2 * Unix SMB/CIFS implementation.
4 * NTLMSSP Signing routines
5 * Copyright (C) Andrew Bartlett 2003-2005
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 Foundation,
19 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 #define CLI_SIGN "session key to client-to-server signing key magic constant"
25 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
26 #define SRV_SIGN "session key to server-to-client signing key magic constant"
27 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
30 * Some notes on then NTLM2 code:
32 * NTLM2 is a AEAD system. This means that the data encrypted is not
33 * all the data that is signed. In DCE-RPC case, the headers of the
34 * DCE-RPC packets are also signed. This prevents some of the
35 * fun-and-games one might have by changing them.
39 static void calc_ntlmv2_key(unsigned char subkey
[16],
40 DATA_BLOB session_key
,
43 struct MD5Context ctx3
;
45 MD5Update(&ctx3
, session_key
.data
, session_key
.length
);
46 MD5Update(&ctx3
, (const unsigned char *)constant
, strlen(constant
)+1);
47 MD5Final(subkey
, &ctx3
);
50 enum ntlmssp_direction
{
55 static NTSTATUS
ntlmssp_make_packet_signature(NTLMSSP_STATE
*ntlmssp_state
,
56 const uchar
*data
, size_t length
,
57 const uchar
*whole_pdu
, size_t pdu_length
,
58 enum ntlmssp_direction direction
,
62 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_NTLM2
) {
67 *sig
= data_blob(NULL
, NTLMSSP_SIG_SIZE
);
69 return NT_STATUS_NO_MEMORY
;
74 DEBUG(100,("ntlmssp_make_packet_signature: SEND seq = %u, len = %u, pdu_len = %u\n",
75 ntlmssp_state
->ntlm2_send_seq_num
,
77 (unsigned int)pdu_length
));
79 SIVAL(seq_num
, 0, ntlmssp_state
->ntlm2_send_seq_num
);
80 ntlmssp_state
->ntlm2_send_seq_num
++;
81 hmac_md5_init_limK_to_64(ntlmssp_state
->send_sign_key
, 16, &ctx
);
85 DEBUG(100,("ntlmssp_make_packet_signature: RECV seq = %u, len = %u, pdu_len = %u\n",
86 ntlmssp_state
->ntlm2_recv_seq_num
,
88 (unsigned int)pdu_length
));
90 SIVAL(seq_num
, 0, ntlmssp_state
->ntlm2_recv_seq_num
);
91 ntlmssp_state
->ntlm2_recv_seq_num
++;
92 hmac_md5_init_limK_to_64(ntlmssp_state
->recv_sign_key
, 16, &ctx
);
96 dump_data_pw("pdu data ", whole_pdu
, pdu_length
);
98 hmac_md5_update(seq_num
, 4, &ctx
);
99 hmac_md5_update(whole_pdu
, pdu_length
, &ctx
);
100 hmac_md5_final(digest
, &ctx
);
102 if (encrypt_sig
&& (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_KEY_EXCH
)) {
105 smb_arc4_crypt(ntlmssp_state
->send_seal_arc4_state
, digest
, 8);
107 case NTLMSSP_RECEIVE
:
108 smb_arc4_crypt(ntlmssp_state
->recv_seal_arc4_state
, digest
, 8);
113 SIVAL(sig
->data
, 0, NTLMSSP_SIGN_VERSION
);
114 memcpy(sig
->data
+ 4, digest
, 8);
115 memcpy(sig
->data
+ 12, seq_num
, 4);
117 dump_data_pw("ntlmssp v2 sig ", sig
->data
, sig
->length
);
121 crc
= crc32_calc_buffer((const char *)data
, length
);
122 if (!msrpc_gen(sig
, "dddd", NTLMSSP_SIGN_VERSION
, 0, crc
, ntlmssp_state
->ntlmv1_seq_num
)) {
123 return NT_STATUS_NO_MEMORY
;
126 ntlmssp_state
->ntlmv1_seq_num
++;
128 dump_data_pw("ntlmssp hash:\n", ntlmssp_state
->ntlmv1_arc4_state
,
129 sizeof(ntlmssp_state
->ntlmv1_arc4_state
));
130 smb_arc4_crypt(ntlmssp_state
->ntlmv1_arc4_state
, sig
->data
+4, sig
->length
-4);
135 NTSTATUS
ntlmssp_sign_packet(NTLMSSP_STATE
*ntlmssp_state
,
136 const uchar
*data
, size_t length
,
137 const uchar
*whole_pdu
, size_t pdu_length
,
142 if (!(ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_SIGN
