SMB3: Fix 3.11 encryption to Windows and handle encrypted smb3 tcon

Temporarily disable AES-GCM, as AES-CCM is only currently
enabled mechanism on client side.  This fixes SMB3.11
encrypted mounts to Windows.

Also the tree connect request itself should be encrypted if
requested encryption ("seal" on mount), in addition we should be
enabling encryption in 3.11 based on whether we got any valid
encryption ciphers back in negprot (the corresponding session flag is
not set as it is in 3.0 and 3.02)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 0f044c4a2dc9..9aea138dd71f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -383,10 +383,10 @@ static void
 build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
 {
         pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
-        pneg_ctxt->DataLength = cpu_to_le16(6);
-        pneg_ctxt->CipherCount = cpu_to_le16(2);
-        pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
-        pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM;
+        pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + le16 cipher */
+        pneg_ctxt->CipherCount = cpu_to_le16(1);
+/* pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;*/ /* not supported yet */
+        pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_CCM;
 }
 
 static void
@@ -444,6 +444,7 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server,
                 return -EINVAL;
         }
         server->cipher_type = ctxt->Ciphers[0];
+        server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
         return 0;
 }