source: trunk-3.0/source/auth/auth_server.c@ 103

Last change on this file since 103 was 62, checked in by Paul Smedley, 18 years ago

Update source to 3.0.25c level
File size: 12.7 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Authenticate to a remote server
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Andrew Bartlett 2001
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 2 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, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20*/
21
22#include "includes.h"
23
24#undef DBGC_CLASS
25#define DBGC_CLASS DBGC_AUTH
26
27extern userdom_struct current_user_info;
28
29/****************************************************************************
30 Support for server level security.
31****************************************************************************/
32
33static struct cli_state *server_cryptkey(TALLOC_CTX *mem_ctx)
34{
35 struct cli_state *cli = NULL;
36 fstring desthost;
37 struct in_addr dest_ip;
38 const char *p;
39 char *pserver;
40 BOOL connected_ok = False;
41
42 if (!(cli = cli_initialise()))
43 return NULL;
44
45 /* security = server just can't function with spnego */
46 cli->use_spnego = False;
47
48 pserver = talloc_strdup(mem_ctx, lp_passwordserver());
49 p = pserver;
50
51 while(next_token( &p, desthost, LIST_SEP, sizeof(desthost))) {
52 NTSTATUS status;
53
54 standard_sub_basic(current_user_info.smb_name, current_user_info.domain,
55 desthost, sizeof(desthost));
56 strupper_m(desthost);
57
58 if(!resolve_name( desthost, &dest_ip, 0x20)) {
59 DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
60 continue;
61 }
62
63 if (ismyip(dest_ip)) {
64 DEBUG(1,("Password server loop - disabling password server %s\n",desthost));
65 continue;
66 }
67
68 /* we use a mutex to prevent two connections at once - when a
69 Win2k PDC get two connections where one hasn't completed a
70 session setup yet it will send a TCP reset to the first
71 connection (tridge) */
72
73 if (!grab_server_mutex(desthost)) {
74 return NULL;
75 }
76
77 status = cli_connect(cli, desthost, &dest_ip);
78 if (NT_STATUS_IS_OK(status)) {
79 DEBUG(3,("connected to password server %s\n",desthost));
80 connected_ok = True;
81 break;
82 }
83 DEBUG(10,("server_cryptkey: failed to connect to server %s. Error %s\n",
84 desthost, nt_errstr(status) ));
85 }
86
87 if (!connected_ok) {
88 release_server_mutex();
89 DEBUG(0,("password server not available\n"));
90 cli_shutdown(cli);
91 return NULL;
92 }
93
94 if (!attempt_netbios_session_request(&cli, global_myname(),
95 desthost, &dest_ip)) {
96 release_server_mutex();
97 DEBUG(1,("password server fails session request\n"));
98 cli_shutdown(cli);
99 return NULL;
100 }
101
102 if (strequal(desthost,myhostname())) {
103 exit_server_cleanly("Password server loop!");
104 }
105
106 DEBUG(3,("got session\n"));
107
108 if (!cli_negprot(cli)) {
109 DEBUG(1,("%s rejected the negprot\n",desthost));
110 release_server_mutex();
111 cli_shutdown(cli);
112 return NULL;
113 }
114
115 if (cli->protocol < PROTOCOL_LANMAN2 ||
116 !(cli->sec_mode & NEGOTIATE_SECURITY_USER_LEVEL)) {
117 DEBUG(1,("%s isn't in user level security mode\n",desthost));
118 release_server_mutex();
119 cli_shutdown(cli);
120 return NULL;
121 }
122
123 /* Get the first session setup done quickly, to avoid silly
124 Win2k bugs. (The next connection to the server will kill
125 this one...
126 */
127
128 if (!NT_STATUS_IS_OK(cli_session_setup(cli, "", "", 0, "", 0,
129 ""))) {
130 DEBUG(0,("%s rejected the initial session setup (%s)\n",
131 desthost, cli_errstr(cli)));
132 release_server_mutex();
133 cli_shutdown(cli);
134 return NULL;
135 }
136
137 release_server_mutex();
138
139 DEBUG(3,("password server OK\n"));
140
141 return cli;
142}
143
144/****************************************************************************
145 Clean up our allocated cli.
146****************************************************************************/
147
148static void free_server_private_data(void **private_data_pointer)
149{
150 struct cli_state **cli = (struct cli_state **)private_data_pointer;
151 if (*cli && (*cli)->initialised) {
152 DEBUG(10, ("Shutting down smbserver connection\n"));
153 cli_shutdown(*cli);
154 }
155 *private_data_pointer = NULL;
