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Introduce setting "desired" for 'smb encrypt' and 'client/server signing'
[Samba.git] / source4 / smb_server / smb2 / negprot.c
blob6a8f6efc2df8210d5ec46b3ec2838a433c847ebc
1 /*
2 Unix SMB2 implementation.
3
4 Copyright (C) Andrew Bartlett 2001-2005
5 Copyright (C) Stefan Metzmacher 2005
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 "auth/credentials/credentials.h"
23 #include "auth/auth.h"
24 #include "auth/gensec/gensec.h"
25 #include "libcli/raw/libcliraw.h"
26 #include "libcli/raw/raw_proto.h"
27 #include "libcli/smb2/smb2.h"
28 #include "libcli/smb2/smb2_calls.h"
29 #include "smb_server/smb_server.h"
30 #include "smb_server/smb2/smb2_server.h"
31 #include "smbd/service_stream.h"
32 #include "param/param.h"
33
34 static NTSTATUS smb2srv_negprot_secblob(struct smb2srv_request *req, DATA_BLOB *_blob)
35 {
36 struct gensec_security *gensec_security;
37 DATA_BLOB null_data_blob = data_blob(NULL, 0);
38 DATA_BLOB blob;
39 NTSTATUS nt_status;
40 struct cli_credentials *server_credentials;
41
42 server_credentials = cli_credentials_init(req);
43 if (!server_credentials) {
44 smbsrv_terminate_connection(req->smb_conn, "Failed to init server credentials\n");
45 return NT_STATUS_NO_MEMORY;
46 }
47
48 cli_credentials_set_conf(server_credentials, req->smb_conn->lp_ctx);
49 nt_status = cli_credentials_set_machine_account(server_credentials, req->smb_conn->lp_ctx);
50 if (!NT_STATUS_IS_OK(nt_status)) {
51 DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(nt_status)));
52 talloc_free(server_credentials);
53 server_credentials = NULL;
54 }
55
56 req->smb_conn->negotiate.server_credentials = talloc_steal(req->smb_conn, server_credentials);
57
58 nt_status = samba_server_gensec_start(req,
59 req->smb_conn->connection->event.ctx,
60 req->smb_conn->connection->msg_ctx,
61 req->smb_conn->lp_ctx,
62 server_credentials,
63 "cifs",
64 &gensec_security);
65 if (!NT_STATUS_IS_OK(nt_status)) {
66 DEBUG(0, ("Failed to start GENSEC: %s\n", nt_errstr(nt_status)));
67 smbsrv_terminate_connection(req->smb_conn, "Failed to start GENSEC\n");
68 return nt_status;
69 }
70
71 gensec_set_target_service(gensec_security, "cifs");
72
73 gensec_set_credentials(gensec_security, server_credentials);
74
75 nt_status = gensec_start_mech_by_oid(gensec_security, GENSEC_OID_SPNEGO);
76 if (!NT_STATUS_IS_OK(nt_status)) {
77 DEBUG(0, ("Failed to start SPNEGO: %s\n", nt_errstr(nt_status)));
78 smbsrv_terminate_connection(req->smb_conn, "Failed to start SPNEGO\n");
79 return nt_status;
80 }
81
82 nt_status = gensec_update(gensec_security, req, req->smb_conn->connection->event.ctx, null_data_blob, &blob);
83 if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
84 DEBUG(0, ("Failed to get SPNEGO to give us the first token: %s\n", nt_errstr(nt_status)));
85 smbsrv_terminate_connection(req->smb_conn, "Failed to start SPNEGO - no first token\n");
86 return nt_status;
87 }
88
89 *_blob = blob;
90 return NT_STATUS_OK;
91 }
92
93 static NTSTATUS smb2srv_negprot_backend(struct smb2srv_request *req, struct smb2_negprot *io)
94 {
95 NTSTATUS status;
96 struct timeval current_time;
97 struct timeval boot_time;
98 uint16_t i;
99 uint16_t dialect = 0;
100 enum smb_signing_setting signing_setting;
101 struct loadparm_context *lp_ctx = req->smb_conn->lp_ctx;
102
103 /* we only do one dialect for now */
104 if (io->in.dialect_count < 1) {
105 return NT_STATUS_NOT_SUPPORTED;
106 }
107 for (i=0; i < io->in.dialect_count; i++) {
108 dialect = io->in.dialects[i];
109 if (dialect == SMB2_DIALECT_REVISION_202) {
