Fix up MLKEM768_marshal_private_key to not use a passed in CBB

Even though this should remain internal, make it the same
as the public key marshal function, and make the needed
fallout changes in regress.

This does not yet do the bikeshed of renaming the structure
field in the regress ctx, that will wait until a follow on
to convert 1024 in a similar manner

ok tb@

1 files changed, 3 insertions, 3 deletions

diff --git a/src/lib/libcrypto/mlkem/mlkem_internal.h b/src/lib/libcrypto/mlkem/mlkem_internal.h
index 7a51197c36..aed051e980 100644
--- a/src/lib/libcrypto/mlkem/mlkem_internal.h
+++ b/src/lib/libcrypto/mlkem/mlkem_internal.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: mlkem_internal.h,v 1.5 2025/05/19 06:47:40 beck Exp $ */
+/*      $OpenBSD: mlkem_internal.h,v 1.6 2025/05/19 07:53:00 beck Exp $ */
 /*
  * Copyright (c) 2023, Google Inc.
  *
@@ -57,8 +57,8 @@ int MLKEM768_generate_key_external_entropy(
  * format for ML-KEM private keys. It returns one on success or zero on
  * allocation error.
  */
-int MLKEM768_marshal_private_key(CBB *out,
-    const struct MLKEM768_private_key *private_key);
+int MLKEM768_marshal_private_key(const struct MLKEM768_private_key *private_key,
+    uint8_t **out_private_key, size_t *out_private_key_len);
 
 /*
  * MLKEM_encap_external_entropy behaves like |MLKEM_encap|, but uses