blob: 21aa5925a0c900d6245bc04f08afe230eb65e581 [file] [log] [blame]
From: Stefan Metzmacher <metze@samba.org>
Date: Tue, 3 May 2016 10:52:30 +0200
Subject: fs/cifs: correctly to anonymous authentication via NTLMSSP
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);