source4/auth/gensec/schannel.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    dcerpc schannel operations
   5
   6    Copyright (C) Andrew Tridgell 2004
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "librpc/gen_ndr/ndr_schannel.h"
  25 #include "auth/auth.h"
  26 #include "auth/credentials/credentials.h"
  27 #include "auth/gensec/gensec.h"
  28 #include "auth/gensec/gensec_proto.h"
  29 #include "../libcli/auth/schannel.h"
  30 #include "auth/gensec/schannel_state.h"
  31 #include "librpc/rpc/dcerpc.h"
  32 #include "param/param.h"
  33
  34 static size_t schannel_sig_size(struct gensec_security *gensec_security, size_t data_size)
  35 {
  36         return 32;
  37 }
  38
  39 static NTSTATUS schannel_session_key(struct gensec_security *gensec_security,
  40                                             DATA_BLOB *session_key)
  41 {
  42         return NT_STATUS_NOT_IMPLEMENTED;
  43 }
  44
  45 static NTSTATUS schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
  46                                        const DATA_BLOB in, DATA_BLOB *out)
  47 {
  48         struct schannel_state *state = (struct schannel_state *)gensec_security->private_data;
  49         NTSTATUS status;
  50         enum ndr_err_code ndr_err;
  51         struct NL_AUTH_MESSAGE bind_schannel;
  52         struct NL_AUTH_MESSAGE bind_schannel_ack;
  53         struct netlogon_creds_CredentialState *creds;
  54         struct ldb_context *schannel_ldb;
  55         const char *workstation;
  56         const char *domain;
  57         uint32_t required_flags;
  58
  59         *out = data_blob(NULL, 0);
  60
  61         switch (gensec_security->gensec_role) {
  62         case GENSEC_CLIENT:
  63                 if (state->state != SCHANNEL_STATE_START) {
  64                         /* we could parse the bind ack, but we don't know what it is yet */
  65                         return NT_STATUS_OK;
  66                 }
  67
  68                 state->creds = talloc_reference(state, cli_credentials_get_netlogon_creds(gensec_security->credentials));
  69
  70                 bind_schannel.MessageType = NL_NEGOTIATE_REQUEST;
  71 #if 0
  72                 /* to support this we'd need to have access to the full domain name */
  73                 /* 0x17, 23 */
  74                 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
  75                                       NL_FLAG_OEM_NETBIOS_COMPUTER_NAME |
  76                                       NL_FLAG_UTF8_DNS_DOMAIN_NAME |
  77                                       NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME;
  78                 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
  79                 bind_schannel.oem_netbios_computer.a = cli_credentials_get_workstation(gensec_security->credentials);
  80                 bind_schannel.utf8_dns_domain = cli_credentials_get_realm(gensec_security->credentials);
  81                 /* w2k3 refuses us if we use the full DNS workstation?
  82                  why? perhaps because we don't fill in the dNSHostName
  83                  attribute in the machine account? */
  84                 bind_schannel.utf8_netbios_computer = cli_credentials_get_workstation(gensec_security->credentials);
  85 #else
  86                 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
  87                                       NL_FLAG_OEM_NETBIOS_COMPUTER_NAME;
  88                 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
  89                 bind_schannel.oem_netbios_computer.a = cli_credentials_get_workstation(gensec_security->credentials);
  90 #endif
  91
  92                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx,
  93                                                gensec_security->settings->iconv_convenience, &bind_schannel,
  94                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
  95                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  96                         status = ndr_map_error2ntstatus(ndr_err);
  97                         DEBUG(3, ("Could not create schannel bind: %s\n",
  98                                   nt_errstr(status)));
  99                         return status;
 100                 }
 101
 102                 state->state = SCHANNEL_STATE_UPDATE_1;
 103
 104                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 105         case GENSEC_SERVER:
 106
 107                 required_flags = NL_FLAG_OEM_NETBIOS_COMPUTER_NAME |
 108                                  NL_FLAG_OEM_NETBIOS_DOMAIN_NAME;
 109
 110                 if (state->state != SCHANNEL_STATE_START) {
 111                         /* no third leg on this protocol */
 112                         return NT_STATUS_INVALID_PARAMETER;
 113                 }
 114
 115                 /* parse the schannel startup blob */
 116                 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx,
 117                         gensec_security->settings->iconv_convenience,
 118                         &bind_schannel,
 119                         (ndr_pull_flags_fn_t)ndr_pull_NL_AUTH_MESSAGE);
 120                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 121                         status = ndr_map_error2ntstatus(ndr_err);
 122                         DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
 123                                   nt_errstr(status)));
 124                         return status;
 125                 }
