source/auth/ntlmssp/ntlmssp.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    handle NLTMSSP, client server side parsing
   5
   6    Copyright (C) Andrew Tridgell      2001
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
   8    Copyright (C) Stefan Metzmacher 2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "auth/ntlmssp/ntlmssp.h"
  26 #include "auth/ntlmssp/msrpc_parse.h"
  27 #include "librpc/gen_ndr/ndr_dcerpc.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "auth/gensec/gensec.h"
  30 #include "auth/gensec/gensec_proto.h"
  31 #include "auth/auth.h"
  32 #include "auth/ntlm/auth_proto.h"
  33 #include "param/param.h"
  34
  35 /**
  36  * Callbacks for NTLMSSP - for both client and server operating modes
  37  *
  38  */
  39
  40 static const struct ntlmssp_callbacks {
  41         enum ntlmssp_role role;
  42         enum ntlmssp_message_type command;
  43         NTSTATUS (*sync_fn)(struct gensec_security *gensec_security,
  44                             TALLOC_CTX *out_mem_ctx,
  45                             DATA_BLOB in, DATA_BLOB *out);
  46 } ntlmssp_callbacks[] = {
  47         {
  48                 .role           = NTLMSSP_CLIENT,
  49                 .command        = NTLMSSP_INITIAL,
  50                 .sync_fn        = ntlmssp_client_initial,
  51         },{
  52                 .role           = NTLMSSP_SERVER,
  53                 .command        = NTLMSSP_NEGOTIATE,
  54                 .sync_fn        = ntlmssp_server_negotiate,
  55         },{
  56                 .role           = NTLMSSP_CLIENT,
  57                 .command        = NTLMSSP_CHALLENGE,
  58                 .sync_fn        = ntlmssp_client_challenge,
  59         },{
  60                 .role           = NTLMSSP_SERVER,
  61                 .command        = NTLMSSP_AUTH,
  62                 .sync_fn        = ntlmssp_server_auth,
  63         }
  64 };
  65
  66
  67 /**
  68  * Print out the NTLMSSP flags for debugging
  69  * @param neg_flags The flags from the packet
  70  */
  71
  72 void debug_ntlmssp_flags(uint32_t neg_flags)
  73 {
  74         DEBUG(3,("Got NTLMSSP neg_flags=0x%08x\n", neg_flags));
  75
  76         if (neg_flags & NTLMSSP_NEGOTIATE_UNICODE)
  77                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_UNICODE\n"));
  78         if (neg_flags & NTLMSSP_NEGOTIATE_OEM)
  79                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_OEM\n"));
  80         if (neg_flags & NTLMSSP_REQUEST_TARGET)
  81                 DEBUGADD(4, ("  NTLMSSP_REQUEST_TARGET\n"));
  82         if (neg_flags & NTLMSSP_NEGOTIATE_SIGN)
  83                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_SIGN\n"));
  84         if (neg_flags & NTLMSSP_NEGOTIATE_SEAL)
  85                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_SEAL\n"));
  86         if (neg_flags & NTLMSSP_NEGOTIATE_DATAGRAM_STYLE)
  87                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_DATAGRAM_STYLE\n"));
  88         if (neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
  89                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_LM_KEY\n"));
  90         if (neg_flags & NTLMSSP_NEGOTIATE_NETWARE)
  91                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NETWARE\n"));
  92         if (neg_flags & NTLMSSP_NEGOTIATE_NTLM)
  93                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NTLM\n"));
  94         if (neg_flags & NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED)
  95                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED\n"));
  96         if (neg_flags & NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED)
  97                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED\n"));
  98         if (neg_flags & NTLMSSP_NEGOTIATE_THIS_IS_LOCAL_CALL)
  99                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_THIS_IS_LOCAL_CALL\n"));
 100         if (neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN)
 101                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_ALWAYS_SIGN\n"));
 102         if (neg_flags & NTLMSSP_CHAL_ACCEPT_RESPONSE)
 103                 DEBUGADD(4, ("  NTLMSSP_CHAL_ACCEPT_RESPONSE\n"));
 104         if (neg_flags & NTLMSSP_CHAL_NON_NT_SESSION_KEY)
 105                 DEBUGADD(4, ("  NTLMSSP_CHAL_NON_NT_SESSION_KEY\n"));
 106         if (neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 107                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NTLM2\n"));
 108         if (neg_flags & NTLMSSP_CHAL_TARGET_INFO)
