From 4bd6478ff8f0d0fa75f69c8edbc3535aa6de357d Mon Sep 17 00:00:00 2001
From: Steve French <smfrench@gmail.com>
Date: Fri, 20 Apr 2018 23:44:48 -0500
Subject: [PATCH] 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 +++++----
2 files changed, 21 insertions(+), 20 deletions(-)
@@ -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
@@ -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;
}
--
2.14.1
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)