cifsd: add support for AES256 encryption

Now that 256 bit encryption can be negotiated, update
names of the nonces to match the updated official protocol
documentation (e.g. AES_GCM_NONCE instead of AES_128GCM_NONCE)
since they apply to both 128 bit and 256 bit encryption.
update smb encryption code to set 32 byte key length and to
set gcm256/ccm256 when requested on mount.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifsd/crypto_ctx.h b/fs/cifsd/crypto_ctx.h
index 64a11df..b0d3cd6 100644
--- a/fs/cifsd/crypto_ctx.h
+++ b/fs/cifsd/crypto_ctx.h
@@ -21,8 +21,8 @@ enum {
 };
 
 enum {
-	CRYPTO_AEAD_AES128_GCM = 16,
-	CRYPTO_AEAD_AES128_CCM,
+	CRYPTO_AEAD_AES_GCM = 16,
+	CRYPTO_AEAD_AES_CCM,
 	CRYPTO_AEAD_MAX,
 };
 
@@ -55,8 +55,8 @@ struct ksmbd_crypto_ctx {
 #define CRYPTO_MD4_TFM(c)	((c)->desc[CRYPTO_SHASH_MD4]->tfm)
 #define CRYPTO_MD5_TFM(c)	((c)->desc[CRYPTO_SHASH_MD5]->tfm)
 
-#define CRYPTO_GCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES128_GCM])
-#define CRYPTO_CCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES128_CCM])
+#define CRYPTO_GCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES_GCM])
+#define CRYPTO_CCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES_CCM])
 
 void ksmbd_release_crypto_ctx(struct ksmbd_crypto_ctx *ctx);