source4/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 2 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, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "auth/auth.h"
  27 #include "auth/ntlmssp/ntlmssp.h"
  28 #include "auth/ntlmssp/msrpc_parse.h"
  29 #include "librpc/gen_ndr/ndr_dcerpc.h"
  30
  31 /**
  32  * Callbacks for NTLMSSP - for both client and server operating modes
  33  *
  34  */
  35
  36 static const struct ntlmssp_callbacks {
  37         enum ntlmssp_role role;
  38         enum ntlmssp_message_type command;
  39         NTSTATUS (*sync_fn)(struct gensec_security *gensec_security,
  40                             TALLOC_CTX *out_mem_ctx,
  41                             DATA_BLOB in, DATA_BLOB *out);
  42 } ntlmssp_callbacks[] = {
  43         {
  44                 .role           = NTLMSSP_CLIENT,
  45                 .command        = NTLMSSP_INITIAL,
  46                 .sync_fn        = ntlmssp_client_initial,
  47         },{
  48                 .role           = NTLMSSP_SERVER,
  49                 .command        = NTLMSSP_NEGOTIATE,
  50                 .sync_fn        = ntlmssp_server_negotiate,
  51         },{
  52                 .role           = NTLMSSP_CLIENT,
  53                 .command        = NTLMSSP_CHALLENGE,
  54                 .sync_fn        = ntlmssp_client_challenge,
  55         },{
  56                 .role           = NTLMSSP_SERVER,
  57                 .command        = NTLMSSP_AUTH,
  58                 .sync_fn        = ntlmssp_server_auth,
  59         }
  60 };
  61
  62
  63 /**
  64  * Print out the NTLMSSP flags for debugging
  65  * @param neg_flags The flags from the packet
  66  */
  67
  68 void debug_ntlmssp_flags(uint32_t neg_flags)
  69 {
  70         DEBUG(3,("Got NTLMSSP neg_flags=0x%08x\n", neg_flags));
  71
  72         if (neg_flags & NTLMSSP_NEGOTIATE_UNICODE)
  73                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_UNICODE\n"));
  74         if (neg_flags & NTLMSSP_NEGOTIATE_OEM)
  75                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_OEM\n"));
  76         if (neg_flags & NTLMSSP_REQUEST_TARGET)
  77                 DEBUGADD(4, ("  NTLMSSP_REQUEST_TARGET\n"));
  78         if (neg_flags & NTLMSSP_NEGOTIATE_SIGN)
  79                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_SIGN\n"));
  80         if (neg_flags & NTLMSSP_NEGOTIATE_SEAL)
  81                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_SEAL\n"));
  82         if (neg_flags & NTLMSSP_NEGOTIATE_DATAGRAM_STYLE)
  83                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_DATAGRAM_STYLE\n"));
  84         if (neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
  85                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_LM_KEY\n"));
  86         if (neg_flags & NTLMSSP_NEGOTIATE_NETWARE)
  87                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NETWARE\n"));
  88         if (neg_flags & NTLMSSP_NEGOTIATE_NTLM)
  89                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NTLM\n"));
  90         if (neg_flags & NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED)
  91                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED\n"));
  92         if (neg_flags & NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED)
  93                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED\n"));
  94         if (neg_flags & NTLMSSP_NEGOTIATE_THIS_IS_LOCAL_CALL)
  95                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_THIS_IS_LOCAL_CALL\n"));
  96         if (neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN)
  97                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_ALWAYS_SIGN\n"));
  98         if (neg_flags & NTLMSSP_CHAL_ACCEPT_RESPONSE)
  99                 DEBUGADD(4, ("  NTLMSSP_CHAL_ACCEPT_RESPONSE\n"));
 100         if (neg_flags & NTLMSSP_CHAL_NON_NT_SESSION_KEY)
 101                 DEBUGADD(4, ("  NTLMSSP_CHAL_NON_NT_SESSION_KEY\n"));
 102         if (neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
 103                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_NTLM2\n"));
 104         if (neg_flags & NTLMSSP_CHAL_TARGET_INFO)
 105                 DEBUGADD(4, ("  NTLMSSP_CHAL_TARGET_INFO\n"));
 106         if (neg_flags & NTLMSSP_NEGOTIATE_128)
