s4:smb_server: change the default for "server signing" to "default"
[kai/samba-autobuild/.git] / source4 / smb_server / smb2 / negprot.c
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_DOMAIN_CONTROLLER) {
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_SUPPORTED:
154                 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
155                 break;
156         case SMB_SIGNING_REQUIRED:
157                 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
158                 /* force signing on immediately */
159                 req->smb_conn->smb2_signing_required = true;
160                 break;
161         }
162         io->out.dialect_revision   = dialect;
163         io->out.capabilities       = 0;
164         io->out.max_transact_size  = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
165                                                    "smb2", "max transaction size", 0x10000);
166         io->out.max_read_size      = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
167                                                    "smb2", "max read size", 0x10000);
168         io->out.max_write_size     = lpcfg_parm_ulong(req->smb_conn->lp_ctx, NULL,
169                                                    "smb2", "max write size", 0x10000);
170         io->out.system_time        = timeval_to_nttime(&current_time);
171         io->out.server_start_time  = timeval_to_nttime(&boot_time);
172         io->out.reserved2          = 0;
173         status = smb2srv_negprot_secblob(req, &io->out.secblob);
174         NT_STATUS_NOT_OK_RETURN(status);
175
176         return NT_STATUS_OK;
177 }
178
179 static void smb2srv_negprot_send(struct smb2srv_request *req, struct smb2_negprot *io)
180 {
181         NTSTATUS status;
182
183         if (NT_STATUS_IS_ERR(req->status)) {
184                 smb2srv_send_error(req, req->status); /* TODO: is this correct? */
185                 return;
186         }
187
188         status = smb2srv_setup_reply(req, 0x40, true, io->out.secblob.length);
189         if (!NT_STATUS_IS_OK(status)) {
190                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
191                 talloc_free(req);
192                 return;
193         }
194
195         SSVAL(req->out.body, 0x02, io->out.security_mode);
196         SIVAL(req->out.body, 0x04, io->out.dialect_revision);
197         SIVAL(req->out.body, 0x06, io->out.reserved);
198         status = smbcli_push_guid(req->out.body, 0x08, &io->out.server_guid);
199         if (!NT_STATUS_IS_OK(status)) {
200                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
201                 talloc_free(req);
202                 return;
203         }
204         SIVAL(req->out.body, 0x18, io->out.capabilities);
205         SIVAL(req->out.body, 0x1C, io->out.max_transact_size);
206         SIVAL(req->out.body, 0x20, io->out.max_read_size);
207         SIVAL(req->out.body, 0x24, io->out.max_write_size);
208         push_nttime(req->out.body, 0x28, io->out.system_time);
209         push_nttime(req->out.body, 0x30, io->out.server_start_time);
210         SIVAL(req->out.body, 0x3C, io->out.reserved2);
211         status = smb2_push_o16s16_blob(&req->out, 0x38, io->out.secblob);
212         if (!NT_STATUS_IS_OK(status)) {
213                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
214                 talloc_free(req);
215                 return;
216         }
217
218         smb2srv_send_reply(req);
219 }
220
221 void smb2srv_negprot_recv(struct smb2srv_request *req)
222 {
223         struct smb2_negprot *io;
224         int i;
225
226         if (req->in.body_size < 0x26) {
227                 smbsrv_terminate_connection(req->smb_conn, "Bad body size in SMB2 negprot");
228                 return;
229         }
230
231         io = talloc(req, struct smb2_negprot);
232         if (!io) {
