source/auth/gensec/schannel_state.c

   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 "lib/ldb/include/ldb_errors.h"
  25 #include "dsdb/samdb/samdb.h"
  26 #include "db_wrap.h"
  27 #include "libcli/auth/libcli_auth.h"
  28 #include "auth/auth.h"
  29 #include "param/param.h"
  30
  31 /**
  32   connect to the schannel ldb
  33 */
  34 struct ldb_context *schannel_db_connect(TALLOC_CTX *mem_ctx)
  35 {
  36         char *path;
  37         struct ldb_context *ldb;
  38         bool existed;
  39         const char *init_ldif =
  40                 "dn: @ATTRIBUTES\n" \
  41                 "computerName: CASE_INSENSITIVE\n" \
  42                 "flatname: CASE_INSENSITIVE\n";
  43
  44         path = smbd_tmp_path(mem_ctx, global_loadparm, "schannel.ldb");
  45         if (!path) {
  46                 return NULL;
  47         }
  48
  49         existed = file_exist(path);
  50
  51         ldb = ldb_wrap_connect(mem_ctx, global_loadparm, path,
  52                                system_session(mem_ctx),
  53                                NULL, LDB_FLG_NOSYNC, NULL);
  54         talloc_free(path);
  55         if (!ldb) {
  56                 return NULL;
  57         }
  58
  59         if (!existed) {
  60                 gendb_add_ldif(ldb, init_ldif);
  61         }
  62
  63         return ldb;
  64 }
  65
  66 /*
  67   remember an established session key for a netr server authentication
  68   use a simple ldb structure
  69 */
  70 NTSTATUS schannel_store_session_key_ldb(TALLOC_CTX *mem_ctx,
  71                                         struct ldb_context *ldb,
  72                                         struct creds_CredentialState *creds)
  73 {
  74         struct ldb_message *msg;
  75         struct ldb_val val, seed, client_state, server_state;
  76         char *f;
  77         char *sct;
  78         int ret;
  79
  80         f = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->negotiate_flags);
  81
  82         if (f == NULL) {
  83                 return NT_STATUS_NO_MEMORY;
  84         }
  85
  86         sct = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->secure_channel_type);
  87
  88         if (sct == NULL) {
  89                 return NT_STATUS_NO_MEMORY;
  90         }
  91
  92         msg = ldb_msg_new(ldb);
  93         if (msg == NULL) {
  94                 return NT_STATUS_NO_MEMORY;
  95         }
  96
  97         msg->dn = ldb_dn_new_fmt(msg, ldb, "computerName=%s", creds->computer_name);
  98         if ( ! msg->dn) {
  99                 return NT_STATUS_NO_MEMORY;
 100         }
 101
 102         val.data = creds->session_key;
 103         val.length = sizeof(creds->session_key);
 104
 105         seed.data = creds->seed.data;
 106         seed.length = sizeof(creds->seed.data);
 107
 108         client_state.data = creds->client.data;
 109         client_state.length = sizeof(creds->client.data);
 110         server_state.data = creds->server.data;
 111         server_state.length = sizeof(creds->server.data);
 112
 113         ldb_msg_add_string(msg, "objectClass", "schannelState");
 114         ldb_msg_add_value(msg, "sessionKey", &val, NULL);
 115         ldb_msg_add_value(msg, "seed", &seed, NULL);
 116         ldb_msg_add_value(msg, "clientState", &client_state, NULL);
 117         ldb_msg_add_value(msg, "serverState", &server_state, NULL);
 118         ldb_msg_add_string(msg, "negotiateFlags", f);
 119         ldb_msg_add_string(msg, "secureChannelType", sct);
 120         ldb_msg_add_string(msg, "accountName", creds->account_name);
 121         ldb_msg_add_string(msg, "computerName", creds->computer_name);
 122         ldb_msg_add_string(msg, "flatname", creds->domain);
 123         samdb_msg_add_dom_sid(ldb, mem_ctx, msg, "objectSid", creds->sid);
 124
 125         ldb_delete(ldb, msg->dn);
 126
 127         ret = ldb_add(ldb, msg);
 128
 129         if (ret != 0) {
 130                 DEBUG(0,("Unable to add %s to session key db - %s\n",
 131                          ldb_dn_get_linearized(msg->dn), ldb_errstring(ldb)));
 132                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 133         }
 134
 135         return NT_STATUS_OK;
 136 }
 137
 138 NTSTATUS schannel_store_session_key(TALLOC_CTX *mem_ctx,
 139                                     struct creds_CredentialState *creds)
 140 {
 141         struct ldb_context *ldb;
 142         NTSTATUS nt_status;
 143         int ret;
 144
 145         ldb = schannel_db_connect(mem_ctx);
 146         if (!ldb) {
 147                 return NT_STATUS_ACCESS_DENIED;
 148         }
 149
 150         ret = ldb_transaction_start(ldb);
 151         if (ret != 0) {
 152                 talloc_free(ldb);
 153                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 154         }
 155
 156         nt_status = schannel_store_session_key_ldb(mem_ctx, ldb, creds);
 157
 158         if (NT_STATUS_IS_OK(nt_status)) {
 159                 ret = ldb_transaction_commit(ldb);
 160         } else {
 161                 ret = ldb_transaction_cancel(ldb);
 162         }
 163
 164         if (ret != 0) {
 165                 DEBUG(0,("Unable to commit adding credentials for %s to schannel key db - %s\n",
 166                          creds->computer_name, ldb_errstring(ldb)));
 167                 talloc_free(ldb);