 107                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_128\n"));
 108         if (neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)
 109                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_KEY_EXCH\n"));
 110         if (neg_flags & NTLMSSP_NEGOTIATE_56)
 111                 DEBUGADD(4, ("  NTLMSSP_NEGOTIATE_56\n"));
 112 }
 113
 114 static NTSTATUS gensec_ntlmssp_magic(struct gensec_security *gensec_security,
 115                                      const DATA_BLOB *first_packet)
 116 {
 117         if (first_packet->length > 8 && memcmp("NTLMSSP\0", first_packet->data, 8) == 0) {
 118                 return NT_STATUS_OK;
 119         } else {
 120                 return NT_STATUS_INVALID_PARAMETER;
 121         }
 122 }
 123
 124 static NTSTATUS gensec_ntlmssp_update_find(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 125                                            const DATA_BLOB input, uint32_t *idx)
 126 {
 127         struct gensec_security *gensec_security = gensec_ntlmssp_state->gensec_security;
 128         uint32_t ntlmssp_command;
 129         uint32_t i;
 130
 131         if (gensec_ntlmssp_state->expected_state == NTLMSSP_DONE) {
 132                 /* We are strict here because other modules, which we
 133                  * don't fully control (such as GSSAPI) are also
 134                  * strict, but are tested less often */
 135
 136                 DEBUG(1, ("Called NTLMSSP after state machine was 'done'\n"));
 137                 return NT_STATUS_INVALID_PARAMETER;
 138         }
 139
 140         if (!input.length) {
 141                 switch (gensec_ntlmssp_state->role) {
 142                 case NTLMSSP_CLIENT:
 143                         ntlmssp_command = NTLMSSP_INITIAL;
 144                         break;
 145                 case NTLMSSP_SERVER:
 146                         if (gensec_security->want_features & GENSEC_FEATURE_DATAGRAM_MODE) {
 147                                 /* 'datagram' mode - no neg packet */
 148                                 ntlmssp_command = NTLMSSP_NEGOTIATE;
 149                         } else {
 150                                 /* This is normal in SPNEGO mech negotiation fallback */
 151                                 DEBUG(2, ("Failed to parse NTLMSSP packet: zero length\n"));
 152                                 return NT_STATUS_INVALID_PARAMETER;
 153                         }
 154                         break;
 155                 }
 156         } else {
 157                 if (!msrpc_parse(gensec_ntlmssp_state,
 158                                  &input, "Cd",
 159                                  "NTLMSSP",
 160                                  &ntlmssp_command)) {
 161                         DEBUG(1, ("Failed to parse NTLMSSP packet, could not extract NTLMSSP command\n"));
 162                         dump_data(2, input.data, input.length);
 163                         return NT_STATUS_INVALID_PARAMETER;
 164                 }
 165         }
 166
 167         if (ntlmssp_command != gensec_ntlmssp_state->expected_state) {
 168                 DEBUG(2, ("got NTLMSSP command %u, expected %u\n", ntlmssp_command, gensec_ntlmssp_state->expected_state));
 169                 return NT_STATUS_INVALID_PARAMETER;
 170         }
 171
 172         for (i=0; i < ARRAY_SIZE(ntlmssp_callbacks); i++) {
 173                 if (ntlmssp_callbacks[i].role == gensec_ntlmssp_state->role &&
 174                     ntlmssp_callbacks[i].command == ntlmssp_command) {
 175                         *idx = i;
 176                         return NT_STATUS_OK;
 177                 }
 178         }
 179
 180         DEBUG(1, ("failed to find NTLMSSP callback for NTLMSSP mode %u, command %u\n",
 181                   gensec_ntlmssp_state->role, ntlmssp_command));
 182
 183         return NT_STATUS_INVALID_PARAMETER;
 184 }
 185
 186 /**
 187  * Next state function for the wrapped NTLMSSP state machine
 188  *
 189  * @param gensec_security GENSEC state, initialised to NTLMSSP
 190  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 191  * @param in The request, as a DATA_BLOB
 192  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 193  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 194  *                or NT_STATUS_OK if the user is authenticated.
