?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
lib-pyldb: Block elements should be surrounded by {} in py_msg.setitem()
[Samba.git] / auth / ntlmssp / ntlmssp_sign.c
blobc0be91465b32a43e7c8021a2a88b8ca01876459c
1 /*
2 * Unix SMB/CIFS implementation.
3 * Version 3.0
4 * NTLMSSP Signing routines
5 * Copyright (C) Andrew Bartlett 2003-2005
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 3 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, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "includes.h"
22 #include "../auth/ntlmssp/ntlmssp.h"
23 #include "../libcli/auth/libcli_auth.h"
24 #include "../lib/crypto/md5.h"
25 #include "../lib/crypto/hmacmd5.h"
26 #include "../lib/crypto/crc32.h"
27 #include "../auth/ntlmssp/ntlmssp_private.h"
28
29 #define CLI_SIGN "session key to client-to-server signing key magic constant"
30 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
31 #define SRV_SIGN "session key to server-to-client signing key magic constant"
32 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
33
34 /**
35 * Some notes on the NTLM2 code:
36 *
37 * NTLM2 is a AEAD system. This means that the data encrypted is not
38 * all the data that is signed. In DCE-RPC case, the headers of the
39 * DCE-RPC packets are also signed. This prevents some of the
40 * fun-and-games one might have by changing them.
41 *
42 */
43
44 static void dump_arc4_state(const char *description,
45 struct arcfour_state *state)
46 {
47 dump_data_pw(description, state->sbox, sizeof(state->sbox));
48 }
49
50 static void calc_ntlmv2_key(uint8_t subkey[16],
51 DATA_BLOB session_key,
52 const char *constant)
53 {
54 MD5_CTX ctx3;
55 MD5Init(&ctx3);
56 MD5Update(&ctx3, session_key.data, session_key.length);
57 MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
58 MD5Final(subkey, &ctx3);
59 }
60
61 enum ntlmssp_direction {
62 NTLMSSP_SEND,
63 NTLMSSP_RECEIVE
64 };
65
66 static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
67 TALLOC_CTX *sig_mem_ctx,
68 const uint8_t *data, size_t length,
69 const uint8_t *whole_pdu, size_t pdu_length,
70 enum ntlmssp_direction direction,
71 DATA_BLOB *sig, bool encrypt_sig)
72 {
73 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
74 HMACMD5Context ctx;
75 uint8_t digest[16];
76 uint8_t seq_num[4];
77
78 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
79 if (!sig->data) {
80 return NT_STATUS_NO_MEMORY;
81 }
82
83 switch (direction) {
84 case NTLMSSP_SEND:
85 DEBUG(100,("ntlmssp_make_packet_signature: SEND seq = %u, len = %u, pdu_len = %u\n",
86 ntlmssp_state->crypt->ntlm2.sending.seq_num,
87 (unsigned int)length,
88 (unsigned int)pdu_length));
89
90 SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.sending.seq_num);
91 ntlmssp_state->crypt->ntlm2.sending.seq_num++;
92 hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.sending.sign_key, 16, &ctx);
93 break;
94 case NTLMSSP_RECEIVE:
95
96 DEBUG(100,("ntlmssp_make_packet_signature: RECV seq = %u, len = %u, pdu_len = %u\n",
97 ntlmssp_state->crypt->ntlm2.receiving.seq_num,
98 (unsigned int)length,
99 (unsigned int)pdu_length));
100
101 SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.receiving.seq_num);
102 ntlmssp_state->crypt->ntlm2.receiving.seq_num++;
103 hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16, &ctx);
104 break;
105 }
106
107 dump_data_pw("pdu data ", whole_pdu, pdu_length);
108
109 hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
110 hmac_md5_update(whole_pdu, pdu_length, &ctx);
111 hmac_md5_final(digest, &ctx);
112
113 if (encrypt_sig && (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)) {
114 switch (direction) {
115 case NTLMSSP_SEND:
116 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
117 digest, 8);
118 break;
119 case NTLMSSP_RECEIVE:
