1 files changed, 89 insertions, 0 deletions
diff --git a/src/leap/soledad/u1db/remote/oauth_middleware.py b/src/leap/soledad/u1db/remote/oauth_middleware.py
new file mode 100644
index 00000000..5772580a
--- /dev/null
+++ b/src/leap/soledad/u1db/remote/oauth_middleware.py
@@ -0,0 +1,89 @@
+# Copyright 2012 Canonical Ltd.
+#
+# This file is part of u1db.
+#
+# u1db is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation.
+#
+# u1db is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with u1db.  If not, see <http://www.gnu.org/licenses/>.
+"""U1DB OAuth authorisation WSGI middleware."""
+import httplib
+from oauth import oauth
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
+from urllib import quote
+from wsgiref.util import shift_path_info
+
+
+sign_meth_HMAC_SHA1 = oauth.OAuthSignatureMethod_HMAC_SHA1()
+sign_meth_PLAINTEXT = oauth.OAuthSignatureMethod_PLAINTEXT()
+
+
+class OAuthMiddleware(object):
+    """U1DB OAuth Authorisation WSGI middleware."""
+
+    # max seconds the request timestamp is allowed to  be shifted
+    # from arrival time
+    timestamp_threshold = 300
+
+    def __init__(self, app, base_url, prefix='/~/'):
+        self.app = app
+        self.base_url = base_url
+        self.prefix = prefix
+
+    def get_oauth_data_store(self):
+        """Provide a oauth.OAuthDataStore."""
+        raise NotImplementedError(self.get_oauth_data_store)
+
+    def _error(self, start_response, status, description, message=None):
+        start_response("%d %s" % (status, httplib.responses[status]),
+                       [('content-type', 'application/json')])
+        err = {"error": description}
+        if message:
+            err['message'] = message
+        return [json.dumps(err)]
+
+    def __call__(self, environ, start_response):
+        if self.prefix and not environ['PATH_INFO'].startswith(self.prefix):
+            return self._error(start_response, 400, "bad request")
+        headers = {}
+        if 'HTTP_AUTHORIZATION' in environ:
+            headers['Authorization'] = environ['HTTP_AUTHORIZATION']
+        oauth_req = oauth.OAuthRequest.from_request(
+            http_method=environ['REQUEST_METHOD'],
+            http_url=self.base_url + environ['PATH_INFO'],
+            headers=headers,
+            query_string=environ['QUERY_STRING']
+            )
+        if oauth_req is None:
+            return self._error(start_response, 401, "unauthorized",
+                               "Missing OAuth.")
+        try:
+            self.verify(environ, oauth_req)
+        except oauth.OAuthError, e:
+            return self._error(start_response, 401, "unauthorized",
+                               e.message)
+        shift_path_info(environ)
+        return self.app(environ, start_response)
+
+    def verify(self, environ, oauth_req):
+        """Verify OAuth request, put user_id in the environ."""
+        oauth_server = oauth.OAuthServer(self.get_oauth_data_store())
+        oauth_server.timestamp_threshold = self.timestamp_threshold
+        oauth_server.add_signature_method(sign_meth_HMAC_SHA1)
+        oauth_server.add_signature_method(sign_meth_PLAINTEXT)
+        consumer, token, parameters = oauth_server.verify_request(oauth_req)
+        # filter out oauth bits
+        environ['QUERY_STRING'] = '&'.join("%s=%s" % (quote(k, safe=''),
+                                                      quote(v, safe=''))
+                                           for k, v in parameters.iteritems())
+        return consumer, token