source4/smb_server/smb/negprot.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    negprot reply code
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22 #include "auth/auth.h"
  23 #include "smb_server/smb_server.h"
  24 #include "libcli/smb2/smb2.h"
  25 #include "smb_server/smb2/smb2_server.h"
  26 #include "smb_server/service_smb_proto.h"
  27 #include "smbd/service_stream.h"
  28 #include "lib/stream/packet.h"
  29
  30
  31 /* initialise the auth_context for this server and return the cryptkey */
  32 static NTSTATUS get_challenge(struct smbsrv_connection *smb_conn, uint8_t buff[8])
  33 {
  34         NTSTATUS nt_status;
  35         const uint8_t *challenge;
  36
  37         /* muliple negprots are not premitted */
  38         if (smb_conn->negotiate.auth_context) {
  39                 DEBUG(3,("get challenge: is this a secondary negprot?  auth_context is non-NULL!\n"));
  40                 return NT_STATUS_FOOBAR;
  41         }
  42
  43         DEBUG(10, ("get challenge: creating negprot_global_auth_context\n"));
  44
  45         nt_status = auth_context_create(smb_conn, lp_auth_methods(),
  46                                         &smb_conn->negotiate.auth_context,
  47                                         smb_conn->connection->event.ctx);
  48         if (!NT_STATUS_IS_OK(nt_status)) {
  49                 DEBUG(0, ("auth_context_create() returned %s", nt_errstr(nt_status)));
  50                 return nt_status;
  51         }
  52
  53         nt_status = auth_get_challenge(smb_conn->negotiate.auth_context, &challenge);
  54         if (!NT_STATUS_IS_OK(nt_status)) {
  55                 DEBUG(0, ("auth_get_challenge() returned %s", nt_errstr(nt_status)));
  56                 return nt_status;
  57         }
  58
  59         memcpy(buff, challenge, 8);
  60
  61         return NT_STATUS_OK;
  62 }
  63
  64 /****************************************************************************
  65  Reply for the core protocol.
  66 ****************************************************************************/
  67 static void reply_corep(struct smbsrv_request *req, uint16_t choice)
  68 {
  69         smbsrv_setup_reply(req, 1, 0);
  70
  71         SSVAL(req->out.vwv, VWV(0), choice);
  72
  73         req->smb_conn->negotiate.protocol = PROTOCOL_CORE;
  74
  75         if (req->smb_conn->signing.mandatory_signing) {
  76                 smbsrv_terminate_connection(req->smb_conn,
  77                                             "CORE does not support SMB signing, and it is mandatory\n");
  78                 return;
  79         }
  80
  81         smbsrv_send_reply(req);
  82 }
  83
  84 /****************************************************************************
  85  Reply for the coreplus protocol.
  86 this is quite incomplete - we only fill in a small part of the reply, but as nobody uses
  87 this any more it probably doesn't matter
  88 ****************************************************************************/
  89 static void reply_coreplus(struct smbsrv_request *req, uint16_t choice)
  90 {
  91         uint16_t raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);
  92
  93         smbsrv_setup_reply(req, 13, 0);
  94
  95         /* Reply, SMBlockread, SMBwritelock supported. */
  96         SCVAL(req->out.hdr,HDR_FLG,
  97               CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);
  98
  99         SSVAL(req->out.vwv, VWV(0), choice);
 100         SSVAL(req->out.vwv, VWV(1), 0x1); /* user level security, don't encrypt */
 101
 102         /* tell redirector we support
 103            readbraw and writebraw (possibly) */
 104         SSVAL(req->out.vwv, VWV(5), raw);
 105
 106         req->smb_conn->negotiate.protocol = PROTOCOL_COREPLUS;
 107
 108         if (req->smb_conn->signing.mandatory_signing) {
 109                 smbsrv_terminate_connection(req->smb_conn,
 110                                             "COREPLUS does not support SMB signing, and it is mandatory\n");
 111                 return;
 112         }
 113
 114         smbsrv_send_reply(req);
 115 }
 116
 117 /****************************************************************************