)) {
143 DEBUG(3, ("NTLMSSP Signing not negotiated - cannot sign packet!\n"));
144 return NT_STATUS_INVALID_PARAMETER
;
147 if (!ntlmssp_state
->session_key
.length
) {
148 DEBUG(3, ("NO session key, cannot check sign packet\n"));
149 return NT_STATUS_NO_USER_SESSION_KEY
;
152 nt_status
= ntlmssp_make_packet_signature(ntlmssp_state
,
154 whole_pdu
, pdu_length
,
155 NTLMSSP_SEND
, sig
, True
);
161 * Check the signature of an incoming packet
162 * @note caller *must* check that the signature is the size it expects
166 NTSTATUS
ntlmssp_check_packet(NTLMSSP_STATE
*ntlmssp_state
,
167 const uchar
*data
, size_t length
,
168 const uchar
*whole_pdu
, size_t pdu_length
,
169 const DATA_BLOB
*sig
)
174 if (!ntlmssp_state
->session_key
.length
) {
175 DEBUG(3, ("NO session key, cannot check packet signature\n"));
176 return NT_STATUS_NO_USER_SESSION_KEY
;
179 if (sig
->length
< 8) {
180 DEBUG(0, ("NTLMSSP packet check failed due to short signature (%lu bytes)!\n",
181 (unsigned long)sig
->length
));
184 nt_status
= ntlmssp_make_packet_signature(ntlmssp_state
,
186 whole_pdu
, pdu_length
,
187 NTLMSSP_RECEIVE
, &local_sig
, True
);
189 if (!NT_STATUS_IS_OK(nt_status
)) {
190 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status
)));
191 data_blob_free(&local_sig
);
195 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_NTLM2
) {
196 if (local_sig
.length
!= sig
->length
||
197 memcmp(local_sig
.data
, sig
->data
, sig
->length
) != 0) {
198 DEBUG(5, ("BAD SIG NTLM2: wanted signature of\n"));
199 dump_data(5, (const char *)local_sig
.data
, local_sig
.length
);
201 DEBUG(5, ("BAD SIG: got signature of\n"));
202 dump_data(5, (const char *)sig
->data
, sig
->length
);
204 DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
205 data_blob_free(&local_sig
);
206 return NT_STATUS_ACCESS_DENIED
;
209 if (local_sig
.length
!= sig
->length
||
210 memcmp(local_sig
.data
+ 8, sig
->data
+ 8, sig
->length
- 8) != 0) {
211 DEBUG(5, ("BAD SIG NTLM1: wanted signature of\n"));
212 dump_data(5, (const char *)local_sig
.data
, local_sig
.length
);
214 DEBUG(5, ("BAD SIG: got signature of\n"));
215 dump_data(5, (const char *)sig
->data
, sig
->length
);
217 DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
218 data_blob_free(&local_sig
);
219 return NT_STATUS_ACCESS_DENIED
;
222 dump_data_pw("checked ntlmssp signature\n", sig
->data
, sig
->length
);
223 DEBUG(10,("ntlmssp_check_packet: NTLMSSP signature OK !\n"));
225 data_blob_free(&local_sig
);
230 * Seal data with the NTLMSSP algorithm
234 NTSTATUS
ntlmssp_seal_packet(NTLMSSP_STATE
*ntlmssp_state
,
235 uchar
*data
, size_t length
,
236 uchar
*whole_pdu
, size_t pdu_length
,
239 if (!(ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_SEAL
)) {
240 DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
241 return NT_STATUS_INVALID_PARAMETER
;
244 if (!ntlmssp_state
->session_key
.length
) {
245 DEBUG(3, ("NO session key, cannot seal packet\n"));
246 return NT_STATUS_NO_USER_SESSION_KEY
;
249 DEBUG(10,("ntlmssp_seal_data: seal\n"));
250 dump_data_pw("ntlmssp clear data\n", data
, length
);
251 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_NTLM2
) {
252 /* The order of these two operations matters - we must first seal the packet,
253 then seal the sequence number - this is becouse the send_seal_hash is not
254 constant, but is is rather updated with each iteration */
255 NTSTATUS nt_status
