2 * Unix SMB/CIFS implementation.
4 * NTLMSSP Signing routines
5 * Copyright (C) Luke Kenneth Casson Leighton 1996-2001
6 * Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003-2005
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <http://www.gnu.org/licenses/>.
23 #include "auth/auth.h"
24 #include "auth/ntlmssp/ntlmssp.h"
25 #include "auth/ntlmssp/msrpc_parse.h"
26 #include "../lib/crypto/crypto.h"
27 #include "auth/credentials/credentials.h"
28 #include "auth/gensec/gensec.h"
29 #include "param/param.h"
31 #define CLI_SIGN "session key to client-to-server signing key magic constant"
32 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
33 #define SRV_SIGN "session key to server-to-client signing key magic constant"
34 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
37 * Some notes on the NTLM2 code:
39 * NTLM2 is a AEAD system. This means that the data encrypted is not
40 * all the data that is signed. In DCE-RPC case, the headers of the
41 * DCE-RPC packets are also signed. This prevents some of the
42 * fun-and-games one might have by changing them.
46 static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx,
48 DATA_BLOB session_key,
51 struct MD5Context ctx3;
52 *subkey = data_blob_talloc(mem_ctx, NULL, 16);
54 MD5Update(&ctx3, session_key.data, session_key.length);
55 MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
56 MD5Final(subkey->data, &ctx3);
59 enum ntlmssp_direction {
64 static NTSTATUS ntlmssp_make_packet_signature(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
65 TALLOC_CTX *sig_mem_ctx,
66 const uint8_t *data, size_t length,
67 const uint8_t *whole_pdu, size_t pdu_length,
68 enum ntlmssp_direction direction,
69 DATA_BLOB *sig, bool encrypt_sig)
71 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
77 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
79 return NT_STATUS_NO_MEMORY;
84 SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.send_seq_num);
85 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num++;
86 hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
87 gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length, &ctx);
90 SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num);
91 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num++;
92 hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
93 gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length, &ctx);
96 hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
97 hmac_md5_update(whole_pdu, pdu_length, &ctx);
98 hmac_md5_final(digest, &ctx);
100 if (encrypt_sig && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
103 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8);
105 case NTLMSSP_RECEIVE:
106 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, digest, 8);
111 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
112 memcpy(sig->data + 4, digest, 8);
113 memcpy(sig->data + 12, seq_num, 4);
115 DEBUG(10, ("NTLM2: created signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
116 dump_data(11, sig->data, sig->length);
120 crc = crc32_calc_buffer(data, length);
121 if (!msrpc_gen(sig_mem_ctx,
122 sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
123 return NT_STATUS_NO_MEMORY;
125 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
127 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
129 DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length));
130 dump_data(11, sig->data, sig->length);
135 /* TODO: make this non-public */
136 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
137 TALLOC_CTX *sig_mem_ctx,
138 const uint8_t *data, size_t length,
139 const uint8_t *whole_pdu, size_t pdu_length,
142 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
144 return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
146 whole_pdu, pdu_length,
147 NTLMSSP_SEND, sig, true);
151 * Check the signature of an incoming packet
155 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
156 TALLOC_CTX *sig_mem_ctx,
157 const uint8_t *data, size_t length,
158 const uint8_t *whole_pdu, size_t pdu_length,
159 const DATA_BLOB *sig)
161 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
166 if (!gensec_ntlmssp_state->session_key.length) {
167 DEBUG(3, ("NO session key, cannot check packet signature\n"));
168 return NT_STATUS_NO_USER_SESSION_KEY;
171 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
173 whole_pdu, pdu_length,
174 NTLMSSP_RECEIVE, &local_sig, true);
176 if (!NT_STATUS_IS_OK(nt_status)) {
177 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
181 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
182 if (local_sig.length != sig->length ||
183 memcmp(local_sig.data,
184 sig->data, sig->length) != 0) {
185 DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
186 dump_data(5, local_sig.data, local_sig.length);
188 DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
189 dump_data(5, sig->data, sig->length);
191 DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length));
192 return NT_STATUS_ACCESS_DENIED;
195 if (local_sig.length != sig->length ||
196 memcmp(local_sig.data + 8,
197 sig->data + 8, sig->length - 8) != 0) {
198 DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length));
199 dump_data(5, local_sig.data, local_sig.length);
201 DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length));
202 dump_data(5, sig->data, sig->length);
204 DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length));
205 return NT_STATUS_ACCESS_DENIED;
208 dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
215 * Seal data with the NTLMSSP algorithm
219 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
220 TALLOC_CTX *sig_mem_ctx,
221 uint8_t *data, size_t length,
222 const uint8_t *whole_pdu, size_t pdu_length,
225 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
227 if (!gensec_ntlmssp_state->session_key.length) {
228 DEBUG(3, ("NO session key, cannot seal packet\n"));
229 return NT_STATUS_NO_USER_SESSION_KEY;
232 DEBUG(10,("ntlmssp_seal_data: seal\n"));
233 dump_data_pw("ntlmssp clear data\n", data, length);
234 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
235 /* The order of these two operations matters - we must first seal the packet,
236 then seal the sequence number - this is becouse the send_seal_hash is not
237 constant, but is is rather updated with each iteration */
238 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
240 whole_pdu, pdu_length,
241 NTLMSSP_SEND, sig, false);
242 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
243 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
244 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
248 crc = crc32_calc_buffer(data, length);
249 if (!msrpc_gen(sig_mem_ctx,
250 sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
251 return NT_STATUS_NO_MEMORY;
254 /* The order of these two operations matters - we must
255 first seal the packet, then seal the sequence
256 number - this is becouse the ntlmssp_hash is not
257 constant, but is is rather updated with each
260 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
261 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
262 /* increment counter on send */
263 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
264 nt_status = NT_STATUS_OK;
266 dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
267 dump_data_pw("ntlmssp sealed data\n", data, length);
274 * Unseal data with the NTLMSSP algorithm
279 wrappers for the ntlmssp_*() functions
281 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
282 TALLOC_CTX *sig_mem_ctx,
283 uint8_t *data, size_t length,
284 const uint8_t *whole_pdu, size_t pdu_length,
285 const DATA_BLOB *sig)
287 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
288 if (!gensec_ntlmssp_state->session_key.length) {
289 DEBUG(3, ("NO session key, cannot unseal packet\n"));
290 return NT_STATUS_NO_USER_SESSION_KEY;
293 dump_data_pw("ntlmssp sealed data\n", data, length);
294 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
295 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
297 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
299 dump_data_pw("ntlmssp clear data\n", data, length);