 118  Reply for the lanman 1.0 protocol.
 119 ****************************************************************************/
 120 static void reply_lanman1(struct smbsrv_request *req, uint16_t choice)
 121 {
 122         int raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);
 123         int secword=0;
 124         time_t t = req->request_time.tv_sec;
 125
 126         req->smb_conn->negotiate.encrypted_passwords = lp_encrypted_passwords();
 127
 128         if (lp_security() != SEC_SHARE)
 129                 secword |= NEGOTIATE_SECURITY_USER_LEVEL;
 130
 131         if (req->smb_conn->negotiate.encrypted_passwords)
 132                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 133
 134         req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN1;
 135
 136         smbsrv_setup_reply(req, 13, req->smb_conn->negotiate.encrypted_passwords ? 8 : 0);
 137
 138         /* SMBlockread, SMBwritelock supported. */
 139         SCVAL(req->out.hdr,HDR_FLG,
 140               CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);
 141
 142         SSVAL(req->out.vwv, VWV(0), choice);
 143         SSVAL(req->out.vwv, VWV(1), secword);
 144         SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv);
 145         SSVAL(req->out.vwv, VWV(3), lp_maxmux());
 146         SSVAL(req->out.vwv, VWV(4), 1);
 147         SSVAL(req->out.vwv, VWV(5), raw);
 148         SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id);
 149         srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t);
 150         SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60);
 151         SIVAL(req->out.vwv, VWV(11), 0); /* reserved */
 152
 153         /* Create a token value and add it to the outgoing packet. */
 154         if (req->smb_conn->negotiate.encrypted_passwords) {
 155                 NTSTATUS nt_status;
 156
 157                 SSVAL(req->out.vwv, VWV(11), 8);
 158
 159                 nt_status = get_challenge(req->smb_conn, req->out.data);
 160                 if (!NT_STATUS_IS_OK(nt_status)) {
 161                         smbsrv_terminate_connection(req->smb_conn, "LANMAN1 get_challenge failed\n");
 162                         return;
 163                 }
 164         }
 165
 166         if (req->smb_conn->signing.mandatory_signing) {
 167                 smbsrv_terminate_connection(req->smb_conn,
 168                                             "LANMAN1 does not support SMB signing, and it is mandatory\n");
 169                 return;
 170         }
 171
 172         smbsrv_send_reply(req);
 173 }
 174
 175 /****************************************************************************
 176  Reply for the lanman 2.0 protocol.
 177 ****************************************************************************/
 178 static void reply_lanman2(struct smbsrv_request *req, uint16_t choice)
 179 {
 180         int raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);
 181         int secword=0;
 182         time_t t = req->request_time.tv_sec;
 183
 184         req->smb_conn->negotiate.encrypted_passwords = lp_encrypted_passwords();
 185
 186         if (lp_security() != SEC_SHARE)
 187                 secword |= NEGOTIATE_SECURITY_USER_LEVEL;
 188
 189         if (req->smb_conn->negotiate.encrypted_passwords)
 190                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 191
 192         req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN2;
 193
 194         smbsrv_setup_reply(req, 13, 0);
 195
 196         SSVAL(req->out.vwv, VWV(0), choice);
 197         SSVAL(req->out.vwv, VWV(1), secword);
 198         SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv);
 199         SSVAL(req->out.vwv, VWV(3), lp_maxmux());
 200         SSVAL(req->out.vwv, VWV(4), 1);
 201         SSVAL(req->out.vwv, VWV(5), raw);
 202         SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id);
 203         srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t);
 204         SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60);
 205         SIVAL(req->out.vwv, VWV(11), 0);
 206
 207         /* Create a token value and add it to the outgoing packet. */
 208         if (req->smb_conn->negotiate.encrypted_passwords) {
 209                 SSVAL(req->out.vwv, VWV(11), 8);
 210                 req_grow_data(req, 8);
 211                 get_challenge(req->smb_conn, req->out.data);
 212         }
 213
 214         req_push_str(req, NULL, lp_workgroup(), -1, STR_TERMINATE);
 215
 216         if (req->smb_conn->signing.mandatory_signing) {
 217                 smbsrv_terminate_connection(req->smb_conn,
 218                                             "LANMAN2 does not support SMB signing, and it is mandatory\n");
 219                 return;
 220         }
 221
 222         smbsrv_send_reply(req);
 223 }
 224
 225 static void reply_nt1_orig(struct smbsrv_request *req)
 226 {
 227         /* Create a token value and add it to the outgoing packet. */
 228         if (req->smb_conn->negotiate.encrypted_passwords) {
 229                 req_grow_data(req, 8);
 230                 /* note that we do not send a challenge at all if
 231                    we are using plaintext */
 232                 get_challenge(req->smb_conn, req->out.ptr);
 233                 req->out.ptr += 8;
 234                 SCVAL(req->out.vwv+1, VWV(16), 8);
 235         }
 236         req_push_str(req, NULL, lp_workgroup(), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN);
 237         req_push_str(req, NULL, lp_netbios_name(), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN);
 238         DEBUG(3,("not using extended security (SPNEGO or NTLMSSP)\n"));
 239 }
 240
 241 /****************************************************************************
