smb: client: Remove obsolete crypto_shash allocations

Now that the SMB client accesses MD5, HMAC-MD5, HMAC-SHA256, and SHA-512
only via the library API and not via crypto_shash, allocating
crypto_shash objects for these algorithms is no longer necessary.
Remove all these allocations, their corresponding kconfig selections,
and their corresponding module soft dependencies.

Reviewed-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: Eric Biggers

fs/smb/client/Kconfig

@@ -5,11 +5,7 @@ config CIFS
 	select NLS
 	select NLS_UCS2_UTILS
 	select CRYPTO
-	select CRYPTO_MD5
-	select CRYPTO_SHA256
-	select CRYPTO_SHA512
 	select CRYPTO_CMAC
-	select CRYPTO_HMAC
 	select CRYPTO_AEAD2
 	select CRYPTO_CCM
 	select CRYPTO_GCM

fs/smb/client/cifsencrypt.c

@@ -693,9 +693,6 @@ void
 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 {
 	cifs_free_hash(&server->secmech.aes_cmac);
-	cifs_free_hash(&server->secmech.hmacsha256);
-	cifs_free_hash(&server->secmech.md5);
-	cifs_free_hash(&server->secmech.sha512);
 
 	if (server->secmech.enc) {
 		crypto_free_aead(server->secmech.enc);

fs/smb/client/cifsfs.c

@@ -2139,13 +2139,9 @@ MODULE_DESCRIPTION
 	"also older servers complying with the SNIA CIFS Specification)");
 MODULE_VERSION(CIFS_VERSION);
 MODULE_SOFTDEP("ecb");
-MODULE_SOFTDEP("hmac");
-MODULE_SOFTDEP("md5");
 MODULE_SOFTDEP("nls");
 MODULE_SOFTDEP("aes");
 MODULE_SOFTDEP("cmac");
-MODULE_SOFTDEP("sha256");
-MODULE_SOFTDEP("sha512");
 MODULE_SOFTDEP("aead2");
 MODULE_SOFTDEP("ccm");
 MODULE_SOFTDEP("gcm");

fs/smb/client/cifsglob.h

@@ -222,9 +222,6 @@ struct session_key {
 
 /* crypto hashing related structure/fields, not specific to a sec mech */
 struct cifs_secmech {
-	struct shash_desc *md5; /* md5 hash function, for CIFS/SMB1 signatures */
-	struct shash_desc *hmacsha256; /* hmac-sha256 hash function, for SMB2 signatures */
-	struct shash_desc *sha512; /* sha512 hash function, for SMB3.1.1 preauth hash */
 	struct shash_desc *aes_cmac; /* block-cipher based MAC function, for SMB3 signatures */
 
 	struct crypto_aead *enc; /* smb3 encryption AEAD TFM (AES-CCM and AES-GCM) */

fs/smb/client/smb2transport.c

@@ -31,49 +31,18 @@ static int
 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
 {
 	struct cifs_secmech *p = &server->secmech;
-	int rc;
-
-	rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256);
-	if (rc)
-		goto err;
-
-	rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
-	if (rc)
-		goto err;
 
-	return 0;
-err:
-	cifs_free_hash(&p->hmacsha256);
-	return rc;
+	return cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
 }
 
 int
 smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
 {
 	struct cifs_secmech *p = &server->secmech;
-	int rc = 0;
 
-	rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256);
-	if (rc)
-		return rc;
-
-	rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
-	if (rc)
-		goto err;
-
-	rc = cifs_alloc_hash("sha512", &p->sha512);
-	if (rc)
-		goto err;
-
-	return 0;
-
-err:
-	cifs_free_hash(&p->aes_cmac);
-	cifs_free_hash(&p->hmacsha256);
-	return rc;
+	return cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
 }
 
-
 static
 int smb3_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
 {