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 lp_iconv_convenience(gensec_ntlmssp_state->gensec_security->lp_ctx),
123 sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
124 return NT_STATUS_NO_MEMORY;
126 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
128 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
130 DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length));
131 dump_data(11, sig->data, sig->length);
136 /* TODO: make this non-public */
137 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
138 TALLOC_CTX *sig_mem_ctx,
139 const uint8_t *data, size_t length,
140 const uint8_t *whole_pdu, size_t pdu_length,
143 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
145 return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
147 whole_pdu, pdu_length,
148 NTLMSSP_SEND, sig, true);
152 * Check the signature of an incoming packet
156 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
157 TALLOC_CTX *sig_mem_ctx,
158 const uint8_t *data, size_t length,
159 const uint8_t *whole_pdu, size_t pdu_length,
160 const DATA_BLOB *sig)
162 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
167 if (!gensec_ntlmssp_state->session_key.length) {
168 DEBUG(3, ("NO session key, cannot check packet signature\n"));
169 return NT_STATUS_NO_USER_SESSION_KEY;
172 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
174 whole_pdu, pdu_length,
175 NTLMSSP_RECEIVE, &local_sig, true);
177 if (!NT_STATUS_IS_OK(nt_status)) {
178 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
182 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
183 if (local_sig.length != sig->length ||
184 memcmp(local_sig.data,
185 sig->data, sig->length) != 0) {
186 DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
187 dump_data(5, local_sig.data, local_sig.length);
189 DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
190 dump_data(5, sig->data, sig->length);
192 DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length));
193 return NT_STATUS_ACCESS_DENIED;
196 if (local_sig.length != sig->length ||
197 memcmp(local_sig.data + 8,
198 sig->data + 8, sig->length - 8) != 0) {
199 DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length));
200 dump_data(5, local_sig.data, local_sig.length);
202 DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length));
203 dump_data(5, sig->data, sig->length);
205 DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length));
206 return NT_STATUS_ACCESS_DENIED;
209 dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
216 * Seal data with the NTLMSSP algorithm
220 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
221 TALLOC_CTX *sig_mem_ctx,
222 uint8_t *data, size_t length,
223 const uint8_t *whole_pdu, size_t pdu_length,
226 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
228 if (!gensec_ntlmssp_state->session_key.length) {
229 DEBUG(3, ("NO session key, cannot seal packet\n"));
230 return NT_STATUS_NO_USER_SESSION_KEY;
233 DEBUG(10,("ntlmssp_seal_data: seal\n"));
234 dump_data_pw("ntlmssp clear data\n", data, length);
235 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
236 /* The order of these two operations matters - we must first seal the packet,
237 then seal the sequence number - this is becouse the send_seal_hash is not
238 constant, but is is rather updated with each iteration */
239 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
241 whole_pdu, pdu_length,
242 NTLMSSP_SEND, sig, false);
243 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
244 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
245 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
249 crc = crc32_calc_buffer(data, length);
250 if (!msrpc_gen(sig_mem_ctx,
251 lp_iconv_convenience(gensec_security->lp_ctx),
252 sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
253 return NT_STATUS_NO_MEMORY;
256 /* The order of these two operations matters - we must
257 first seal the packet, then seal the sequence
258 number - this is becouse the ntlmssp_hash is not
259 constant, but is is rather updated with each
262 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
263 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
264 /* increment counter on send */
265 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
266 nt_status = NT_STATUS_OK;
268 dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
269 dump_data_pw("ntlmssp sealed data\n", data, length);
276 * Unseal data with the NTLMSSP algorithm
281 wrappers for the ntlmssp_*() functions
283 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
284 TALLOC_CTX *sig_mem_ctx,
285 uint8_t *data, size_t length,
286 const uint8_t *whole_pdu, size_t pdu_length,
287 const DATA_BLOB *sig)
289 struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
290 if (!gensec_ntlmssp_state->session_key.length) {
291 DEBUG(3, ("NO session key, cannot unseal packet\n"));
292 return NT_STATUS_NO_USER_SESSION_KEY;
295 dump_data_pw("ntlmssp sealed data\n", data, length);
296 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
297 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
299 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
301 dump_data_pw("ntlmssp clear data\n", data, length);
