2 Unix SMB/CIFS implementation.
3 Authenticate to a remote server
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Andrew Bartlett 2001
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.
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.
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.
25 #define DBGC_CLASS DBGC_AUTH
27 /****************************************************************************
28 Support for server level security.
29 ****************************************************************************/
31 static struct smbcli_state *server_cryptkey(TALLOC_CTX *mem_ctx)
33 struct smbcli_state *cli = NULL;
35 struct ipv4_addr dest_ip;
38 BOOL connected_ok = False;
40 if (!(cli = smbcli_initialise(cli)))
43 /* security = server just can't function with spnego */
44 cli->use_spnego = False;
46 pserver = talloc_strdup(mem_ctx, lp_passwordserver());
49 while(next_token( &p, desthost, LIST_SEP, sizeof(desthost))) {
52 if(!resolve_name( desthost, &dest_ip, 0x20)) {
53 DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
57 if (ismyip(dest_ip)) {
58 DEBUG(1,("Password server loop - disabling password server %s\n",desthost));
62 /* we use a mutex to prevent two connections at once - when a
63 Win2k PDC get two connections where one hasn't completed a
64 session setup yet it will send a TCP reset to the first
65 connection (tridge) */
67 if (!grab_server_mutex(desthost)) {
71 if (smbcli_connect(cli, desthost, &dest_ip)) {
72 DEBUG(3,("connected to password server %s\n",desthost));
79 release_server_mutex();
80 DEBUG(0,("password server not available\n"));
85 if (!attempt_netbios_session_request(cli, lp_netbios_name(),
86 desthost, &dest_ip)) {
87 release_server_mutex();
88 DEBUG(1,("password server fails session request\n"));
93 if (strequal(desthost,myhostname(mem_ctx))) {
94 exit_server("Password server loop!");
97 DEBUG(3,("got session\n"));
99 if (!smbcli_negprot(cli)) {
100 DEBUG(1,("%s rejected the negprot\n",desthost));
101 release_server_mutex();
102 smbcli_shutdown(cli);
106 if (cli->protocol < PROTOCOL_LANMAN2 ||
107 !(cli->sec_mode & NEGOTIATE_SECURITY_USER_LEVEL)) {
108 DEBUG(1,("%s isn't in user level security mode\n",desthost));
109 release_server_mutex();
110 smbcli_shutdown(cli);
114 /* Get the first session setup done quickly, to avoid silly
115 Win2k bugs. (The next connection to the server will kill
119 if (!smbcli_session_setup(cli, "", "", 0, "", 0,
121 DEBUG(0,("%s rejected the initial session setup (%s)\n",
122 desthost, smbcli_errstr(cli)));
123 release_server_mutex();
124 smbcli_shutdown(cli);
128 release_server_mutex();
130 DEBUG(3,("password server OK\n"));
135 /****************************************************************************
136 Clean up our allocated cli.
137 ****************************************************************************/
139 static void free_server_private_data(void **private_data_pointer)
141 struct smbcli_state **cli = (struct smbcli_state **)private_data_pointer;
142 if (*cli && (*cli)->initialised) {
143 smbcli_shutdown(*cli);
147 /****************************************************************************
148 Get the challenge out of a password server.
149 ****************************************************************************/
151 static DATA_BLOB auth_get_challenge_server(const struct auth_context *auth_context,
152 void **my_private_data,
155 struct smbcli_state *cli = server_cryptkey(mem_ctx);
158 DEBUG(3,("using password server validation\n"));
160 if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
161 /* We can't work with unencrypted password servers
162 unless 'encrypt passwords = no' */
163 DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n"));
165 /* However, it is still a perfectly fine connection
166 to pass that unencrypted password over */
167 *my_private_data = (void *)cli;
168 return data_blob(NULL, 0);
170 } else if (cli->secblob.length < 8) {
171 /* We can't do much if we don't get a full challenge */
172 DEBUG(2,("make_auth_info_server: Didn't receive a full challenge from server\n"));
173 smbcli_shutdown(cli);
174 return data_blob(NULL, 0);
177 *my_private_data = (void *)cli;
179 /* The return must be allocated on the caller's mem_ctx, as our own will be
180 destoyed just after the call. */
181 return data_blob_talloc(auth_context->mem_ctx, cli->secblob.data,8);
183 return data_blob(NULL, 0);
188 /****************************************************************************
189 Check for a valid username and password in security=server mode.
190 - Validate a password with the password server.
191 ****************************************************************************/
193 static NTSTATUS check_smbserver_security(const struct auth_context *auth_context,
194 void *my_private_data,
196 const auth_usersupplied_info *user_info,
197 auth_serversupplied_info **server_info)
199 struct smbcli_state *cli;
200 static uint8_t badpass[24];
201 static fstring baduser;
202 static BOOL tested_password_server = False;
203 static BOOL bad_password_server = False;
204 NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
205 BOOL locally_made_cli = False;
208 * Check that the requested domain is not our own machine name.
