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/ntlmssp/ntlmssp.h"
  24 #include "../librpc/gen_ndr/ntlmssp.h"
  25 #include "../libcli/auth/libcli_auth.h"
  26 #include "../lib/crypto/crypto.h"
  27 #include "auth/gensec/gensec.h"
  28
  29 #define CLI_SIGN "session key to client-to-server signing key magic constant"
  30 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
  31 #define SRV_SIGN "session key to server-to-client signing key magic constant"
  32 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
  33
  34 /**
  35  * Some notes on the NTLM2 code:
  36  *
  37  * NTLM2 is a AEAD system.  This means that the data encrypted is not
  38  * all the data that is signed.  In DCE-RPC case, the headers of the
  39  * DCE-RPC packets are also signed.  This prevents some of the
  40  * fun-and-games one might have by changing them.
  41  *
  42  */
  43
  44 static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx,
  45                             DATA_BLOB *subkey,
  46                             DATA_BLOB session_key,
  47                             const char *constant)
  48 {
  49         struct MD5Context ctx3;
  50         *subkey = data_blob_talloc(mem_ctx, NULL, 16);
  51         MD5Init(&ctx3);
  52         MD5Update(&ctx3, session_key.data, session_key.length);
  53         MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
  54         MD5Final(subkey->data, &ctx3);
  55 }
  56
  57 enum ntlmssp_direction {
  58         NTLMSSP_SEND,
  59         NTLMSSP_RECEIVE
  60 };
  61
  62 static NTSTATUS ntlmssp_make_packet_signature(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
  63                                               TALLOC_CTX *sig_mem_ctx,
  64                                               const uint8_t *data, size_t length,
  65                                               const uint8_t *whole_pdu, size_t pdu_length,
  66                                               enum ntlmssp_direction direction,
  67                                               DATA_BLOB *sig, bool encrypt_sig)
  68 {
  69         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
  70
  71                 HMACMD5Context ctx;
  72                 uint8_t digest[16];
  73                 uint8_t seq_num[4];
  74
  75                 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
  76                 if (!sig->data) {
  77                         return NT_STATUS_NO_MEMORY;
  78                 }
  79
  80                 switch (direction) {
  81                 case NTLMSSP_SEND:
  82                         SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.send_seq_num);
  83                         gensec_ntlmssp_state->crypt.ntlm2.send_seq_num++;
  84                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
  85                                                  gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length, &ctx);
  86                         break;
  87                 case NTLMSSP_RECEIVE:
  88                         SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num);
  89                         gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num++;
  90                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
  91                                                  gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length, &ctx);
  92                         break;
  93                 }
  94                 hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
  95                 hmac_md5_update(whole_pdu, pdu_length, &ctx);
  96                 hmac_md5_final(digest, &ctx);
  97
  98                 if (encrypt_sig && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
  99                         switch (direction) {
 100                         case NTLMSSP_SEND:
 101                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8);
 102                                 break;
 103                         case NTLMSSP_RECEIVE:
 104                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, digest, 8);
 105                                 break;
 106                         }
 107                 }
 108
 109                 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
 110                 memcpy(sig->data + 4, digest, 8);
 111                 memcpy(sig->data + 12, seq_num, 4);
 112
 113                 DEBUG(10, ("NTLM2: created signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
 114                 dump_data(11, sig->data, sig->length);
 115
 116         } else {
 117                 uint32_t crc;
 118                 crc = crc32_calc_buffer(data, length);
 119                 if (!msrpc_gen(sig_mem_ctx,
 120                                sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 121                         return NT_STATUS_NO_MEMORY;
 122                 }
 123                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 124
 125                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
 126
 127                 DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length));
 128                 dump_data(11, sig->data, sig->length);
 129         }
 130         return NT_STATUS_OK;
 131 }
 132
 133 /* TODO: make this non-public */
 134 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
 135                                     TALLOC_CTX *sig_mem_ctx,
 136                                     const uint8_t *data, size_t length,
 137                                     const uint8_t *whole_pdu, size_t pdu_length,
 138                                     DATA_BLOB *sig)
 139 {
 140         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 141
 142         return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 143                                              data, length,
 144                                              whole_pdu, pdu_length,
 145                                              NTLMSSP_SEND, sig, true);
 146 }
 147
 148 /**
 149  * Check the signature of an incoming packet
 150  *
 151  */
 152
 153 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
 154                                      TALLOC_CTX *sig_mem_ctx,
 155                                      const uint8_t *data, size_t length,
 156                                      const uint8_t *whole_pdu, size_t pdu_length,
 157                                      const DATA_BLOB *sig)
 158 {
 159         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 160
