From bb949b25eacc567826a61b8121dbcd704c4a02bc Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Fri, 18 Mar 2022 22:43:38 +0100
Subject: [PATCH] EVP_DecryptFinal_ex: fix check for return value

seems like the current docs were updated.
was "positive return code".
now specifically mentions 0 and 1.
---
 src/borg/crypto/low_level.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/borg/crypto/low_level.pyx b/src/borg/crypto/low_level.pyx
index 1a12aafba..8a944745f 100644
--- a/src/borg/crypto/low_level.pyx
+++ b/src/borg/crypto/low_level.pyx
@@ -568,7 +568,7 @@ cdef class _AEAD_BASE:
                 raise CryptoError('EVP_DecryptUpdate failed')
             offset += olen
             rc = EVP_DecryptFinal_ex(self.ctx, odata+offset, &olen)
-            if rc <= 0:
+            if not rc:
                 # a failure here means corrupted or tampered tag (mac) or data.
                 raise IntegrityError('Authentication / EVP_DecryptFinal_ex failed')
             offset += olen