 126
 127                 if (!(required_flags == (bind_schannel.Flags & required_flags))) {
 128                         return NT_STATUS_INVALID_PARAMETER;
 129                 }
 130
 131                 workstation = bind_schannel.oem_netbios_computer.a;
 132                 domain = bind_schannel.oem_netbios_domain.a;
 133
 134                 if (strcasecmp_m(domain, lp_workgroup(gensec_security->settings->lp_ctx)) != 0) {
 135                         DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
 136                                   domain, lp_workgroup(gensec_security->settings->lp_ctx)));
 137
 138                         return NT_STATUS_LOGON_FAILURE;
 139                 }
 140
 141                 schannel_ldb = schannel_db_connect(out_mem_ctx, gensec_security->event_ctx,
 142                                                    gensec_security->settings->lp_ctx);
 143                 if (!schannel_ldb) {
 144                         return NT_STATUS_ACCESS_DENIED;
 145                 }
 146                 /* pull the session key for this client */
 147                 status = schannel_fetch_session_key_ldb(schannel_ldb,
 148                                                         out_mem_ctx, workstation, &creds);
 149                 talloc_unlink(out_mem_ctx, schannel_ldb);
 150                 if (!NT_STATUS_IS_OK(status)) {
 151                         DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
 152                                   workstation, nt_errstr(status)));
 153                         if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
 154                                 return NT_STATUS_LOGON_FAILURE;
 155                         }
 156                         return status;
 157                 }
 158
 159                 state->creds = talloc_reference(state, creds);
 160
 161                 bind_schannel_ack.MessageType = NL_NEGOTIATE_RESPONSE;
 162                 bind_schannel_ack.Flags = 0;
 163                 bind_schannel_ack.Buffer.dummy = 0x6c0000; /* actually I think
 164                                                             * this does not have
 165                                                             * any meaning here
 166                                                             * - gd */
 167
 168                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx,
 169                                                gensec_security->settings->iconv_convenience, &bind_schannel_ack,
 170                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
 171                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 172                         status = ndr_map_error2ntstatus(ndr_err);
 173                         DEBUG(3, ("Could not return schannel bind ack for client %s: %s\n",
 174                                   workstation, nt_errstr(status)));
 175                         return status;
 176                 }
 177
 178                 state->state = SCHANNEL_STATE_UPDATE_1;
 179
 180                 return NT_STATUS_OK;
 181         }
 182         return NT_STATUS_INVALID_PARAMETER;
 183 }
 184
 185 /**
 186  * Return the struct netlogon_creds_CredentialState.
 187  *
 188  * Make sure not to call this unless gensec is using schannel...
 189  */
 190
 191 /* TODO: make this non-public */
 192
 193 _PUBLIC_ NTSTATUS dcerpc_schannel_creds(struct gensec_security *gensec_security,
 194                                         TALLOC_CTX *mem_ctx,
 195                                         struct netlogon_creds_CredentialState **creds)
 196 {
 197         struct schannel_state *state = talloc_get_type(gensec_security->private_data, struct schannel_state);
 198
 199         *creds = talloc_reference(mem_ctx, state->creds);
 200         if (!*creds) {
 201                 return NT_STATUS_NO_MEMORY;
 202         }
 203         return NT_STATUS_OK;
 204 }
 205
 206
 207 /**
 208  * Returns anonymous credentials for schannel, matching Win2k3.
 209  *
 210  */
 211
 212 static NTSTATUS schannel_session_info(struct gensec_security *gensec_security,
 213                                          struct auth_session_info **_session_info)
 214 {
 215         struct schannel_state *state = talloc_get_type(gensec_security->private_data, struct schannel_state);
 216         return auth_anonymous_session_info(state, gensec_security->event_ctx, gensec_security->settings->lp_ctx, _session_info);
 217 }
 218
 219 static NTSTATUS schannel_start(struct gensec_security *gensec_security)
 220 {
 221         struct schannel_state *state;
 222
 223         state = talloc(gensec_security, struct schannel_state);
 224         if (!state) {
 225                 return NT_STATUS_NO_MEMORY;
 226         }
 227
 228         state->state = SCHANNEL_STATE_START;
 229         state->seq_num = 0;
 230         gensec_security->private_data = state;
 231
 232         return NT_STATUS_OK;
 233 }
 234
 235 static NTSTATUS schannel_server_start(struct gensec_security *gensec_security)
 236 {
 237         NTSTATUS status;
 238         struct schannel_state *state;
 239
 240         status = schannel_start(gensec_security);
 241         if (!NT_STATUS_IS_OK(status)) {
 242                 return status;
 243         }
 244
 245         state = (struct schannel_state *)gensec_security->private_data;
 246         state->initiator = false;
 247
 248         return NT_STATUS_OK;
 249 }
 250
