Provider bugfixes (main branch)

[mamckee]

This PR ports the bugfixes from #165 to the main branch.

In addition

• Fixes a bug in ML-KEM decode (p_scossl_SubjectPublicKeyInfo_to_mlkem), where the incorrect free function was called on subjPubKeyInfo, which could potentially lead to a memory leak.
• Fixes a compiler warning in the generic skeymgmt interface

[Copilot]

Pull request overview

Ports SymCrypt provider bugfixes from #165 into main, plus additional fixes around ML-KEM decoding cleanup and a generic skeymgmt compiler warning.

Changes:

• Harden RSA cipher encrypt/decrypt buffer sizing behavior (incl. TLS padding) and fix RSA key matching private exponent comparison.
• Fix X25519 sizing/validation by centralizing the constant and enforcing key-length checks during import.
• Fix memory management/cleanup issues (ML-KEM SubjectPublicKeyInfo free) and add MAC initialization-state tracking to prevent use-before-key.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
SymCryptProvider/src/skeymgmt/p_scossl_generic_skeymgmt.c	Adjusts generic skey export parameter construction (addresses compiler warning).
SymCryptProvider/src/p_scossl_ecc.h	Introduces shared X25519 key-size constant.
SymCryptProvider/src/p_scossl_ecc.c	Uses the shared X25519 key-size constant for sizing.
SymCryptProvider/src/keymgmt/p_scossl_rsa_keymgmt.c	Fixes RSA key match logic (private exponent comparison) and minor formatting.
SymCryptProvider/src/keymgmt/p_scossl_ecc_keymgmt.c	Hardens X25519 import (length checks, safer key replacement/cleanup).
SymCryptProvider/src/keymgmt/p_scossl_dh_keymgmt.c	Fixes DH group duplication allocation sizing (bits vs bytes).
SymCryptProvider/src/decoder/p_scossl_decode_mlkem.c	Fixes ML-KEM SPKI decode cleanup to use correct ASN.1 free routine.
SymCryptProvider/src/ciphers/p_scossl_aes.c	Fixes TLS MAC size validation to check the parameter value being set.
SymCryptProvider/src/asymcipher/p_scossl_rsa_cipher.c	Deep-copies OAEP label on dupctx and adds output length/buffer checks for RSA encrypt/decrypt.
ScosslCommon/src/scossl_mac.c	Tracks MAC initialization state and blocks update/final prior to key initialization.
ScosslCommon/src/scossl_helpers.c	Registers function names for new MAC function codes.
ScosslCommon/src/scossl_dh.c	Fixes DH group copy allocation sizing (bits vs bytes).
ScosslCommon/inc/scossl_mac.h	Adds initialized flag to MAC context struct.
ScosslCommon/inc/scossl_helpers.h	Adds new function codes for MAC update/final.

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