source4/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/events/events.h"
  24 #include "lib/ldb/include/ldb.h"
  25 #include "lib/ldb/include/ldb_errors.h"
  26 #include "dsdb/samdb/samdb.h"
  27 #include "ldb_wrap.h"
  28 #include "../lib/util/util_ldb.h"
  29 #include "libcli/auth/libcli_auth.h"
  30 #include "auth/auth.h"
  31 #include "param/param.h"
  32 #include "auth/gensec/schannel_state.h"
  33
  34 /**
  35   connect to the schannel ldb
  36 */
  37 struct ldb_context *schannel_db_connect(TALLOC_CTX *mem_ctx, struct tevent_context *ev_ctx,
  38                                         struct loadparm_context *lp_ctx)
  39 {
  40         char *path;
  41         struct ldb_context *ldb;
  42         bool existed;
  43         const char *init_ldif =
  44                 "dn: @ATTRIBUTES\n" \
  45                 "computerName: CASE_INSENSITIVE\n" \
  46                 "flatname: CASE_INSENSITIVE\n";
  47
  48         path = private_path(mem_ctx, lp_ctx, "schannel.ldb");
  49         if (!path) {
  50                 return NULL;
  51         }
  52
  53         existed = file_exist(path);
  54
  55         ldb = ldb_wrap_connect(mem_ctx, ev_ctx, lp_ctx, path,
  56                                system_session(mem_ctx, lp_ctx),
  57                                NULL, LDB_FLG_NOSYNC, NULL);
  58         talloc_free(path);
  59         if (!ldb) {
  60                 return NULL;
  61         }
  62
  63         if (!existed) {
  64                 gendb_add_ldif(ldb, init_ldif);
  65         }
  66
  67         return ldb;
  68 }
  69
  70 /*
  71   remember an established session key for a netr server authentication
  72   use a simple ldb structure
  73 */
  74 NTSTATUS schannel_store_session_key_ldb(TALLOC_CTX *mem_ctx,
  75                                         struct ldb_context *ldb,
  76                                         struct creds_CredentialState *creds)
  77 {
  78         struct ldb_message *msg;
  79         struct ldb_val val, seed, client_state, server_state;
  80         char *f;
  81         char *sct;
  82         int ret;
  83
  84         f = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->negotiate_flags);
  85
  86         if (f == NULL) {
  87                 return NT_STATUS_NO_MEMORY;
  88         }
  89
  90         sct = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->secure_channel_type);
  91
  92         if (sct == NULL) {
  93                 return NT_STATUS_NO_MEMORY;
  94         }
  95
  96         msg = ldb_msg_new(ldb);
  97         if (msg == NULL) {
  98                 return NT_STATUS_NO_MEMORY;
  99         }
 100
 101         msg->dn = ldb_dn_new_fmt(msg, ldb, "computerName=%s", creds->computer_name);
 102         if ( ! msg->dn) {
 103                 return NT_STATUS_NO_MEMORY;
 104         }
 105
 106         val.data = creds->session_key;
 107         val.length = sizeof(creds->session_key);
 108
 109         seed.data = creds->seed.data;
 110         seed.length = sizeof(creds->seed.data);
 111
 112         client_state.data = creds->client.data;
 113         client_state.length = sizeof(creds->client.data);
 114         server_state.data = creds->server.data;
 115         server_state.length = sizeof(creds->server.data);
 116
 117         ldb_msg_add_string(msg, "objectClass", "schannelState");
 118         ldb_msg_add_value(msg, "sessionKey", &val, NULL);
 119         ldb_msg_add_value(msg, "seed", &seed, NULL);
 120         ldb_msg_add_value(msg, "clientState", &client_state, NULL);
 121         ldb_msg_add_value(msg, "serverState", &server_state, NULL);
 122         ldb_msg_add_string(msg, "negotiateFlags", f);
 123         ldb_msg_add_string(msg, "secureChannelType", sct);
 124         ldb_msg_add_string(msg, "accountName", creds->account_name);
 125         ldb_msg_add_string(msg, "computerName", creds->computer_name);
 126         ldb_msg_add_string(msg, "flatname", creds->domain);
 127         samdb_msg_add_dom_sid(ldb, mem_ctx, msg, "objectSid", creds->sid);
 128
 129         ldb_delete(ldb, msg->dn);
 130
 131         ret = ldb_add(ldb, msg);
 132
 133         if (ret != 0) {
 134                 DEBUG(0,("Unable to add %s to session key db - %s\n",
 135                          ldb_dn_get_linearized(msg->dn), ldb_errstring(ldb)));
 136                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 137         }
 138