120 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
121 digest, 8);
122 break;
123 }
124 }
125
126 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
127 memcpy(sig->data + 4, digest, 8);
128 memcpy(sig->data + 12, seq_num, 4);
129
130 dump_data_pw("ntlmssp v2 sig ", sig->data, sig->length);
131
132 } else {
133 NTSTATUS status;
134 uint32_t crc;
135
136 crc = crc32_calc_buffer(data, length);
137
138 status = msrpc_gen(sig_mem_ctx,
139 sig, "dddd",
140 NTLMSSP_SIGN_VERSION, 0, crc,
141 ntlmssp_state->crypt->ntlm.seq_num);
142 if (!NT_STATUS_IS_OK(status)) {
143 return status;
144 }
145
146 ntlmssp_state->crypt->ntlm.seq_num++;
147
148 dump_arc4_state("ntlmssp hash: \n",
149 &ntlmssp_state->crypt->ntlm.seal_state);
150 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
151 sig->data+4, sig->length-4);
152 }
153 return NT_STATUS_OK;
154 }
155
156 NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
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 DATA_BLOB *sig)
161 {
162 NTSTATUS nt_status;
163
164 if (!(ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN)) {
165 DEBUG(3, ("NTLMSSP Signing not negotiated - cannot sign packet!\n"));
166 return NT_STATUS_INVALID_PARAMETER;
167 }
168
169 if (!ntlmssp_state->session_key.length) {
170 DEBUG(3, ("NO session key, cannot check sign packet\n"));
171 return NT_STATUS_NO_USER_SESSION_KEY;
172 }
173
174 nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
175 sig_mem_ctx,
176 data, length,
177 whole_pdu, pdu_length,
178 NTLMSSP_SEND, sig, true);
179
180 return nt_status;
181 }
182
183 /**
184 * Check the signature of an incoming packet
185 * @note caller *must* check that the signature is the size it expects
186 *
187 */
188
189 NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
190 const uint8_t *data, size_t length,
191 const uint8_t *whole_pdu, size_t pdu_length,
192 const DATA_BLOB *sig)
193 {
194 DATA_BLOB local_sig;
195 NTSTATUS nt_status;
196 TALLOC_CTX *tmp_ctx;
197
198 if (!ntlmssp_state->session_key.length) {
199 DEBUG(3, ("NO session key, cannot check packet signature\n"));
200 return NT_STATUS_NO_USER_SESSION_KEY;
201 }
202
203 if (sig->length < 8) {
204 DEBUG(0, ("NTLMSSP packet check failed due to short signature (%lu bytes)!\n",
205 (unsigned long)sig->length));
206 }
207
208 tmp_ctx = talloc_new(ntlmssp_state);
209 if (!tmp_ctx) {
210 return NT_STATUS_NO_MEMORY;
211 }
212
213 nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
214 tmp_ctx,
215 data, length,
216 whole_pdu, pdu_length,
217 NTLMSSP_RECEIVE,
218 &local_sig, true);
219
220 if (!NT_STATUS_IS_OK(nt_status)) {
221 DEBUG(0,("NTLMSSP packet sig creation failed with %s\n",
222 nt_errstr(nt_status)));
223 talloc_free(tmp_ctx);
224 return nt_status;
225 }
226
227 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
228 if (local_sig.length != sig->length ||
229 memcmp(local_sig.data, sig->data, sig->length) != 0) {
230 DEBUG(5, ("BAD SIG NTLM2: wanted signature of\n"));
231 dump_data(5, local_sig.data, local_sig.length);
232
233 DEBUG(5, ("BAD SIG: got signature of\n"));
234 dump_data(5, sig->data, sig->length);
235
236 DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
237 talloc_free(tmp_ctx);
238 return NT_STATUS_ACCESS_DENIED;
239 }
240 } else {
241 if (local_sig.length != sig->length ||
242 memcmp(local_sig.data + 8, sig->data + 8, sig->length - 8) != 0) {
243 DEBUG(5, ("BAD SIG NTLM1: wanted signature of\n"));
244 dump_data(5, local_sig.data, local_sig.length);
245
246 DEBUG(5, ("BAD SIG: got signature of\n"));
247 dump_data(5, sig->data, sig->length);
248
249 DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
250 talloc_free(tmp_ctx);
251 return NT_STATUS_ACCESS_DENIED;
252 }
253 }
254 dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