 161         DATA_BLOB local_sig;
 162         NTSTATUS nt_status;
 163
 164         if (!gensec_ntlmssp_state->session_key.length) {
 165                 DEBUG(3, ("NO session key, cannot check packet signature\n"));
 166                 return NT_STATUS_NO_USER_SESSION_KEY;
 167         }
 168
 169         nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 170                                                   data, length,
 171                                                   whole_pdu, pdu_length,
 172                                                   NTLMSSP_RECEIVE, &local_sig, true);
 173
 174         if (!NT_STATUS_IS_OK(nt_status)) {
 175                 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
 176                 return nt_status;
 177         }
 178
 179         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 180                 if (local_sig.length != sig->length ||
 181                     memcmp(local_sig.data,
 182                            sig->data, sig->length) != 0) {
 183                         DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
 184                         dump_data(5, local_sig.data, local_sig.length);
 185
 186                         DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
 187                         dump_data(5, sig->data, sig->length);
 188
 189                         DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length));
 190                         return NT_STATUS_ACCESS_DENIED;
 191                 }
 192         } else {
 193                 if (local_sig.length != sig->length ||
 194                     memcmp(local_sig.data + 8,
 195                            sig->data + 8, sig->length - 8) != 0) {
 196                         DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length));
 197                         dump_data(5, local_sig.data, local_sig.length);
 198
 199                         DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length));
 200                         dump_data(5, sig->data, sig->length);
 201
 202                         DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length));
 203                         return NT_STATUS_ACCESS_DENIED;
 204                 }
 205         }
 206         dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
 207
 208         return NT_STATUS_OK;
 209 }
 210
 211
 212 /**
 213  * Seal data with the NTLMSSP algorithm
 214  *
 215  */
 216
 217 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security,
 218                                     TALLOC_CTX *sig_mem_ctx,
 219                                     uint8_t *data, size_t length,
 220                                     const uint8_t *whole_pdu, size_t pdu_length,
 221                                     DATA_BLOB *sig)
 222 {
 223         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 224         NTSTATUS nt_status;
 225         if (!gensec_ntlmssp_state->session_key.length) {
 226                 DEBUG(3, ("NO session key, cannot seal packet\n"));
 227                 return NT_STATUS_NO_USER_SESSION_KEY;
 228         }
 229
 230         DEBUG(10,("ntlmssp_seal_data: seal\n"));
 231         dump_data_pw("ntlmssp clear data\n", data, length);
 232         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 233                 /* The order of these two operations matters - we must first seal the packet,
 234                    then seal the sequence number - this is becouse the send_seal_hash is not
 235                    constant, but is is rather updated with each iteration */
 236                 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx,
 237                                                           data, length,
 238                                                           whole_pdu, pdu_length,
 239                                                           NTLMSSP_SEND, sig, false);
 240                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
 241                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 242                         arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
 243                 }
 244         } else {
 245                 uint32_t crc;
 246                 crc = crc32_calc_buffer(data, length);
 247                 if (!msrpc_gen(sig_mem_ctx,
 248                                sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
 249                         return NT_STATUS_NO_MEMORY;
 250                 }
 251
 252                 /* The order of these two operations matters - we must
 253                    first seal the packet, then seal the sequence
 254                    number - this is becouse the ntlmssp_hash is not
 255                    constant, but is is rather updated with each
 256                    iteration */
 257
 258                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 259                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
 260                 /* increment counter on send */
 261                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
 262                 nt_status = NT_STATUS_OK;
 263         }
 264         dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
 265         dump_data_pw("ntlmssp sealed data\n", data, length);
 266
 267
 268         return nt_status;
 269 }
 270
 271 /**
 272  * Unseal data with the NTLMSSP algorithm
 273  *
 274  */
 275
 276 /*
 277   wrappers for the ntlmssp_*() functions
 278 */
 279 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
 280                                       TALLOC_CTX *sig_mem_ctx,
 281                                       uint8_t *data, size_t length,
 282                                       const uint8_t *whole_pdu, size_t pdu_length,
 283                                       const DATA_BLOB *sig)
 284 {
 285         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 286         if (!gensec_ntlmssp_state->session_key.length) {
 287                 DEBUG(3, ("NO session key, cannot unseal packet\n"));
 288                 return NT_STATUS_NO_USER_SESSION_KEY;
 289         }
 290
 291         dump_data_pw("ntlmssp sealed data\n", data, length);
 292         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 293                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
 294         } else {
 295                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
 296         }
 297         dump_data_pw("ntlmssp clear data\n", data, length);