 168                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 169         }
 170
 171         talloc_free(ldb);
 172         return nt_status;
 173 }
 174
 175 /*
 176   read back a credentials back for a computer
 177 */
 178 NTSTATUS schannel_fetch_session_key_ldb(TALLOC_CTX *mem_ctx,
 179                                         struct ldb_context *ldb,
 180                                         const char *computer_name,
 181                                         const char *domain,
 182                                         struct creds_CredentialState **creds)
 183 {
 184         struct ldb_result *res;
 185         int ret;
 186         const struct ldb_val *val;
 187
 188         *creds = talloc_zero(mem_ctx, struct creds_CredentialState);
 189         if (!*creds) {
 190                 return NT_STATUS_NO_MEMORY;
 191         }
 192
 193         ret = ldb_search_exp_fmt(ldb, mem_ctx, &res,
 194                                  NULL, LDB_SCOPE_SUBTREE, NULL,
 195                                 "(&(computerName=%s)(flatname=%s))", computer_name, domain);
 196         if (ret != LDB_SUCCESS) {
 197                 DEBUG(3,("schannel: Failed to find a record for client %s: %s\n", computer_name, ldb_errstring(ldb)));
 198                 return NT_STATUS_INVALID_HANDLE;
 199         }
 200         if (res->count != 1) {
 201                 DEBUG(3,("schannel: Failed to find a record for client: %s (found %d records)\n", computer_name, res->count));
 202                 talloc_free(res);
 203                 return NT_STATUS_INVALID_HANDLE;
 204         }
 205
 206         val = ldb_msg_find_ldb_val(res->msgs[0], "sessionKey");
 207         if (val == NULL || val->length != 16) {
 208                 DEBUG(1,("schannel: record in schannel DB must contain a sessionKey of length 16, when searching for client: %s\n", computer_name));
 209                 talloc_free(res);
 210                 return NT_STATUS_INTERNAL_ERROR;
 211         }
 212
 213         memcpy((*creds)->session_key, val->data, 16);
 214
 215         val = ldb_msg_find_ldb_val(res->msgs[0], "seed");
 216         if (val == NULL || val->length != 8) {
 217                 DEBUG(1,("schannel: record in schannel DB must contain a vaid seed of length 8, when searching for client: %s\n", computer_name));
 218                 talloc_free(res);
 219                 return NT_STATUS_INTERNAL_ERROR;
 220         }
 221
 222         memcpy((*creds)->seed.data, val->data, 8);
 223
 224         val = ldb_msg_find_ldb_val(res->msgs[0], "clientState");
 225         if (val == NULL || val->length != 8) {
 226                 DEBUG(1,("schannel: record in schannel DB must contain a vaid clientState of length 8, when searching for client: %s\n", computer_name));
 227                 talloc_free(res);
 228                 return NT_STATUS_INTERNAL_ERROR;
 229         }
 230         memcpy((*creds)->client.data, val->data, 8);
 231
 232         val = ldb_msg_find_ldb_val(res->msgs[0], "serverState");
 233         if (val == NULL || val->length != 8) {
 234                 DEBUG(1,("schannel: record in schannel DB must contain a vaid serverState of length 8, when searching for client: %s\n", computer_name));
 235                 talloc_free(res);
 236                 return NT_STATUS_INTERNAL_ERROR;
 237         }
 238         memcpy((*creds)->server.data, val->data, 8);
 239
 240         (*creds)->negotiate_flags = ldb_msg_find_attr_as_int(res->msgs[0], "negotiateFlags", 0);
 241
 242         (*creds)->secure_channel_type = ldb_msg_find_attr_as_int(res->msgs[0], "secureChannelType", 0);
 243
 244         (*creds)->account_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "accountName", NULL));
 245         if ((*creds)->account_name == NULL) {
 246                 talloc_free(res);
 247                 return NT_STATUS_NO_MEMORY;
 248         }
 249
 250         (*creds)->computer_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "computerName", NULL));
 251         if ((*creds)->computer_name == NULL) {
 252                 talloc_free(res);
 253                 return NT_STATUS_NO_MEMORY;
 254         }
 255
 256         (*creds)->domain = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "flatname", NULL));
 257         if ((*creds)->domain == NULL) {
 258                 talloc_free(res);
 259                 return NT_STATUS_NO_MEMORY;
 260         }
 261
 262         (*creds)->sid = samdb_result_dom_sid(*creds, res->msgs[0], "objectSid");
 263
 264         talloc_free(res);
 265         return NT_STATUS_OK;
 266 }
 267
 268 NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
 269                                         const char *computer_name,
 270                                         const char *domain,
 271                                         struct creds_CredentialState **creds)
 272 {
 273         NTSTATUS nt_status;
 274         struct ldb_context *ldb;
 275
 276         ldb = schannel_db_connect(mem_ctx);
 277         if (!ldb) {
 278                 return NT_STATUS_ACCESS_DENIED;
 279         }
 280
 281         nt_status = schannel_fetch_session_key_ldb(mem_ctx, ldb,
 282                                                    computer_name, domain,
 283                                                    creds);
 284         talloc_free(ldb);
 285         return nt_status;
 286 }