 195  */
 196
 197 static NTSTATUS gensec_ntlmssp_update(struct gensec_security *gensec_security,
 198                                       TALLOC_CTX *out_mem_ctx,
 199                                       const DATA_BLOB input, DATA_BLOB *out)
 200 {
 201         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 202         NTSTATUS status;
 203         uint32_t i;
 204
 205         *out = data_blob(NULL, 0);
 206
 207         if (!out_mem_ctx) {
 208                 /* if the caller doesn't want to manage/own the memory,
 209                    we can put it on our context */
 210                 out_mem_ctx = gensec_ntlmssp_state;
 211         }
 212
 213         status = gensec_ntlmssp_update_find(gensec_ntlmssp_state, input, &i);
 214         NT_STATUS_NOT_OK_RETURN(status);
 215
 216         status = ntlmssp_callbacks[i].sync_fn(gensec_security, out_mem_ctx, input, out);
 217         NT_STATUS_NOT_OK_RETURN(status);
 218
 219         return NT_STATUS_OK;
 220 }
 221
 222 /**
 223  * Return the NTLMSSP master session key
 224  *
 225  * @param gensec_ntlmssp_state NTLMSSP State
 226  */
 227
 228 NTSTATUS gensec_ntlmssp_session_key(struct gensec_security *gensec_security,
 229                                     DATA_BLOB *session_key)
 230 {
 231         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 232
 233         if (!gensec_ntlmssp_state->session_key.data) {
 234                 return NT_STATUS_NO_USER_SESSION_KEY;
 235         }
 236         *session_key = gensec_ntlmssp_state->session_key;
 237
 238         return NT_STATUS_OK;
 239 }
 240
 241 void ntlmssp_handle_neg_flags(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 242                               uint32_t neg_flags, BOOL allow_lm)
 243 {
 244         if (neg_flags & NTLMSSP_NEGOTIATE_UNICODE) {
 245                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
 246                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_OEM;
 247                 gensec_ntlmssp_state->unicode = True;
 248         } else {
 249                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_UNICODE;
 250                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
 251                 gensec_ntlmssp_state->unicode = False;
 252         }
 253
 254         if ((neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) && allow_lm && !gensec_ntlmssp_state->use_ntlmv2) {
 255                 /* other end forcing us to use LM */
 256                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_LM_KEY;
 257                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 258         } else {
 259                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 260         }
 261
 262         if (neg_flags & NTLMSSP_NEGOTIATE_ALWAYS_SIGN) {
 263                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
 264         }
 265
 266         if (!(neg_flags & NTLMSSP_NEGOTIATE_SIGN)) {
 267                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_SIGN;
 268         }
 269
 270         if (!(neg_flags & NTLMSSP_NEGOTIATE_SEAL)) {
 271                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_SEAL;
 272         }
 273
 274         if (!(neg_flags & NTLMSSP_NEGOTIATE_NTLM2)) {
 275                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 276         }
 277
 278         if (!(neg_flags & NTLMSSP_NEGOTIATE_128)) {
 279                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_128;
 280         }
 281
 282         if (!(neg_flags & NTLMSSP_NEGOTIATE_56)) {
 283                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_56;
 284         }
 285
 286         if (!(neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)) {
 287                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_KEY_EXCH;
 288         }
 289
 290         /* Woop Woop - unknown flag for Windows compatibility...
 291            What does this really do ? JRA. */
 292         if (!(neg_flags & NTLMSSP_UNKNOWN_02000000)) {
 293                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_UNKNOWN_02000000;
 294         }
 295
 296         if ((neg_flags & NTLMSSP_REQUEST_TARGET)) {
 297                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_REQUEST_TARGET;
 298         }
 299
 300 }
 301
 302 /**
 303    Weaken NTLMSSP keys to cope with down-level clients and servers.
 304
 305    We probably should have some parameters to control this, but as
 306    it only occours for LM_KEY connections, and this is controlled
 307    by the client lanman auth/lanman auth parameters, it isn't too bad.
 308 */
 309
 310 DATA_BLOB ntlmssp_weakend_key(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
 311                               TALLOC_CTX *mem_ctx)
 312 {
 313         DATA_BLOB weakened_key = data_blob_talloc(mem_ctx,
 314                                                   gensec_ntlmssp_state->session_key.data,
 315                                                   gensec_ntlmssp_state->session_key.length);
 316         /* Nothing to weaken.  We certainly don't want to 'extend' the length... */
 317         if (weakened_key.length < 16) {
 318                 /* perhaps there was no key? */
 319                 return weakened_key;
 320         }
 321
 322         /* Key weakening not performed on the master key for NTLM2
 323            and does not occour for NTLM1.  Therefore we only need
 324            to do this for the LM_KEY.
