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 3 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, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "includes.h"
  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"
  30
  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"
  35
  36 /**
  37  * Some notes on the NTLM2 code:
  38  *
  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.
  43  *
  44  */
  45
  46 static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx,
  47                             DATA_BLOB *subkey,
  48                             DATA_BLOB session_key,
  49                             const char *constant)
  50 {
  51         struct MD5Context ctx3;
  52         *subkey = data_blob_talloc(mem_ctx, NULL, 16);
  53         MD5Init(&ctx3);
  54         MD5Update(&ctx3, session_key.data, session_key.length);
  55         MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
  56         MD5Final(subkey->data, &ctx3);
  57 }
  58
  59 enum ntlmssp_direction {
  60         NTLMSSP_SEND,
  61         NTLMSSP_RECEIVE
  62 };
  63
  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)
  70 {
  71         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
  72
  73                 HMACMD5Context ctx;
  74                 uint8_t digest[16];
  75                 uint8_t seq_num[4];
  76
  77                 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
  78                 if (!sig->data) {
  79                         return NT_STATUS_NO_MEMORY;
  80                 }
  81
  82                 switch (direction) {
  83                 case NTLMSSP_SEND:
  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);
  88                         break;
  89                 case NTLMSSP_RECEIVE:
  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);
  94                         break;
  95                 }
  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);
  99
 100                 if (encrypt_sig && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 101                         switch (direction) {
 102                         case NTLMSSP_SEND:
 103                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8);
 104                                 break;
 105                         case NTLMSSP_RECEIVE:
 106                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, digest, 8);
 107                                 break;
 108                         }
 109                 }
 110
 111                 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
 112                 memcpy(sig->data + 4, digest, 8);
 113                 memcpy(sig->data + 12, seq_num, 4);
 114
 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);
 117
 118         } else {
 119                 uint32_t crc;
 120                 crc = crc32_calc_buffer(data, length);
 121                 if (!msrpc_gen(sig_mem_ctx,
 122                                sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 123                         return NT_STATUS_NO_MEMORY;
 124                 }
 125                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 126
 127                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
 128
 129                 DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length));
 130                 dump_data(11, sig->data, sig->length);
 131         }
 132         return NT_STATUS_OK;
 133 }
 134
 135 /* TODO: make this non-public */
 136 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
 137                                     TALLOC_CTX *sig_mem_ctx,
 138                                     const uint8_t *data, size_t length,
 139                                     const uint8_t *whole_pdu, size_t pdu_length,
 140                                     DATA_BLOB *sig)
 141 {
 142         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 143
 144         return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 145                                              data, length,
 146                                              whole_pdu, pdu_length,
 147                                              NTLMSSP_SEND, sig, true);
 148 }
 149
 150 /**
 151  * Check the signature of an incoming packet
 152  *
 153  */
 154
 155 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
 156                                      TALLOC_CTX *sig_mem_ctx,
 157                                      const uint8_t *data, size_t length,
 158                                      const uint8_t *whole_pdu, size_t pdu_length,
 159                                      const DATA_BLOB *sig)
 160 {
 161         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 162
 163         DATA_BLOB local_sig;
 164         NTSTATUS nt_status;
 165
 166         if (!gensec_ntlmssp_state->session_key.length) {
 167                 DEBUG(3, ("NO session key, cannot check packet signature\n"));
 168                 return NT_STATUS_NO_USER_SESSION_KEY;
 169         }
 170
 171         nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 172                                                   data, length,
 173                                                   whole_pdu, pdu_length,
 174                                                   NTLMSSP_RECEIVE, &local_sig, true);
 175
 176         if (!NT_STATUS_IS_OK(nt_status)) {
 177                 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
 178                 return nt_status;
 179         }
 180
 181         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 182                 if (local_sig.length != sig->length ||
 183                     memcmp(local_sig.data,
 184                            sig->data, sig->length) != 0) {
 185                         DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
 186                         dump_data(5, local_sig.data, local_sig.length);
 187
 188                         DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
 189                         dump_data(5, sig->data, sig->length);
 190
 191                         DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length));
 192                         return NT_STATUS_ACCESS_DENIED;
 193                 }
 194         } else {
 195                 if (local_sig.length != sig->length ||
 196                     memcmp(local_sig.data + 8,
 197                            sig->data + 8, sig->length - 8) != 0) {
 198                         DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length));
 199                         dump_data(5, local_sig.data, local_sig.length);
 200
 201                         DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length));
 202                         dump_data(5, sig->data, sig->length);
 203
 204                         DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length));
 205                         return NT_STATUS_ACCESS_DENIED;
 206                 }
 207         }
 208         dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
 209
 210         return NT_STATUS_OK;
 211 }
 212
 213
 214 /**