255 DEBUG(10,("ntlmssp_check_packet: NTLMSSP signature OK !\n"));
256
257 talloc_free(tmp_ctx);
258 return NT_STATUS_OK;
259 }
260
261 /**
262 * Seal data with the NTLMSSP algorithm
263 *
264 */
265
266 NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
267 TALLOC_CTX *sig_mem_ctx,
268 uint8_t *data, size_t length,
269 const uint8_t *whole_pdu, size_t pdu_length,
270 DATA_BLOB *sig)
271 {
272 if (!(ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL)) {
273 DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
274 return NT_STATUS_INVALID_PARAMETER;
275 }
276
277 if (!(ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN)) {
278 DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
279 return NT_STATUS_INVALID_PARAMETER;
280 }
281
282 if (!ntlmssp_state->session_key.length) {
283 DEBUG(3, ("NO session key, cannot seal packet\n"));
284 return NT_STATUS_NO_USER_SESSION_KEY;
285 }
286
287 DEBUG(10,("ntlmssp_seal_data: seal\n"));
288 dump_data_pw("ntlmssp clear data\n", data, length);
289 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
290 NTSTATUS nt_status;
291 /*
292 * The order of these two operations matters - we
293 * must first seal the packet, then seal the
294 * sequence number - this is because the
295 * send_seal_hash is not constant, but is is rather
296 * updated with each iteration
297 */
298 nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
299 sig_mem_ctx,
300 data, length,
301 whole_pdu, pdu_length,
302 NTLMSSP_SEND,
303 sig, false);
304 if (!NT_STATUS_IS_OK(nt_status)) {
305 return nt_status;
306 }
307
308 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
309 data, length);
310 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
311 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
312 sig->data+4, 8);
313 }
314 } else {
315 NTSTATUS status;
316 uint32_t crc;
317
318 crc = crc32_calc_buffer(data, length);
319
320 status = msrpc_gen(sig_mem_ctx,
321 sig, "dddd",
322 NTLMSSP_SIGN_VERSION, 0, crc,
323 ntlmssp_state->crypt->ntlm.seq_num);
324 if (!NT_STATUS_IS_OK(status)) {
325 return status;
326 }
327
328 /*
329 * The order of these two operations matters - we
330 * must first seal the packet, then seal the
331 * sequence number - this is because the ntlmv1_arc4_state
332 * is not constant, but is is rather updated with
333 * each iteration
334 */
335
336 dump_arc4_state("ntlmv1 arc4 state:\n",
337 &ntlmssp_state->crypt->ntlm.seal_state);
338 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
339 data, length);
340
341 dump_arc4_state("ntlmv1 arc4 state:\n",
342 &ntlmssp_state->crypt->ntlm.seal_state);
343
344 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
345 sig->data+4, sig->length-4);
346
347 ntlmssp_state->crypt->ntlm.seq_num++;
348 }
349 dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
350 dump_data_pw("ntlmssp sealed data\n", data, length);
351
352 return NT_STATUS_OK;
353 }
354
355 /**
356 * Unseal data with the NTLMSSP algorithm
357 *
358 */
359
360 NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
361 uint8_t *data, size_t length,
362 const uint8_t *whole_pdu, size_t pdu_length,
363 const DATA_BLOB *sig)
364 {
365 NTSTATUS status;
366 if (!ntlmssp_state->session_key.length) {
367 DEBUG(3, ("NO session key, cannot unseal packet\n"));
368 return NT_STATUS_NO_USER_SESSION_KEY;
369 }
370
371 DEBUG(10,("ntlmssp_unseal_packet: seal\n"));
372 dump_data_pw("ntlmssp sealed data\n", data, length);
373
374 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
375 /* First unseal the data. */
376 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
377 data, length);
378 dump_data_pw("ntlmv2 clear data\n", data, length);
379 } else {
380 arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
