1 files changed, 89 insertions, 0 deletions
diff --git a/macaroonbakery/httpbakery/_browser.py b/macaroonbakery/httpbakery/_browser.py
new file mode 100644
index 0000000..a1ccbb0
--- /dev/null
+++ b/macaroonbakery/httpbakery/_browser.py
@@ -0,0 +1,89 @@
+# Copyright 2017 Canonical Ltd.
+# Licensed under the LGPLv3, see LICENCE file for details.
+import base64
+from collections import namedtuple
+
+import requests
+from ._error import InteractionError
+from ._interactor import (
+    WEB_BROWSER_INTERACTION_KIND,
+    DischargeToken,
+    Interactor,
+    LegacyInteractor,
+)
+from macaroonbakery._utils import visit_page_with_browser
+
+from six.moves.urllib.parse import urljoin
+
+
+class WebBrowserInteractor(Interactor, LegacyInteractor):
+    ''' Handles web-browser-based interaction-required errors by opening a
+    web browser to allow the user to prove their credentials interactively.
+    '''
+    def __init__(self, open=visit_page_with_browser):
+        '''Create a WebBrowserInteractor that uses the given function
+        to open a browser window. The open function is expected to take
+        a single argument of string type, the URL to open.
+        '''
+        self._open_web_browser = open
+
+    def kind(self):
+        return WEB_BROWSER_INTERACTION_KIND
+
+    def legacy_interact(self, ctx, location, visit_url):
+        '''Implement LegacyInteractor.legacy_interact by opening the
+        web browser window'''
+        self._open_web_browser(visit_url)
+
+    def interact(self, ctx, location, ir_err):
+        '''Implement Interactor.interact by opening the browser window
+        and waiting for the discharge token'''
+        p = ir_err.interaction_method(self.kind(), WebBrowserInteractionInfo)
+        if not location.endswith('/'):
+            location += '/'
+        visit_url = urljoin(location, p.visit_url)
+        wait_token_url = urljoin(location, p.wait_token_url)
+        self._open_web_browser(visit_url)
+        return self._wait_for_token(ctx, wait_token_url)
+
+    def _wait_for_token(self, ctx, wait_token_url):
+        ''' Returns a token from a the wait token URL
+        @param wait_token_url URL to wait for (string)
+        :return DischargeToken
+        '''
+        resp = requests.get(wait_token_url)
+        if resp.status_code != 200:
+            raise InteractionError('cannot get {}'.format(wait_token_url))
+        json_resp = resp.json()
+        kind = json_resp.get('kind')
+        if kind is None:
+            raise InteractionError(
+                'cannot get kind token from {}'.format(wait_token_url))
+        token_val = json_resp.get('token')
+        if token_val is None:
+            token_val = json_resp.get('token64')
+            if token_val is None:
+                raise InteractionError(
+                    'cannot get token from {}'.format(wait_token_url))
+            token_val = base64.b64decode(token_val)
+        return DischargeToken(kind=kind, value=token_val)
+
+
+class WebBrowserInteractionInfo(namedtuple('WebBrowserInteractionInfo',
+                                           'visit_url, wait_token_url')):
+    ''' holds the information expected in the browser-window interaction
+    entry in an interaction-required error.
+
+    :param visit_url holds the URL to be visited in a web browser.
+    :param wait_token_url holds a URL that will block on GET until the browser
+    interaction has completed.
+    '''
+    @classmethod
+    def from_dict(cls, info_dict):
+        '''Create a new instance of WebBrowserInteractionInfo, as expected
+        by the Error.interaction_method method.
+        @param info_dict The deserialized JSON object
+        @return a new WebBrowserInteractionInfo object.
+        '''
+        return WebBrowserInteractionInfo(visit_url=info_dict.get('VisitURL'),
+                                         wait_token_url=info_dict('WaitURL'))