source4/auth/ntlmssp/ntlmssp_sign.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Version 3.0
   4  *  NTLMSSP Signing routines
   5  *  Copyright (C) Luke Kenneth Casson Leighton 1996-2001
   6  *  Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003-2005
   7  *
   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 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  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.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software Foundation,
  20  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include "includes.h"
  24 #include "auth/auth.h"
  25 #include "auth/ntlmssp/ntlmssp.h"
  26 #include "lib/crypto/crypto.h"
  27
  28 #define CLI_SIGN "session key to client-to-server signing key magic constant"
  29 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
  30 #define SRV_SIGN "session key to server-to-client signing key magic constant"
  31 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
  32
  33 /**
  34  * Some notes on then NTLM2 code:
  35  *
  36  * NTLM2 is a AEAD system.  This means that the data encrypted is not
  37  * all the data that is signed.  In DCE-RPC case, the headers of the
  38  * DCE-RPC packets are also signed.  This prevents some of the
  39  * fun-and-games one might have by changing them.
  40  *
  41  */
  42
  43 static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx,
  44                             DATA_BLOB *subkey,
  45                             DATA_BLOB session_key,
  46                             const char *constant)
  47 {
  48         struct MD5Context ctx3;
  49         *subkey = data_blob_talloc(mem_ctx, NULL, 16);
  50         MD5Init(&ctx3);
  51         MD5Update(&ctx3, session_key.data, session_key.length);
  52         MD5Update(&ctx3, constant, strlen(constant)+1);
  53         MD5Final(subkey->data, &ctx3);
  54 }
  55
  56 enum ntlmssp_direction {
  57         NTLMSSP_SEND,
  58         NTLMSSP_RECEIVE
  59 };
  60
  61 static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
  62                                               TALLOC_CTX *sig_mem_ctx,
  63                                               const uint8_t *data, size_t length,
  64                                               const uint8_t *whole_pdu, size_t pdu_length,
  65                                               enum ntlmssp_direction direction,
  66                                               DATA_BLOB *sig, BOOL encrypt_sig)
  67 {
  68         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
  69
  70                 HMACMD5Context ctx;
  71                 uint8_t digest[16];
  72                 uint8_t seq_num[4];
  73
  74                 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
  75                 if (!sig->data) {
  76                         return NT_STATUS_NO_MEMORY;
  77                 }
  78
  79                 switch (direction) {
  80                 case NTLMSSP_SEND:
  81                         SIVAL(seq_num, 0, ntlmssp_state->ntlm2_send_seq_num);
  82                         ntlmssp_state->ntlm2_send_seq_num++;
  83                         hmac_md5_init_limK_to_64(ntlmssp_state->send_sign_key.data,
  84                                                  ntlmssp_state->send_sign_key.length, &ctx);
  85                         break;
  86                 case NTLMSSP_RECEIVE:
  87                         SIVAL(seq_num, 0, ntlmssp_state->ntlm2_recv_seq_num);
  88                         ntlmssp_state->ntlm2_recv_seq_num++;
  89                         hmac_md5_init_limK_to_64(ntlmssp_state->recv_sign_key.data,
  90                                                  ntlmssp_state->recv_sign_key.length, &ctx);
  91                         break;
  92                 }
  93                 hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
  94                 hmac_md5_update(whole_pdu, pdu_length, &ctx);
  95                 hmac_md5_final(digest, &ctx);
  96
  97                 if (encrypt_sig && ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
  98                         switch (direction) {
  99                         case NTLMSSP_SEND:
 100                                 arcfour_crypt_sbox(ntlmssp_state->send_seal_hash, digest, 8);
 101                                 break;
 102                         case NTLMSSP_RECEIVE:
 103                                 arcfour_crypt_sbox(ntlmssp_state->recv_seal_hash, digest, 8);
 104                                 break;
 105                         }
 106                 }
 107
 108                 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
 109                 memcpy(sig->data + 4, digest, 8);
 110                 memcpy(sig->data + 12, seq_num, 4);
 111
 112         } else {
 113                 uint32_t crc;
 114                 crc = crc32_calc_buffer(data, length);
 115                 if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlm_seq_num)) {
 116                         return NT_STATUS_NO_MEMORY;
 117                 }
 118                 ntlmssp_state->ntlm_seq_num++;
 119