 242  Reply for the nt protocol.
 243 ****************************************************************************/
 244 static void reply_nt1(struct smbsrv_request *req, uint16_t choice)
 245 {
 246         /* dual names + lock_and_read + nt SMBs + remote API calls */
 247         int capabilities;
 248         int secword=0;
 249         time_t t = req->request_time.tv_sec;
 250         NTTIME nttime;
 251         BOOL negotiate_spnego = False;
 252
 253         unix_to_nt_time(&nttime, t);
 254
 255         capabilities =
 256                 CAP_NT_FIND | CAP_LOCK_AND_READ |
 257                 CAP_LEVEL_II_OPLOCKS | CAP_NT_SMBS | CAP_RPC_REMOTE_APIS;
 258
 259         req->smb_conn->negotiate.encrypted_passwords = lp_encrypted_passwords();
 260
 261         /* do spnego in user level security if the client
 262            supports it and we can do encrypted passwords */
 263
 264         if (req->smb_conn->negotiate.encrypted_passwords &&
 265             (lp_security() != SEC_SHARE) &&
 266             lp_use_spnego() &&
 267             (req->flags2 & FLAGS2_EXTENDED_SECURITY)) {
 268                 negotiate_spnego = True;
 269                 capabilities |= CAP_EXTENDED_SECURITY;
 270         }
 271
 272         if (lp_unix_extensions()) {
 273                 capabilities |= CAP_UNIX;
 274         }
 275
 276         if (lp_large_readwrite()) {
 277                 capabilities |= CAP_LARGE_READX | CAP_LARGE_WRITEX | CAP_W2K_SMBS;
 278         }
 279
 280         capabilities |= CAP_LARGE_FILES;
 281
 282         if (lp_readraw() && lp_writeraw()) {
 283                 capabilities |= CAP_RAW_MODE;
 284         }
 285
 286         /* allow for disabling unicode */
 287         if (lp_unicode()) {
 288                 capabilities |= CAP_UNICODE;
 289         }
 290
 291         if (lp_nt_status_support()) {
 292                 capabilities |= CAP_STATUS32;
 293         }
 294
 295         if (lp_host_msdfs()) {
 296                 capabilities |= CAP_DFS;
 297         }
 298
 299         if (lp_security() != SEC_SHARE) {
 300                 secword |= NEGOTIATE_SECURITY_USER_LEVEL;
 301         }
 302
 303         if (req->smb_conn->negotiate.encrypted_passwords) {
 304                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 305         }
 306
 307         if (req->smb_conn->signing.allow_smb_signing) {
 308                 secword |= NEGOTIATE_SECURITY_SIGNATURES_ENABLED;
 309         }
 310
 311         if (req->smb_conn->signing.mandatory_signing) {
 312                 secword |= NEGOTIATE_SECURITY_SIGNATURES_REQUIRED;
 313         }
 314
 315         req->smb_conn->negotiate.protocol = PROTOCOL_NT1;
 316
 317         smbsrv_setup_reply(req, 17, 0);
 318
 319         SSVAL(req->out.vwv, VWV(0), choice);
 320         SCVAL(req->out.vwv, VWV(1), secword);
 321
 322         /* notice the strange +1 on vwv here? That's because
 323            this is the one and only SMB packet that is malformed in
 324            the specification - all the command words after the secword
 325            are offset by 1 byte */
 326         SSVAL(req->out.vwv+1, VWV(1), lp_maxmux());
 327         SSVAL(req->out.vwv+1, VWV(2), 1); /* num vcs */
 328         SIVAL(req->out.vwv+1, VWV(3), req->smb_conn->negotiate.max_recv);
 329         SIVAL(req->out.vwv+1, VWV(5), 0x10000); /* raw size. full 64k */
 330         SIVAL(req->out.vwv+1, VWV(7), req->smb_conn->connection->server_id); /* session key */
 331         SIVAL(req->out.vwv+1, VWV(9), capabilities);
 332         push_nttime(req->out.vwv+1, VWV(11), nttime);
 333         SSVALS(req->out.vwv+1,VWV(15), req->smb_conn->negotiate.zone_offset/60);
 334
 335         if (!negotiate_spnego) {
 336                 reply_nt1_orig(req);
 337         } else {
 338                 struct cli_credentials *server_credentials;
 339                 struct gensec_security *gensec_security;
 340                 DATA_BLOB null_data_blob = data_blob(NULL, 0);
 341                 DATA_BLOB blob;
 342                 const char *oid;
 343                 NTSTATUS nt_status = gensec_server_start(req->smb_conn,
 344                                                          &gensec_security,
 345                                                          req->smb_conn->connection->event.ctx);