 109                 DEBUGADD(4, ("  NTLMSSP_CHAL_TARGET_INFO\n"));
 110         if (neg_flags & NTLMSSP_NEGOTIATE_128)
 111                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_128\n"));
 112         if (neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)
 113                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_KEY_EXCH\n"));
 114         if (neg_flags & NTLMSSP_NEGOTIATE_56)
 115                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_56\n"));
 116 }
 117
 118 static NTSTATUS gensec_ntlmssp_magic(struct gensec_security *gensec_security,
 119                                      const DATA_BLOB *first_packet)
 120 {
 121         if (first_packet->length > 8 && memcmp("NTLMSSP\0", first_packet->data, 8) == 0) {
 122                 return NT_STATUS_OK;
 123         } else {
 124                 return NT_STATUS_INVALID_PARAMETER;
 125         }
 126 }
 127
 128 static NTSTATUS gensec_ntlmssp_update_find(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 129                                            const DATA_BLOB input, uint32_t *idx)
 130 {
 131         struct gensec_security *gensec_security = gensec_ntlmssp_state->gensec_security;
 132         uint32_t ntlmssp_command;
 133         uint32_t i;
 134
 135         if (gensec_ntlmssp_state->expected_state == NTLMSSP_DONE) {
 136                 /* We are strict here because other modules, which we
 137                  * don't fully control (such as GSSAPI) are also
 138                  * strict, but are tested less often */
 139
 140                 DEBUG(1, ("Called NTLMSSP after state machine was 'done'\n"));
 141                 return NT_STATUS_INVALID_PARAMETER;
 142         }
 143
 144         if (!input.length) {
 145                 switch (gensec_ntlmssp_state->role) {
 146                 case NTLMSSP_CLIENT:
 147                         ntlmssp_command = NTLMSSP_INITIAL;
 148                         break;
 149                 case NTLMSSP_SERVER:
 150                         if (gensec_security->want_features & GENSEC_FEATURE_DATAGRAM_MODE) {
 151                                 /* 'datagram' mode - no neg packet */
 152                                 ntlmssp_command = NTLMSSP_NEGOTIATE;
 153                         } else {
 154                                 /* This is normal in SPNEGO mech negotiation fallback */
 155                                 DEBUG(2, ("Failed to parse NTLMSSP packet: zero length\n"));
 156                                 return NT_STATUS_INVALID_PARAMETER;
 157                         }
 158                         break;
 159                 }
 160         } else {
 161                 if (!msrpc_parse(gensec_ntlmssp_state,
 162                                  lp_iconv_convenience(gensec_security->lp_ctx),
 163                                  &input, "Cd",
 164                                  "NTLMSSP",
 165                                  &ntlmssp_command)) {
 166                         DEBUG(1, ("Failed to parse NTLMSSP packet, could not extract NTLMSSP command\n"));
 167                         dump_data(2, input.data, input.length);
 168                         return NT_STATUS_INVALID_PARAMETER;
 169                 }
 170         }
 171
 172         if (ntlmssp_command != gensec_ntlmssp_state->expected_state) {
 173                 DEBUG(2, ("got NTLMSSP command %u, expected %u\n", ntlmssp_command, gensec_ntlmssp_state->expected_state));
 174                 return NT_STATUS_INVALID_PARAMETER;
 175         }
 176
 177         for (i=0; i < ARRAY_SIZE(ntlmssp_callbacks); i++) {
 178                 if (ntlmssp_callbacks[i].role == gensec_ntlmssp_state->role &&
 179                     ntlmssp_callbacks[i].command == ntlmssp_command) {
 180                         *idx = i;
 181                         return NT_STATUS_OK;
 182                 }
 183         }
 184
 185         DEBUG(1, ("failed to find NTLMSSP callback for NTLMSSP mode %u, command %u\n",
 186                   gensec_ntlmssp_state->role, ntlmssp_command));
 187
 188         return NT_STATUS_INVALID_PARAMETER;
 189 }
 190
 191 /**
 192  * Next state function for the wrapped NTLMSSP state machine
 193  *
 194  * @param gensec_security GENSEC state, initialised to NTLMSSP
 195  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 196  * @param in The request, as a DATA_BLOB
 197  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 198  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 199  *                or NT_STATUS_OK if the user is authenticated.