209 * If it is, we should never check the PDC here, we use our own local
213 if(is_myname(user_info->domain.str)) {
214 DEBUG(3,("check_smbserver_security: Requested domain was for this machine.\n"));
215 return NT_STATUS_LOGON_FAILURE;
218 cli = my_private_data;
222 cli = server_cryptkey(mem_ctx);
223 locally_made_cli = True;
226 if (!cli || !cli->initialised) {
227 DEBUG(1,("password server is not connected (cli not initilised)\n"));
228 return NT_STATUS_LOGON_FAILURE;
231 if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
232 if (user_info->encrypted) {
233 DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli->desthost));
234 return NT_STATUS_LOGON_FAILURE;
237 if (memcmp(cli->secblob.data, auth_context->challenge.data, 8) != 0) {
238 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));
239 return NT_STATUS_LOGON_FAILURE;
244 memset(badpass, 0x1f, sizeof(badpass));
246 if((user_info->nt_resp.length == sizeof(badpass)) &&
247 !memcmp(badpass, user_info->nt_resp.data, sizeof(badpass))) {
249 * Very unlikely, our random bad password is the same as the users
252 memset(badpass, badpass[0]+1, sizeof(badpass));
255 if(baduser[0] == 0) {
256 fstrcpy(baduser, INVALID_USER_PREFIX);
257 fstrcat(baduser, lp_netbios_name());
261 * Attempt a session setup with a totally incorrect password.
262 * If this succeeds with the guest bit *NOT* set then the password
263 * server is broken and is not correctly setting the guest bit. We
264 * need to detect this as some versions of NT4.x are broken. JRA.
267 /* I sure as hell hope that there aren't servers out there that take
268 * NTLMv2 and have this bug, as we don't test for that...
269 * - abartlet@samba.org
272 if ((!tested_password_server) && (lp_paranoid_server_security())) {
273 if (smbcli_session_setup(cli, baduser, (char *)badpass, sizeof(badpass),
274 (char *)badpass, sizeof(badpass), user_info->domain.str)) {
277 * We connected to the password server so we
278 * can say we've tested it.
280 tested_password_server = True;
282 if ((SVAL(cli->inbuf,smb_vwv2) & 1) == 0) {
283 DEBUG(0,("server_validate: password server %s allows users as non-guest \
284 with a bad password.\n", cli->desthost));
285 DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
286 use this machine as the password server.\n"));
290 * Password server has the bug.
292 bad_password_server = True;
293 return NT_STATUS_LOGON_FAILURE;
300 * We have already tested the password server.
301 * Fail immediately if it has the bug.
304 if(bad_password_server) {
305 DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
306 with a bad password.\n", cli->desthost));
307 DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
308 use this machine as the password server.\n"));
309 return NT_STATUS_LOGON_FAILURE;
314 * Now we know the password server will correctly set the guest bit, or is
315 * not guest enabled, we can try with the real password.
318 if (!user_info->encrypted) {
319 /* Plaintext available */
320 if (!smbcli_session_setup(cli, user_info->smb_name.str,
321 (char *)user_info->plaintext_password.data,
322 user_info->plaintext_password.length,
324 user_info->domain.str)) {
325 DEBUG(1,("password server %s rejected the password\n", cli->desthost));
326 /* Make this smbcli_nt_error() when the conversion is in */
327 nt_status = smbcli_nt_error(cli);
329 nt_status = NT_STATUS_OK;
332 if (!smbcli_session_setup(cli, user_info->smb_name.str,
333 (char *)user_info->lm_resp.data,
334 user_info->lm_resp.length,
335 (char *)user_info->nt_resp.data,
336 user_info->nt_resp.length,
337 user_info->domain.str)) {
338 DEBUG(1,("password server %s rejected the password\n", cli->desthost));
339 /* Make this smbcli_nt_error() when the conversion is in */
340 nt_status = smbcli_nt_error(cli);
342 nt_status = NT_STATUS_OK;
346 /* if logged in as guest then reject */
347 if ((SVAL(cli->inbuf,smb_vwv2) & 1) != 0) {
348 DEBUG(1,("password server %s gave us guest only\n", cli->desthost));
349 nt_status = NT_STATUS_LOGON_FAILURE;
354 if NT_STATUS_IS_OK(nt_status) {
355 struct passwd *pass = Get_Pwnam(user_info->internal_username.str);
357 nt_status = make_server_info_pw(auth_context, server_info, pass);
359 nt_status = NT_STATUS_NO_SUCH_USER;
363 if (locally_made_cli) {
364 smbcli_shutdown(cli);
370 NTSTATUS auth_init_smbserver(struct auth_context *auth_context, const char* param, auth_methods **auth_method)
372 if (!make_auth_methods(auth_context, auth_method)) {
373 return NT_STATUS_NO_MEMORY;
375 (*auth_method)->name = "smbserver";
376 (*auth_method)->auth = check_smbserver_security;
377 (*auth_method)->get_chal = auth_get_challenge_server;
378 (*auth_method)->send_keepalive = send_server_keepalive;
379 (*auth_method)->free_private_data = free_server_private_data;