110 break;
111 }
112 }
113 if (dialect != SMB2_DIALECT_REVISION_202) {
114 DEBUG(0,("Got unexpected SMB2 dialect %u\n", dialect));
115 return NT_STATUS_NOT_SUPPORTED;
116 }
117
118 req->smb_conn->negotiate.protocol = PROTOCOL_SMB2_02;
119
120 current_time = timeval_current(); /* TODO: handle timezone?! */
121 boot_time = timeval_current(); /* TODO: fix me */
122
123 ZERO_STRUCT(io->out);
124
125 signing_setting = lpcfg_server_signing(lp_ctx);
126 if (signing_setting == SMB_SIGNING_DEFAULT) {
127 /*
128 * If we are a domain controller, SMB signing is
129 * really important, as it can prevent a number of
130 * attacks on communications between us and the
131 * clients
132 *
133 * However, it really sucks (no sendfile, CPU
134 * overhead) performance-wise when used on a
135 * file server, so disable it by default
136 * on non-DCs
137 */
138
139 if (lpcfg_server_role(lp_ctx) >= ROLE_ACTIVE_DIRECTORY_DC) {
140 signing_setting = SMB_SIGNING_REQUIRED;
141 } else {
142 signing_setting = SMB_SIGNING_OFF;
143 }
144 }
145
146 switch (signing_setting) {
147 case SMB_SIGNING_DEFAULT:
148 smb_panic(__location__);
149 break;
150 case SMB_SIGNING_OFF:
151 io->out.security_mode = 0;
152 break;
153 case SMB_SIGNING_DESIRED:
154 case SMB_SIGNING_IF_REQUIRED:
155 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
156 break;
157 case SMB_SIGNING_REQUIRED:
158 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
159 /* force signing on immediately */
160 req->smb_conn->smb2_signing_required = true;
161 break;
162 }
163 io->out.dialect_revision = dialect;
164 io->out.capabilities = 0;
165 io->out.max_transact_size = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
166 "smb2", "max transaction size", 0x10000);
167 io->out.max_read_size = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
168 "smb2", "max read size", 0x10000);
169 io->out.max_write_size = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
170 "smb2", "max write size", 0x10000);
171 io->out.system_time = timeval_to_nttime(&current_time);
172 io->out.server_start_time = timeval_to_nttime(&boot_time);
173 io->out.reserved2 = 0;
174 status = smb2srv_negprot_secblob(req, &io->out.secblob);
175 NT_STATUS_NOT_OK_RETURN(status);
176
177 return NT_STATUS_OK;
178 }
179
180 static void smb2srv_negprot_send(struct smb2srv_request *req, struct smb2_negprot *io)
181 {
182 NTSTATUS status;
183
184 if (NT_STATUS_IS_ERR(req->status)) {
185 smb2srv_send_error(req, req->status); /* TODO: is this correct? */
186 return;
187 }
188
189 status = smb2srv_setup_reply(req, 0x40, true, io->out.secblob.length);
190 if (!NT_STATUS_IS_OK(status)) {
191 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
192 talloc_free(req);
193 return;
194 }
195
196 SSVAL(req->out.body, 0x02, io->out.security_mode);
197 SIVAL(req->out.body, 0x04, io->out.dialect_revision);
198 SIVAL(req->out.body, 0x06, io->out.reserved);
199 status = smbcli_push_guid(req->out.body, 0x08, &io->out.server_guid);
200 if (!NT_STATUS_IS_OK(status)) {
201 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
202 talloc_free(req);
203 return;
204 }
205 SIVAL(req->out.body, 0x18, io->out.capabilities);
206 SIVAL(req->out.body, 0x1C, io->out.max_transact_size);
207 SIVAL(req->out.body, 0x20, io->out.max_read_size);
208 SIVAL(req->out.body, 0x24, io->out.max_write_size);
209 push_nttime(req->out.body, 0x28, io->out.system_time);
210 push_nttime(req->out.body, 0x30, io->out.server_start_time);
211 SIVAL(req->out.body, 0x3C, io->out.reserved2);
212 status = smb2_push_o16s16_blob(&req->out, 0x38, io->out.secblob);
