From 06f4f824d89251c5c2aa474f93ec790a587d08ae Mon Sep 17 00:00:00 2001
From: Thomas Sileo <t@a4.io>
Date: Fri, 25 May 2018 23:57:29 +0200
Subject: [PATCH] Tweak the webfinger resolution

---
 README.md          |  2 ++
 config.py          |  1 +
 utils/urlutils.py  | 11 ++++++++
 utils/webfinger.py | 68 ++++++++++++++++++++++++++--------------------
 4 files changed, 52 insertions(+), 30 deletions(-)

diff --git a/README.md b/README.md
index 9c96c79..d0a34da 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,8 @@
    - Privacy-aware image upload endpoint that strip EXIF meta data before storing the file
  - No JavaScript, that's it, even the admin UI is pure HTML/CSS
  - Easy to customize (the theme is written Sass)
+   - mobile-friendly theme
+   - with dark and light version
  - Microformats aware (exports `h-feed`, `h-entry`, `h-cards`, ...)
  - Exports RSS/Atom feeds
  - Comes with a tiny HTTP API to help posting new content and performing basic actions
diff --git a/config.py b/config.py
index 12f0ae9..6002350 100644
--- a/config.py
+++ b/config.py
@@ -44,6 +44,7 @@ with open('config/me.yml') as f:
     ICON_URL = conf['icon_url']
     PASS = conf['pass']
     PUBLIC_INSTANCES = conf.get('public_instances')
+    # TODO(tsileo): choose dark/light style
     THEME_COLOR = conf.get('theme_color')
 
 USER_AGENT = (
diff --git a/utils/urlutils.py b/utils/urlutils.py
index 3e9087e..be37c99 100644
--- a/utils/urlutils.py
+++ b/utils/urlutils.py
@@ -9,6 +9,10 @@ from . import strtobool
 logger = logging.getLogger(__name__)
 
 
+class InvalidURLError(Exception):
+    pass
+
+
 def is_url_valid(url: str) -> bool:
     parsed = urlparse(url)
     if parsed.scheme not in ['http', 'https']:
@@ -33,3 +37,10 @@ def is_url_valid(url: str) -> bool:
         return False
 
     return True
+
+
+def check_url(url: str) -> None:
+    if not is_url_valid(url):
+        raise InvalidURLError(f'"{url}" is invalid')
+
+    return None
diff --git a/utils/webfinger.py b/utils/webfinger.py
index 296ecae..93f33df 100644
--- a/utils/webfinger.py
+++ b/utils/webfinger.py
@@ -1,15 +1,25 @@
-from typing import Optional
 from urllib.parse import urlparse
+from typing import Dict, Any
+from typing import Optional
+import logging
 
 import requests
 
-def get_remote_follow_template(resource: str) -> Optional[str]:
-    """Mastodon-like WebFinger resolution to retrieve the activity stream Actor URL.
+from .urlutils import check_url
 
-    Returns:
-        the Actor URL or None if the resolution failed.
+
+logger = logging.getLogger(__name__)
+
+
+def webfinger(resource: str) -> Optional[Dict[str, Any]]:
+    """Mastodon-like WebFinger resolution to retrieve the activity stream Actor URL.
     """
-    if resource.startswith('http'):
+    logger.info(f'performing webfinger resolution for {resource}')
+    protos = ['https', 'http']
+    if resource.startswith('http://'):
+        protos.reverse()
+        host = urlparse(resource).netloc
+    elif resource.startswith('https://'):
         host = urlparse(resource).netloc
     else:
         if resource.startswith('acct:'):
@@ -18,15 +28,30 @@ def get_remote_follow_template(resource: str) -> Optional[str]:
             resource = resource[1:]
         _, host = resource.split('@', 1)
         resource='acct:'+resource
-    resp = requests.get(
-        f'https://{host}/.well-known/webfinger',
-        {'resource': resource}
-    )
-    print(resp, resp.request.url)
+
+    # Security check on the url (like not calling localhost)
+    check_url(f'https://{host}')
+
+    for i, proto in enumerate(protos):
+        try:
+            url = f'{proto}://{host}/.well-known/webfinger'
+            resp = requests.get(
+                url,
+                {'resource': resource}
+            )
+        except requests.ConnectionError:
+            # If we tried https first and the domain is "http only"
+            if i == 0:
+                continue
+            break
     if resp.status_code == 404:
         return None
     resp.raise_for_status()
-    data = resp.json()
+    return resp.json()
+ 
+
+def get_remote_follow_template(resource: str) -> Optional[str]:
+    data = webfinger(resource)
     for link in data['links']:
         if link.get('rel') == 'http://ostatus.org/schema/1.0/subscribe':
             return link.get('template')
@@ -39,24 +64,7 @@ def get_actor_url(resource: str) -> Optional[str]:
     Returns:
         the Actor URL or None if the resolution failed.
     """
-    if resource.startswith('http'):
-        host = urlparse(resource).netloc
-    else:
-        if resource.startswith('acct:'):
-            resource = resource[5:]
-        if resource.startswith('@'):
-            resource = resource[1:]
-        _, host = resource.split('@', 1)
-        resource='acct:'+resource
-    resp = requests.get(
-        f'https://{host}/.well-known/webfinger',
-        {'resource': resource}
-    )
-    print(resp, resp.request.url)
-    if resp.status_code == 404:
-        return None
-    resp.raise_for_status()
-    data = resp.json()
+    data = webfinger(resource)
     for link in data['links']:
         if link.get('rel') == 'self' and link.get('type') == 'application/activity+json':
             return link.get('href')