root/source4/auth/gensec/schannel_state.c

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DEFINITIONS

This source file includes following definitions.
  1. schannel_dom_sid_ldb_val
  2. schannel_ldb_val_dom_sid
  3. schannel_db_connect
  4. schannel_store_session_key_ldb
  5. schannel_store_session_key
  6. schannel_fetch_session_key_ldb
  7. schannel_fetch_session_key

   1 /* 
   2    Unix SMB/CIFS implementation.
   3 
   4    module to store/fetch session keys for the schannel server
   5 
   6    Copyright (C) Andrew Tridgell 2004
   7    
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12    
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17    
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21 
  22 #include "includes.h"
  23 #include "lib/ldb/include/ldb.h"
  24 #include "librpc/gen_ndr/ndr_security.h"
  25 #include "ldb_wrap.h"
  26 #include "../lib/util/util_ldb.h"
  27 #include "libcli/auth/libcli_auth.h"
  28 #include "auth/auth.h"
  29 #include "param/param.h"
  30 #include "auth/gensec/schannel_state.h"
  31 
  32 static struct ldb_val *schannel_dom_sid_ldb_val(TALLOC_CTX *mem_ctx,
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  33                                                 struct smb_iconv_convenience *smbiconv,
  34                                                 struct dom_sid *sid)
  35 {
  36         enum ndr_err_code ndr_err;
  37         struct ldb_val *v;
  38 
  39         v = talloc(mem_ctx, struct ldb_val);
  40         if (!v) return NULL;
  41 
  42         ndr_err = ndr_push_struct_blob(v, mem_ctx, smbiconv, sid,
  43                                        (ndr_push_flags_fn_t)ndr_push_dom_sid);
  44         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  45                 talloc_free(v);
  46                 return NULL;
  47         }
  48 
  49         return v;
  50 }
  51 
  52 static struct dom_sid *schannel_ldb_val_dom_sid(TALLOC_CTX *mem_ctx,
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  53                                                  const struct ldb_val *v)
  54 {
  55         enum ndr_err_code ndr_err;
  56         struct dom_sid *sid;
  57 
  58         sid = talloc(mem_ctx, struct dom_sid);
  59         if (!sid) return NULL;
  60 
  61         ndr_err = ndr_pull_struct_blob(v, sid, NULL, sid,
  62                                         (ndr_pull_flags_fn_t)ndr_pull_dom_sid);
  63         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  64                 talloc_free(sid);
  65                 return NULL;
  66         }
  67         return sid;
  68 }
  69 
  70 
  71 /**
  72   connect to the schannel ldb
  73 */
  74 struct ldb_context *schannel_db_connect(TALLOC_CTX *mem_ctx, struct tevent_context *ev_ctx,
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  75                                         struct loadparm_context *lp_ctx)
  76 {
  77         char *path;
  78         struct ldb_context *ldb;
  79         bool existed;
  80         const char *init_ldif = 
  81                 "dn: @ATTRIBUTES\n" \
  82                 "computerName: CASE_INSENSITIVE\n" \
  83                 "flatname: CASE_INSENSITIVE\n";
  84 
  85         path = private_path(mem_ctx, lp_ctx, "schannel.ldb");
  86         if (!path) {
  87                 return NULL;
  88         }
  89 
  90         existed = file_exist(path);
  91         
  92         ldb = ldb_wrap_connect(mem_ctx, ev_ctx, lp_ctx, path, 
  93                                system_session(mem_ctx, lp_ctx), 
  94                                NULL, LDB_FLG_NOSYNC, NULL);
  95         talloc_free(path);
  96         if (!ldb) {
  97                 return NULL;
  98         }
  99         
 100         if (!existed) {
 101                 gendb_add_ldif(ldb, init_ldif);
 102         }
 103 
 104         return ldb;
 105 }
 106 
 107 /*
 108   remember an established session key for a netr server authentication
 109   use a simple ldb structure
 110 */
 111 NTSTATUS schannel_store_session_key_ldb(TALLOC_CTX *mem_ctx,
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 112                                         struct ldb_context *ldb,
 113                                         struct creds_CredentialState *creds)
 114 {
 115         struct ldb_message *msg;
 116         struct ldb_val val, seed, client_state, server_state;
 117         struct smb_iconv_convenience *smbiconv;
 118         struct ldb_val *sid_val;
 119         char *f;
 120         char *sct;
 121         int ret;
 122 
 123         f = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->negotiate_flags);
 124 
 125         if (f == NULL) {
 126                 return NT_STATUS_NO_MEMORY;
 127         }
 128 
 129         sct = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->secure_channel_type);
 130 
 131         if (sct == NULL) {
