1/*
2   Unix SMB/CIFS implementation.
3   Core SMB2 server
4
5   Copyright (C) Stefan Metzmacher 2009
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22#include "smbd/globals.h"
23#include "../libcli/smb/smb_common.h"
24#include "../libcli/auth/spnego.h"
25
26static NTSTATUS smbd_smb2_session_setup(struct smbd_smb2_request *req,
27					uint64_t in_session_id,
28					uint8_t in_security_mode,
29					DATA_BLOB in_security_buffer,
30					uint16_t *out_session_flags,
31					DATA_BLOB *out_security_buffer,
32					uint64_t *out_session_id);
33
34NTSTATUS smbd_smb2_request_process_sesssetup(struct smbd_smb2_request *req)
35{
36	const uint8_t *inhdr;
37	const uint8_t *inbody;
38	int i = req->current_idx;
39	uint8_t *outhdr;
40	DATA_BLOB outbody;
41	DATA_BLOB outdyn;
42	size_t expected_body_size = 0x19;
43	size_t body_size;
44	uint64_t in_session_id;
45	uint8_t in_security_mode;
46	uint16_t in_security_offset;
47	uint16_t in_security_length;
48	DATA_BLOB in_security_buffer;
49	uint16_t out_session_flags;
50	uint64_t out_session_id;
51	uint16_t out_security_offset;
52	DATA_BLOB out_security_buffer;
53	NTSTATUS status;
54
55	inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
56
57	if (req->in.vector[i+1].iov_len != (expected_body_size & 0xFFFFFFFE)) {
58		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
59	}
60
61	inbody = (const uint8_t *)req->in.vector[i+1].iov_base;
62
63	body_size = SVAL(inbody, 0x00);
64	if (body_size != expected_body_size) {
65		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
66	}
67
68	in_security_offset = SVAL(inbody, 0x0C);
69	in_security_length = SVAL(inbody, 0x0E);
70
71	if (in_security_offset != (SMB2_HDR_BODY + (body_size & 0xFFFFFFFE))) {
72		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
73	}
74
75	if (in_security_length > req->in.vector[i+2].iov_len) {
76		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
77	}
78
79	in_session_id = BVAL(inhdr, SMB2_HDR_SESSION_ID);
80	in_security_mode = CVAL(inbody, 0x03);
81	in_security_buffer.data = (uint8_t *)req->in.vector[i+2].iov_base;
82	in_security_buffer.length = in_security_length;
83
84	status = smbd_smb2_session_setup(req,
85					 in_session_id,
86					 in_security_mode,
87					 in_security_buffer,
88					 &out_session_flags,
89					 &out_security_buffer,
90					 &out_session_id);
91	if (!NT_STATUS_IS_OK(status) &&
92	    !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
93		status = nt_status_squash(status);
94		return smbd_smb2_request_error(req, status);
95	}
96
97	out_security_offset = SMB2_HDR_BODY + 0x08;
98
99	outhdr = (uint8_t *)req->out.vector[i].iov_base;
100
101	outbody = data_blob_talloc(req->out.vector, NULL, 0x08);
102	if (outbody.data == NULL) {
103		return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
104	}
105
106	SBVAL(outhdr, SMB2_HDR_SESSION_ID, out_session_id);
107
108	SSVAL(outbody.data, 0x00, 0x08 + 1);	/* struct size */
109	SSVAL(outbody.data, 0x02,
110	      out_session_flags);		/* session flags */
111	SSVAL(outbody.data, 0x04,
112	      out_security_offset);		/* security buffer offset */
113	SSVAL(outbody.data, 0x06,
114	      out_security_buffer.length);	/* security buffer length */
115
116	outdyn = out_security_buffer;
117
118	return smbd_smb2_request_done_ex(req, status, outbody, &outdyn,
119					 __location__);
120}
121
122static int smbd_smb2_session_destructor(struct smbd_smb2_session *session)
123{
124	if (session->sconn == NULL) {
125		return 0;
126	}
127
128	/* first free all tcons */
129	while (session->tcons.list) {
130		talloc_free(session->tcons.list);
131	}
132
133	idr_remove(session->sconn->smb2.sessions.idtree, session->vuid);
134	DLIST_REMOVE(session->sconn->smb2.sessions.list, session);
135	invalidate_vuid(session->sconn, session->vuid);
136
137	session->vuid = 0;
138	session->status = NT_STATUS_USER_SESSION_DELETED;
139	session->sconn = NULL;
140
141	return 0;
142}
143
144static NTSTATUS smbd_smb2_session_setup(struct smbd_smb2_request *req,
145					uint64_t in_session_id,
146					uint8_t in_security_mode,
147					DATA_BLOB in_security_buffer,
148					uint16_t *out_session_flags,