 251 static NTSTATUS schannel_client_start(struct gensec_security *gensec_security)
 252 {
 253         NTSTATUS status;
 254         struct schannel_state *state;
 255
 256         status = schannel_start(gensec_security);
 257         if (!NT_STATUS_IS_OK(status)) {
 258                 return status;
 259         }
 260
 261         state = (struct schannel_state *)gensec_security->private_data;
 262         state->initiator = true;
 263
 264         return NT_STATUS_OK;
 265 }
 266
 267
 268 static bool schannel_have_feature(struct gensec_security *gensec_security,
 269                                          uint32_t feature)
 270 {
 271         if (feature & (GENSEC_FEATURE_SIGN |
 272                        GENSEC_FEATURE_SEAL)) {
 273                 return true;
 274         }
 275         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 276                 return true;
 277         }
 278         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 279                 return true;
 280         }
 281         return false;
 282 }
 283
 284 /*
 285   unseal a packet
 286 */
 287 static NTSTATUS schannel_unseal_packet(struct gensec_security *gensec_security,
 288                                        TALLOC_CTX *mem_ctx,
 289                                        uint8_t *data, size_t length,
 290                                        const uint8_t *whole_pdu, size_t pdu_length,
 291                                        const DATA_BLOB *sig)
 292 {
 293         struct schannel_state *state =
 294                 talloc_get_type(gensec_security->private_data,
 295                                 struct schannel_state);
 296
 297         return netsec_incoming_packet(state, mem_ctx, true,
 298                                       discard_const_p(uint8_t, data),
 299                                       length, sig);
 300 }
 301
 302 /*
 303   check the signature on a packet
 304 */
 305 static NTSTATUS schannel_check_packet(struct gensec_security *gensec_security,
 306                                       TALLOC_CTX *mem_ctx,
 307                                       const uint8_t *data, size_t length,
 308                                       const uint8_t *whole_pdu, size_t pdu_length,
 309                                       const DATA_BLOB *sig)
 310 {
 311         struct schannel_state *state =
 312                 talloc_get_type(gensec_security->private_data,
 313                                 struct schannel_state);
 314
 315         return netsec_incoming_packet(state, mem_ctx, false,
 316                                       discard_const_p(uint8_t, data),
 317                                       length, sig);
 318 }
 319 /*
 320   seal a packet
 321 */
 322 static NTSTATUS schannel_seal_packet(struct gensec_security *gensec_security,
 323                                      TALLOC_CTX *mem_ctx,
 324                                      uint8_t *data, size_t length,
 325                                      const uint8_t *whole_pdu, size_t pdu_length,
 326                                      DATA_BLOB *sig)
 327 {
 328         struct schannel_state *state =
 329                 talloc_get_type(gensec_security->private_data,
 330                                 struct schannel_state);
 331
 332         return netsec_outgoing_packet(state, mem_ctx, true,
 333                                       data, length, sig);
 334 }
 335
 336 /*
 337   sign a packet
 338 */
 339 static NTSTATUS schannel_sign_packet(struct gensec_security *gensec_security,
 340                                      TALLOC_CTX *mem_ctx,
 341                                      const uint8_t *data, size_t length,
 342                                      const uint8_t *whole_pdu, size_t pdu_length,
 343                                      DATA_BLOB *sig)
 344 {
 345         struct schannel_state *state =
 346                 talloc_get_type(gensec_security->private_data,
 347                                 struct schannel_state);
 348
 349         return netsec_outgoing_packet(state, mem_ctx, false,
 350                                       discard_const_p(uint8_t, data),
 351                                       length, sig);
 352 }
 353
 354 static const struct gensec_security_ops gensec_schannel_security_ops = {
 355         .name           = "schannel",
 356         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 357         .client_start   = schannel_client_start,
 358         .server_start   = schannel_server_start,
 359         .update         = schannel_update,
 360         .seal_packet    = schannel_seal_packet,
 361         .sign_packet    = schannel_sign_packet,
 362         .check_packet   = schannel_check_packet,
 363         .unseal_packet  = schannel_unseal_packet,
 364         .session_key    = schannel_session_key,
 365         .session_info   = schannel_session_info,
 366         .sig_size       = schannel_sig_size,
 367         .have_feature   = schannel_have_feature,
 368         .enabled        = true,
 369         .priority       = GENSEC_SCHANNEL
 370 };
 371
 372 _PUBLIC_ NTSTATUS gensec_schannel_init(void)
 373 {
 374         NTSTATUS ret;
 375         ret = gensec_register(&gensec_schannel_security_ops);
 376         if (!NT_STATUS_IS_OK(ret)) {
 377                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 378                         gensec_schannel_security_ops.name));
 379                 return ret;
 380         }
 381
 382         return ret;
 383 }