 120                 arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4);
 121         }
 122         dump_data_pw("calculated ntlmssp signature\n", sig->data, sig->length);
 123         return NT_STATUS_OK;
 124 }
 125
 126 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
 127                                            TALLOC_CTX *sig_mem_ctx,
 128                                            const uint8_t *data, size_t length,
 129                                            const uint8_t *whole_pdu, size_t pdu_length,
 130                                            DATA_BLOB *sig)
 131 {
 132         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 133         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
 134
 135         if (!ntlmssp_state->session_key.length) {
 136                 DEBUG(3, ("NO session key, cannot check sign packet\n"));
 137                 return NT_STATUS_NO_USER_SESSION_KEY;
 138         }
 139
 140         if (!ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) {
 141                 DEBUG(3, ("NTLMSSP Signing not negotiated - cannot sign packet!\n"));
 142                 return NT_STATUS_INVALID_PARAMETER;
 143         }
 144
 145         return ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx,
 146                                              data, length,
 147                                              whole_pdu, pdu_length,
 148                                              NTLMSSP_SEND, sig, True);
 149 }
 150
 151 /**
 152  * Check the signature of an incoming packet
 153  *
 154  */
 155
 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)
 161 {
 162         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 163         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
 164
 165         DATA_BLOB local_sig;
 166         NTSTATUS nt_status;
 167
 168         if (!ntlmssp_state->session_key.length) {
 169                 DEBUG(3, ("NO session key, cannot check packet signature\n"));
 170                 return NT_STATUS_NO_USER_SESSION_KEY;
 171         }
 172
 173         if (sig->length < 8) {
 174                 DEBUG(0, ("NTLMSSP packet check failed due to short signature (%lu bytes)!\n",
 175                           (unsigned long)sig->length));
 176         }
 177
 178         nt_status = ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx,
 179                                                   data, length,
 180                                                   whole_pdu, pdu_length,
 181                                                   NTLMSSP_RECEIVE, &local_sig, True);
 182
 183         if (!NT_STATUS_IS_OK(nt_status)) {
 184                 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
 185                 return nt_status;
 186         }
 187
 188         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 189                 if (local_sig.length != sig->length ||
 190                     memcmp(local_sig.data,
 191                            sig->data, sig->length) != 0) {
 192                         DEBUG(5, ("BAD SIG NTLM2: wanted signature of\n"));
 193                         dump_data(5, local_sig.data, local_sig.length);
 194
 195                         DEBUG(5, ("BAD SIG: got signature of\n"));
 196                         dump_data(5, sig->data, sig->length);
 197
 198                         DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
 199                         return NT_STATUS_ACCESS_DENIED;
 200                 }
 201         } else {
 202                 if (local_sig.length != sig->length ||
 203                     memcmp(local_sig.data + 8,
 204                            sig->data + 8, sig->length - 8) != 0) {
 205                         DEBUG(5, ("BAD SIG NTLM1: wanted signature of\n"));
 206                         dump_data(5, local_sig.data, local_sig.length);
 207
 208                         DEBUG(5, ("BAD SIG: got signature of\n"));
 209                         dump_data(5, sig->data, sig->length);
 210
 211                         DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
 212                         return NT_STATUS_ACCESS_DENIED;
 213                 }
 214         }
 215         dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
 216
 217         return NT_STATUS_OK;
 218 }
 219
 220
 221 /**
 222  * Seal data with the NTLMSSP algorithm
 223  *
 224  */
 225
 226 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
 227                                     TALLOC_CTX *sig_mem_ctx,
 228                                     uint8_t *data, size_t length,
 229                                     const uint8_t *whole_pdu, size_t pdu_length,
 230                                     DATA_BLOB *sig)
 231 {
 232         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 233         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
 234         NTSTATUS nt_status;
 235         if (!ntlmssp_state->session_key.length) {
 236                 DEBUG(3, ("NO session key, cannot seal packet\n"));
 237                 return NT_STATUS_NO_USER_SESSION_KEY;
 238         }
 239