 325         */
 326         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
 327                 /* LM key doesn't support 128 bit crypto, so this is
 328                  * the best we can do.  If you negotiate 128 bit, but
 329                  * not 56, you end up with 40 bit... */
 330                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
 331                         weakened_key.data[7] = 0xa0;
 332                         weakened_key.length = 8;
 333                 } else { /* forty bits */
 334                         weakened_key.data[5] = 0xe5;
 335                         weakened_key.data[6] = 0x38;
 336                         weakened_key.data[7] = 0xb0;
 337                         weakened_key.length = 8;
 338                 }
 339         }
 340         return weakened_key;
 341 }
 342
 343 static BOOL gensec_ntlmssp_have_feature(struct gensec_security *gensec_security,
 344                                         uint32_t feature)
 345 {
 346         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
 347         if (feature & GENSEC_FEATURE_SIGN) {
 348                 if (!gensec_ntlmssp_state->session_key.length) {
 349                         return False;
 350                 }
 351                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) {
 352                         return True;
 353                 }
 354         }
 355         if (feature & GENSEC_FEATURE_SEAL) {
 356                 if (!gensec_ntlmssp_state->session_key.length) {
 357                         return False;
 358                 }
 359                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 360                         return True;
 361                 }
 362         }
 363         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 364                 if (gensec_ntlmssp_state->session_key.length) {
 365                         return True;
 366                 }
 367         }
 368         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 369                 return True;
 370         }
 371         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 372                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 373                         return True;
 374                 }
 375         }
 376         return False;
 377 }
 378
 379 NTSTATUS gensec_ntlmssp_start(struct gensec_security *gensec_security)
 380 {
 381         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 382
 383         gensec_ntlmssp_state = talloc_zero(gensec_security, struct gensec_ntlmssp_state);
 384         if (!gensec_ntlmssp_state) {
 385                 return NT_STATUS_NO_MEMORY;
 386         }
 387
 388         gensec_ntlmssp_state->gensec_security = gensec_security;
 389         gensec_ntlmssp_state->auth_context = NULL;
 390         gensec_ntlmssp_state->server_info = NULL;
 391
 392         gensec_security->private_data = gensec_ntlmssp_state;
 393         return NT_STATUS_OK;
 394 }
 395
 396 static const char *gensec_ntlmssp_oids[] = {
 397         GENSEC_OID_NTLMSSP,
 398         NULL
 399 };
 400
 401 static const struct gensec_security_ops gensec_ntlmssp_security_ops = {
 402         .name           = "ntlmssp",
 403         .sasl_name      = "NTLM",
 404         .auth_type      = DCERPC_AUTH_TYPE_NTLMSSP,
 405         .oid            = gensec_ntlmssp_oids,
 406         .client_start   = gensec_ntlmssp_client_start,
 407         .server_start   = gensec_ntlmssp_server_start,
 408         .magic          = gensec_ntlmssp_magic,
 409         .update         = gensec_ntlmssp_update,
 410         .sig_size       = gensec_ntlmssp_sig_size,
 411         .sign_packet    = gensec_ntlmssp_sign_packet,
 412         .check_packet   = gensec_ntlmssp_check_packet,
 413         .seal_packet    = gensec_ntlmssp_seal_packet,
 414         .unseal_packet  = gensec_ntlmssp_unseal_packet,
 415         .wrap           = gensec_ntlmssp_wrap,
 416         .unwrap         = gensec_ntlmssp_unwrap,
 417         .session_key    = gensec_ntlmssp_session_key,
 418         .session_info   = gensec_ntlmssp_session_info,
 419         .have_feature   = gensec_ntlmssp_have_feature,
 420         .enabled        = True,
 421         .order          = GENSEC_NTLMSSP
 422 };
 423
 424
 425 NTSTATUS gensec_ntlmssp_init(void)
 426 {
 427         NTSTATUS ret;
 428
 429         auth_init();
 430
 431         ret = gensec_register(&gensec_ntlmssp_security_ops);
 432         if (!NT_STATUS_IS_OK(ret)) {
 433                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 434                         gensec_ntlmssp_security_ops.name));
 435                 return ret;
 436         }
 437
 438         return ret;
 439 }