python: Turn the signature buffer into a bytearray.

This is a workaround for a bug where signature verification would
overwrite the variable holding the signature.

This only happens on python2.

Signed-off-by: Damir Jelić <poljar@termina.org.uk>

1 files changed, 16 insertions, 0 deletions

diff --git a/python/tests/account_test.py b/python/tests/account_test.py
index 4fef72c..7ee6d2b 100644
--- a/python/tests/account_test.py
+++ b/python/tests/account_test.py
@@ -98,3 +98,19 @@ class TestClass(object):
 
         with pytest.raises(OlmVerifyError):
             ed25519_verify(signing_key, message, signature)
+
+    @given(text())
+    def test_signature_verification_twice(self, message):
+        alice = Account()
+
+        signature = alice.sign(message)
+        signing_key = alice.identity_keys["ed25519"]
+
+        assert signature
+        assert signing_key
+
+        ed25519_verify(signing_key, message, signature)
+        assert signature == alice.sign(message)
+
+        ed25519_verify(signing_key, message, signature)
+        assert signature == alice.sign(message)