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samba-mirror/source4/libcli/smb2/session.c
Stefan Metzmacher 5188454bdc s4:libcli: allow a fallback to NTLMSSP if SPNEGO is not supported locally
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
2018-07-24 06:55:24 +02:00

478 lines
12 KiB
C

/*
Unix SMB/CIFS implementation.
SMB2 client session handling
Copyright (C) Andrew Tridgell 2005
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "system/network.h"
#include <tevent.h>
#include "lib/util/tevent_ntstatus.h"
#include "libcli/raw/libcliraw.h"
#include "libcli/smb2/smb2.h"
#include "libcli/smb2/smb2_calls.h"
#include "auth/gensec/gensec.h"
#include "auth/credentials/credentials.h"
#include "../libcli/smb/smbXcli_base.h"
/**
initialise a smb2_session structure
*/
struct smb2_session *smb2_session_init(struct smb2_transport *transport,
struct gensec_settings *settings,
TALLOC_CTX *parent_ctx)
{
struct smb2_session *session;
NTSTATUS status;
session = talloc_zero(parent_ctx, struct smb2_session);
if (!session) {
return NULL;
}
session->transport = talloc_steal(session, transport);
session->smbXcli = smbXcli_session_create(session, transport->conn);
if (session->smbXcli == NULL) {
talloc_free(session);
return NULL;
}
/* prepare a gensec context for later use */
status = gensec_client_start(session, &session->gensec,
settings);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(session);
return NULL;
}
gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
return session;
}
/*
* Note: that the caller needs to keep 'transport' around as
* long as the returned session is active!
*/
struct smb2_session *smb2_session_channel(struct smb2_transport *transport,
struct gensec_settings *settings,
TALLOC_CTX *parent_ctx,
struct smb2_session *base_session)
{
struct smb2_session *session;
NTSTATUS status;
session = talloc_zero(parent_ctx, struct smb2_session);
if (!session) {
return NULL;
}
session->transport = transport;
status = smb2cli_session_create_channel(session,
base_session->smbXcli,
transport->conn,
&session->smbXcli);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(session);
return NULL;
}
session->needs_bind = true;
/* prepare a gensec context for later use */
status = gensec_client_start(session, &session->gensec,
settings);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(session);
return NULL;
}
gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
return session;
}
struct smb2_session_setup_spnego_state {
struct tevent_context *ev;
struct smb2_session *session;
struct cli_credentials *credentials;
uint64_t previous_session_id;
bool session_bind;
bool reauth;
NTSTATUS gensec_status;
NTSTATUS remote_status;
DATA_BLOB in_secblob;
DATA_BLOB out_secblob;
struct iovec *recv_iov;
};
static void smb2_session_setup_spnego_gensec_next(struct tevent_req *req);
static void smb2_session_setup_spnego_gensec_done(struct tevent_req *subreq);
static void smb2_session_setup_spnego_smb2_next(struct tevent_req *req);
static void smb2_session_setup_spnego_smb2_done(struct tevent_req *subreq);
static void smb2_session_setup_spnego_both_ready(struct tevent_req *req);
/*
a composite function that does a full SPNEGO session setup
*/
struct tevent_req *smb2_session_setup_spnego_send(
TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct smb2_session *session,
struct cli_credentials *credentials,
uint64_t previous_session_id)
{
struct smb2_transport *transport = session->transport;
struct tevent_req *req;
struct smb2_session_setup_spnego_state *state;
uint64_t current_session_id;
const char *chosen_oid;
NTSTATUS status;
const DATA_BLOB *server_gss_blob;
struct timeval endtime;
bool ok;
req = tevent_req_create(mem_ctx, &state,
struct smb2_session_setup_spnego_state);
if (req == NULL) {
return NULL;
}