302 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
306 Initialise the state for NTLMSSP signing.
308 /* TODO: make this non-public */
309 NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
311 TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state);
314 return NT_STATUS_NO_MEMORY;
317 DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
318 debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
320 if (gensec_ntlmssp_state->session_key.length < 8) {
321 talloc_free(mem_ctx);
322 DEBUG(3, ("NO session key, cannot intialise signing\n"));
323 return NT_STATUS_NO_USER_SESSION_KEY;
326 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
328 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
329 const char *send_sign_const;
330 const char *send_seal_const;
331 const char *recv_sign_const;
332 const char *recv_seal_const;
334 DATA_BLOB send_seal_key;
335 DATA_BLOB recv_seal_key;
337 switch (gensec_ntlmssp_state->role) {
339 send_sign_const = CLI_SIGN;
340 send_seal_const = CLI_SEAL;
341 recv_sign_const = SRV_SIGN;
342 recv_seal_const = SRV_SEAL;
345 send_sign_const = SRV_SIGN;
346 send_seal_const = SRV_SEAL;
347 recv_sign_const = CLI_SIGN;
348 recv_seal_const = CLI_SEAL;
351 talloc_free(mem_ctx);
352 return NT_STATUS_INTERNAL_ERROR;
355 gensec_ntlmssp_state->crypt.ntlm2.send_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);
357 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
358 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
361 Weaken NTLMSSP keys to cope with down-level
362 clients, servers and export restrictions.
364 We probably should have some parameters to control
365 this, once we get NTLM2 working.
368 /* Key weakening was not performed on the master key
369 * for NTLM2 (in ntlmssp_weaken_keys()), but must be
370 * done on the encryption subkeys only. That is why
371 * we don't have this code for the ntlmv1 case.
374 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
376 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
377 weak_session_key.length = 7;
378 } else { /* forty bits */
379 weak_session_key.length = 5;
381 dump_data_pw("NTLMSSP weakend master key:\n",
382 weak_session_key.data,
383 weak_session_key.length);
386 calc_ntlmv2_key(gensec_ntlmssp_state,
387 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key,
388 gensec_ntlmssp_state->session_key, send_sign_const);
389 dump_data_pw("NTLMSSP send sign key:\n",
390 gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
391 gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
393 /* SEND: seal ARCFOUR pad */
394 calc_ntlmv2_key(mem_ctx,
396 weak_session_key, send_seal_const);
397 dump_data_pw("NTLMSSP send seal key:\n",
399 send_seal_key.length);
400 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state,
402 dump_data_pw("NTLMSSP send sesl hash:\n",
403 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox,
404 sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
407 calc_ntlmv2_key(gensec_ntlmssp_state,
408 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key,
409 gensec_ntlmssp_state->session_key, recv_sign_const);
410 dump_data_pw("NTLMSSP recv sign key:\n",
411 gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
412 gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
414 /* RECV: seal ARCFOUR pad */
415 calc_ntlmv2_key(mem_ctx,
417 weak_session_key, recv_seal_const);
418 dump_data_pw("NTLMSSP recv seal key:\n",
420 recv_seal_key.length);
421 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state,
423 dump_data_pw("NTLMSSP receive seal hash:\n",
424 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox,
425 sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
427 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
428 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
431 DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx);
432 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
434 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
435 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
437 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state,
439 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
440 sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
442 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
445 talloc_free(mem_ctx);
449 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size)
451 return NTLMSSP_SIG_SIZE;
454 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
455 TALLOC_CTX *sig_mem_ctx,
462 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
464 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
466 return NT_STATUS_NO_MEMORY;
468 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
470 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
471 out->data + NTLMSSP_SIG_SIZE,
472 out->length - NTLMSSP_SIG_SIZE,
473 out->data + NTLMSSP_SIG_SIZE,
474 out->length - NTLMSSP_SIG_SIZE,
477 if (NT_STATUS_IS_OK(nt_status)) {
478 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
482 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
484 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
486 return NT_STATUS_NO_MEMORY;
488 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
490 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
491 out->data + NTLMSSP_SIG_SIZE,
492 out->length - NTLMSSP_SIG_SIZE,
493 out->data + NTLMSSP_SIG_SIZE,
494 out->length - NTLMSSP_SIG_SIZE,
497 if (NT_STATUS_IS_OK(nt_status)) {
498 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
509 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
510 TALLOC_CTX *sig_mem_ctx,
516 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
517 if (in->length < NTLMSSP_SIG_SIZE) {
518 return NT_STATUS_INVALID_PARAMETER;
521 sig.length = NTLMSSP_SIG_SIZE;
523 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
525 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
526 out->data, out->length,
527 out->data, out->length,
530 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
531 if (in->length < NTLMSSP_SIG_SIZE) {
532 return NT_STATUS_INVALID_PARAMETER;
535 sig.length = NTLMSSP_SIG_SIZE;
537 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
539 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
540 out->data, out->length,
541 out->data, out->length,