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