state->ev = ev;
state->session = session;
state->credentials = credentials;
state->previous_session_id = previous_session_id;
state->gensec_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
state->remote_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
endtime = timeval_current_ofs(transport->options.request_timeout, 0);
ok = tevent_req_set_endtime(req, ev, endtime);
if (!ok) {
return tevent_req_post(req, ev);
}
current_session_id = smb2cli_session_current_id(state->session->smbXcli);
if (state->session->needs_bind) {
state->session_bind = true;
} else if (current_session_id != 0) {
state->reauth = true;
}
server_gss_blob = smbXcli_conn_server_gss_blob(session->transport->conn);
if (server_gss_blob) {
state->out_secblob = *server_gss_blob;
}
status = gensec_set_credentials(session->gensec, credentials);
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
status = gensec_set_target_hostname(session->gensec,
smbXcli_conn_remote_name(session->transport->conn));
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
status = gensec_set_target_service(session->gensec, "cifs");
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
if (state->out_secblob.length > 0) {
chosen_oid = GENSEC_OID_SPNEGO;
status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to start set GENSEC client mechanism %s: %s\n",
gensec_get_name_by_oid(session->gensec,
chosen_oid),
nt_errstr(status)));
state->out_secblob = data_blob_null;
chosen_oid = GENSEC_OID_NTLMSSP;
status = gensec_start_mech_by_oid(session->gensec,
chosen_oid);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to start set (fallback) GENSEC client mechanism %s: %s\n",
gensec_get_name_by_oid(session->gensec,
chosen_oid),
nt_errstr(status)));
}
}
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
} else {
chosen_oid = GENSEC_OID_NTLMSSP;
status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to start set GENSEC client mechanism %s: %s\n",
gensec_get_name_by_oid(session->gensec,
chosen_oid),
nt_errstr(status)));
}
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
}
smb2_session_setup_spnego_gensec_next(req);
if (!tevent_req_is_in_progress(req)) {
return tevent_req_post(req, ev);
}
return req;
}
static void smb2_session_setup_spnego_gensec_next(struct tevent_req *req)
{
struct smb2_session_setup_spnego_state *state =
tevent_req_data(req,
struct smb2_session_setup_spnego_state);
struct smb2_session *session = state->session;
struct tevent_req *subreq = NULL;
if (NT_STATUS_IS_OK(state->gensec_status)) {
tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
return;
}
subreq = gensec_update_send(state, state->ev,
session->gensec,
state->out_secblob);
if (tevent_req_nomem(subreq, req)) {
return;
}
tevent_req_set_callback(subreq,
smb2_session_setup_spnego_gensec_done,
req);
}
static void smb2_session_setup_spnego_gensec_done(struct tevent_req *subreq)
{
struct tevent_req *req =
tevent_req_callback_data(subreq,
struct tevent_req);
struct smb2_session_setup_spnego_state *state =
tevent_req_data(req,
struct smb2_session_setup_spnego_state);
NTSTATUS status;
status = gensec_update_recv(subreq, state,
&state->in_secblob);
state->gensec_status = status;
state->out_secblob = data_blob_null;
if (!NT_STATUS_IS_OK(status) &&
!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
tevent_req_nterror(req, status);
return;
}
if (NT_STATUS_IS_OK(state->remote_status) &&
NT_STATUS_IS_OK(state->gensec_status)) {
smb2_session_setup_spnego_both_ready(req);
return;
}
smb2_session_setup_spnego_smb2_next(req);
}
static void smb2_session_setup_spnego_smb2_next(struct tevent_req *req)
{
struct smb2_session_setup_spnego_state *state =
tevent_req_data(req,
struct smb2_session_setup_spnego_state);
struct smb2_session *session = state->session;
uint32_t timeout_msec;
uint8_t in_flags = 0;