381 data, length);
382 dump_data_pw("ntlmv1 clear data\n", data, length);
383 }
384 status = ntlmssp_check_packet(ntlmssp_state,
385 data, length,
386 whole_pdu, pdu_length,
387 sig);
388
389 if (!NT_STATUS_IS_OK(status)) {
390 DEBUG(1,("NTLMSSP packet check for unseal failed due to invalid signature on %llu bytes of input:\n",
391 (unsigned long long)length));
392 }
393 return status;
394 }
395
396 NTSTATUS ntlmssp_wrap(struct ntlmssp_state *ntlmssp_state,
397 TALLOC_CTX *out_mem_ctx,
398 const DATA_BLOB *in,
399 DATA_BLOB *out)
400 {
401 NTSTATUS nt_status;
402 DATA_BLOB sig;
403
404 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
405 if (in->length + NTLMSSP_SIG_SIZE < in->length) {
406 return NT_STATUS_INVALID_PARAMETER;
407 }
408
409 *out = data_blob_talloc(out_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
410 if (!out->data) {
411 return NT_STATUS_NO_MEMORY;
412 }
413 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
414
415 nt_status = ntlmssp_seal_packet(ntlmssp_state, out_mem_ctx,
416 out->data + NTLMSSP_SIG_SIZE,
417 out->length - NTLMSSP_SIG_SIZE,
418 out->data + NTLMSSP_SIG_SIZE,
419 out->length - NTLMSSP_SIG_SIZE,
420 &sig);
421
422 if (NT_STATUS_IS_OK(nt_status)) {
423 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
424 talloc_free(sig.data);
425 }
426 return nt_status;
427
428 } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) {
429 if (in->length + NTLMSSP_SIG_SIZE < in->length) {
430 return NT_STATUS_INVALID_PARAMETER;
431 }
432
433 *out = data_blob_talloc(out_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
434 if (!out->data) {
435 return NT_STATUS_NO_MEMORY;
436 }
437 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
438
439 nt_status = ntlmssp_sign_packet(ntlmssp_state, out_mem_ctx,
440 out->data + NTLMSSP_SIG_SIZE,
441 out->length - NTLMSSP_SIG_SIZE,
442 out->data + NTLMSSP_SIG_SIZE,
443 out->length - NTLMSSP_SIG_SIZE,
444 &sig);
445
446 if (NT_STATUS_IS_OK(nt_status)) {
447 memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
448 talloc_free(sig.data);
449 }
450 return nt_status;
451 } else {
452 *out = data_blob_talloc(out_mem_ctx, in->data, in->length);
453 if (!out->data) {
454 return NT_STATUS_NO_MEMORY;
455 }
456 return NT_STATUS_OK;
457 }
458 }
459
460 NTSTATUS ntlmssp_unwrap(struct ntlmssp_state *ntlmssp_state,
461 TALLOC_CTX *out_mem_ctx,
462 const DATA_BLOB *in,
463 DATA_BLOB *out)
464 {
465 DATA_BLOB sig;
466
467 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
468 if (in->length < NTLMSSP_SIG_SIZE) {
469 return NT_STATUS_INVALID_PARAMETER;
470 }
471 sig.data = in->data;
472 sig.length = NTLMSSP_SIG_SIZE;
473
474 *out = data_blob_talloc(out_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
475
476 return ntlmssp_unseal_packet(ntlmssp_state,
477 out->data, out->length,
478 out->data, out->length,
479 &sig);
480
481 } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) {
482 NTSTATUS status;
483 struct ntlmssp_crypt_direction save_direction;
484
485 if (in->length < NTLMSSP_SIG_SIZE) {
486 return NT_STATUS_INVALID_PARAMETER;
487 }
488 sig.data = in->data;
489 sig.length = NTLMSSP_SIG_SIZE;
490 *out = data_blob_talloc(out_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
491
492 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
493 save_direction = ntlmssp_state->crypt->ntlm2.receiving;
494 } else {
495 save_direction = ntlmssp_state->crypt->ntlm;
496 }
497
498 status = ntlmssp_check_packet(ntlmssp_state,
499 out->data, out->length,
500 out->data, out->length,
501 &sig);
502 if (!NT_STATUS_IS_OK(status)) {
503 NTSTATUS check_status = status;
504 /*
505 * The Windows LDAP libraries seems to have a bug
506 * and always use sealing even if only signing was
507 * negotiated. So we need to fallback.