 240         if (!ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 241                 DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
 242                 return NT_STATUS_INVALID_PARAMETER;
 243         }
 244
 245         DEBUG(10,("ntlmssp_seal_data: seal\n"));
 246         dump_data_pw("ntlmssp clear data\n", data, length);
 247         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 248                 /* The order of these two operations matters - we must first seal the packet,
 249                    then seal the sequence number - this is becouse the send_seal_hash is not
 250                    constant, but is is rather updated with each iteration */
 251                 nt_status = ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx,
 252                                                           data, length,
 253                                                           whole_pdu, pdu_length,
 254                                                           NTLMSSP_SEND, sig, False);
 255                 arcfour_crypt_sbox(ntlmssp_state->send_seal_hash, data, length);
 256                 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 257                         arcfour_crypt_sbox(ntlmssp_state->send_seal_hash, sig->data+4, 8);
 258                 }
 259         } else {
 260                 uint32_t crc;
 261                 crc = crc32_calc_buffer(data, length);
 262                 if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlm_seq_num)) {
 263                         return NT_STATUS_NO_MEMORY;
 264                 }
 265
 266                 /* The order of these two operations matters - we must
 267                    first seal the packet, then seal the sequence
 268                    number - this is becouse the ntlmssp_hash is not
 269                    constant, but is is rather updated with each
 270                    iteration */
 271
 272                 arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, data, length);
 273                 arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4);
 274                 /* increment counter on send */
 275                 ntlmssp_state->ntlm_seq_num++;
 276                 nt_status = NT_STATUS_OK;
 277         }
 278         dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
 279         dump_data_pw("ntlmssp sealed data\n", data, length);
 280
 281
 282         return nt_status;
 283 }
 284
 285 /**
 286  * Unseal data with the NTLMSSP algorithm
 287  *
 288  */
 289
 290 /*
 291   wrappers for the ntlmssp_*() functions
 292 */
 293 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
 294                                       TALLOC_CTX *sig_mem_ctx,
 295                                       uint8_t *data, size_t length,
 296                                       const uint8_t *whole_pdu, size_t pdu_length,
 297                                       const DATA_BLOB *sig)
 298 {
 299         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 300         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
 301         DATA_BLOB local_sig;
 302         NTSTATUS nt_status;
 303         if (!ntlmssp_state->session_key.length) {
 304                 DEBUG(3, ("NO session key, cannot unseal packet\n"));
 305                 return NT_STATUS_NO_USER_SESSION_KEY;
 306         }
 307
 308         dump_data_pw("ntlmssp sealed data\n", data, length);
 309         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 310                 arcfour_crypt_sbox(ntlmssp_state->recv_seal_hash, data, length);
 311
 312                 nt_status = ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx,
 313                                                           data, length,
 314                                                           whole_pdu, pdu_length,
 315                                                           NTLMSSP_RECEIVE, &local_sig, True);
 316                 if (!NT_STATUS_IS_OK(nt_status)) {
 317                         return nt_status;
 318                 }
 319
 320                 if (local_sig.length != sig->length ||
 321                     memcmp(local_sig.data,
 322                            sig->data, sig->length) != 0) {
 323                         DEBUG(5, ("BAD SIG NTLM2: wanted signature of\n"));
 324                         dump_data(5, local_sig.data, local_sig.length);
 325
 326                         DEBUG(5, ("BAD SIG: got signature of\n"));
 327                         dump_data(5, sig->data, sig->length);
 328
 329                         DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
 330                         return NT_STATUS_ACCESS_DENIED;
 331                 }
 332
 333                 dump_data_pw("ntlmssp clear data\n", data, length);
 334                 return NT_STATUS_OK;
 335         } else {
 336                 arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, data, length);
 337                 dump_data_pw("ntlmssp clear data\n", data, length);
 338                 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 339         }
