router.add_get("/", self._start)
+        self.web_app.router.add_get("/oauth2/msal", self._oauth2_msal)
+
+    async def go(self):
+        self.runner = aiohttp.web.AppRunner(self.web_app)
+        await self.runner.setup()
+        site = aiohttp.web.TCPSite(self.runner, 'localhost', 8080)
+        await site.start()
+
+    async def close(self):
+        if self.runner:
+            await self.runner.cleanup()
+
+    async def auth_redir(self, url, state):
+        """Call as part of an OAUTH flow to hand the URL off to interactive browser
+        based authentication.  The flow will resume when the OAUTH server
+        redirects back to the localhost server.  The final query paremeters
+        will be returned by this function"""
+        queue = asyncio.Queue()
+        self.auth_redirs[state] = (url, queue)
+        return await queue.get()
+
+    def _start(self, request):
+        """Feed redirects to the web browser until all authing is done.  FIXME: Some
+        fancy java script should be used to fetch new interactive auth
+        requests"""
+        for I in self.auth_redirs.values():
+            raise aiohttp.web.HTTPFound(I[0])
+        return aiohttp.web.Response(text="Authentication done")
+
+    def _oauth2_msal(self, request):
+        """Use for the Azure AD authentication response redirection"""
+        state = request.query["state"]
+        try:
+            queue = self.auth_redirs[state][1]
+            del self.auth_redirs[state]
+            queue.put_nowait(request.query)
+        except KeyError:
+            pass
+
+        for I in self.auth_redirs.values():
+            raise aiohttp.web.HTTPFound(I[0])
+        raise aiohttp.web.HTTPFound(self.url)