508 */
509
510 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
511 ntlmssp_state->crypt->ntlm2.receiving = save_direction;
512 } else {
513 ntlmssp_state->crypt->ntlm = save_direction;
514 }
515
516 status = ntlmssp_unseal_packet(ntlmssp_state,
517 out->data,
518 out->length,
519 out->data,
520 out->length,
521 &sig);
522 if (NT_STATUS_IS_OK(status)) {
523 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
524 } else {
525 status = check_status;
526 }
527 }
528
529 if (!NT_STATUS_IS_OK(status)) {
530 DEBUG(1, ("NTLMSSP packet check for unwrap failed due to invalid signature\n"));
531 }
532 return status;
533 } else {
534 *out = data_blob_talloc(out_mem_ctx, in->data, in->length);
535 if (!out->data) {
536 return NT_STATUS_NO_MEMORY;
537 }
538 return NT_STATUS_OK;
539 }
540 }
541
542 /**
543 Initialise the state for NTLMSSP signing.
544 */
545 NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
546 {
547 DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
548 debug_ntlmssp_flags(ntlmssp_state->neg_flags);
549
550 if (ntlmssp_state->session_key.length < 8) {
551 DEBUG(3, ("NO session key, cannot intialise signing\n"));
552 return NT_STATUS_NO_USER_SESSION_KEY;
553 }
554
555 ntlmssp_state->crypt = talloc_zero(ntlmssp_state,
556 union ntlmssp_crypt_state);
557 if (ntlmssp_state->crypt == NULL) {
558 return NT_STATUS_NO_MEMORY;
559 }
560
561 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
562 DATA_BLOB weak_session_key = ntlmssp_state->session_key;
563 const char *send_sign_const;
564 const char *send_seal_const;
565 const char *recv_sign_const;
566 const char *recv_seal_const;
567 uint8_t send_seal_key[16];
568 DATA_BLOB send_seal_blob = data_blob_const(send_seal_key,
569 sizeof(send_seal_key));
570 uint8_t recv_seal_key[16];
571 DATA_BLOB recv_seal_blob = data_blob_const(recv_seal_key,
572 sizeof(recv_seal_key));
573
574 switch (ntlmssp_state->role) {
575 case NTLMSSP_CLIENT:
576 send_sign_const = CLI_SIGN;
577 send_seal_const = CLI_SEAL;
578 recv_sign_const = SRV_SIGN;
579 recv_seal_const = SRV_SEAL;
580 break;
581 case NTLMSSP_SERVER:
582 send_sign_const = SRV_SIGN;
583 send_seal_const = SRV_SEAL;
584 recv_sign_const = CLI_SIGN;
585 recv_seal_const = CLI_SEAL;
586 break;
587 default:
588 return NT_STATUS_INTERNAL_ERROR;
589 }
590
591 /*
592 * Weaken NTLMSSP keys to cope with down-level
593 * clients, servers and export restrictions.
