aes_wrap: prevent crash on update without a key

aes_wrap: prevent crash on update without a key

EVP_CipherInit_ex2 with a NULL key followed by EVP_CipherUpdate
on AES-WRAP/WRAP-PAD/WRAP-INV ciphers dereferenced an uninitialised
function pointer because aes_wrap_init installs ctx->block only
when a key is supplied. aes_wrap_cipher_internal had no guard
before dispatching.

Track key state in ctx->key_set, matching OCB/CCM/GCM/Poly1305,
and refuse update if no key has been installed.

Added a regression test covering AES-256-WRAP, AES-256-WRAP-PAD
and AES-256-WRAP-INV.

CLA: trivial

Fixes: ca392b294359 "Add aes_wrap cipher to providers"
Reviewed-by: Eugene Syromiatnikov <esyr@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.foundation>
MergeDate: Wed Jun  3 11:52:05 2026
(Merged from https://github.com/openssl/openssl/pull/31292)