TypeError: Incorrect padding

[cedwards]

I'm running d-note on CentOS 7 using uwsgi Emperor. I get the following exception in the /var/log/dnote.log:

[pid: 8395|app: 0|req: 13/58] 10.30.82.185 () {44 vars in 732 bytes} [Tue Mar 17 08:45:58 2015] GET /dnote/ => generated 4990 bytes in 386 msecs (HTTP/1.1 200) 2 headers in 81 bytes (1 switches on core 1)
ERROR:dnote:Exception on /on.ico [GET]
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/srv/http/dnote/dnote/__init__.py", line 62, in fetch_url
    note = Note(random_url)
  File "/srv/http/dnote/dnote/note.py", line 68, in __init__
    self.decode_url(url)
  File "/srv/http/dnote/dnote/note.py", line 111, in decode_url
    self.nonce = base64.urlsafe_b64decode(url.encode("utf-8"))
  File "/usr/lib64/python2.7/base64.py", line 112, in urlsafe_b64decode
    return b64decode(s, '-_')
  File "/usr/lib64/python2.7/base64.py", line 76, in b64decode
    raise TypeError(msg)
TypeError: Incorrect padding

[Thijssss]

I ran in to this same issue. Apache cannot overwrite the DocumentError for WSGI unless its running as a deamon. I figured I would just patch it locally for now to get around the issue all together. I used a random word which works OK to get back a regular error message:

--- /linux/d-note-master/dnote/note.py  2015-10-29 21:16:22.000000000 +0100
+++ note.py     2017-01-09 11:51:28.030837067 +0100
@@ -108,8 +108,14 @@

         self.url = url
         url = url + "==" # add the padding back
-        self.nonce = base64.urlsafe_b64decode(url.encode("utf-8"))
-        self.f_key = KDF.PBKDF2(
+
+        try:
+               self.nonce = base64.urlsafe_b64decode(url.encode("utf-8"))
+       except:
+               url = "errormessage=="
+               self.nonce = base64.urlsafe_b64decode(url.encode("utf-8"))
+
+       self.f_key = KDF.PBKDF2(
             self.nonce, dconfig.nonce_salt.decode("hex"), 16)
         self.aes_key = KDF.PBKDF2(
             self.nonce, dconfig.aes_salt.decode("hex"), 32)