Fix signature and semantics of EVP_{CIPHER,MD}_CTX_init()

When the EVP_CIPHER_CTX and the EVP_MD_CTX were still expected to live
on the stack, these initialization APIs were wrappers around memset.
In OpenSSL 1.1, somebody removed them and carelessly made _init() an
alias of _reset() aka _cleanup(). As a consequence, both signature and
semantics changed.

Unsurprisingly, there is now code out there that actually uses the new
semantics, which causes leaks on LibreSSL and older OpenSSL. This aligns
our _init() with OpenSSL 1.1 semantics.

ok jsing

1 files changed, 5 insertions, 5 deletions

diff --git a/src/lib/libcrypto/evp/evp_cipher.c b/src/lib/libcrypto/evp/evp_cipher.c
index c2a88a5591..48aaea0f1b 100644
--- a/src/lib/libcrypto/evp/evp_cipher.c
+++ b/src/lib/libcrypto/evp/evp_cipher.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: evp_cipher.c,v 1.20 2024/02/24 08:00:37 tb Exp $ */
+/* $OpenBSD: evp_cipher.c,v 1.21 2024/03/02 09:55:30 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -613,15 +613,15 @@ EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
 }
 
 void
-EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
+EVP_CIPHER_CTX_legacy_clear(EVP_CIPHER_CTX *ctx)
 {
         memset(ctx, 0, sizeof(*ctx));
 }
 
-void
-EVP_CIPHER_CTX_legacy_clear(EVP_CIPHER_CTX *ctx)
+int
+EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
 {
-        memset(ctx, 0, sizeof(*ctx));
+        return EVP_CIPHER_CTX_cleanup(ctx);
 }
 
 int