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