= ntlmssp_make_packet_signature(ntlmssp_state
,
257 whole_pdu
, pdu_length
,
258 NTLMSSP_SEND
, sig
, False
);
259 if (!NT_STATUS_IS_OK(nt_status
)) {
263 smb_arc4_crypt(ntlmssp_state
->send_seal_arc4_state
, data
, length
);
264 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_KEY_EXCH
) {
265 smb_arc4_crypt(ntlmssp_state
->send_seal_arc4_state
, sig
->data
+4, 8);
269 crc
= crc32_calc_buffer((const char *)data
, length
);
270 if (!msrpc_gen(sig
, "dddd", NTLMSSP_SIGN_VERSION
, 0, crc
, ntlmssp_state
->ntlmv1_seq_num
)) {
271 return NT_STATUS_NO_MEMORY
;
274 /* The order of these two operations matters - we must first seal the packet,
275 then seal the sequence number - this is becouse the ntlmv1_arc4_state is not
276 constant, but is is rather updated with each iteration */
278 dump_data_pw("ntlmv1 arc4 state:\n", ntlmssp_state
->ntlmv1_arc4_state
,
279 sizeof(ntlmssp_state
->ntlmv1_arc4_state
));
280 smb_arc4_crypt(ntlmssp_state
->ntlmv1_arc4_state
, data
, length
);
282 dump_data_pw("ntlmv1 arc4 state:\n", ntlmssp_state
->ntlmv1_arc4_state
,
283 sizeof(ntlmssp_state
->ntlmv1_arc4_state
));
285 smb_arc4_crypt(ntlmssp_state
->ntlmv1_arc4_state
, sig
->data
+4, sig
->length
-4);
287 ntlmssp_state
->ntlmv1_seq_num
++;
289 dump_data_pw("ntlmssp signature\n", sig
->data
, sig
->length
);
290 dump_data_pw("ntlmssp sealed data\n", data
, length
);
296 * Unseal data with the NTLMSSP algorithm
300 NTSTATUS
ntlmssp_unseal_packet(NTLMSSP_STATE
*ntlmssp_state
,
301 uchar
*data
, size_t length
,
302 uchar
*whole_pdu
, size_t pdu_length
,
305 if (!ntlmssp_state
->session_key
.length
) {
306 DEBUG(3, ("NO session key, cannot unseal packet\n"));
307 return NT_STATUS_NO_USER_SESSION_KEY
;
310 DEBUG(10,("ntlmssp_unseal_data: seal\n"));
311 dump_data_pw("ntlmssp sealed data\n", data
, length
);
313 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_NTLM2
) {
314 /* First unseal the data. */
315 smb_arc4_crypt(ntlmssp_state
->recv_seal_arc4_state
, data
, length
);
316 dump_data_pw("ntlmv2 clear data\n", data
, length
);
318 smb_arc4_crypt(ntlmssp_state
->ntlmv1_arc4_state
, data
, length
);
319 dump_data_pw("ntlmv1 clear data\n", data
, length
);
321 return ntlmssp_check_packet(ntlmssp_state
, data
, length
, whole_pdu
, pdu_length
, sig
);
325 Initialise the state for NTLMSSP signing.
327 NTSTATUS
ntlmssp_sign_init(NTLMSSP_STATE
*ntlmssp_state
)
329 unsigned char p24
[24];
333 mem_ctx
= talloc_init("weak_keys");
335 return NT_STATUS_NO_MEMORY
;
338 DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
339 debug_ntlmssp_flags(ntlmssp_state
->neg_flags
);
341 if (ntlmssp_state
->session_key
.length
< 8) {
342 TALLOC_FREE(mem_ctx
);
343 DEBUG(3, ("NO session key, cannot intialise signing\n"));
344 return NT_STATUS_NO_USER_SESSION_KEY
;
347 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_NTLM2
) {
348 DATA_BLOB weak_session_key
= ntlmssp_state
->session_key
;
349 const char *send_sign_const
;
350 const char *send_seal_const
;
351 const char *recv_sign_const
;
352 const char *recv_seal_const
;
354 switch (ntlmssp_state
->role
) {
356 send_sign_const
= CLI_SIGN
;
357 send_seal_const
= CLI_SEAL
;
358 recv_sign_const
= SRV_SIGN
;
359 recv_seal_const
= SRV_SEAL
;
362 send_sign_const
= SRV_SIGN
;
363 send_seal_const
= SRV_SEAL
;
364 recv_sign_const
= CLI_SIGN
;
365 recv_seal_const
= CLI_SEAL
;
368 TALLOC_FREE(mem_ctx
);
369 return NT_STATUS_INTERNAL_ERROR
;