149					DATA_BLOB *out_security_buffer,
150					uint64_t *out_session_id)
151{
152	struct smbd_smb2_session *session;
153	NTSTATUS status;
154
155	*out_session_flags = 0;
156	*out_session_id = 0;
157
158	if (in_session_id == 0) {
159		int id;
160
161		/* create a new session */
162		session = talloc_zero(req->sconn, struct smbd_smb2_session);
163		if (session == NULL) {
164			return NT_STATUS_NO_MEMORY;
165		}
166		session->status = NT_STATUS_MORE_PROCESSING_REQUIRED;
167		id = idr_get_new_random(req->sconn->smb2.sessions.idtree,
168					session,
169					req->sconn->smb2.sessions.limit);
170		if (id == -1) {
171			return NT_STATUS_INSUFFICIENT_RESOURCES;
172		}
173		session->vuid = id;
174
175		session->tcons.idtree = idr_init(session);
176		if (session->tcons.idtree == NULL) {
177			return NT_STATUS_NO_MEMORY;
178		}
179		session->tcons.limit = 0x0000FFFE;
180		session->tcons.list = NULL;
181
182		DLIST_ADD_END(req->sconn->smb2.sessions.list, session,
183			      struct smbd_smb2_session *);
184		session->sconn = req->sconn;
185		talloc_set_destructor(session, smbd_smb2_session_destructor);
186	} else {
187		void *p;
188
189		/* lookup an existing session */
190		p = idr_find(req->sconn->smb2.sessions.idtree, in_session_id);
191		if (p == NULL) {
192			return NT_STATUS_USER_SESSION_DELETED;
193		}
194		session = talloc_get_type_abort(p, struct smbd_smb2_session);
195	}
196
197	if (NT_STATUS_IS_OK(session->status)) {
198		return NT_STATUS_REQUEST_NOT_ACCEPTED;
199	}
200
201	if (session->auth_ntlmssp_state == NULL) {
202		status = auth_ntlmssp_start(&session->auth_ntlmssp_state);
203		if (!NT_STATUS_IS_OK(status)) {
204			TALLOC_FREE(session);
205			return status;
206		}
207	}
208
209	if (in_security_buffer.data[0] == ASN1_APPLICATION(0)) {
210		DATA_BLOB secblob_in;
211		DATA_BLOB chal_out;
212		char *kerb_mech = NULL;
213
214		status = parse_spnego_mechanisms(in_security_buffer,
215				&secblob_in, &kerb_mech);
216		if (!NT_STATUS_IS_OK(status)) {
217			TALLOC_FREE(session);
218			return nt_status_squash(status);
219		}
220
221		/* For now, just SPNEGO NTLMSSP - krb5 goes here later.. */
222		status = auth_ntlmssp_update(session->auth_ntlmssp_state,
223					     secblob_in,
224					     &chal_out);
225
226		if (!NT_STATUS_IS_OK(status) &&
227				!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
228			auth_ntlmssp_end(&session->auth_ntlmssp_state);
229			TALLOC_FREE(session);
230			return nt_status_squash(status);
231		}
232
233		*out_security_buffer = spnego_gen_auth_response(&chal_out,
234                                status, OID_NTLMSSP);
235
236		*out_session_id = session->vuid;
237		return status;
238	} else if (in_security_buffer.data[0] == ASN1_CONTEXT(1)) {
239		DATA_BLOB auth = data_blob_null;
240		DATA_BLOB auth_out = data_blob_null;
241
242		/* its an auth packet */
243		if (!spnego_parse_auth(in_security_buffer, &auth)) {
244			TALLOC_FREE(session);
245			return NT_STATUS_LOGON_FAILURE;
246		}
247		/* For now, just SPNEGO NTLMSSP - krb5 goes here later.. */
248		status = auth_ntlmssp_update(session->auth_ntlmssp_state,
249					     auth,
250					     &auth_out);
251		if (!NT_STATUS_IS_OK(status)) {
252			auth_ntlmssp_end(&session->auth_ntlmssp_state);
253			TALLOC_FREE(session);
254			return nt_status_squash(status);
255		}
256
257		*out_security_buffer = spnego_gen_auth_response(&auth_out,
258                                status, NULL);
259
260		*out_session_id = session->vuid;
261	} else if (strncmp((char *)(in_security_buffer.data), "NTLMSSP", 7) == 0) {
262
263		/* RAW NTLMSSP */
264		status = auth_ntlmssp_update(session->auth_ntlmssp_state,
265					     in_security_buffer,
266					     out_security_buffer);
267
268		if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
269			*out_session_id = session->vuid;
270			return status;
271		}
272		if (!NT_STATUS_IS_OK(status)) {
273			auth_ntlmssp_end(&session->auth_ntlmssp_state);
274			TALLOC_FREE(session);
275			return nt_status_squash(status);
276		}
277		*out_session_id = session->vuid;
278	}
279
280	/* TODO: setup session key for signing */
281
