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, (const uint8_t *)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 gensec_ntlmssp_state *gensec_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 (gensec_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, gensec_ntlmssp_state->crypt.ntlm2.send_seq_num);
  82                         gensec_ntlmssp_state->crypt.ntlm2.send_seq_num++;
  83                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
  84                                                  gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length, &ctx);
  85                         break;
  86                 case NTLMSSP_RECEIVE:
  87                         SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num);
  88                         gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num++;
  89                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
  90                                                  gensec_ntlmssp_state->crypt.ntlm2.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 && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
  98                         switch (direction) {
  99                         case NTLMSSP_SEND:
 100                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8);
 101                                 break;
 102                         case NTLMSSP_RECEIVE:
 103                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, 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, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 116                         return NT_STATUS_NO_MEMORY;
 117                 }
 118                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 119
 120                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, 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
 134         return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 135                                              data, length,
 136                                              whole_pdu, pdu_length,
 137                                              NTLMSSP_SEND, sig, True);
 138 }
 139
 140 /**
 141  * Check the signature of an incoming packet
 142  *
 143  */
 144
 145 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
 146                                      TALLOC_CTX *sig_mem_ctx,
 147                                      const uint8_t *data, size_t length,
 148                                      const uint8_t *whole_pdu, size_t pdu_length,
 149                                      const DATA_BLOB *sig)
 150 {
 151         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 152
 153         DATA_BLOB local_sig;
 154         NTSTATUS nt_status;
 155
 156         if (!gensec_ntlmssp_state->session_key.length) {
 157                 DEBUG(3, ("NO session key, cannot check packet signature\n"));
 158                 return NT_STATUS_NO_USER_SESSION_KEY;
 159         }
 160
 161         if (sig->length < 8) {
 162                 DEBUG(0, ("NTLMSSP packet check failed due to short signature (%lu bytes)!\n",
 163                           (unsigned long)sig->length));
 164         }
 165
 166         nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 167                                                   data, length,
 168                                                   whole_pdu, pdu_length,
 169                                                   NTLMSSP_RECEIVE, &local_sig, True);
 170
 171         if (!NT_STATUS_IS_OK(nt_status)) {
 172                 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
 173                 return nt_status;
 174         }
 175
 176         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 177                 if (local_sig.length != sig->length ||
 178                     memcmp(local_sig.data,
 179                            sig->data, sig->length) != 0) {
 180                         DEBUG(5, ("BAD SIG NTLM2: wanted signature of\n"));
 181                         dump_data(5, local_sig.data, local_sig.length);
 182
 183                         DEBUG(5, ("BAD SIG: got signature of\n"));
 184                         dump_data(5, sig->data, sig->length);
 185
 186                         DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
 187                         return NT_STATUS_ACCESS_DENIED;
 188                 }
 189         } else {
 190                 if (local_sig.length != sig->length ||
 191                     memcmp(local_sig.data + 8,
 192                            sig->data + 8, sig->length - 8) != 0) {
 193                         DEBUG(5, ("BAD SIG NTLM1: wanted signature of\n"));
 194                         dump_data(5, local_sig.data, local_sig.length);
 195
 196                         DEBUG(5, ("BAD SIG: got signature of\n"));
 197                         dump_data(5, sig->data, sig->length);
 198
 199                         DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
 200                         return NT_STATUS_ACCESS_DENIED;
 201                 }
 202         }
 203         dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
 204
 205         return NT_STATUS_OK;
 206 }
 207
 208
 209 /**
 210  * Seal data with the NTLMSSP algorithm
 211  *
 212  */
 213
 214 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
 215                                     TALLOC_CTX *sig_mem_ctx,
 216                                     uint8_t *data, size_t length,
 217                                     const uint8_t *whole_pdu, size_t pdu_length,
 218                                     DATA_BLOB *sig)
 219 {
 220         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 221         NTSTATUS nt_status;
 222         if (!gensec_ntlmssp_state->session_key.length) {
 223                 DEBUG(3, ("NO session key, cannot seal packet\n"));
 224                 return NT_STATUS_NO_USER_SESSION_KEY;
 225         }
 226
 227         DEBUG(10,("ntlmssp_seal_data: seal\n"));
 228         dump_data_pw("ntlmssp clear data\n", data, length);
