2 Unix SMB/Netbios implementation.
4 handle NLTMSSP, client server side parsing
6 Copyright (C) Andrew Tridgell 2001
7 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
8 Copyright (C) Stefan Metzmacher 2005
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #include "auth/auth.h"
27 #include "auth/ntlmssp/ntlmssp.h"
28 #include "lib/crypto/crypto.h"
30 /*********************************************************************
32 *********************************************************************/
35 * Next state function for the Initial packet
37 * @param ntlmssp_state NTLMSSP State
38 * @param out_mem_ctx The DATA_BLOB *out will be allocated on this context
39 * @param in A NULL data blob (input ignored)
40 * @param out The initial negotiate request to the server, as an talloc()ed DATA_BLOB, on out_mem_ctx
41 * @return Errors or NT_STATUS_OK.
44 NTSTATUS ntlmssp_client_initial(struct gensec_security *gensec_security,
45 TALLOC_CTX *out_mem_ctx,
46 DATA_BLOB in, DATA_BLOB *out)
48 struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
50 if (gensec_ntlmssp_state->unicode) {
51 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
53 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
56 if (gensec_ntlmssp_state->use_ntlmv2) {
57 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
60 /* generate the ntlmssp negotiate packet */
61 msrpc_gen(out_mem_ctx,
65 gensec_ntlmssp_state->neg_flags,
66 gensec_ntlmssp_state->get_domain(),
67 cli_credentials_get_workstation(gensec_security->credentials));
69 gensec_ntlmssp_state->expected_state = NTLMSSP_CHALLENGE;
71 return NT_STATUS_MORE_PROCESSING_REQUIRED;
75 * Next state function for the Challenge Packet. Generate an auth packet.
77 * @param gensec_security GENSEC state
78 * @param out_mem_ctx Memory context for *out
79 * @param in The server challnege, as a DATA_BLOB. reply.data must be NULL
80 * @param out The next request (auth packet) to the server, as an allocated DATA_BLOB, on the out_mem_ctx context
81 * @return Errors or NT_STATUS_OK.
84 NTSTATUS ntlmssp_client_challenge(struct gensec_security *gensec_security,
85 TALLOC_CTX *out_mem_ctx,
86 const DATA_BLOB in, DATA_BLOB *out)
88 struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
89 uint32_t chal_flags, ntlmssp_command, unkn1, unkn2;
90 DATA_BLOB server_domain_blob;
91 DATA_BLOB challenge_blob;
92 DATA_BLOB struct_blob = data_blob(NULL, 0);
94 const char *chal_parse_string;
95 const char *auth_gen_string;
97 DATA_BLOB lm_response = data_blob(NULL, 0);
98 DATA_BLOB nt_response = data_blob(NULL, 0);
99 DATA_BLOB session_key = data_blob(NULL, 0);
100 DATA_BLOB lm_session_key = data_blob(NULL, 0);
101 DATA_BLOB encrypted_session_key = data_blob(NULL, 0);
104 const char *user, *domain, *password;
106 if (!msrpc_parse(out_mem_ctx,
112 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
113 dump_data(2, in.data, in.length);
115 return NT_STATUS_INVALID_PARAMETER;
118 data_blob_free(&server_domain_blob);
120 DEBUG(3, ("Got challenge flags:\n"));
121 debug_ntlmssp_flags(chal_flags);
123 ntlmssp_handle_neg_flags(gensec_ntlmssp_state, chal_flags, gensec_ntlmssp_state->allow_lm_key);
125 if (gensec_ntlmssp_state->unicode) {
126 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
127 chal_parse_string = "CdUdbddB";
129 chal_parse_string = "CdUdbdd";
131 auth_gen_string = "CdBBUUUBd";
133 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
134 chal_parse_string = "CdAdbddB";
136 chal_parse_string = "CdAdbdd";
139 auth_gen_string = "CdBBAAABd";
142 DEBUG(3, ("NTLMSSP: Set final flags:\n"));
143 debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
145 if (!msrpc_parse(out_mem_ctx,
146 &in, chal_parse_string,
154 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
155 dump_data(2, in.data, in.length);
156 return NT_STATUS_INVALID_PARAMETER;
159 gensec_ntlmssp_state->server_domain = server_domain;
161 if (challenge_blob.length != 8) {
162 return NT_STATUS_INVALID_PARAMETER;
165 /* Correctly handle username in the original form of user@REALM, which is valid */
166 if (gensec_security->credentials->realm_obtained
167 > gensec_security->credentials->domain_obtained) {
168 user = talloc_asprintf(out_mem_ctx, "%s@%s",