 340 }
 341
 342 /**
 343    Initialise the state for NTLMSSP signing.
 344 */
 345 NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
 346 {
 347         uint8_t p24[24];
 348         ZERO_STRUCT(p24);
 349
 350         DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
 351         debug_ntlmssp_flags(ntlmssp_state->neg_flags);
 352
 353         if (!ntlmssp_state->session_key.length) {
 354                 DEBUG(3, ("NO session key, cannot intialise signing\n"));
 355                 return NT_STATUS_NO_USER_SESSION_KEY;
 356         }
 357
 358         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 359         {
 360                 DATA_BLOB weak_session_key = ntlmssp_state->session_key;
 361                 const char *send_sign_const;
 362                 const char *send_seal_const;
 363                 const char *recv_sign_const;
 364                 const char *recv_seal_const;
 365
 366                 switch (ntlmssp_state->role) {
 367                 case NTLMSSP_CLIENT:
 368                         send_sign_const = CLI_SIGN;
 369                         send_seal_const = CLI_SEAL;
 370                         recv_sign_const = SRV_SIGN;
 371                         recv_seal_const = SRV_SEAL;
 372                         break;
 373                 case NTLMSSP_SERVER:
 374                         send_sign_const = SRV_SIGN;
 375                         send_seal_const = SRV_SEAL;
 376                         recv_sign_const = CLI_SIGN;
 377                         recv_seal_const = CLI_SEAL;
 378                         break;
 379                 default:
 380                         return NT_STATUS_INTERNAL_ERROR;
 381                 }
 382
 383                 /**
 384                    Weaken NTLMSSP keys to cope with down-level clients, servers and export restrictions.
 385
 386                    We probably should have some parameters to control this, once we get NTLM2 working.
 387                 */
 388
 389
 390                 if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
 391
 392                 } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 393                         weak_session_key.length = 6;
 394                 } else { /* forty bits */
 395                         weak_session_key.length = 5;
 396                 }
 397                 dump_data_pw("NTLMSSP weakend master key:\n",
 398                              weak_session_key.data,
 399                              weak_session_key.length);
 400
 401                 /* SEND */
 402                 calc_ntlmv2_key(ntlmssp_state,
 403                                 &ntlmssp_state->send_sign_key,
 404                                 ntlmssp_state->session_key, send_sign_const);
 405                 dump_data_pw("NTLMSSP send sign key:\n",
 406                              ntlmssp_state->send_sign_key.data,
 407                              ntlmssp_state->send_sign_key.length);
 408
 409                 calc_ntlmv2_key(ntlmssp_state,
 410                                 &ntlmssp_state->send_seal_key,
 411                                 weak_session_key, send_seal_const);
 412                 dump_data_pw("NTLMSSP send seal key:\n",
 413                              ntlmssp_state->send_seal_key.data,
 414                              ntlmssp_state->send_seal_key.length);
 415
 416                 arcfour_init(ntlmssp_state->send_seal_hash,
 417                              &ntlmssp_state->send_seal_key);
 418
 419                 dump_data_pw("NTLMSSP send sesl hash:\n",
 420                              ntlmssp_state->send_seal_hash,
 421                              sizeof(ntlmssp_state->send_seal_hash));
 422
 423                 /* RECV */
 424                 calc_ntlmv2_key(ntlmssp_state,
 425                                 &ntlmssp_state->recv_sign_key,
 426                                 ntlmssp_state->session_key, recv_sign_const);
 427                 dump_data_pw("NTLMSSP recv sign key:\n",
 428                              ntlmssp_state->recv_sign_key.data,
 429                              ntlmssp_state->recv_sign_key.length);
 430
 431                 calc_ntlmv2_key(ntlmssp_state,
 432                                 &ntlmssp_state->recv_seal_key,
 433                                 weak_session_key, recv_seal_const);
 434                 dump_data_pw("NTLMSSP recv seal key:\n",
 435                              ntlmssp_state->recv_seal_key.data,
 436                              ntlmssp_state->recv_seal_key.length);
 437                 arcfour_init(ntlmssp_state->recv_seal_hash,
 438                              &ntlmssp_state->recv_seal_key);
 439
 440                 dump_data_pw("NTLMSSP receive seal hash:\n",
 441                              ntlmssp_state->recv_seal_hash,
 442                              sizeof(ntlmssp_state->recv_seal_hash));
 443         } else {
 444                 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
 445