 298         return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 299 }
 300
 301 /**
 302    Initialise the state for NTLMSSP signing.
 303 */
 304 /* TODO: make this non-public */
 305 NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
 306 {
 307         TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state);
 308
 309         if (!mem_ctx) {
 310                 return NT_STATUS_NO_MEMORY;
 311         }
 312
 313         DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
 314         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 315
 316         if (gensec_ntlmssp_state->session_key.length < 8) {
 317                 talloc_free(mem_ctx);
 318                 DEBUG(3, ("NO session key, cannot intialise signing\n"));
 319                 return NT_STATUS_NO_USER_SESSION_KEY;
 320         }
 321
 322         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 323         {
 324                 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
 325                 const char *send_sign_const;
 326                 const char *send_seal_const;
 327                 const char *recv_sign_const;
 328                 const char *recv_seal_const;
 329
 330                 DATA_BLOB send_seal_key;
 331                 DATA_BLOB recv_seal_key;
 332
 333                 switch (gensec_ntlmssp_state->role) {
 334                 case NTLMSSP_CLIENT:
 335                         send_sign_const = CLI_SIGN;
 336                         send_seal_const = CLI_SEAL;
 337                         recv_sign_const = SRV_SIGN;
 338                         recv_seal_const = SRV_SEAL;
 339                         break;
 340                 case NTLMSSP_SERVER:
 341                         send_sign_const = SRV_SIGN;
 342                         send_seal_const = SRV_SEAL;
 343                         recv_sign_const = CLI_SIGN;
 344                         recv_seal_const = CLI_SEAL;
 345                         break;
 346                 default:
 347                         talloc_free(mem_ctx);
 348                         return NT_STATUS_INTERNAL_ERROR;
 349                 }
 350
 351                 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 352                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
 353                 gensec_ntlmssp_state->crypt.ntlm2.recv_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
 356                 /**
 357                    Weaken NTLMSSP keys to cope with down-level
 358                    clients, servers and export restrictions.
 359
 360                    We probably should have some parameters to control
 361                    this, once we get NTLM2 working.
 362                 */
 363
 364                 /* Key weakening was not performed on the master key
 365                  * for NTLM2 (in ntlmssp_weaken_keys()), but must be
 366                  * done on the encryption subkeys only.  That is why
 367                  * we don't have this code for the ntlmv1 case.
 368                  */
 369
 370                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
 371
 372                 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 373                         weak_session_key.length = 7;
 374                 } else { /* forty bits */
 375                         weak_session_key.length = 5;
 376                 }
 377                 dump_data_pw("NTLMSSP weakend master key:\n",
 378                              weak_session_key.data,
 379                              weak_session_key.length);
 380
 381                 /* SEND: sign key */
 382                 calc_ntlmv2_key(gensec_ntlmssp_state,
 383                                 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key,
 384                                 gensec_ntlmssp_state->session_key, send_sign_const);
 385                 dump_data_pw("NTLMSSP send sign key:\n",
 386                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data,
 387                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
 388
 389                 /* SEND: seal ARCFOUR pad */
 390                 calc_ntlmv2_key(mem_ctx,
 391                                 &send_seal_key,
 392                                 weak_session_key, send_seal_const);
 393                 dump_data_pw("NTLMSSP send seal key:\n",
 394                              send_seal_key.data,
 395                              send_seal_key.length);
 396                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state,
 397                              &send_seal_key);
 398                 dump_data_pw("NTLMSSP send sesl hash:\n",
 399                              gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox,
 400                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
 401
 402                 /* RECV: sign key */
 403                 calc_ntlmv2_key(gensec_ntlmssp_state,
 404                                 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key,
 405                                 gensec_ntlmssp_state->session_key, recv_sign_const);
 406                 dump_data_pw("NTLMSSP recv sign key:\n",
 407                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
 408                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
 409
 410                 /* RECV: seal ARCFOUR pad */
 411                 calc_ntlmv2_key(mem_ctx,
 412                                 &recv_seal_key,
 413                                 weak_session_key, recv_seal_const);
 414                 dump_data_pw("NTLMSSP recv seal key:\n",
 415                              recv_seal_key.data,
 416                              recv_seal_key.length);
 417                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state,
 418                              &recv_seal_key);
 419                 dump_data_pw("NTLMSSP receive seal hash:\n",
 420                              gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox,
 421                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
 422
 423                 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
 424                 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
 425
 426         } else {
 427                 DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx);
 428                 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
 429
 430                 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
 431                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
 432
 433                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state,
 434                              &weak_session_key);
 435                 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
 436                              sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
 437
 438                 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
 439         }
 440
 441         talloc_free(mem_ctx);
 442         return NT_STATUS_OK;
 443 }
 444
 445 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size)
 446 {
 447         return NTLMSSP_SIG_SIZE;
 448 }
 449
 450 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security,
 451                              TALLOC_CTX *sig_mem_ctx,
 452                              const DATA_BLOB *in,