233                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
234                 talloc_free(req);
235                 return;
236         }
237
238         io->in.dialect_count = SVAL(req->in.body, 0x02);
239         io->in.security_mode = SVAL(req->in.body, 0x04);
240         io->in.reserved      = SVAL(req->in.body, 0x06);
241         io->in.capabilities  = IVAL(req->in.body, 0x08);
242         req->status = smbcli_pull_guid(req->in.body, 0xC, &io->in.client_guid);
243         if (!NT_STATUS_IS_OK(req->status)) {
244                 smbsrv_terminate_connection(req->smb_conn, "Bad GUID in SMB2 negprot");
245                 talloc_free(req);
246                 return;
247         }
248         io->in.start_time = smbcli_pull_nttime(req->in.body, 0x1C);
249
250         io->in.dialects = talloc_array(req, uint16_t, io->in.dialect_count);
251         if (io->in.dialects == NULL) {
252                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
253                 talloc_free(req);
254                 return;
255         }
256         for (i=0;i<io->in.dialect_count;i++) {
257                 io->in.dialects[i] = SVAL(req->in.body, 0x24+i*2);
258         }
259
260         req->status = smb2srv_negprot_backend(req, io);
261
262         if (req->control_flags & SMB2SRV_REQ_CTRL_FLAG_NOT_REPLY) {
263                 talloc_free(req);
264                 return;
265         }
266         smb2srv_negprot_send(req, io);
267 }
268
269 /*
270  * reply to a SMB negprot request with dialect "SMB 2.002"
271  */
272 void smb2srv_reply_smb_negprot(struct smbsrv_request *smb_req)
273 {
274         struct smb2srv_request *req;
275         uint32_t body_fixed_size = 0x26;
276
277         req = talloc_zero(smb_req->smb_conn, struct smb2srv_request);
278         if (!req) goto nomem;
279         req->smb_conn           = smb_req->smb_conn;
280         req->request_time       = smb_req->request_time;
281         talloc_steal(req, smb_req);
282
283         req->in.size      = NBT_HDR_SIZE+SMB2_HDR_BODY+body_fixed_size;
284         req->in.allocated = req->in.size;
285         req->in.buffer    = talloc_array(req, uint8_t, req->in.allocated);
286         if (!req->in.buffer) goto nomem;
287         req->in.hdr       = req->in.buffer + NBT_HDR_SIZE;
288         req->in.body      = req->in.hdr + SMB2_HDR_BODY;
289         req->in.body_size = body_fixed_size;
290         req->in.dynamic   = NULL;
291
292         smb2srv_setup_bufinfo(req);
293
294         SIVAL(req->in.hdr, 0,                           SMB2_MAGIC);
295         SSVAL(req->in.hdr, SMB2_HDR_LENGTH,             SMB2_HDR_BODY);
296         SSVAL(req->in.hdr, SMB2_HDR_EPOCH,              0);
297         SIVAL(req->in.hdr, SMB2_HDR_STATUS,             0);
298         SSVAL(req->in.hdr, SMB2_HDR_OPCODE,             SMB2_OP_NEGPROT);
299         SSVAL(req->in.hdr, SMB2_HDR_CREDIT,             0);
300         SIVAL(req->in.hdr, SMB2_HDR_FLAGS,              0);
301         SIVAL(req->in.hdr, SMB2_HDR_NEXT_COMMAND,       0);
302         SBVAL(req->in.hdr, SMB2_HDR_MESSAGE_ID,         0);
303         SIVAL(req->in.hdr, SMB2_HDR_PID,                0);
304         SIVAL(req->in.hdr, SMB2_HDR_TID,                0);
305         SBVAL(req->in.hdr, SMB2_HDR_SESSION_ID,         0);
306         memset(req->in.hdr+SMB2_HDR_SIGNATURE, 0, 16);
307
308         /* this seems to be a bug, they use 0x24 but the length is 0x26 */
309         SSVAL(req->in.body, 0x00, 0x24);
310
311         SSVAL(req->in.body, 0x02, 1);
312         memset(req->in.body+0x04, 0, 32);
313         SSVAL(req->in.body, 0x24, SMB2_DIALECT_REVISION_202);
314
315         smb2srv_negprot_recv(req);
316         return;
317 nomem:
318         smbsrv_terminate_connection(smb_req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
319         talloc_free(req);
320         return;
321 }