156}
157
158/****************************************************************************
159 Send a 'keepalive' packet down the cli pipe.
160****************************************************************************/
161
162static void send_server_keepalive(void **private_data_pointer)
163{
164 /* also send a keepalive to the password server if its still
165 connected */
166 if (private_data_pointer) {
167 struct cli_state *cli = (struct cli_state *)(*private_data_pointer);
168 if (cli && cli->initialised) {
169 if (!send_keepalive(cli->fd)) {
170 DEBUG( 2, ( "send_server_keepalive: password server keepalive failed.\n"));
171 cli_shutdown(cli);
172 *private_data_pointer = NULL;
173 }
174 }
175 }
176}
177
178/****************************************************************************
179 Get the challenge out of a password server.
180****************************************************************************/
181
182static DATA_BLOB auth_get_challenge_server(const struct auth_context *auth_context,
183 void **my_private_data,
184 TALLOC_CTX *mem_ctx)
185{
186 struct cli_state *cli = server_cryptkey(mem_ctx);
187
188 if (cli) {
189 DEBUG(3,("using password server validation\n"));
190
191 if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
192 /* We can't work with unencrypted password servers
193 unless 'encrypt passwords = no' */
194 DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n"));
195
196 /* However, it is still a perfectly fine connection
197 to pass that unencrypted password over */
198 *my_private_data = (void *)cli;
199 return data_blob(NULL, 0);
200
201 } else if (cli->secblob.length < 8) {
202 /* We can't do much if we don't get a full challenge */
203 DEBUG(2,("make_auth_info_server: Didn't receive a full challenge from server\n"));
204 cli_shutdown(cli);
205 return data_blob(NULL, 0);
206 }
207
208 *my_private_data = (void *)cli;
209
210 /* The return must be allocated on the caller's mem_ctx, as our own will be
211 destoyed just after the call. */
212 return data_blob_talloc(auth_context->mem_ctx, cli->secblob.data,8);
213 } else {
214 return data_blob(NULL, 0);
215 }
216}
217
218
219/****************************************************************************
220 Check for a valid username and password in security=server mode.
221 - Validate a password with the password server.
222****************************************************************************/
223
224static NTSTATUS check_smbserver_security(const struct auth_context *auth_context,
225 void *my_private_data,
226 TALLOC_CTX *mem_ctx,
227 const auth_usersupplied_info *user_info,
228 auth_serversupplied_info **server_info)
229{
230 struct cli_state *cli;
231 static unsigned char badpass[24];
232 static fstring baduser;
233 static BOOL tested_password_server = False;
234 static BOOL bad_password_server = False;
235 NTSTATUS nt_status = NT_STATUS_NOT_IMPLEMENTED;
236 BOOL locally_made_cli = False;
237
238 cli = (struct cli_state *)my_private_data;
239
240 if (cli) {
241 } else {
242 cli = server_cryptkey(mem_ctx);
243 locally_made_cli = True;
244 }
245
246 if (!cli || !cli->initialised) {
247 DEBUG(1,("password server is not connected (cli not initilised)\n"));
248 return NT_STATUS_LOGON_FAILURE;
249 }
250
251 if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
252 if (user_info->encrypted) {
253 DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli->desthost));
254 return NT_STATUS_LOGON_FAILURE;
255 }
256 } else {
257 if (memcmp(cli->secblob.data, auth_context->challenge.data, 8) != 0) {
258 DEBUG(1,("the challenge that the password server (%s) supplied us is not the one we gave our client. This just can't work :-(\n", cli->desthost));
259 return NT_STATUS_LOGON_FAILURE;
260 }
261 }
262
263 if(badpass[0] == 0)
264 memset(badpass, 0x1f, sizeof(badpass));
265
266 if((user_info->nt_resp.length == sizeof(badpass)) &&
267 !memcmp(badpass, user_info->nt_resp.data, sizeof(badpass))) {
268 /*
269 * Very unlikely, our random bad password is the same as the users
270 * password.
271 */
272 memset(badpass, badpass[0]+1, sizeof(badpass));
273 }
274
275 if(baduser[0] == 0) {
276 fstrcpy(baduser, INVALID_USER_PREFIX);
277 fstrcat(baduser, global_myname());
278 }
279
280 /*
281 * Attempt a session setup with a totally incorrect password.
282 * If this succeeds with the guest bit *NOT* set then the password
283 * server is broken and is not correctly setting the guest bit. We
284 * need to detect this as some versions of NT4.x are broken. JRA.