300 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
304 Initialise the state for NTLMSSP signing.
306 /* TODO: make this non-public */
307 NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
309 TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state);
312 return NT_STATUS_NO_MEMORY;
315 DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
316 debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
318 if (gensec_ntlmssp_state->session_key.length < 8) {
319 talloc_free(mem_ctx);
320 DEBUG(3, ("NO session key, cannot intialise signing\n"));
321 return NT_STATUS_NO_USER_SESSION_KEY;
324 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
326 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
327 const char *send_sign_const;
328 const char *send_seal_const;
329 const char *recv_sign_const;
330 const char *recv_seal_const;
332 DATA_BLOB send_seal_key;
333 DATA_BLOB recv_seal_key;
335 switch (gensec_ntlmssp_state->role) {
337 send_sign_const = CLI_SIGN;
338 send_seal_const = CLI_SEAL;
339 recv_sign_const = SRV_SIGN;
340 recv_seal_const = SRV_SEAL;
343 send_sign_const = SRV_SIGN;
344 send_seal_const = SRV_SEAL;
345 recv_sign_const = CLI_SIGN;
346 recv_seal_const = CLI_SEAL;
349 talloc_free(mem_ctx);
350 return NT_STATUS_INTERNAL_ERROR;
353 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
354 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
355 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
356 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
359 Weaken NTLMSSP keys to cope with down-level
360 clients, servers and export restrictions.
362 We probably should have some parameters to control
363 this, once we get NTLM2 working.
366 /* Key weakening was not performed on the master key
367 * for NTLM2 (in ntlmssp_weaken_keys()), but must be
368 * done on the encryption subkeys only. That is why
369 * we don't have this code for the ntlmv1 case.
372 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
374 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
375 weak_session_key.length = 7;
376 } else { /* forty bits */
377 weak_session_key.length = 5;
379 dump_data_pw("NTLMSSP weakend master key:\n",
380 weak_session_key.data,
381 weak_session_key.length);
384 calc_ntlmv2_key(gensec_ntlmssp_state,
385 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key,
386 gensec_ntlmssp_state->session_key, send_sign_const);
387 dump_data_pw("NTLMSSP send sign key:\n",
388 gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
389 gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
391 /* SEND: seal ARCFOUR pad */
392 calc_ntlmv2_key(mem_ctx,
394 weak_session_key, send_seal_const);
395 dump_data_pw("NTLMSSP send seal key:\n",
397 send_seal_key.length);
398 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state,
400 dump_data_pw("NTLMSSP send sesl hash:\n",
401 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox,
402 sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
405 calc_ntlmv2_key(gensec_ntlmssp_state,
406 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key,
407 gensec_ntlmssp_state->session_key, recv_sign_const);
408 dump_data_pw("NTLMSSP recv sign key:\n",
409 gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
410 gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
412 /* RECV: seal ARCFOUR pad */
413 calc_ntlmv2_key(mem_ctx,
415 weak_session_key, recv_seal_const);
416 dump_data_pw("NTLMSSP recv seal key:\n",
418 recv_seal_key.length);
419 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state,
421 dump_data_pw("NTLMSSP receive seal hash:\n",
422 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox,
423 sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
425 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
426 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
429 DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx);
430 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
432 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
433 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
435 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state,
437 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
438 sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
440 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
443 talloc_free(mem_ctx);
447 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size)
449 return NTLMSSP_SIG_SIZE;
452 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
453 TALLOC_CTX *sig_mem_ctx,
460 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
462 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
464 return NT_STATUS_NO_MEMORY;
466 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
468 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
469 out->data + NTLMSSP_SIG_SIZE,
470 out->length - NTLMSSP_SIG_SIZE,
471 out->data + NTLMSSP_SIG_SIZE,
472 out->length - NTLMSSP_SIG_SIZE,
475 if (NT_STATUS_IS_OK(nt_status)) {
476 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
480 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
482 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
484 return NT_STATUS_NO_MEMORY;
486 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
488 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
489 out->data + NTLMSSP_SIG_SIZE,
490 out->length - NTLMSSP_SIG_SIZE,
491 out->data + NTLMSSP_SIG_SIZE,
492 out->length - NTLMSSP_SIG_SIZE,
495 if (NT_STATUS_IS_OK(nt_status)) {
496 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
507 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
508 TALLOC_CTX *sig_mem_ctx,
514 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
515 if (in->length < NTLMSSP_SIG_SIZE) {
516 return NT_STATUS_INVALID_PARAMETER;
519 sig.length = NTLMSSP_SIG_SIZE;
521 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
523 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
524 out->data, out->length,
525 out->data, out->length,
528 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
529 if (in->length < NTLMSSP_SIG_SIZE) {
530 return NT_STATUS_INVALID_PARAMETER;
533 sig.length = NTLMSSP_SIG_SIZE;
535 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
537 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
538 out->data, out->length,
539 out->data, out->length,