 446                 arcfour_init(ntlmssp_state->ntlmssp_hash,
 447                              &ntlmssp_state->session_key);
 448                 dump_data_pw("NTLMSSP hash:\n", ntlmssp_state->ntlmssp_hash,
 449                              sizeof(ntlmssp_state->ntlmssp_hash));
 450         }
 451
 452         ntlmssp_state->ntlm_seq_num = 0;
 453         ntlmssp_state->ntlm2_send_seq_num = 0;
 454         ntlmssp_state->ntlm2_recv_seq_num = 0;
 455
 456         return NT_STATUS_OK;
 457 }
 458
 459 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security)
 460 {
 461         return NTLMSSP_SIG_SIZE;
 462 }
 463
 464 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
 465                              TALLOC_CTX *sig_mem_ctx,
 466                              const DATA_BLOB *in,
 467                              DATA_BLOB *out)
 468 {
 469         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 470         DATA_BLOB sig;
 471         NTSTATUS nt_status;
 472
 473         if (gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 474
 475                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 476                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 477
 478                 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
 479                                                        out->data + NTLMSSP_SIG_SIZE,
 480                                                        out->length - NTLMSSP_SIG_SIZE,
 481                                                        out->data + NTLMSSP_SIG_SIZE,
 482                                                        out->length - NTLMSSP_SIG_SIZE,
 483                                                        &sig);
 484
 485                 if (NT_STATUS_IS_OK(nt_status)) {
 486                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 487                 }
 488                 return nt_status;
 489
 490         } else if ((gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN)
 491                    || (gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN)) {
 492
 493                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 494                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 495
 496                 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
 497                                                 out->data + NTLMSSP_SIG_SIZE,
 498                                                 out->length - NTLMSSP_SIG_SIZE,
 499                                                 out->data + NTLMSSP_SIG_SIZE,
 500                                                 out->length - NTLMSSP_SIG_SIZE,
 501                                                 &sig);
 502
 503                 if (NT_STATUS_IS_OK(nt_status)) {
 504                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 505                 }
 506                 return nt_status;
 507
 508         } else {
 509                 *out = *in;
 510                 return NT_STATUS_OK;
 511         }
 512 }
 513
 514
 515 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
 516                                TALLOC_CTX *sig_mem_ctx,
 517                                const DATA_BLOB *in,
 518                                DATA_BLOB *out)
 519 {
 520         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 521         DATA_BLOB sig;
 522
 523         if (gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 524                 if (in->length < NTLMSSP_SIG_SIZE) {
 525                         return NT_STATUS_INVALID_PARAMETER;
 526                 }
 527                 sig.data = in->data;
 528                 sig.length = NTLMSSP_SIG_SIZE;
 529
 530                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 531
 532                 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
 533                                                     out->data, out->length,
 534                                                     out->data, out->length,
 535                                                     &sig);
 536
 537         } else if ((gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN)
 538                    || (gensec_ntlmssp_state->ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN)) {
 539                 if (in->length < NTLMSSP_SIG_SIZE) {
 540                         return NT_STATUS_INVALID_PARAMETER;
 541                 }
 542                 sig.data = in->data;
 543                 sig.length = NTLMSSP_SIG_SIZE;
 544
 545                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 546
 547                 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
 548                                             out->data, out->length,
 549                                             out->data, out->length,
 550                                             &sig);
 551         } else {
 552                 *out = *in;
 553                 return NT_STATUS_OK;
 554         }
 555 }
 556