 229         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 230                 /* The order of these two operations matters - we must first seal the packet,
 231                    then seal the sequence number - this is becouse the send_seal_hash is not
 232                    constant, but is is rather updated with each iteration */
 233                 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 234                                                           data, length,
 235                                                           whole_pdu, pdu_length,
 236                                                           NTLMSSP_SEND, sig, False);
 237                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
 238                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 239                         arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
 240                 }
 241         } else {
 242                 uint32_t crc;
 243                 crc = crc32_calc_buffer(data, length);
 244                 if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 245                         return NT_STATUS_NO_MEMORY;
 246                 }
 247
 248                 /* The order of these two operations matters - we must
 249                    first seal the packet, then seal the sequence
 250                    number - this is becouse the ntlmssp_hash is not
 251                    constant, but is is rather updated with each
 252                    iteration */
 253
 254                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 255                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
 256                 /* increment counter on send */
 257                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 258                 nt_status = NT_STATUS_OK;
 259         }
 260         dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
 261         dump_data_pw("ntlmssp sealed data\n", data, length);
 262
 263
 264         return nt_status;
 265 }
 266
 267 /**
 268  * Unseal data with the NTLMSSP algorithm
 269  *
 270  */
 271
 272 /*
 273   wrappers for the ntlmssp_*() functions
 274 */
 275 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
 276                                       TALLOC_CTX *sig_mem_ctx,
 277                                       uint8_t *data, size_t length,
 278                                       const uint8_t *whole_pdu, size_t pdu_length,
 279                                       const DATA_BLOB *sig)
 280 {
 281         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 282         if (!gensec_ntlmssp_state->session_key.length) {
 283                 DEBUG(3, ("NO session key, cannot unseal packet\n"));
 284                 return NT_STATUS_NO_USER_SESSION_KEY;
 285         }
 286
 287         dump_data_pw("ntlmssp sealed data\n", data, length);
 288         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 289                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
 290         } else {
 291                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 292         }
 293         dump_data_pw("ntlmssp clear data\n", data, length);
 294         return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 295 }
 296
 297 /**
 298    Initialise the state for NTLMSSP signing.
 299 */
 300 NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
 301 {
 302         uint8_t p24[24];
 303         ZERO_STRUCT(p24);
 304
 305         DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
 306         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 307
 308         if (!gensec_ntlmssp_state->session_key.length) {
 309                 DEBUG(3, ("NO session key, cannot intialise signing\n"));
 310                 return NT_STATUS_NO_USER_SESSION_KEY;
 311         }
 312
 313         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 314         {
 315                 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
 316                 const char *send_sign_const;
 317                 const char *send_seal_const;
 318                 const char *recv_sign_const;
 319                 const char *recv_seal_const;
 320
 321                 DATA_BLOB send_seal_key;
 322                 DATA_BLOB recv_seal_key;
 323
 324                 switch (gensec_ntlmssp_state->role) {
 325                 case NTLMSSP_CLIENT:
 326                         send_sign_const = CLI_SIGN;
 327                         send_seal_const = CLI_SEAL;
 328                         recv_sign_const = SRV_SIGN;
 329                         recv_seal_const = SRV_SEAL;
 330                         break;
 331                 case NTLMSSP_SERVER:
 332                         send_sign_const = SRV_SIGN;
 333                         send_seal_const = SRV_SEAL;
 334                         recv_sign_const = CLI_SIGN;
 335                         recv_seal_const = CLI_SEAL;
 336                         break;
 337                 default:
 338                         return NT_STATUS_INTERNAL_ERROR;
 339                 }
 340
 341                 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 342                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
 343                 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 344                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
 345
 346                 /**
 347                    Weaken NTLMSSP keys to cope with down-level
 348                    clients, servers and export restrictions.
 349
 350                    We probably should have some parameters to control
 351                    this, once we get NTLM2 working.
 352                 */
 353
 354                 /* Key weakening was not performed on the master key
 355                  * for NTLM2 (in ntlmssp_weaken_keys()), but must be
 356                  * done on the encryption subkeys only.  That is why
 357                  * we don't have this code for the ntlmv1 case.
