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