lkml.org 
[lkml]   [2016]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.2 25/94] fs/cifs: correctly to anonymous authentication via NTLMSSP
3.2.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit cfda35d98298131bf38fbad3ce4cd5ecb3cf18db upstream.

See [MS-NLMP] 3.2.5.1.2 Server Receives an AUTHENTICATE_MESSAGE from the Client:

...
Set NullSession to FALSE
If (AUTHENTICATE_MESSAGE.UserNameLen == 0 AND
AUTHENTICATE_MESSAGE.NtChallengeResponse.Length == 0 AND
(AUTHENTICATE_MESSAGE.LmChallengeResponse == Z(1)
OR
AUTHENTICATE_MESSAGE.LmChallengeResponse.Length == 0))
-- Special case: client requested anonymous authentication
Set NullSession to TRUE
...

Only server which map unknown users to guest will allow
access using a non-null NTChallengeResponse.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
[bwh: Backported to 3.2: keep using cERROR()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -480,19 +480,27 @@ static int build_ntlmssp_auth_blob(unsig
sec_blob->LmChallengeResponse.MaximumLength = 0;

sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
- rc = setup_ntlmv2_rsp(ses, nls_cp);
- if (rc) {
- cERROR(1, "Error %d during NTLMSSP authentication", rc);
- goto setup_ntlmv2_ret;
- }
- memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
- ses->auth_key.len - CIFS_SESS_KEY_SIZE);
- tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
+ if (ses->user_name != NULL) {
+ rc = setup_ntlmv2_rsp(ses, nls_cp);
+ if (rc) {
+ cERROR(1, "Error %d during NTLMSSP authentication", rc);
+ goto setup_ntlmv2_ret;
+ }
+ memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+ ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

- sec_blob->NtChallengeResponse.Length =
- cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
- sec_blob->NtChallengeResponse.MaximumLength =
- cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ sec_blob->NtChallengeResponse.Length =
+ cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ sec_blob->NtChallengeResponse.MaximumLength =
+ cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ } else {
+ /*
+ * don't send an NT Response for anonymous access
+ */
+ sec_blob->NtChallengeResponse.Length = 0;
+ sec_blob->NtChallengeResponse.MaximumLength = 0;
+ }

if (ses->domainName == NULL) {
sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
\
 
 \ /
  Last update: 2016-09-17 09:56    [W:0.376 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site