373 Weaken NTLMSSP keys to cope with down-level clients, servers and export restrictions.
374 We probably should have some parameters to control this, once we get NTLM2 working.
377 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_128
) {
379 } else if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_56
) {
380 weak_session_key
.length
= 7;
381 } else { /* forty bits */
382 weak_session_key
.length
= 5;
385 dump_data_pw("NTLMSSP weakend master key:\n",
386 weak_session_key
.data
,
387 weak_session_key
.length
);
390 calc_ntlmv2_key(ntlmssp_state
->send_sign_key
,
391 ntlmssp_state
->session_key
, send_sign_const
);
392 dump_data_pw("NTLMSSP send sign key:\n",
393 ntlmssp_state
->send_sign_key
, 16);
395 /* SEND: seal ARCFOUR pad */
396 calc_ntlmv2_key(ntlmssp_state
->send_seal_key
,
397 weak_session_key
, send_seal_const
);
398 dump_data_pw("NTLMSSP send seal key:\n",
399 ntlmssp_state
->send_seal_key
, 16);
401 smb_arc4_init(ntlmssp_state
->send_seal_arc4_state
,
402 ntlmssp_state
->send_seal_key
, 16);
404 dump_data_pw("NTLMSSP send seal arc4 state:\n",
405 ntlmssp_state
->send_seal_arc4_state
,
406 sizeof(ntlmssp_state
->send_seal_arc4_state
));
409 calc_ntlmv2_key(ntlmssp_state
->recv_sign_key
,
410 ntlmssp_state
->session_key
, recv_sign_const
);
411 dump_data_pw("NTLMSSP recv send sign key:\n",
412 ntlmssp_state
->recv_sign_key
, 16);
414 /* RECV: seal ARCFOUR pad */
415 calc_ntlmv2_key(ntlmssp_state
->recv_seal_key
,
416 weak_session_key
, recv_seal_const
);
418 dump_data_pw("NTLMSSP recv seal key:\n",
419 ntlmssp_state
->recv_seal_key
, 16);
421 smb_arc4_init(ntlmssp_state
->recv_seal_arc4_state
,
422 ntlmssp_state
->recv_seal_key
, 16);
424 dump_data_pw("NTLMSSP recv seal arc4 state:\n",
425 ntlmssp_state
->recv_seal_arc4_state
,
426 sizeof(ntlmssp_state
->recv_seal_arc4_state
));
428 ntlmssp_state
->ntlm2_send_seq_num
= 0;
429 ntlmssp_state
->ntlm2_recv_seq_num
= 0;
434 /* Hmmm. Shouldn't we also weaken keys for ntlmv1 ? JRA. */
436 DATA_BLOB weak_session_key
= ntlmssp_state
->session_key
;
438 Weaken NTLMSSP keys to cope with down-level clients, servers and export restrictions.
439 We probably should have some parameters to control this, once we get NTLM2 working.
442 if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_128
) {
444 } else if (ntlmssp_state
->neg_flags
& NTLMSSP_NEGOTIATE_56
) {
445 weak_session_key
.length
= 6;
446 } else { /* forty bits */
447 weak_session_key
.length
= 5;
449 dump_data_pw("NTLMSSP weakend master key:\n",
450 weak_session_key
.data
,
451 weak_session_key
.length
);
454 DATA_BLOB weak_session_key
= ntlmssp_weaken_keys(ntlmssp_state
, mem_ctx
);
456 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
458 smb_arc4_init(ntlmssp_state
->ntlmv1_arc4_state
,
459 weak_session_key
.data
, weak_session_key
.length
);
461 dump_data_pw("NTLMv1 arc4 state:\n", ntlmssp_state
->ntlmv1_arc4_state
,
462 sizeof(ntlmssp_state
->ntlmv1_arc4_state
));
464 ntlmssp_state
->ntlmv1_seq_num
= 0;
467 TALLOC_FREE(mem_ctx
);