282	if ((in_security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) ||
283	    lp_server_signing() == Required) {
284		session->do_signing = true;
285	}
286
287	if (session->auth_ntlmssp_state->server_info->guest) {
288		/* we map anonymous to guest internally */
289		*out_session_flags |= SMB2_SESSION_FLAG_IS_GUEST;
290		*out_session_flags |= SMB2_SESSION_FLAG_IS_NULL;
291		/* force no signing */
292		session->do_signing = false;
293	}
294
295	session->server_info = session->auth_ntlmssp_state->server_info;
296	data_blob_free(&session->server_info->user_session_key);
297	session->server_info->user_session_key =
298			data_blob_talloc(
299			session->server_info,
300			session->auth_ntlmssp_state->ntlmssp_state->session_key.data,
301			session->auth_ntlmssp_state->ntlmssp_state->session_key.length);
302	if (session->auth_ntlmssp_state->ntlmssp_state->session_key.length > 0) {
303		if (session->server_info->user_session_key.data == NULL) {
304			TALLOC_FREE(session);
305			return NT_STATUS_NO_MEMORY;
306		}
307	}
308	session->session_key = session->server_info->user_session_key;
309
310	session->compat_vuser = talloc_zero(session, user_struct);
311	if (session->compat_vuser == NULL) {
312		TALLOC_FREE(session);
313		return NT_STATUS_NO_MEMORY;
314	}
315	session->compat_vuser->auth_ntlmssp_state = session->auth_ntlmssp_state;
316	session->compat_vuser->homes_snum = -1;
317	session->compat_vuser->server_info = session->server_info;
318	session->compat_vuser->session_keystr = NULL;
319	session->compat_vuser->vuid = session->vuid;
320	DLIST_ADD(session->sconn->smb1.sessions.validated_users, session->compat_vuser);
321
322	session->status = NT_STATUS_OK;
323
324	/*
325	 * we attach the session to the request
326	 * so that the response can be signed
327	 */
328	req->session = session;
329	if (session->do_signing) {
330		req->do_signing = true;
331	}
332
333	*out_session_id = session->vuid;
334	return status;
335}
336
337NTSTATUS smbd_smb2_request_check_session(struct smbd_smb2_request *req)
338{
339	const uint8_t *inhdr;
340	int i = req->current_idx;
341	uint64_t in_session_id;
342	void *p;
343	struct smbd_smb2_session *session;
344
345	inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
346
347	in_session_id = BVAL(inhdr, SMB2_HDR_SESSION_ID);
348
349	/* lookup an existing session */
350	p = idr_find(req->sconn->smb2.sessions.idtree, in_session_id);
351	if (p == NULL) {
352		return NT_STATUS_USER_SESSION_DELETED;
353	}
354	session = talloc_get_type_abort(p, struct smbd_smb2_session);
355
356	if (!NT_STATUS_IS_OK(session->status)) {
357		return NT_STATUS_ACCESS_DENIED;
358	}
359
360	set_current_user_info(session->server_info->sanitized_username,
361			      session->server_info->unix_name,
362			      pdb_get_domain(session->server_info->sam_account));
363
364	req->session = session;
365	return NT_STATUS_OK;
366}
367
368NTSTATUS smbd_smb2_request_process_logoff(struct smbd_smb2_request *req)
369{
370	const uint8_t *inbody;
371	int i = req->current_idx;
372	DATA_BLOB outbody;
373	size_t expected_body_size = 0x04;
374	size_t body_size;
375
376	if (req->in.vector[i+1].iov_len != (expected_body_size & 0xFFFFFFFE)) {
377		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
378	}
379
380	inbody = (const uint8_t *)req->in.vector[i+1].iov_base;
381
382	body_size = SVAL(inbody, 0x00);
383	if (body_size != expected_body_size) {
384		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
385	}
386
387	/*
388	 * TODO: cancel all outstanding requests on the session
389	 *       and delete all tree connections.
390	 */
391	smbd_smb2_session_destructor(req->session);
392	/*
393	 * we may need to sign the response, so we need to keep
394	 * the session until the response is sent to the wire.
395	 */
396	talloc_steal(req, req->session);
397
398	outbody = data_blob_talloc(req->out.vector, NULL, 0x04);
399	if (outbody.data == NULL) {
400		return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
401	}
402
403	SSVAL(outbody.data, 0x00, 0x04);	/* struct size */
404	SSVAL(outbody.data, 0x02, 0);		/* reserved */
405
406	return smbd_smb2_request_done(req, outbody, NULL);
407}
408