 346
 347                 if (!NT_STATUS_IS_OK(nt_status)) {
 348                         DEBUG(0, ("Failed to start GENSEC: %s\n", nt_errstr(nt_status)));
 349                         smbsrv_terminate_connection(req->smb_conn, "Failed to start GENSEC\n");
 350                         return;
 351                 }
 352
 353                 if (req->smb_conn->negotiate.auth_context) {
 354                         smbsrv_terminate_connection(req->smb_conn, "reply_nt1: is this a secondary negprot?  auth_context is non-NULL!\n");
 355                         return;
 356                 }
 357
 358                 server_credentials
 359                         = cli_credentials_init(req);
 360                 if (!server_credentials) {
 361                         smbsrv_terminate_connection(req->smb_conn, "Failed to init server credentials\n");
 362                         return;
 363                 }
 364
 365                 cli_credentials_set_conf(server_credentials);
 366                 nt_status = cli_credentials_set_machine_account(server_credentials);
 367                 if (!NT_STATUS_IS_OK(nt_status)) {
 368                         DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(nt_status)));
 369                         talloc_free(server_credentials);
 370                         server_credentials = NULL;
 371                 }
 372
 373                 req->smb_conn->negotiate.server_credentials = talloc_steal(req->smb_conn, server_credentials);
 374
 375                 gensec_set_target_service(gensec_security, "cifs");
 376
 377                 gensec_set_credentials(gensec_security, server_credentials);
 378
 379                 oid = GENSEC_OID_SPNEGO;
 380                 nt_status = gensec_start_mech_by_oid(gensec_security, oid);
 381
 382                 if (NT_STATUS_IS_OK(nt_status)) {
 383                         /* Get and push the proposed OID list into the packets */
 384                         nt_status = gensec_update(gensec_security, req, null_data_blob, &blob);
 385
 386                         if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 387                                 DEBUG(1, ("Failed to get SPNEGO to give us the first token: %s\n", nt_errstr(nt_status)));
 388                         }
 389                 }
 390
 391                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 392                         DEBUG(3,("using SPNEGO\n"));
 393                 } else {
 394                         DEBUG(5, ("Failed to start SPNEGO, falling back to NTLMSSP only: %s\n", nt_errstr(nt_status)));
 395                         oid = GENSEC_OID_NTLMSSP;
 396                         nt_status = gensec_start_mech_by_oid(gensec_security, oid);
 397
 398                         if (!NT_STATUS_IS_OK(nt_status)) {
 399                                 DEBUG(0, ("Failed to start SPNEGO as well as NTLMSSP fallback: %s\n", nt_errstr(nt_status)));
 400                                 reply_nt1_orig(req);
 401                                 return;
 402                         }
 403                         /* NTLMSSP is a client-first exchange */
 404                         blob = data_blob(NULL, 0);
 405                         DEBUG(3,("using raw-NTLMSSP\n"));
 406                 }
 407
 408                 req->smb_conn->negotiate.oid = oid;
 409
 410                 req_grow_data(req, blob.length + 16);
 411                 /* a NOT very random guid, perhaps we should get it
 412                  * from the credentials (kitchen sink...) */
 413                 memset(req->out.ptr, '\0', 16);
 414                 req->out.ptr += 16;
 415
 416                 memcpy(req->out.ptr, blob.data, blob.length);
 417                 SCVAL(req->out.vwv+1, VWV(16), blob.length + 16);
 418                 req->out.ptr += blob.length;
 419         }
 420
 421         smbsrv_send_reply_nosign(req);
 422 }
 423
 424 /****************************************************************************
 425  Reply for the SMB2 2.001 protocol
 426 ****************************************************************************/
 427 static void reply_smb2(struct smbsrv_request *req, uint16_t choice)
 428 {
 429         struct smbsrv_connection *smb_conn = req->smb_conn;