 132                 return NT_STATUS_NO_MEMORY;
 133         }
 134 
 135         msg = ldb_msg_new(ldb);
 136         if (msg == NULL) {
 137                 return NT_STATUS_NO_MEMORY;
 138         }
 139 
 140         msg->dn = ldb_dn_new_fmt(msg, ldb, "computerName=%s", creds->computer_name);
 141         if ( ! msg->dn) {
 142                 return NT_STATUS_NO_MEMORY;
 143         }
 144 
 145         smbiconv = lp_iconv_convenience(ldb_get_opaque(ldb, "loadparm"));
 146         sid_val = schannel_dom_sid_ldb_val(msg, smbiconv, creds->sid);
 147         if (sid_val == NULL) {
 148                 return NT_STATUS_NO_MEMORY;
 149         }
 150 
 151         val.data = creds->session_key;
 152         val.length = sizeof(creds->session_key);
 153 
 154         seed.data = creds->seed.data;
 155         seed.length = sizeof(creds->seed.data);
 156 
 157         client_state.data = creds->client.data;
 158         client_state.length = sizeof(creds->client.data);
 159         server_state.data = creds->server.data;
 160         server_state.length = sizeof(creds->server.data);
 161 
 162         ldb_msg_add_string(msg, "objectClass", "schannelState");
 163         ldb_msg_add_value(msg, "sessionKey", &val, NULL);
 164         ldb_msg_add_value(msg, "seed", &seed, NULL);
 165         ldb_msg_add_value(msg, "clientState", &client_state, NULL);
 166         ldb_msg_add_value(msg, "serverState", &server_state, NULL);
 167         ldb_msg_add_string(msg, "negotiateFlags", f);
 168         ldb_msg_add_string(msg, "secureChannelType", sct);
 169         ldb_msg_add_string(msg, "accountName", creds->account_name);
 170         ldb_msg_add_string(msg, "computerName", creds->computer_name);
 171         ldb_msg_add_string(msg, "flatname", creds->domain);
 172         ldb_msg_add_value(msg, "objectSid", sid_val, NULL);
 173 
 174         ldb_delete(ldb, msg->dn);
 175 
 176         ret = ldb_add(ldb, msg);
 177 
 178         if (ret != 0) {
 179                 DEBUG(0,("Unable to add %s to session key db - %s\n", 
 180                          ldb_dn_get_linearized(msg->dn), ldb_errstring(ldb)));
 181                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 182         }
 183 
 184         return NT_STATUS_OK;
 185 }
 186 
 187 NTSTATUS schannel_store_session_key(TALLOC_CTX *mem_ctx,
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 188                                     struct tevent_context *ev_ctx,
 189                                     struct loadparm_context *lp_ctx,
 190                                     struct creds_CredentialState *creds)
 191 {
 192         struct ldb_context *ldb;
 193         NTSTATUS nt_status;
 194         int ret;
 195                 
 196         ldb = schannel_db_connect(mem_ctx, ev_ctx, lp_ctx);
 197         if (!ldb) {
 198                 return NT_STATUS_ACCESS_DENIED;
 199         }
 200 
 201         ret = ldb_transaction_start(ldb);
 202         if (ret != 0) {
 203                 talloc_free(ldb);
 204                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 205         }
 206 
 207         nt_status = schannel_store_session_key_ldb(mem_ctx, ldb, creds);
 208 
 209         if (NT_STATUS_IS_OK(nt_status)) {
 210                 ret = ldb_transaction_commit(ldb);
 211         } else {
 212                 ret = ldb_transaction_cancel(ldb);
 213         }
 214 
 215         if (ret != 0) {
 216                 DEBUG(0,("Unable to commit adding credentials for %s to schannel key db - %s\n", 
 217                          creds->computer_name, ldb_errstring(ldb)));
 218                 talloc_free(ldb);
 219                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 220         }
 221 
 222         talloc_free(ldb);
 223         return nt_status;
 224 }
 225 
 226 /*
 227   read back a credentials back for a computer
 228 */
 229 NTSTATUS schannel_fetch_session_key_ldb(TALLOC_CTX *mem_ctx,
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 230                                         struct ldb_context *ldb,
 231                                         const char *computer_name, 
 232                                         const char *domain,
 233                                         struct creds_CredentialState **creds)
 234 {
 235         struct ldb_result *res;
 236         int ret;
 237         const struct ldb_val *val;
 238 
 239         *creds = talloc_zero(mem_ctx, struct creds_CredentialState);
 240         if (!*creds) {
 241                 return NT_STATUS_NO_MEMORY;
 242         }
 243 
 244         ret = ldb_search(ldb, mem_ctx, &res,
 245                                  NULL, LDB_SCOPE_SUBTREE, NULL,
 246                                 "(&(computerName=%s)(flatname=%s))", computer_name, domain);
 247         if (ret != LDB_SUCCESS) {
 248                 DEBUG(3,("schannel: Failed to find a record for client %s: %s\n", computer_name, ldb_errstring(ldb)));