169 cli_credentials_get_username(gensec_security->credentials),
170 cli_credentials_get_realm(gensec_security->credentials));
173 user = cli_credentials_get_username(gensec_security->credentials);
174 domain = cli_credentials_get_domain(gensec_security->credentials);
177 password = cli_credentials_get_password(gensec_security->credentials);
180 static const uint8_t zeros[16];
181 /* do nothing - blobs are zero length */
183 /* session key is all zeros */
184 session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
185 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
187 lm_response = data_blob(NULL, 0);
188 nt_response = data_blob(NULL, 0);
190 /* not doing NLTM2 without a password */
191 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
192 } else if (gensec_ntlmssp_state->use_ntlmv2) {
194 if (!struct_blob.length) {
195 /* be lazy, match win2k - we can't do NTLMv2 without it */
196 DEBUG(1, ("Server did not provide 'target information', required for NTLMv2\n"));
197 return NT_STATUS_INVALID_PARAMETER;
200 /* TODO: if the remote server is standalone, then we should replace 'domain'
201 with the server name as supplied above */
203 if (!SMBNTLMv2encrypt(user,
205 password, &challenge_blob,
207 &lm_response, &nt_response,
208 NULL, &session_key)) {
209 data_blob_free(&challenge_blob);
210 data_blob_free(&struct_blob);
211 return NT_STATUS_NO_MEMORY;
214 /* LM Key is incompatible... */
215 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
217 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
218 struct MD5Context md5_session_nonce_ctx;
220 uint8_t session_nonce[16];
221 uint8_t session_nonce_hash[16];
222 uint8_t user_session_key[16];
223 E_md4hash(password, nt_hash);
225 lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
226 generate_random_buffer(lm_response.data, 8);
227 memset(lm_response.data+8, 0, 16);
229 memcpy(session_nonce, challenge_blob.data, 8);
230 memcpy(&session_nonce[8], lm_response.data, 8);
232 MD5Init(&md5_session_nonce_ctx);
233 MD5Update(&md5_session_nonce_ctx, challenge_blob.data, 8);
234 MD5Update(&md5_session_nonce_ctx, lm_response.data, 8);
235 MD5Final(session_nonce_hash, &md5_session_nonce_ctx);
237 DEBUG(5, ("NTLMSSP challenge set by NTLM2\n"));
238 DEBUG(5, ("challenge is: \n"));
239 dump_data(5, session_nonce_hash, 8);
241 nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
242 SMBNTencrypt(password,
246 session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
248 SMBsesskeygen_ntv1(nt_hash, user_session_key);
249 hmac_md5(user_session_key, session_nonce, sizeof(session_nonce), session_key.data);
250 dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length);
252 /* LM Key is incompatible... */
253 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
257 if (gensec_ntlmssp_state->use_nt_response) {
258 nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
259 SMBNTencrypt(password,challenge_blob.data,
261 E_md4hash(password, nt_hash);
262 session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
263 SMBsesskeygen_ntv1(nt_hash, session_key.data);
264 dump_data_pw("NT session key:\n", session_key.data, session_key.length);
267 /* lanman auth is insecure, it may be disabled */
268 if (lp_client_lanman_auth()) {
269 lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
270 if (!SMBencrypt(password,challenge_blob.data,
272 /* If the LM password was too long (and therefore the LM hash being
273 of the first 14 chars only), don't send it */
274 data_blob_free(&lm_response);
276 /* LM Key is incompatible with 'long' passwords */
277 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
279 E_deshash(password, lm_hash);
280 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
281 memcpy(lm_session_key.data, lm_hash, 8);
282 memset(&lm_session_key.data[8], '\0', 8);
284 if (!gensec_ntlmssp_state->use_nt_response) {
285 session_key = lm_session_key;
289 /* LM Key is incompatible... */
290 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
294 if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
295 && lp_client_lanman_auth() && lm_session_key.length == 16) {
296 DATA_BLOB new_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
