From 36a3f9bd0cc7029e5150b1931efbd62da975e8b9 Mon Sep 17 00:00:00 2001
From: StefanBruens <stefan.bruens@rwth-aachen.de>
Date: Mon, 21 Oct 2019 02:07:19 +0200
Subject: [PATCH] Catch BadSignatureError raised by ecdsa 0.13.3 on
 verification errors (#448)

The new ecdsa no longer uses AssertionError when the signature is too long.
This happens in the test suite, where "123" is appended to the signature.

Fixes #447
---
 jwt/contrib/algorithms/py_ecdsa.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/jwt/contrib/algorithms/py_ecdsa.py b/jwt/contrib/algorithms/py_ecdsa.py
index bf0dea5..f1170a6 100644
--- a/jwt/contrib/algorithms/py_ecdsa.py
+++ b/jwt/contrib/algorithms/py_ecdsa.py
@@ -56,5 +56,7 @@ def verify(self, msg, key, sig):
         try:
             return key.verify(sig, msg, hashfunc=self.hash_alg,
                               sigdecode=ecdsa.util.sigdecode_string)
-        except AssertionError:
+        # ecdsa <= 0.13.2 raises AssertionError on too long signatures,
+        # ecdsa >= 0.13.3 raises BadSignatureError for verification errors.
+        except (AssertionError, ecdsa.BadSignatureError):
             return False
