[CIFS][PATCH] Warn if per-share encryption requested

[Steve French]

From 0cbaa53cdd33080c1e2d67ad9295b83c7954f2b3 Mon Sep 17 00:00:00 2001

From: Steve French <smfrench-***@public.gmane.org>
Date: Fri, 15 Nov 2013 23:50:24 -0600
Subject: [PATCH] [CIFS] Warn if SMB3 encryption required by server

We do not support SMB3 encryption yet, warn if server responds
that SMB3 encryption is mandatory.

Signed-off-by: Steve French <smfrench-***@public.gmane.org>
---
fs/cifs/smb2pdu.c | 2 ++
fs/cifs/smb2pdu.h | 18 ++++++++++++++++++
2 files changed, 20 insertions(+)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index ca7f307..d65270c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -630,6 +630,8 @@ ssetup_ntlmssp_authenticate:
goto ssetup_exit;

ses->session_flags = le16_to_cpu(rsp->SessionFlags);
+ if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA)
+ cifs_dbg(VFS, "SMB3 encryption not supported yet\n");
ssetup_exit:
free_rsp_buf(resp_buftype, rsp);

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index b50a129..f88320b 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -122,6 +122,23 @@ struct smb2_pdu {
__le16 StructureSize2; /* size of wct area (varies, request specific) */
} __packed;

+struct smb2_transform_hdr {
+ __be32 smb2_buf_length; /* big endian on wire */
+ /* length is only two or three bytes - with
+ one or two byte type preceding it that MBZ */
+ __u8 ProtocolId[4]; /* 0xFD 'S' 'M' 'B' */
+ __u8 Signature[16];
+ __u8 Nonce[11];
+ __u8 Reserved[5];
+ __le32 OriginalMessageSize;
+ __u16 Reserved1;
+ __le16 EncryptionAlgorithm;
+ __u64 SessionId;
+} __packed;
+
+/* Encryption Algorithms */
+#define SMB2_ENCRYPTION_AES128_CCM __constant_cpu_to_le16(0x0001)
+
/*
* SMB2 flag definitions
*/
@@ -237,6 +254,7 @@ struct smb2_sess_setup_req {
/* Currently defined SessionFlags */
#define SMB2_SESSION_FLAG_IS_GUEST 0x0001
#define SMB2_SESSION_FLAG_IS_NULL 0x0002
+#define SMB2_SESSION_FLAG_ENCRYPT_DATA 0x0004
struct smb2_sess_setup_rsp {
struct smb2_hdr hdr;
__le16 StructureSize; /* Must be 9 */