diff mbox

encrypt the tcon itself if seal requested on mount and set encryption support for 3.11 properly

Message ID CAH2r5msZO0=OF6v90D-PKS1ZxyJjbCXg6rDnBv=LNO399DOR0w@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Steve French April 22, 2018, 11:21 p.m. UTC 
Version 3 of patch attached (works to Samba and Windows with 3.11)



On Sun, Apr 22, 2018 at 10:44 AM, Steve French <smfrench@gmail.com> wrote:
> Needed to add one additional minor change for Samba (samba server
> doesn't allow the two byte pad at the end of the negotiate context
> that was the result of removing one of the ciphers and returned an
> error on SMB311 negprot
>
> I need to add:
>
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index 6093e5142b2b..d28f358022c5 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -297,7 +297,7 @@ struct smb2_encryption_neg_context {
>         __le16  DataLength;
>         __le32  Reserved;
>         __le16  CipherCount; /* AES-128-GCM and AES-128-CCM */
> -       __le16  Ciphers[2]; /* Ciphers[0] since only one used now */
> +       __le16  Ciphers[1]; /* Ciphers[0] since only one used now */
>  } __packed;
>
>  struct smb2_negotiate_rsp {
> sfrench@Ubuntu-17-Virtual-Ma
>
> On Sat, Apr 21, 2018 at 12:04 PM, Steve French <smfrench@gmail.com> wrote:
>> Any extra testing would be appreciated of this - I tried to Windows
>> 2016 with and without encrypted share and also to Samba 4.7
>>
>> On Fri, Apr 20, 2018 at 11:55 PM, Steve French <smfrench@gmail.com> wrote:
>>> On Fri, Apr 20, 2018 at 7:14 PM, Pavel Shilovsky <piastryyy@gmail.com> wrote:
>>>> Looks good. Please also fix the encryption negotiate context:
>>>
>>>  Fixed. Disabled AES-128GCM.  See attached.
>>>
>>> Seems to work ok to Windows 3.11 now, and SMB3 tconx is also now
>>> encrypted if "seal" chosen on mount - tried it to Windows 2016 and to
>>> Samba 4.7
>>>
>>> Main remaining problem that I see is smb3.11 reconnect (it looks like
>>> we are clearing the hash - but must be missing something)
>>> --
>>> Thanks,
>>>
>>> Steve
>>
>>
>>
>> --
>> Thanks,
>>
>> Steve
>
>
>
> --
> Thanks,
>
> Steve
diff mbox

Patch

From 0d5efcd4fa736ff71a4dc6b894b70323222df796 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Sun, 22 Apr 2018 15:14:58 -0500
Subject: [PATCH 42/42] 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>
CC: Stable <stable@vger.kernel.org>
---
 fs/cifs/connect.c | 32 ++++++++++++++++----------------
 fs/cifs/smb2pdu.c |  9 +++++----
 fs/cifs/smb2pdu.h |  2 +-
 3 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e8830f076a7f..a5aa158d535a 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2959,6 +2959,22 @@  cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 		}
 	}
 
+	if (volume_info->seal) {
+		if (ses->server->vals->protocol_id == 0) {
+			cifs_dbg(VFS,
+				 "SMB3 or later required for encryption\n");
+			rc = -EOPNOTSUPP;
+			goto out_fail;
+		} else if (tcon->ses->server->capabilities &
+					SMB2_GLOBAL_CAP_ENCRYPTION)
+			tcon->seal = true;
+		else {
+			cifs_dbg(VFS, "Encryption is not supported on share\n");
+			rc = -EOPNOTSUPP;
+			goto out_fail;
+		}
+	}
+
 	/*
 	 * BB Do we need to wrap session_mutex around this TCon call and Unix
 	 * SetFS as we do on SessSetup and reconnect?
@@ -3007,22 +3023,6 @@  cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 		tcon->use_resilient = true;
 	}
 
-	if (volume_info->seal) {
-		if (ses->server->vals->protocol_id == 0) {
-			cifs_dbg(VFS,
-				 "SMB3 or later required for encryption\n");
-			rc = -EOPNOTSUPP;
-			goto out_fail;
-		} else if (tcon->ses->server->capabilities &
-					SMB2_GLOBAL_CAP_ENCRYPTION)
-			tcon->seal = true;
-		else {
-			cifs_dbg(VFS, "Encryption is not supported on share\n");
-			rc = -EOPNOTSUPP;
-			goto out_fail;
-		}
-	}
-
 	/*
 	 * We can have only one retry value for a connection to a share so for
 	 * resources mounted more than once to the same server share the last
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;
 }
 
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 6093e5142b2b..d28f358022c5 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -297,7 +297,7 @@  struct smb2_encryption_neg_context {
 	__le16	DataLength;
 	__le32	Reserved;
 	__le16	CipherCount; /* AES-128-GCM and AES-128-CCM */
-	__le16	Ciphers[2]; /* Ciphers[0] since only one used now */
+	__le16	Ciphers[1]; /* Ciphers[0] since only one used now */
 } __packed;
 
 struct smb2_negotiate_rsp {
-- 
2.14.1