297 if (lm_response.length == 24) {
298 SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
299 new_session_key.data);
301 static const uint8_t zeros[24];
302 SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
303 new_session_key.data);
305 new_session_key.length = 16;
306 session_key = new_session_key;
307 dump_data_pw("LM session key\n", session_key.data, session_key.length);
311 /* Key exchange encryptes a new client-generated session key with
312 the password-derived key */
313 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
314 /* Make up a new session key */
315 uint8_t client_session_key[16];
316 generate_random_buffer(client_session_key, sizeof(client_session_key));
318 /* Encrypt the new session key with the old one */
319 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
320 client_session_key, sizeof(client_session_key));
321 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
322 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
323 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
325 /* Mark the new session key as the 'real' session key */
326 session_key = data_blob_talloc(gensec_ntlmssp_state, client_session_key, sizeof(client_session_key));
329 /* this generates the actual auth packet */
330 if (!msrpc_gen(out_mem_ctx,
331 out, auth_gen_string,
334 lm_response.data, lm_response.length,
335 nt_response.data, nt_response.length,
338 cli_credentials_get_workstation(gensec_security->credentials),
339 encrypted_session_key.data, encrypted_session_key.length,
340 gensec_ntlmssp_state->neg_flags)) {
342 return NT_STATUS_NO_MEMORY;
345 gensec_ntlmssp_state->session_key = session_key;
347 /* The client might be using 56 or 40 bit weakened keys */
348 ntlmssp_weaken_keys(gensec_ntlmssp_state);
350 gensec_ntlmssp_state->chal = challenge_blob;
351 gensec_ntlmssp_state->lm_resp = lm_response;
352 gensec_ntlmssp_state->nt_resp = nt_response;
354 gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
356 nt_status = ntlmssp_sign_init(gensec_ntlmssp_state);
357 if (!NT_STATUS_IS_OK(nt_status)) {
358 DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
359 nt_errstr(nt_status)));
366 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
368 struct gensec_ntlmssp_state *gensec_ntlmssp_state;
371 nt_status = gensec_ntlmssp_start(gensec_security);
372 NT_STATUS_NOT_OK_RETURN(nt_status);
374 gensec_ntlmssp_state = gensec_security->private_data;
376 gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
378 gensec_ntlmssp_state->get_domain = lp_workgroup;
380 gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
382 gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
384 gensec_ntlmssp_state->allow_lm_key = (lp_lanman_auth()
385 && lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False));
387 gensec_ntlmssp_state->use_ntlmv2 = lp_client_ntlmv2_auth();
389 gensec_ntlmssp_state->expected_state = NTLMSSP_INITIAL;
391 gensec_ntlmssp_state->neg_flags =
392 NTLMSSP_NEGOTIATE_NTLM |
393 NTLMSSP_REQUEST_TARGET;
395 if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
396 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
399 if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
400 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
403 if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
404 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
406 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
407 gensec_ntlmssp_state->use_ntlmv2 = False;
410 if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
412 * We need to set this to allow a later SetPassword
413 * via the SAMR pipe to succeed. Strange.... We could
414 * also add NTLMSSP_NEGOTIATE_SEAL here. JRA.
416 * Without this, Windows will not create the master key
417 * that it thinks is only used for NTLMSSP signing and
418 * sealing. (It is actually pulled out and used directly)
420 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
422 if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
423 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
425 if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
426 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
429 gensec_security->private_data = gensec_ntlmssp_state;