213 if (!NT_STATUS_IS_OK(status)) {
214 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
215 talloc_free(req);
216 return;
217 }
218
219 smb2srv_send_reply(req);
220 }
221
222 void smb2srv_negprot_recv(struct smb2srv_request *req)
223 {
224 struct smb2_negprot *io;
225 int i;
226
227 if (req->in.body_size < 0x26) {
228 smbsrv_terminate_connection(req->smb_conn, "Bad body size in SMB2 negprot");
229 return;
230 }
231
232 io = talloc(req, struct smb2_negprot);
233 if (!io) {
234 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
235 talloc_free(req);
236 return;
237 }
238
239 io->in.dialect_count = SVAL(req->in.body, 0x02);
240 io->in.security_mode = SVAL(req->in.body, 0x04);
241 io->in.reserved = SVAL(req->in.body, 0x06);
242 io->in.capabilities = IVAL(req->in.body, 0x08);
243 req->status = smbcli_pull_guid(req->in.body, 0xC, &io->in.client_guid);
244 if (!NT_STATUS_IS_OK(req->status)) {
245 smbsrv_terminate_connection(req->smb_conn, "Bad GUID in SMB2 negprot");
246 talloc_free(req);
247 return;
248 }
249 io->in.start_time = smbcli_pull_nttime(req->in.body, 0x1C);
250
251 io->in.dialects = talloc_array(req, uint16_t, io->in.dialect_count);
252 if (io->in.dialects == NULL) {
253 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
254 talloc_free(req);
255 return;
256 }
257 for (i=0;i<io->in.dialect_count;i++) {
258 io->in.dialects[i] = SVAL(req->in.body, 0x24+i*2);
259 }
260
261 req->status = smb2srv_negprot_backend(req, io);
262
263 if (req->control_flags & SMB2SRV_REQ_CTRL_FLAG_NOT_REPLY) {
264 talloc_free(req);
265 return;
266 }
267 smb2srv_negprot_send(req, io);
268 }
269
270 /*
271 * reply to a SMB negprot request with dialect "SMB 2.002"
272 */
273 void smb2srv_reply_smb_negprot(struct smbsrv_request *smb_req)
274 {
275 struct smb2srv_request *req;
276 uint32_t body_fixed_size = 0x26;
277
278 req = talloc_zero(smb_req->smb_conn, struct smb2srv_request);
279 if (!req) goto nomem;
280 req->smb_conn = smb_req->smb_conn;
281 req->request_time = smb_req->request_time;
282 talloc_steal(req, smb_req);
283
284 req->in.size = NBT_HDR_SIZE+SMB2_HDR_BODY+body_fixed_size;
285 req->in.allocated = req->in.size;
286 req->in.buffer = talloc_array(req, uint8_t, req->in.allocated);
287 if (!req->in.buffer) goto nomem;
288 req->in.hdr = req->in.buffer + NBT_HDR_SIZE;
289 req->in.body = req->in.hdr + SMB2_HDR_BODY;
290 req->in.body_size = body_fixed_size;
291 req->in.dynamic = NULL;
292
293 smb2srv_setup_bufinfo(req);
294
295 SIVAL(req->in.hdr, 0, SMB2_MAGIC);
296 SSVAL(req->in.hdr, SMB2_HDR_LENGTH, SMB2_HDR_BODY);
297 SSVAL(req->in.hdr, SMB2_HDR_EPOCH, 0);
298 SIVAL(req->in.hdr, SMB2_HDR_STATUS, 0);
299 SSVAL(req->in.hdr, SMB2_HDR_OPCODE, SMB2_OP_NEGPROT);
300 SSVAL(req->in.hdr, SMB2_HDR_CREDIT, 0);
301 SIVAL(req->in.hdr, SMB2_HDR_FLAGS, 0);
302 SIVAL(req->in.hdr, SMB2_HDR_NEXT_COMMAND, 0);
303 SBVAL(req->in.hdr, SMB2_HDR_MESSAGE_ID, 0);
304 SIVAL(req->in.hdr, SMB2_HDR_PID, 0);
305 SIVAL(req->in.hdr, SMB2_HDR_TID, 0);
306 SBVAL(req->in.hdr, SMB2_HDR_SESSION_ID, 0);
307 memset(req->in.hdr+SMB2_HDR_SIGNATURE, 0, 16);
308
309 /* this seems to be a bug, they use 0x24 but the length is 0x26 */
310 SSVAL(req->in.body, 0x00, 0x24);
311
312 SSVAL(req->in.body, 0x02, 1);
313 memset(req->in.body+0x04, 0, 32);
314 SSVAL(req->in.body, 0x24, SMB2_DIALECT_REVISION_202);
315
316 smb2srv_negprot_recv(req);
317 return;
318 nomem:
319 smbsrv_terminate_connection(smb_req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
320 talloc_free(req);
321 return;
322 }
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