 200  */
 201
 202 static NTSTATUS gensec_ntlmssp_update(struct gensec_security *gensec_security,
 203                                       TALLOC_CTX *out_mem_ctx,
 204                                       const DATA_BLOB input, DATA_BLOB *out)
 205 {
 206         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 207         NTSTATUS status;
 208         uint32_t i;
 209
 210         *out = data_blob(NULL, 0);
 211
 212         if (!out_mem_ctx) {
 213                 /* if the caller doesn't want to manage/own the memory,
 214                    we can put it on our context */
 215                 out_mem_ctx = gensec_ntlmssp_state;
 216         }
 217
 218         status = gensec_ntlmssp_update_find(gensec_ntlmssp_state, input, &i);
 219         NT_STATUS_NOT_OK_RETURN(status);
 220
 221         status = ntlmssp_callbacks[i].sync_fn(gensec_security, out_mem_ctx, input, out);
 222         NT_STATUS_NOT_OK_RETURN(status);
 223
 224         return NT_STATUS_OK;
 225 }
 226
 227 /**
 228  * Return the NTLMSSP master session key
 229  *
 230  * @param gensec_ntlmssp_state NTLMSSP State
 231  */
 232
 233 NTSTATUS gensec_ntlmssp_session_key(struct gensec_security *gensec_security,
 234                                     DATA_BLOB *session_key)
 235 {
 236         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 237
 238         if (!gensec_ntlmssp_state->session_key.data) {
 239                 return NT_STATUS_NO_USER_SESSION_KEY;
 240         }
 241         *session_key = gensec_ntlmssp_state->session_key;
 242
 243         return NT_STATUS_OK;
 244 }
 245
 246 void ntlmssp_handle_neg_flags(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 247                               uint32_t neg_flags, bool allow_lm)
 248 {
 249         if (neg_flags & NTLMSSP_NEGOTIATE_UNICODE) {
 250                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
 251                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_OEM;
 252                 gensec_ntlmssp_state->unicode = true;
 253         } else {
 254                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_UNICODE;
 255                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
 256                 gensec_ntlmssp_state->unicode = false;
 257         }
 258
 259         if ((neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) && allow_lm && !gensec_ntlmssp_state->use_ntlmv2) {
 260                 /* other end forcing us to use LM */
 261                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_LM_KEY;
 262                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 263         } else {
 264                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 265         }
 266
 267         if (!(neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN)) {
 268                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
 269         }
 270
 271         if (!(neg_flags & NTLMSSP_NEGOTIATE_SIGN)) {
 272                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_SIGN;
 273         }
 274
 275         if (!(neg_flags & NTLMSSP_NEGOTIATE_SEAL)) {
 276                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_SEAL;
 277         }
 278
 279         if (!(neg_flags & NTLMSSP_NEGOTIATE_NTLM2)) {
 280                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 281         }
 282
 283         if (!(neg_flags & NTLMSSP_NEGOTIATE_128)) {
 284                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_128;
 285         }
 286
 287         if (!(neg_flags & NTLMSSP_NEGOTIATE_56)) {
 288                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_56;
 289         }
 290
 291         if (!(neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)) {
 292                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_KEY_EXCH;
 293         }
 294
 295         /* Woop Woop - unknown flag for Windows compatibility...
 296            What does this really do ? JRA. */
 297         if (!(neg_flags & NTLMSSP_UNKNOWN_02000000)) {
 298                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_UNKNOWN_02000000;
 299         }
 300
 301         if ((neg_flags & NTLMSSP_REQUEST_TARGET)) {
 302                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_REQUEST_TARGET;
 303         }
 304
 305 }
 306
 307 /**
 308    Weaken NTLMSSP keys to cope with down-level clients and servers.
 309
 310    We probably should have some parameters to control this, but as
 311    it only occours for LM_KEY connections, and this is controlled
 312    by the client lanman auth/lanman auth parameters, it isn't too bad.
 313 */
 314
 315 DATA_BLOB ntlmssp_weakend_key(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 316                               TALLOC_CTX *mem_ctx)
 317 {
 318         DATA_BLOB weakened_key = data_blob_talloc(mem_ctx,
 319                                                   gensec_ntlmssp_state->session_key.data,
 320                                                   gensec_ntlmssp_state->session_key.length);
 321         /* Nothing to weaken.  We certainly don't want to 'extend' the length... */
 322         if (weakened_key.length < 16) {
 323                 /* perhaps there was no key? */
 324                 return weakened_key;
 325         }
 326
 327         /* Key weakening not performed on the master key for NTLM2
 328            and does not occour for NTLM1.  Therefore we only need
 329            to do this for the LM_KEY.