594 *
595 * We probably should have some parameters to
596 * control this, once we get NTLM2 working.
597 *
598 * Key weakening was not performed on the master key
599 * for NTLM2, but must be done on the encryption subkeys only.
600 */
601
602 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
603 /* nothing to do */
604 } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
605 weak_session_key.length = 7;
606 } else { /* forty bits */
607 weak_session_key.length = 5;
608 }
609
610 dump_data_pw("NTLMSSP weakend master key:\n",
611 weak_session_key.data,
612 weak_session_key.length);
613
614 /* SEND: sign key */
615 calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.sending.sign_key,
616 ntlmssp_state->session_key, send_sign_const);
617 dump_data_pw("NTLMSSP send sign key:\n",
618 ntlmssp_state->crypt->ntlm2.sending.sign_key, 16);
619
620 /* SEND: seal ARCFOUR pad */
621 calc_ntlmv2_key(send_seal_key,
622 weak_session_key, send_seal_const);
623 dump_data_pw("NTLMSSP send seal key:\n", send_seal_key, 16);
624
625 arcfour_init(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
626 &send_seal_blob);
627
628 dump_arc4_state("NTLMSSP send seal arc4 state:\n",
629 &ntlmssp_state->crypt->ntlm2.sending.seal_state);
630
631 /* SEND: seq num */
632 ntlmssp_state->crypt->ntlm2.sending.seq_num = 0;
633
634 /* RECV: sign key */
635 calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.receiving.sign_key,
636 ntlmssp_state->session_key, recv_sign_const);
637 dump_data_pw("NTLMSSP recv sign key:\n",
638 ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16);
639
640 /* RECV: seal ARCFOUR pad */
641 calc_ntlmv2_key(recv_seal_key,
642 weak_session_key, recv_seal_const);
643 dump_data_pw("NTLMSSP recv seal key:\n", recv_seal_key, 16);
644
645 arcfour_init(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
646 &recv_seal_blob);
647
648 dump_arc4_state("NTLMSSP recv seal arc4 state:\n",
649 &ntlmssp_state->crypt->ntlm2.receiving.seal_state);
650
651 /* RECV: seq num */
652 ntlmssp_state->crypt->ntlm2.receiving.seq_num = 0;
653 } else {
654 uint8_t weak_session_key[8];
655 DATA_BLOB seal_session_key = ntlmssp_state->session_key;
656 bool do_weak = false;
657
658 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
659
660 /*
661 * Key weakening not performed on the master key for NTLM2
662 * and does not occour for NTLM1. Therefore we only need
663 * to do this for the LM_KEY.
664 */
665 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
666 do_weak = true;
667 }
668
669 /*
670 * Nothing to weaken.
671 * We certainly don't want to 'extend' the length...
672 */
673 if (seal_session_key.length < 16) {
674 /* TODO: is this really correct? */
675 do_weak = false;
676 }
677
678 if (do_weak) {
679 memcpy(weak_session_key, seal_session_key.data, 8);
680 seal_session_key = data_blob_const(weak_session_key, 8);
681
682 /*
683 * LM key doesn't support 128 bit crypto, so this is
684 * the best we can do. If you negotiate 128 bit, but
685 * not 56, you end up with 40 bit...
686 */
687 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
688 weak_session_key[7] = 0xa0;
689 } else { /* forty bits */
690 weak_session_key[5] = 0xe5;
691 weak_session_key[6] = 0x38;
692 weak_session_key[7] = 0xb0;
693 }
694 }
695
696 arcfour_init(&ntlmssp_state->crypt->ntlm.seal_state,
697 &seal_session_key);
698
699 dump_arc4_state("NTLMv1 arc4 state:\n",
700 &ntlmssp_state->crypt->ntlm.seal_state);
701
702 ntlmssp_state->crypt->ntlm.seq_num = 0;
703 }
704
705 return NT_STATUS_OK;
706 }
Samba GIT mirror