 430
 431         /* reply with a SMB2 packet */
 432         packet_set_callback(smb_conn->packet, smbsrv_recv_smb2_request);
 433         smb2srv_reply_smb_negprot(req);
 434         req = NULL;
 435 }
 436
 437 /* List of supported protocols, most desired first */
 438 static const struct {
 439         const char *proto_name;
 440         const char *short_name;
 441         void (*proto_reply_fn)(struct smbsrv_request *req, uint16_t choice);
 442         int protocol_level;
 443 } supported_protocols[] = {
 444         {"SMB 2.001",                   "SMB2",         reply_smb2,     PROTOCOL_SMB2},
 445         {"NT LANMAN 1.0",               "NT1",          reply_nt1,      PROTOCOL_NT1},
 446         {"NT LM 0.12",                  "NT1",          reply_nt1,      PROTOCOL_NT1},
 447         {"LANMAN2.1",                   "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 448         {"LM1.2X002",                   "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 449         {"Samba",                       "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 450         {"DOS LM1.2X002",               "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 451         {"Windows for Workgroups 3.1a", "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 452         {"LANMAN1.0",                   "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 453         {"MICROSOFT NETWORKS 3.0",      "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 454         {"MICROSOFT NETWORKS 1.03",     "COREPLUS",     reply_coreplus, PROTOCOL_COREPLUS},
 455         {"PC NETWORK PROGRAM 1.0",      "CORE",         reply_corep,    PROTOCOL_CORE},
 456         {NULL,NULL,NULL,0},
 457 };
 458
 459 /****************************************************************************
 460  Reply to a negprot.
 461 ****************************************************************************/
 462
 463 void smbsrv_reply_negprot(struct smbsrv_request *req)
 464 {
 465         int protocol;
 466         uint8_t *p;
 467         uint32_t protos_count = 0;
 468         char **protos = NULL;
 469
 470         if (req->smb_conn->negotiate.done_negprot) {
 471                 smbsrv_terminate_connection(req->smb_conn, "multiple negprot's are not permitted");
 472                 return;
 473         }
 474         req->smb_conn->negotiate.done_negprot = True;
 475
 476         p = req->in.data;
 477         while (True) {
 478                 size_t len;
 479
 480                 protos = talloc_realloc(req, protos, char *, protos_count + 1);
 481                 if (!protos) {
 482                         smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
 483                         return;
 484                 }
 485                 protos[protos_count] = NULL;
 486                 len = req_pull_ascii4(req, (const char **)&protos[protos_count], p, STR_ASCII|STR_TERMINATE);
 487                 p += len;
 488                 if (len == 0 || !protos[protos_count]) break;
 489
 490                 DEBUG(5,("Requested protocol [%d][%s]\n", protos_count, protos[protos_count]));
 491                 protos_count++;
 492         }
 493
 494         /* Check for protocols, most desirable first */
 495         for (protocol = 0; supported_protocols[protocol].proto_name; protocol++) {
 496                 int i;
 497
 498                 if (supported_protocols[protocol].protocol_level > lp_srv_maxprotocol()) continue;
 499                 if (supported_protocols[protocol].protocol_level < lp_srv_minprotocol()) continue;
 500
 501                 for (i = 0; i < protos_count; i++) {
 502                         if (strcmp(supported_protocols[protocol].proto_name, protos[i]) != 0) continue;
 503
 504                         supported_protocols[protocol].proto_reply_fn(req, i);
 505                         sub_set_remote_proto(supported_protocols[protocol].short_name);
 506                         DEBUG(3,("Selected protocol [%d][%s]\n",
 507                                 i, supported_protocols[protocol].proto_name));
 508                         return;
 509                 }
 510         }
 511
 512         smbsrv_terminate_connection(req->smb_conn, "No protocol supported !");
 513 }