Add domain blacklisting

config.yml

@@ -66,3 +66,11 @@ show_github_link: true
 # Boolean: Allow short URLs linking to your site_domain URL
 # Default: false
 selflinks: false
+
+# List: Prevent creation of URLs linking to domains in the blacklist
+# Example of list formatting in yaml:
+# blacklist:
+#     - blacklisted.com
+#     - subdomain.blacklisted.net
+# Default: []
+blacklist: []

liteshort.py

@@ -38,6 +38,7 @@ def load_config():
         "subdomain": "",
         "latest": "l",
         "selflinks": False,
+        "blacklist": [],
     }
 
     config_types = {
@@ -54,6 +55,7 @@ def load_config():
         "subdomain": (str, type(None)),
         "latest": (str, type(None)),
         "selflinks": bool,
+        "blacklist": list,
     }
 
     for option in req_options.keys():
@@ -121,6 +123,14 @@ def check_self_link(long):
     return False
 
 
+def linking_to_blacklist(long):
+    # Removes protocol and other parts of the URL to extract the domain name
+    long = long.split("//")[-1].split("/")[0]
+    if long in current_app.config["blacklist"]:
+        return True
+    return False
+
+
 def check_password(password, pass_config):
     if pass_config["password_hashed"]:
         return bcrypt.checkpw(
@@ -333,6 +343,8 @@ def main_post():
             and not current_app.config["selflinks"]
         ):
             return response(request, None, "You cannot link to this site")
+        if linking_to_blacklist(request.form["long"]):
+            return response(request, None, "You cannot link to this blacklisted site")
         if long_exists and not request.form.get("short"):
             set_latest(request.form["long"])
             get_db().commit()