 215  * Seal data with the NTLMSSP algorithm
 216  *
 217  */
 218
 219 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
 220                                     TALLOC_CTX *sig_mem_ctx,
 221                                     uint8_t *data, size_t length,
 222                                     const uint8_t *whole_pdu, size_t pdu_length,
 223                                     DATA_BLOB *sig)
 224 {
 225         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 226         NTSTATUS nt_status;
 227         if (!gensec_ntlmssp_state->session_key.length) {
 228                 DEBUG(3, ("NO session key, cannot seal packet\n"));
 229                 return NT_STATUS_NO_USER_SESSION_KEY;
 230         }
 231
 232         DEBUG(10,("ntlmssp_seal_data: seal\n"));
 233         dump_data_pw("ntlmssp clear data\n", data, length);
 234         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 235                 /* The order of these two operations matters - we must first seal the packet,
 236                    then seal the sequence number - this is becouse the send_seal_hash is not
 237                    constant, but is is rather updated with each iteration */
 238                 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 239                                                           data, length,
 240                                                           whole_pdu, pdu_length,
 241                                                           NTLMSSP_SEND, sig, false);
 242                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
 243                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 244                         arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
 245                 }
 246         } else {
 247                 uint32_t crc;
 248                 crc = crc32_calc_buffer(data, length);
 249                 if (!msrpc_gen(sig_mem_ctx,
 250                                sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 251                         return NT_STATUS_NO_MEMORY;
 252                 }
 253
 254                 /* The order of these two operations matters - we must
 255                    first seal the packet, then seal the sequence
 256                    number - this is becouse the ntlmssp_hash is not
 257                    constant, but is is rather updated with each
 258                    iteration */
 259
 260                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 261                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
 262                 /* increment counter on send */
 263                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 264                 nt_status = NT_STATUS_OK;
 265         }
 266         dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
 267         dump_data_pw("ntlmssp sealed data\n", data, length);
 268
 269
 270         return nt_status;
 271 }
 272
 273 /**
 274  * Unseal data with the NTLMSSP algorithm
 275  *
 276  */
 277
 278 /*
 279   wrappers for the ntlmssp_*() functions
 280 */
 281 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
 282                                       TALLOC_CTX *sig_mem_ctx,
 283                                       uint8_t *data, size_t length,
 284                                       const uint8_t *whole_pdu, size_t pdu_length,
 285                                       const DATA_BLOB *sig)
 286 {
 287         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 288         if (!gensec_ntlmssp_state->session_key.length) {
 289                 DEBUG(3, ("NO session key, cannot unseal packet\n"));
 290                 return NT_STATUS_NO_USER_SESSION_KEY;
 291         }
 292
 293         dump_data_pw("ntlmssp sealed data\n", data, length);
 294         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 295                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
 296         } else {
 297                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 298         }
 299         dump_data_pw("ntlmssp clear data\n", data, length);
 300         return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 301 }
 302
 303 /**
 304    Initialise the state for NTLMSSP signing.
 305 */
 306 /* TODO: make this non-public */
 307 NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
 308 {
 309         TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state);
 310
 311         if (!mem_ctx) {
 312                 return NT_STATUS_NO_MEMORY;
 313         }
 314
 315         DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
 316         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 317
 318         if (gensec_ntlmssp_state->session_key.length < 8) {
 319                 talloc_free(mem_ctx);
 320                 DEBUG(3, ("NO session key, cannot intialise signing\n"));
 321                 return NT_STATUS_NO_USER_SESSION_KEY;
 322         }
 323
 324         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 325         {
 326                 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
 327                 const char *send_sign_const;
 328                 const char *send_seal_const;
 329                 const char *recv_sign_const;
 330                 const char *recv_seal_const;
 331
 332                 DATA_BLOB send_seal_key;
 333                 DATA_BLOB recv_seal_key;
 334
 335                 switch (gensec_ntlmssp_state->role) {
 336                 case NTLMSSP_CLIENT:
 337                         send_sign_const = CLI_SIGN;
 338                         send_seal_const = CLI_SEAL;
 339                         recv_sign_const = SRV_SIGN;
 340                         recv_seal_const = SRV_SEAL;
 341                         break;
 342                 case NTLMSSP_SERVER:
 343                         send_sign_const = SRV_SIGN;
 344                         send_seal_const = SRV_SEAL;
 345                         recv_sign_const = CLI_SIGN;
 346                         recv_seal_const = CLI_SEAL;
 347                         break;
 348                 default:
 349                         talloc_free(mem_ctx);
 350                         return NT_STATUS_INTERNAL_ERROR;
 351                 }
 352
 353                 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 354                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
 355                 gensec_ntlmssp_state->crypt.ntlm2.recv_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
 358                 /**
 359                    Weaken NTLMSSP keys to cope with down-level
 360                    clients, servers and export restrictions.
 361
 362                    We probably should have some parameters to control
 363                    this, once we get NTLM2 working.
 364                 */
 365
 366                 /* Key weakening was not performed on the master key
 367                  * for NTLM2 (in ntlmssp_weaken_keys()), but must be
 368                  * done on the encryption subkeys only.  That is why
 369                  * we don't have this code for the ntlmv1 case.
