1 files changed, 56 insertions, 0 deletions
diff --git a/macaroonbakery/httpbakery/keyring.py b/macaroonbakery/httpbakery/keyring.py
new file mode 100644
index 0000000..f4e93f7
--- /dev/null
+++ b/macaroonbakery/httpbakery/keyring.py
@@ -0,0 +1,56 @@
+# Copyright 2017 Canonical Ltd.
+# Licensed under the LGPLv3, see LICENCE file for details.
+from six.moves.urllib.parse import urlparse
+import requests
+
+import macaroonbakery
+
+
+class ThirdPartyLocator(macaroonbakery.ThirdPartyLocator):
+    ''' Implements macaroonbakery.ThirdPartyLocator by first looking in the
+    backing cache and, if that fails, making an HTTP request to find the
+    information associated with the given discharge location.
+    '''
+
+    def __init__(self, allow_insecure=False):
+        '''
+        @param url: the url to retrieve public_key
+        @param allow_insecure: By default it refuses to use insecure URLs.
+        '''
+        self._allow_insecure = allow_insecure
+        self._cache = {}
+
+    def third_party_info(self, loc):
+        u = urlparse(loc)
+        if u.scheme != 'https' and not self._allow_insecure:
+            raise macaroonbakery.ThirdPartyInfoNotFound(
+                'untrusted discharge URL {}'.format(loc))
+        loc = loc.rstrip('/')
+        info = self._cache.get(loc)
+        if info is not None:
+            return info
+        url_endpoint = '/discharge/info'
+        resp = requests.get(loc + url_endpoint)
+        status_code = resp.status_code
+        if status_code == 404:
+            url_endpoint = '/publickey'
+            resp = requests.get(loc + url_endpoint)
+            status_code = resp.status_code
+        if status_code != 200:
+            raise macaroonbakery.ThirdPartyInfoNotFound(
+                'unable to get info from {}'.format(url_endpoint))
+        json_resp = resp.json()
+        if json_resp is None:
+            raise macaroonbakery.ThirdPartyInfoNotFound(
+                'no response from /discharge/info')
+        pk = json_resp.get('PublicKey')
+        if pk is None:
+            raise macaroonbakery.ThirdPartyInfoNotFound(
+                'no public key found in /discharge/info')
+        idm_pk = macaroonbakery.PublicKey.deserialize(pk)
+        version = json_resp.get('Version', macaroonbakery.BAKERY_V1)
+        self._cache[loc] = macaroonbakery.ThirdPartyInfo(
+            version=version,
+            public_key=idm_pk
+        )
+        return self._cache.get(loc)