 358                  */
 359
 360                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
 361
 362                 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 363                         weak_session_key.length = 6;
 364                 } else { /* forty bits */
 365                         weak_session_key.length = 5;
 366                 }
 367                 dump_data_pw("NTLMSSP weakend master key:\n",
 368                              weak_session_key.data,
 369                              weak_session_key.length);
 370
 371                 /* SEND */
 372                 calc_ntlmv2_key(gensec_ntlmssp_state,
 373                                 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key,
 374                                 gensec_ntlmssp_state->session_key, send_sign_const);
 375                 dump_data_pw("NTLMSSP send sign key:\n",
 376                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
 377                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
 378
 379                 calc_ntlmv2_key(gensec_ntlmssp_state,
 380                                 &send_seal_key,
 381                                 weak_session_key, send_seal_const);
 382                 dump_data_pw("NTLMSSP send seal key:\n",
 383                              send_seal_key.data,
 384                              send_seal_key.length);
 385
 386                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state,
 387                              &send_seal_key);
 388
 389                 dump_data_pw("NTLMSSP send sesl hash:\n",
 390                              gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox,
 391                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
 392
 393                 /* RECV */
 394                 calc_ntlmv2_key(gensec_ntlmssp_state,
 395                                 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key,
 396                                 gensec_ntlmssp_state->session_key, recv_sign_const);
 397                 dump_data_pw("NTLMSSP recv sign key:\n",
 398                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
 399                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
 400
 401                 calc_ntlmv2_key(gensec_ntlmssp_state,
 402                                 &recv_seal_key,
 403                                 weak_session_key, recv_seal_const);
 404                 dump_data_pw("NTLMSSP recv seal key:\n",
 405                              recv_seal_key.data,
 406                              recv_seal_key.length);
 407                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state,
 408                              &recv_seal_key);
 409
 410                 dump_data_pw("NTLMSSP receive seal hash:\n",
 411                              gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox,
 412                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
 413
 414                 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
 415                 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
 416
 417         } else {
 418                 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
 419
 420                 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 421                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
 422
 423                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state,
 424                              &gensec_ntlmssp_state->session_key);
 425                 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
 426                              sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
 427
 428                 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
 429         }
 430
 431         return NT_STATUS_OK;
 432 }
 433
 434 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security)
 435 {
 436         return NTLMSSP_SIG_SIZE;
 437 }
 438
 439 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
 440                              TALLOC_CTX *sig_mem_ctx,
 441                              const DATA_BLOB *in,
 442                              DATA_BLOB *out)
 443 {
 444         DATA_BLOB sig;
 445         NTSTATUS nt_status;
 446
 447         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 448
 449                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 450                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 451
 452                 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
 453                                                        out->data + NTLMSSP_SIG_SIZE,
 454                                                        out->length - NTLMSSP_SIG_SIZE,
 455                                                        out->data + NTLMSSP_SIG_SIZE,
 456                                                        out->length - NTLMSSP_SIG_SIZE,
 457                                                        &sig);
 458
 459                 if (NT_STATUS_IS_OK(nt_status)) {
 460                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 461                 }
 462                 return nt_status;
 463
 464         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 465
 466                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 467                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 468
 469                 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
 470                                                        out->data + NTLMSSP_SIG_SIZE,
 471                                                        out->length - NTLMSSP_SIG_SIZE,
 472                                                        out->data + NTLMSSP_SIG_SIZE,
 473                                                        out->length - NTLMSSP_SIG_SIZE,
 474                                                        &sig);
 475
 476                 if (NT_STATUS_IS_OK(nt_status)) {
 477                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 478                 }
 479                 return nt_status;
 480
 481         } else {
 482                 *out = *in;
 483                 return NT_STATUS_OK;
 484         }
 485 }
 486
 487
 488 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
 489                                TALLOC_CTX *sig_mem_ctx,
 490                                const DATA_BLOB *in,
 491                                DATA_BLOB *out)
 492 {
 493         DATA_BLOB sig;
 494
 495         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 496                 if (in->length < NTLMSSP_SIG_SIZE) {
 497                         return NT_STATUS_INVALID_PARAMETER;
 498                 }
 499                 sig.data = in->data;
 500                 sig.length = NTLMSSP_SIG_SIZE;
 501
 502                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 503
 504                 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
 505                                                     out->data, out->length,
 506                                                     out->data, out->length,
 507                                                     &sig);
 508
 509         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 510                 if (in->length < NTLMSSP_SIG_SIZE) {
 511                         return NT_STATUS_INVALID_PARAMETER;
 512                 }
 513                 sig.data = in->data;
 514                 sig.length = NTLMSSP_SIG_SIZE;
 515
 516                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 517
 518                 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
 519                                                    out->data, out->length,
 520                                                    out->data, out->length,
 521                                                    &sig);
 522         } else {
 523                 *out = *in;
 524                 return NT_STATUS_OK;
 525         }
 526 }
 527