[PATCH 4.4 04/97] CIFS: Enable encryption during session setup phase

From: Greg Kroah-Hartman
Date: Fri Mar 23 2018 - 06:13:31 EST


4.4-stable review patch. If anyone has any objections, please let me know.

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

From: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>

commit cabfb3680f78981d26c078a26e5c748531257ebb upstream.

In order to allow encryption on SMB connection we need to exchange
a session key and generate encryption and decryption keys.

Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Signed-off-by: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx>
Cc: Steve French <smfrench@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/cifs/sess.c | 22 ++++++++++------------
fs/cifs/smb2pdu.c | 8 +-------
2 files changed, 11 insertions(+), 19 deletions(-)

--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -344,13 +344,12 @@ void build_ntlmssp_negotiate_blob(unsign
/* BB is NTLMV2 session security format easier to use here? */
flags = NTLMSSP_NEGOTIATE_56 | NTLMSSP_REQUEST_TARGET |
NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
- NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
- if (ses->server->sign) {
+ NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
+ NTLMSSP_NEGOTIATE_SEAL;
+ if (ses->server->sign)
flags |= NTLMSSP_NEGOTIATE_SIGN;
- if (!ses->server->session_estab ||
- ses->ntlmssp->sesskey_per_smbsess)
- flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
- }
+ if (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
+ flags |= NTLMSSP_NEGOTIATE_KEY_XCH;

sec_blob->NegotiateFlags = cpu_to_le32(flags);

@@ -407,13 +406,12 @@ int build_ntlmssp_auth_blob(unsigned cha
flags = NTLMSSP_NEGOTIATE_56 |
NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
- NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
- if (ses->server->sign) {
+ NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
+ NTLMSSP_NEGOTIATE_SEAL;
+ if (ses->server->sign)
flags |= NTLMSSP_NEGOTIATE_SIGN;
- if (!ses->server->session_estab ||
- ses->ntlmssp->sesskey_per_smbsess)
- flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
- }
+ if (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
+ flags |= NTLMSSP_NEGOTIATE_KEY_XCH;

tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
sec_blob->NegotiateFlags = cpu_to_le32(flags);
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -832,10 +832,8 @@ ssetup_exit:

if (!rc) {
mutex_lock(&server->srv_mutex);
- if (server->sign && server->ops->generate_signingkey) {
+ if (server->ops->generate_signingkey) {
rc = server->ops->generate_signingkey(ses);
- kfree(ses->auth_key.response);
- ses->auth_key.response = NULL;
if (rc) {
cifs_dbg(FYI,
"SMB3 session key generation failed\n");
@@ -857,10 +855,6 @@ ssetup_exit:
}

keygen_exit:
- if (!server->sign) {
- kfree(ses->auth_key.response);
- ses->auth_key.response = NULL;
- }
if (spnego_key) {
key_invalidate(spnego_key);
key_put(spnego_key);