 453                              DATA_BLOB *out)
 454 {
 455         DATA_BLOB sig;
 456         NTSTATUS nt_status;
 457
 458         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 459
 460                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 461                 if (!out->data) {
 462                         return NT_STATUS_NO_MEMORY;
 463                 }
 464                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 465
 466                 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx,
 467                                                        out->data + NTLMSSP_SIG_SIZE,
 468                                                        out->length - NTLMSSP_SIG_SIZE,
 469                                                        out->data + NTLMSSP_SIG_SIZE,
 470                                                        out->length - NTLMSSP_SIG_SIZE,
 471                                                        &sig);
 472
 473                 if (NT_STATUS_IS_OK(nt_status)) {
 474                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 475                 }
 476                 return nt_status;
 477
 478         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 479
 480                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
 481                 if (!out->data) {
 482                         return NT_STATUS_NO_MEMORY;
 483                 }
 484                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
 485
 486                 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx,
 487                                                        out->data + NTLMSSP_SIG_SIZE,
 488                                                        out->length - NTLMSSP_SIG_SIZE,
 489                                                        out->data + NTLMSSP_SIG_SIZE,
 490                                                        out->length - NTLMSSP_SIG_SIZE,
 491                                                        &sig);
 492
 493                 if (NT_STATUS_IS_OK(nt_status)) {
 494                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
 495                 }
 496                 return nt_status;
 497
 498         } else {
 499                 *out = *in;
 500                 return NT_STATUS_OK;
 501         }
 502 }
 503
 504
 505 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security,
 506                                TALLOC_CTX *sig_mem_ctx,
 507                                const DATA_BLOB *in,
 508                                DATA_BLOB *out)
 509 {
 510         DATA_BLOB sig;
 511
 512         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 513                 if (in->length < NTLMSSP_SIG_SIZE) {
 514                         return NT_STATUS_INVALID_PARAMETER;
 515                 }
 516                 sig.data = in->data;
 517                 sig.length = NTLMSSP_SIG_SIZE;
 518
 519                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 520
 521                 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx,
 522                                                     out->data, out->length,
 523                                                     out->data, out->length,
 524                                                     &sig);
 525
 526         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 527                 struct gensec_ntlmssp_state *gensec_ntlmssp_state =
 528                 (struct gensec_ntlmssp_state *)gensec_security->private_data;
 529                 NTSTATUS status;
 530                 uint32_t ntlm_seqnum;
 531                 struct arcfour_state ntlm_state;
 532                 uint32_t ntlm2_seqnum_r;
 533                 uint8_t ntlm2_key_r[16];
 534                 struct arcfour_state ntlm2_state_r;
 535
 536                 if (in->length < NTLMSSP_SIG_SIZE) {
 537                         return NT_STATUS_INVALID_PARAMETER;
 538                 }
 539                 sig.data = in->data;
 540                 sig.length = NTLMSSP_SIG_SIZE;
 541                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
 542
 543                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 544                         ntlm2_seqnum_r = gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num;
 545                         ntlm2_state_r = *gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state;
 546                         memcpy(ntlm2_key_r,
 547                                gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
 548                                16);
 549                 } else {
 550                         ntlm_seqnum = gensec_ntlmssp_state->crypt.ntlm.seq_num;
 551                         ntlm_state = *gensec_ntlmssp_state->crypt.ntlm.arcfour_state;
 552                 }
 553
 554                 status = gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx,
 555                                                      out->data, out->length,
 556                                                      out->data, out->length,
 557                                                      &sig);
 558                 if (!NT_STATUS_IS_OK(status)) {
 559                         NTSTATUS check_status = status;
 560                         /*
 561                          * The Windows LDAP libraries seems to have a bug
 562                          * and always use sealing even if only signing was
 563                          * negotiated. So we need to fallback.
 564                          */
 565
 566                         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 567                                 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = ntlm2_seqnum_r;
 568                                 *gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = ntlm2_state_r;
 569                                 memcpy(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data,
 570                                        ntlm2_key_r, 16);
 571                         } else {
 572                                 gensec_ntlmssp_state->crypt.ntlm.seq_num = ntlm_seqnum;
 573                                 *gensec_ntlmssp_state->crypt.ntlm.arcfour_state = ntlm_state;
 574                         }
 575
 576                         status = gensec_ntlmssp_unseal_packet(gensec_security,
 577                                                               sig_mem_ctx,
 578                                                               out->data,
 579                                                               out->length,
 580                                                               out->data,
 581                                                               out->length,
 582                                                               &sig);
 583                         if (NT_STATUS_IS_OK(status)) {
 584                                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 585                         } else {
 586                                 status = check_status;
 587                         }
 588                 }
 589                 return status;
 590         } else {
 591                 *out = *in;
 592                 return NT_STATUS_OK;
 593         }
 594 }
 595