 330         */
 331         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
 332                 /* LM key doesn't support 128 bit crypto, so this is
 333                  * the best we can do.  If you negotiate 128 bit, but
 334                  * not 56, you end up with 40 bit... */
 335                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 336                         weakened_key.data[7] = 0xa0;
 337                         weakened_key.length = 8;
 338                 } else { /* forty bits */
 339                         weakened_key.data[5] = 0xe5;
 340                         weakened_key.data[6] = 0x38;
 341                         weakened_key.data[7] = 0xb0;
 342                         weakened_key.length = 8;
 343                 }
 344         }
 345         return weakened_key;
 346 }
 347
 348 static bool gensec_ntlmssp_have_feature(struct gensec_security *gensec_security,
 349                                         uint32_t feature)
 350 {
 351         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
 352         if (feature & GENSEC_FEATURE_SIGN) {
 353                 if (!gensec_ntlmssp_state->session_key.length) {
 354                         return false;
 355                 }
 356                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) {
 357                         return true;
 358                 }
 359         }
 360         if (feature & GENSEC_FEATURE_SEAL) {
 361                 if (!gensec_ntlmssp_state->session_key.length) {
 362                         return false;
 363                 }
 364                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 365                         return true;
 366                 }
 367         }
 368         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 369                 if (gensec_ntlmssp_state->session_key.length) {
 370                         return true;
 371                 }
 372         }
 373         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 374                 return true;
 375         }
 376         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 377                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 378                         return true;
 379                 }
 380         }
 381         return false;
 382 }
 383
 384 NTSTATUS gensec_ntlmssp_start(struct gensec_security *gensec_security)
 385 {
 386         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 387
 388         gensec_ntlmssp_state = talloc_zero(gensec_security, struct gensec_ntlmssp_state);
 389         if (!gensec_ntlmssp_state) {
 390                 return NT_STATUS_NO_MEMORY;
 391         }
 392
 393         gensec_ntlmssp_state->gensec_security = gensec_security;
 394         gensec_ntlmssp_state->auth_context = NULL;
 395         gensec_ntlmssp_state->server_info = NULL;
 396
 397         gensec_security->private_data = gensec_ntlmssp_state;
 398         return NT_STATUS_OK;
 399 }
 400
 401 static const char *gensec_ntlmssp_oids[] = {
 402         GENSEC_OID_NTLMSSP,
 403         NULL
 404 };
 405
 406 static const struct gensec_security_ops gensec_ntlmssp_security_ops = {
 407         .name           = "ntlmssp",
 408         .sasl_name      = "NTLM",
 409         .auth_type      = DCERPC_AUTH_TYPE_NTLMSSP,
 410         .oid            = gensec_ntlmssp_oids,
 411         .client_start   = gensec_ntlmssp_client_start,
 412         .server_start   = gensec_ntlmssp_server_start,
 413         .magic          = gensec_ntlmssp_magic,
 414         .update         = gensec_ntlmssp_update,
 415         .sig_size       = gensec_ntlmssp_sig_size,
 416         .sign_packet    = gensec_ntlmssp_sign_packet,
 417         .check_packet   = gensec_ntlmssp_check_packet,
 418         .seal_packet    = gensec_ntlmssp_seal_packet,
 419         .unseal_packet  = gensec_ntlmssp_unseal_packet,
 420         .wrap           = gensec_ntlmssp_wrap,
 421         .unwrap         = gensec_ntlmssp_unwrap,
 422         .session_key    = gensec_ntlmssp_session_key,
 423         .session_info   = gensec_ntlmssp_session_info,
 424         .have_feature   = gensec_ntlmssp_have_feature,
 425         .enabled        = true,
 426         .priority       = GENSEC_NTLMSSP
 427 };
 428
 429
 430 _PUBLIC_ NTSTATUS gensec_ntlmssp_init(void)
 431 {
 432         NTSTATUS ret;
 433
 434         auth_init();
 435
 436         ret = gensec_register(&gensec_ntlmssp_security_ops);
 437         if (!NT_STATUS_IS_OK(ret)) {
 438                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 439                         gensec_ntlmssp_security_ops.name));
 440                 return ret;
 441         }
 442
 443         return ret;
 444 }