CIFS: Enable encryption during session setup phase

commit cabfb368 upstream.

In order to allow encryption on SMB connection we need to exchange
a session key and generate encryption and decryption keys.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/cifs/sess.c

@@ -344,13 +344,12 @@ void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
 	/* BB is NTLMV2 session security format easier to use here? */
 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
-		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
-	if (ses->server->sign) {
+		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
+		NTLMSSP_NEGOTIATE_SEAL;
+	if (ses->server->sign)
 		flags |= NTLMSSP_NEGOTIATE_SIGN;
-		if (!ses->server->session_estab ||
-				ses->ntlmssp->sesskey_per_smbsess)
-			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
-	}
+	if (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
+		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 
 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
 
@@ -407,13 +406,12 @@ int build_ntlmssp_auth_blob(unsigned char **pbuffer,
 	flags = NTLMSSP_NEGOTIATE_56 |
 		NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
-		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
-	if (ses->server->sign) {
+		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
+		NTLMSSP_NEGOTIATE_SEAL;
+	if (ses->server->sign)
 		flags |= NTLMSSP_NEGOTIATE_SIGN;
-		if (!ses->server->session_estab ||
-				ses->ntlmssp->sesskey_per_smbsess)
-			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
-	}
+	if (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
+		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 
 	tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
 	sec_blob->NegotiateFlags = cpu_to_le32(flags);

fs/cifs/smb2pdu.c

@@ -832,10 +832,8 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 
 	if (!rc) {
 		mutex_lock(&server->srv_mutex);
-		if (server->sign && server->ops->generate_signingkey) {
+		if (server->ops->generate_signingkey) {
 			rc = server->ops->generate_signingkey(ses);
-			kfree(ses->auth_key.response);
-			ses->auth_key.response = NULL;
 			if (rc) {
 				cifs_dbg(FYI,
 					"SMB3 session key generation failed\n");
@@ -857,10 +855,6 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 	}
 
 keygen_exit:
-	if (!server->sign) {
-		kfree(ses->auth_key.response);
-		ses->auth_key.response = NULL;
-	}
 	if (spnego_key) {
 		key_invalidate(spnego_key);
 		key_put(spnego_key);