CIFS: add sha512 secmech

* prepare for SMB3.11 pre-auth integrity
* enable sha512 when SMB311 is enabled in Kconfig
* add sha512 as a soft dependency

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

fs/cifs/Kconfig

@@ -189,6 +189,7 @@ config CIFS_NFSD_EXPORT
 config CIFS_SMB311
 	bool "SMB3.1.1 network file system support (Experimental)"
 	depends on CIFS
+	select CRYPTO_SHA512
 
 	help
 	  This enables experimental support for the newest, SMB3.1.1, dialect.

fs/cifs/cifsencrypt.c

@@ -829,6 +829,11 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 		server->secmech.md5 = NULL;
 	}
 
+	if (server->secmech.md5) {
+		crypto_free_shash(server->secmech.sha512);
+		server->secmech.sha512 = NULL;
+	}
+
 	if (server->secmech.hmacmd5) {
 		crypto_free_shash(server->secmech.hmacmd5);
 		server->secmech.hmacmd5 = NULL;
@@ -852,4 +857,6 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 	server->secmech.sdeschmacmd5 = NULL;
 	kfree(server->secmech.sdescmd5);
 	server->secmech.sdescmd5 = NULL;
+	kfree(server->secmech.sdescsha512);
+	server->secmech.sdescsha512 = NULL;
 }

fs/cifs/cifsfs.c

@@ -1486,6 +1486,7 @@ MODULE_SOFTDEP("pre: nls");
 MODULE_SOFTDEP("pre: aes");
 MODULE_SOFTDEP("pre: cmac");
 MODULE_SOFTDEP("pre: sha256");
+MODULE_SOFTDEP("pre: sha512");
 MODULE_SOFTDEP("pre: aead2");
 MODULE_SOFTDEP("pre: ccm");
 module_init(init_cifs)

fs/cifs/cifsglob.h

@@ -130,10 +130,12 @@ struct cifs_secmech {
 	struct crypto_shash *md5; /* md5 hash function */
 	struct crypto_shash *hmacsha256; /* hmac-sha256 hash function */
 	struct crypto_shash *cmacaes; /* block-cipher based MAC function */
+	struct crypto_shash *sha512; /* sha512 hash function */
 	struct sdesc *sdeschmacmd5;  /* ctxt to generate ntlmv2 hash, CR1 */
 	struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
 	struct sdesc *sdeschmacsha256;  /* ctxt to generate smb2 signature */
 	struct sdesc *sdesccmacaes;  /* ctxt to generate smb3 signature */
+	struct sdesc *sdescsha512; /* ctxt to generate smb3.11 signing key */
 	struct crypto_aead *ccmaesencrypt; /* smb3 encryption aead */
 	struct crypto_aead *ccmaesdecrypt; /* smb3 decryption aead */
 };

fs/cifs/smb2proto.h

@@ -202,4 +202,7 @@ extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *);
 
 extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *,
 					enum securityEnum);
+#ifdef CONFIG_CIFS_SMB311
+extern int smb311_crypto_shash_allocate(struct TCP_Server_Info *server);
+#endif
 #endif			/* _SMB2PROTO_H */

fs/cifs/smb2transport.c

@@ -70,6 +70,36 @@ err:
 	return rc;
 }
 
+#ifdef CONFIG_CIFS_SMB311
+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,
+			     &p->sdeschmacsha256);
+	if (rc)
+		return rc;
+
+	rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
+	if (rc)
+		goto err;
+
+	rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
+	if (rc)
+		goto err;
+
+	return 0;
+
+err:
+	cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
+	cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
+	return rc;
+}
+#endif
+
 static struct cifs_ses *
 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
 {