 249                 return NT_STATUS_INVALID_HANDLE;
 250         }
 251         if (res->count != 1) {
 252                 DEBUG(3,("schannel: Failed to find a record for client: %s (found %d records)\n", computer_name, res->count));
 253                 talloc_free(res);
 254                 return NT_STATUS_INVALID_HANDLE;
 255         }
 256 
 257         val = ldb_msg_find_ldb_val(res->msgs[0], "sessionKey");
 258         if (val == NULL || val->length != 16) {
 259                 DEBUG(1,("schannel: record in schannel DB must contain a sessionKey of length 16, when searching for client: %s\n", computer_name));
 260                 talloc_free(res);
 261                 return NT_STATUS_INTERNAL_ERROR;
 262         }
 263 
 264         memcpy((*creds)->session_key, val->data, 16);
 265 
 266         val = ldb_msg_find_ldb_val(res->msgs[0], "seed");
 267         if (val == NULL || val->length != 8) {
 268                 DEBUG(1,("schannel: record in schannel DB must contain a vaid seed of length 8, when searching for client: %s\n", computer_name));
 269                 talloc_free(res);
 270                 return NT_STATUS_INTERNAL_ERROR;
 271         }
 272 
 273         memcpy((*creds)->seed.data, val->data, 8);
 274 
 275         val = ldb_msg_find_ldb_val(res->msgs[0], "clientState");
 276         if (val == NULL || val->length != 8) {
 277                 DEBUG(1,("schannel: record in schannel DB must contain a vaid clientState of length 8, when searching for client: %s\n", computer_name));
 278                 talloc_free(res);
 279                 return NT_STATUS_INTERNAL_ERROR;
 280         }
 281         memcpy((*creds)->client.data, val->data, 8);
 282 
 283         val = ldb_msg_find_ldb_val(res->msgs[0], "serverState");
 284         if (val == NULL || val->length != 8) {
 285                 DEBUG(1,("schannel: record in schannel DB must contain a vaid serverState of length 8, when searching for client: %s\n", computer_name));
 286                 talloc_free(res);
 287                 return NT_STATUS_INTERNAL_ERROR;
 288         }
 289         memcpy((*creds)->server.data, val->data, 8);
 290 
 291         (*creds)->negotiate_flags = ldb_msg_find_attr_as_int(res->msgs[0], "negotiateFlags", 0);
 292 
 293         (*creds)->secure_channel_type = ldb_msg_find_attr_as_int(res->msgs[0], "secureChannelType", 0);
 294 
 295         (*creds)->account_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "accountName", NULL));
 296         if ((*creds)->account_name == NULL) {
 297                 talloc_free(res);
 298                 return NT_STATUS_NO_MEMORY;
 299         }
 300 
 301         (*creds)->computer_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "computerName", NULL));
 302         if ((*creds)->computer_name == NULL) {
 303                 talloc_free(res);
 304                 return NT_STATUS_NO_MEMORY;
 305         }
 306 
 307         (*creds)->domain = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "flatname", NULL));
 308         if ((*creds)->domain == NULL) {
 309                 talloc_free(res);
 310                 return NT_STATUS_NO_MEMORY;
 311         }
 312 
 313         val = ldb_msg_find_ldb_val(res->msgs[0], "objectSid");
 314         if (val == NULL) {
 315                 DEBUG(1,("schannel: missing ObjectSid for client: %s\n", computer_name));
 316                 talloc_free(res);
 317                 return NT_STATUS_INTERNAL_ERROR;
 318         }
 319         (*creds)->sid = schannel_ldb_val_dom_sid(*creds, val);
 320         if ((*creds)->sid == NULL) {
 321                 talloc_free(res);
 322                 return NT_STATUS_INTERNAL_ERROR;
 323         }
 324 
 325         talloc_free(res);
 326         return NT_STATUS_OK;
 327 }
 328 
 329 NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
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 330                                     struct tevent_context *ev_ctx,
 331                                     struct loadparm_context *lp_ctx,
 332                                         const char *computer_name, 
 333                                         const char *domain, 
 334                                         struct creds_CredentialState **creds)
 335 {
 336         NTSTATUS nt_status;
 337         struct ldb_context *ldb;
 338 
 339         ldb = schannel_db_connect(mem_ctx, ev_ctx, lp_ctx);
 340         if (!ldb) {
 341                 return NT_STATUS_ACCESS_DENIED;
 342         }
 343 
 344         nt_status = schannel_fetch_session_key_ldb(mem_ctx, ldb,
 345                                                    computer_name, domain, 
 346                                                    creds);
 347         talloc_free(ldb);
 348         return nt_status;
 349 }

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