Avoid UbSan false positive in GCC

Unfortunately GCC's UbSan errors out when we cast the function
pointer derived from XMSS_Common_Ops as a XMSS_PrivateKey::*
then use an XMSS_PrivateKey* as this. Clang accepts it.

Curiously, it works in GCC if we use an XMSS_Common_Ops::* instead,
but Clang rejects that at compile time.

Short of compiler specific logic which is probably fragile, just
make everything from XMSS_Common_Ops static instead of being
inherited.

1 files changed, 7 insertions, 6 deletions

diff --git a/src/lib/pubkey/xmss/xmss_signature_operation.cpp b/src/lib/pubkey/xmss/xmss_signature_operation.cpp
index 38659a88b..b7daad7c0 100644
--- a/src/lib/pubkey/xmss/xmss_signature_operation.cpp
+++ b/src/lib/pubkey/xmss/xmss_signature_operation.cpp
@@ -18,12 +18,13 @@
 namespace Botan {
 
 XMSS_Signature_Operation::XMSS_Signature_Operation(
-   const XMSS_PrivateKey& private_key)
-   : XMSS_Common_Ops(private_key.xmss_oid()),
-     m_priv_key(private_key),
-     m_randomness(0),
-     m_leaf_idx(0),
-     m_is_initialized(false)
+   const XMSS_PrivateKey& private_key) :
+   m_priv_key(private_key),
+   m_xmss_params(private_key.xmss_oid()),
+   m_hash(private_key.xmss_hash_function()),
+   m_randomness(0),
+   m_leaf_idx(0),
+   m_is_initialized(false)
    {}
 
 XMSS_WOTS_PublicKey::TreeSignature