285 */
286
287 /* I sure as hell hope that there aren't servers out there that take
288 * NTLMv2 and have this bug, as we don't test for that...
289 * - abartlet@samba.org
290 */
291
292 if ((!tested_password_server) && (lp_paranoid_server_security())) {
293 if (NT_STATUS_IS_OK(cli_session_setup(cli, baduser,
294 (char *)badpass,
295 sizeof(badpass),
296 (char *)badpass,
297 sizeof(badpass),
298 user_info->domain))) {
299
300 /*
301 * We connected to the password server so we
302 * can say we've tested it.
303 */
304 tested_password_server = True;
305
306 if ((SVAL(cli->inbuf,smb_vwv2) & 1) == 0) {
307 DEBUG(0,("server_validate: password server %s allows users as non-guest \
308with a bad password.\n", cli->desthost));
309 DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
310use this machine as the password server.\n"));
311 cli_ulogoff(cli);
312
313 /*
314 * Password server has the bug.
315 */
316 bad_password_server = True;
317 return NT_STATUS_LOGON_FAILURE;
318 }
319 cli_ulogoff(cli);
320 }
321 } else {
322
323 /*
324 * We have already tested the password server.
325 * Fail immediately if it has the bug.
326 */
327
328 if(bad_password_server) {
329 DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
330with a bad password.\n", cli->desthost));
331 DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
332use this machine as the password server.\n"));
333 return NT_STATUS_LOGON_FAILURE;
334 }
335 }
336
337 /*
338 * Now we know the password server will correctly set the guest bit, or is
339 * not guest enabled, we can try with the real password.
340 */
341
342 if (!user_info->encrypted) {
343 /* Plaintext available */
344 nt_status = cli_session_setup(
345 cli, user_info->smb_name,
346 (char *)user_info->plaintext_password.data,
347 user_info->plaintext_password.length,
348 NULL, 0, user_info->domain);
349
350 } else {
351 nt_status = cli_session_setup(
352 cli, user_info->smb_name,
353 (char *)user_info->lm_resp.data,
354 user_info->lm_resp.length,
355 (char *)user_info->nt_resp.data,
356 user_info->nt_resp.length,
357 user_info->domain);
358 }
359
360 if (!NT_STATUS_IS_OK(nt_status)) {
361 DEBUG(1,("password server %s rejected the password: %s\n",
362 cli->desthost, nt_errstr(nt_status)));
363 }
364
365 /* if logged in as guest then reject */
366 if ((SVAL(cli->inbuf,smb_vwv2) & 1) != 0) {
367 DEBUG(1,("password server %s gave us guest only\n", cli->desthost));
368 nt_status = NT_STATUS_LOGON_FAILURE;
369 }
370
371 cli_ulogoff(cli);
372
373 if (NT_STATUS_IS_OK(nt_status)) {
374 fstring real_username;
375 struct passwd *pass;
376
377 if ( (pass = smb_getpwnam( NULL, user_info->internal_username,
378 real_username, True )) != NULL )
379 {
380 /* if a real user check pam account restrictions */
381 /* only really perfomed if "obey pam restriction" is true */
382 nt_status = smb_pam_accountcheck(pass->pw_name);
383 if ( !NT_STATUS_IS_OK(nt_status)) {
384 DEBUG(1, ("PAM account restriction prevents user login\n"));
385 } else {
386
387 nt_status = make_server_info_pw(server_info, pass->pw_name, pass);
388 }
389 TALLOC_FREE(pass);
390 }
391 else
392 {
393 nt_status = NT_STATUS_NO_SUCH_USER;
394 }
395 }
396
397 if (locally_made_cli) {
398 cli_shutdown(cli);
399 }
400
401 return(nt_status);
402}
403
404static NTSTATUS auth_init_smbserver(struct auth_context *auth_context, const char* param, auth_methods **auth_method)
405{
406 if (!make_auth_methods(auth_context, auth_method)) {
407 return NT_STATUS_NO_MEMORY;
408 }
409 (*auth_method)->name = "smbserver";
410 (*auth_method)->auth = check_smbserver_security;
411 (*auth_method)->get_chal = auth_get_challenge_server;
412 (*auth_method)->send_keepalive = send_server_keepalive;
413 (*auth_method)->free_private_data = free_server_private_data;
414 return NT_STATUS_OK;
415}
416
417NTSTATUS auth_server_init(void)
418{
419 return smb_register_auth(AUTH_INTERFACE_VERSION, "smbserver", auth_init_smbserver);
420}
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