 370                  */
 371
 372                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
 373
 374                 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 375                         weak_session_key.length = 7;
 376                 } else { /* forty bits */
 377                         weak_session_key.length = 5;
 378                 }
 379                 dump_data_pw("NTLMSSP weakend master key:\n",
 380                              weak_session_key.data,
 381                              weak_session_key.length);
 382
 383                 /* SEND: sign key */
 384                 calc_ntlmv2_key(gensec_ntlmssp_state,
 385                                 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key,
 386                                 gensec_ntlmssp_state->session_key, send_sign_const);
 387                 dump_data_pw("NTLMSSP send sign key:\n",
 388                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
 389                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
 390
 391                 /* SEND: seal ARCFOUR pad */
 392                 calc_ntlmv2_key(mem_ctx,
 393                                 &send_seal_key,
 394                                 weak_session_key, send_seal_const);
 395                 dump_data_pw("NTLMSSP send seal key:\n",
 396                              send_seal_key.data,
 397                              send_seal_key.length);
 398                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state,
 399                              &send_seal_key);
 400                 dump_data_pw("NTLMSSP send sesl hash:\n",
 401                              gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox,
 402                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
 403
 404                 /* RECV: sign key */
 405                 calc_ntlmv2_key(gensec_ntlmssp_state,
 406                                 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key,
 407                                 gensec_ntlmssp_state->session_key, recv_sign_const);
 408                 dump_data_pw("NTLMSSP recv sign key:\n",
 409                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
 410                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
 411
 412                 /* RECV: seal ARCFOUR pad */
 413                 calc_ntlmv2_key(mem_ctx,
 414                                 &recv_seal_key,
 415                                 weak_session_key, recv_seal_const);
 416                 dump_data_pw("NTLMSSP recv seal key:\n",
 417                              recv_seal_key.data,
 418                              recv_seal_key.length);
 419                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state,
 420                              &recv_seal_key);
 421                 dump_data_pw("NTLMSSP receive seal hash:\n",
 422                              gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox,
 423                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
 424
 425                 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
 426                 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
 427
 428         } else {
 429                 DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx);
 430                 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
 431
 432                 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 433                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
 434
 435                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state,
 436                              &weak_session_key);
 437                 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
 438                              sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
 439
 440                 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
 441         }
 442
 443         talloc_free(mem_ctx);
 444         return NT_STATUS_OK;
 445 }
 446
 447 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size)
 448 {
 449         return NTLMSSP_SIG_SIZE;
 450 }
 451
 452 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
 453                              TALLOC_CTX *sig_mem_ctx,
 454                              const DATA_BLOB *in,
 455                              DATA_BLOB *out)
 456 {
 457         DATA_BLOB sig;
 458         NTSTATUS nt_status;
 459
 460         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 461
 462                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 463                 if (!out->data) {
 464                         return NT_STATUS_NO_MEMORY;
 465                 }
 466                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 467
 468                 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
 469                                                        out->data + NTLMSSP_SIG_SIZE,
 470                                                        out->length - NTLMSSP_SIG_SIZE,
 471                                                        out->data + NTLMSSP_SIG_SIZE,
 472                                                        out->length - NTLMSSP_SIG_SIZE,
 473                                                        &sig);
 474
 475                 if (NT_STATUS_IS_OK(nt_status)) {
 476                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 477                 }
 478                 return nt_status;
 479
 480         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 481
 482                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 483                 if (!out->data) {
 484                         return NT_STATUS_NO_MEMORY;
 485                 }
 486                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 487
 488                 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
 489                                                        out->data + NTLMSSP_SIG_SIZE,
 490                                                        out->length - NTLMSSP_SIG_SIZE,
 491                                                        out->data + NTLMSSP_SIG_SIZE,
 492                                                        out->length - NTLMSSP_SIG_SIZE,
 493                                                        &sig);
 494
 495                 if (NT_STATUS_IS_OK(nt_status)) {
 496                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 497                 }
 498                 return nt_status;
 499
 500         } else {
 501                 *out = *in;
 502                 return NT_STATUS_OK;
 503         }
 504 }
 505
 506
 507 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
 508                                TALLOC_CTX *sig_mem_ctx,
 509                                const DATA_BLOB *in,
 510                                DATA_BLOB *out)
 511 {
 512         DATA_BLOB sig;
 513
 514         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 515                 if (in->length < NTLMSSP_SIG_SIZE) {
 516                         return NT_STATUS_INVALID_PARAMETER;
 517                 }
 518                 sig.data = in->data;
 519                 sig.length = NTLMSSP_SIG_SIZE;
 520
 521                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 522
 523                 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
 524                                                     out->data, out->length,
 525                                                     out->data, out->length,
 526                                                     &sig);
 527
 528         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 529                 if (in->length < NTLMSSP_SIG_SIZE) {
 530                         return NT_STATUS_INVALID_PARAMETER;
 531                 }
 532                 sig.data = in->data;
 533                 sig.length = NTLMSSP_SIG_SIZE;
 534
 535                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 536
 537                 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
 538                                                    out->data, out->length,
 539                                                    out->data, out->length,
 540                                                    &sig);
 541         } else {
 542                 *out = *in;
 543                 return NT_STATUS_OK;
 544         }
 545 }
 546