[PATCH 2/3] sha256/gcrypt: fix memory leak with SHA-256 repos

From: Eric Wong <e@80x24.org>
Date: Jul 31, 2023, 12:08 UTC
Message-ID: <20230731120808.1230210-3-e@80x24.org>
In-Reply-To: <20230731120808.1230210-1-e@80x24.org>

`gcry_md_open' needs to be paired with `gcry_md_close' to ensure resources are released. Since our internal APIs don't have separate close/release callbacks, sticking it into the finalization callback seems appropriate.

Building with SANITIZE=leak and running `git fsck' on a SHA-256 repository no longer reports leaks.

Signed-off-by: Eric Wong <e@80x24.org>
---
 sha256/gcrypt.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sha256/gcrypt.h b/sha256/gcrypt.h
index 68cf6b6a54..1d06a778af 100644
--- a/sha256/gcrypt.h
+++ b/sha256/gcrypt.h
@@ -20,6 +20,7 @@ static inline void gcrypt_SHA256_Update(gcrypt_SHA256_CTX *ctx, const void *data
 static inline void gcrypt_SHA256_Final(unsigned char *digest, gcrypt_SHA256_CTX *ctx)
 {
 	memcpy(digest, gcry_md_read(*ctx, GCRY_MD_SHA256), SHA256_DIGEST_SIZE);
+	gcry_md_close(*ctx);
 }
 
 static inline void gcrypt_SHA256_Clone(gcrypt_SHA256_CTX *dst, const gcrypt_SHA256_CTX *src)