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 "auth/gensec/schannel.h"
  30 #include "librpc/rpc/dcerpc.h"
  31 #include "param/param.h"
  32 #include "auth/session_proto.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 schannel_bind bind_schannel;
  52         struct schannel_bind_ack bind_schannel_ack;
  53         struct netlogon_creds_CredentialState *creds;
  54         struct ldb_context *schannel_ldb;
  55         const char *workstation;
  56         const char *domain;
  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.unknown1 = 0;
  69 #if 0
  70                 /* to support this we'd need to have access to the full domain name */
  71                 bind_schannel.bind_type = 23;
  72                 bind_schannel.u.info23.domain = cli_credentials_get_domain(gensec_security->credentials);
  73                 bind_schannel.u.info23.workstation = cli_credentials_get_workstation(gensec_security->credentials);
  74                 bind_schannel.u.info23.dnsdomain = cli_credentials_get_realm(gensec_security->credentials);
  75                 /* w2k3 refuses us if we use the full DNS workstation?
  76                  why? perhaps because we don't fill in the dNSHostName
  77                  attribute in the machine account? */
  78                 bind_schannel.u.info23.dnsworkstation = cli_credentials_get_workstation(gensec_security->credentials);
  79 #else
  80                 bind_schannel.bind_type = 3;
  81                 bind_schannel.u.info3.domain = cli_credentials_get_domain(gensec_security->credentials);
  82                 bind_schannel.u.info3.workstation = cli_credentials_get_workstation(gensec_security->credentials);
  83 #endif
  84
  85                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx,
  86                                                gensec_security->settings->iconv_convenience, &bind_schannel,
  87                                                (ndr_push_flags_fn_t)ndr_push_schannel_bind);
  88                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  89                         status = ndr_map_error2ntstatus(ndr_err);
  90                         DEBUG(3, ("Could not create schannel bind: %s\n",
  91                                   nt_errstr(status)));
  92                         return status;
  93                 }
  94
  95                 state->state = SCHANNEL_STATE_UPDATE_1;
  96
  97                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  98         case GENSEC_SERVER:
  99
 100                 if (state->state != SCHANNEL_STATE_START) {
 101                         /* no third leg on this protocol */
 102                         return NT_STATUS_INVALID_PARAMETER;
 103                 }
 104
 105                 /* parse the schannel startup blob */
 106                 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx,
 107                         gensec_security->settings->iconv_convenience,
 108                         &bind_schannel,
 109                         (ndr_pull_flags_fn_t)ndr_pull_schannel_bind);
 110                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 111                         status = ndr_map_error2ntstatus(ndr_err);
 112                         DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
 113                                   nt_errstr(status)));
 114                         return status;
 115                 }
 116
 117                 if (bind_schannel.bind_type == 23) {
 118                         workstation = bind_schannel.u.info23.workstation;
 119                         domain = bind_schannel.u.info23.domain;
 120                 } else {
 121                         workstation = bind_schannel.u.info3.workstation;
 122                         domain = bind_schannel.u.info3.domain;
 123                 }
 124
 125                 if (strcasecmp_m(domain, lp_workgroup(gensec_security->settings->lp_ctx)) != 0) {
 126                         DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
 127                                   domain, lp_workgroup(gensec_security->settings->lp_ctx)));
 128
 129                         return NT_STATUS_LOGON_FAILURE;
 130                 }
 131
 132                 schannel_ldb = schannel_db_connect(out_mem_ctx, gensec_security->event_ctx,
 133                                                    gensec_security->settings->lp_ctx);
 134                 if (!schannel_ldb) {
 135                         return NT_STATUS_ACCESS_DENIED;
 136                 }
 137                 /* pull the session key for this client */
 138                 status = schannel_fetch_session_key(schannel_ldb,
 139                                                     out_mem_ctx, workstation, &creds);
 140                 talloc_free(schannel_ldb);
 141                 if (!NT_STATUS_IS_OK(status)) {
 142                         DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
 143                                   workstation, nt_errstr(status)));
 144                         if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
 145                                 return NT_STATUS_LOGON_FAILURE;
 146                         }
 147                         return status;
 148                 }
 149
 150                 state->creds = talloc_reference(state, creds);
 151
 152                 bind_schannel_ack.unknown1 = 1;
 153                 bind_schannel_ack.unknown2 = 0;
 154                 bind_schannel_ack.unknown3 = 0x6c0000;
 155
 156                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx,
 157                                                gensec_security->settings->iconv_convenience, &bind_schannel_ack,
 158                                                (ndr_push_flags_fn_t)ndr_push_schannel_bind_ack);
 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 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->event_ctx, 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 static const struct gensec_security_ops gensec_schannel_security_ops = {
 274         .name           = "schannel",
 275         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 276         .client_start   = schannel_client_start,
 277         .server_start   = schannel_server_start,
 278         .update         = schannel_update,
 279         .seal_packet    = schannel_seal_packet,
 280         .sign_packet    = schannel_sign_packet,
 281         .check_packet   = schannel_check_packet,
 282         .unseal_packet  = schannel_unseal_packet,
 283         .session_key    = schannel_session_key,
 284         .session_info   = schannel_session_info,
 285         .sig_size       = schannel_sig_size,
 286         .have_feature   = schannel_have_feature,
 287         .enabled        = true,
 288         .priority       = GENSEC_SCHANNEL
 289 };
 290
 291 _PUBLIC_ NTSTATUS gensec_schannel_init(void)
 292 {
 293         NTSTATUS ret;
 294         ret = gensec_register(&gensec_schannel_security_ops);
 295         if (!NT_STATUS_IS_OK(ret)) {
 296                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 297                         gensec_schannel_security_ops.name));
 298                 return ret;
 299         }
 300
 301         return ret;
 302 }