struct tevent_req *subreq = NULL;
if (NT_STATUS_IS_OK(state->remote_status)) {
tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
return;
}
timeout_msec = session->transport->options.request_timeout * 1000;
if (state->session_bind) {
in_flags |= SMB2_SESSION_FLAG_BINDING;
}
subreq = smb2cli_session_setup_send(state, state->ev,
session->transport->conn,
timeout_msec,
session->smbXcli,
in_flags,
0, /* in_capabilities */
0, /* in_channel */
state->previous_session_id,
&state->in_secblob);
if (tevent_req_nomem(subreq, req)) {
return;
}
tevent_req_set_callback(subreq,
smb2_session_setup_spnego_smb2_done,
req);
}
/*
handle continuations of the spnego session setup
*/
static void smb2_session_setup_spnego_smb2_done(struct tevent_req *subreq)
{
struct tevent_req *req =
tevent_req_callback_data(subreq,
struct tevent_req);
struct smb2_session_setup_spnego_state *state =
tevent_req_data(req,
struct smb2_session_setup_spnego_state);
NTSTATUS status;
status = smb2cli_session_setup_recv(subreq, state,
&state->recv_iov,
&state->out_secblob);
state->remote_status = status;
state->in_secblob = data_blob_null;
if (!NT_STATUS_IS_OK(status) &&
!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
tevent_req_nterror(req, status);
return;
}
if (NT_STATUS_IS_OK(state->remote_status) &&
NT_STATUS_IS_OK(state->gensec_status)) {
smb2_session_setup_spnego_both_ready(req);
return;
}
smb2_session_setup_spnego_gensec_next(req);
}
static void smb2_session_setup_spnego_both_ready(struct tevent_req *req)
{
struct smb2_session_setup_spnego_state *state =
tevent_req_data(req,
struct smb2_session_setup_spnego_state);
struct smb2_session *session = state->session;
NTSTATUS status;
DATA_BLOB session_key;
if (state->out_secblob.length != 0) {
tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
return;
}
if (state->in_secblob.length != 0) {
tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
return;
}
if (state->reauth) {
tevent_req_done(req);
return;
}
if (cli_credentials_is_anonymous(state->credentials)) {
/*
* Windows server does not set the
* SMB2_SESSION_FLAG_IS_GUEST nor
* SMB2_SESSION_FLAG_IS_NULL flag.
*
* This fix makes sure we do not try
* to verify a signature on the final
* session setup response.
*/
tevent_req_done(req);
return;
}
status = gensec_session_key(session->gensec, state,
&session_key);
if (tevent_req_nterror(req, status)) {
return;
}
if (state->session_bind) {
status = smb2cli_session_set_channel_key(session->smbXcli,
session_key,
state->recv_iov);
if (tevent_req_nterror(req, status)) {
return;
}
session->needs_bind = false;
} else {
status = smb2cli_session_set_session_key(session->smbXcli,
session_key,
state->recv_iov);
if (tevent_req_nterror(req, status)) {
return;
}
}
tevent_req_done(req);
return;
}
/*
receive a composite session setup reply
*/
NTSTATUS smb2_session_setup_spnego_recv(struct tevent_req *req)
{
return tevent_req_simple_recv_ntstatus(req);
}
/*
sync version of smb2_session_setup_spnego
*/
NTSTATUS smb2_session_setup_spnego(struct smb2_session *session,
struct cli_credentials *credentials,
uint64_t previous_session_id)
{
struct tevent_req *subreq;
NTSTATUS status;
bool ok;
TALLOC_CTX *frame = talloc_stackframe();
struct tevent_context *ev = session->transport->ev;
if (frame == NULL) {
return NT_STATUS_NO_MEMORY;
}
subreq = smb2_session_setup_spnego_send(frame, ev,
session, credentials,
previous_session_id);
if (subreq == NULL) {
TALLOC_FREE(frame);
return NT_STATUS_NO_MEMORY;
}
ok = tevent_req_poll(subreq, ev);
if (!ok) {
status = map_nt_error_from_unix_common(errno);
TALLOC_FREE(frame);
return status;
}
status = smb2_session_setup_spnego_recv(subreq);
TALLOC_FREE(subreq);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(frame);
return status;
}
TALLOC_FREE(frame);
return NT_STATUS_OK;
}