 139         return NT_STATUS_OK;
 140 }
 141
 142 NTSTATUS schannel_store_session_key(TALLOC_CTX *mem_ctx,
 143                                     struct tevent_context *ev_ctx,
 144                                     struct loadparm_context *lp_ctx,
 145                                     struct creds_CredentialState *creds)
 146 {
 147         struct ldb_context *ldb;
 148         NTSTATUS nt_status;
 149         int ret;
 150
 151         ldb = schannel_db_connect(mem_ctx, ev_ctx, lp_ctx);
 152         if (!ldb) {
 153                 return NT_STATUS_ACCESS_DENIED;
 154         }
 155
 156         ret = ldb_transaction_start(ldb);
 157         if (ret != 0) {
 158                 talloc_free(ldb);
 159                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 160         }
 161
 162         nt_status = schannel_store_session_key_ldb(mem_ctx, ldb, creds);
 163
 164         if (NT_STATUS_IS_OK(nt_status)) {
 165                 ret = ldb_transaction_commit(ldb);
 166         } else {
 167                 ret = ldb_transaction_cancel(ldb);
 168         }
 169
 170         if (ret != 0) {
 171                 DEBUG(0,("Unable to commit adding credentials for %s to schannel key db - %s\n",
 172                          creds->computer_name, ldb_errstring(ldb)));
 173                 talloc_free(ldb);
 174                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 175         }
 176
 177         talloc_free(ldb);
 178         return nt_status;
 179 }
 180
 181 /*
 182   read back a credentials back for a computer
 183 */
 184 NTSTATUS schannel_fetch_session_key_ldb(TALLOC_CTX *mem_ctx,
 185                                         struct ldb_context *ldb,
 186                                         const char *computer_name,
 187                                         const char *domain,
 188                                         struct creds_CredentialState **creds)
 189 {
 190         struct ldb_result *res;
 191         int ret;
 192         const struct ldb_val *val;
 193
 194         *creds = talloc_zero(mem_ctx, struct creds_CredentialState);
 195         if (!*creds) {
 196                 return NT_STATUS_NO_MEMORY;
 197         }
 198
 199         ret = ldb_search(ldb, mem_ctx, &res,
 200                                  NULL, LDB_SCOPE_SUBTREE, NULL,
 201                                 "(&(computerName=%s)(flatname=%s))", computer_name, domain);
 202         if (ret != LDB_SUCCESS) {
 203                 DEBUG(3,("schannel: Failed to find a record for client %s: %s\n", computer_name, ldb_errstring(ldb)));
 204                 return NT_STATUS_INVALID_HANDLE;
 205         }
 206         if (res->count != 1) {
 207                 DEBUG(3,("schannel: Failed to find a record for client: %s (found %d records)\n", computer_name, res->count));
 208                 talloc_free(res);
 209                 return NT_STATUS_INVALID_HANDLE;
 210         }
 211
 212         val = ldb_msg_find_ldb_val(res->msgs[0], "sessionKey");
 213         if (val == NULL || val->length != 16) {
 214                 DEBUG(1,("schannel: record in schannel DB must contain a sessionKey of length 16, when searching for client: %s\n", computer_name));
 215                 talloc_free(res);
 216                 return NT_STATUS_INTERNAL_ERROR;
 217         }
 218
 219         memcpy((*creds)->session_key, val->data, 16);
 220
 221         val = ldb_msg_find_ldb_val(res->msgs[0], "seed");
 222         if (val == NULL || val->length != 8) {
 223                 DEBUG(1,("schannel: record in schannel DB must contain a vaid seed of length 8, when searching for client: %s\n", computer_name));
 224                 talloc_free(res);
 225                 return NT_STATUS_INTERNAL_ERROR;
 226         }
 227
 228         memcpy((*creds)->seed.data, val->data, 8);
 229
 230         val = ldb_msg_find_ldb_val(res->msgs[0], "clientState");
 231         if (val == NULL || val->length != 8) {
 232                 DEBUG(1,("schannel: record in schannel DB must contain a vaid clientState of length 8, when searching for client: %s\n", computer_name));
 233                 talloc_free(res);
 234                 return NT_STATUS_INTERNAL_ERROR;
 235         }
 236         memcpy((*creds)->client.data, val->data, 8);
 237
 238         val = ldb_msg_find_ldb_val(res->msgs[0], "serverState");
 239         if (val == NULL || val->length != 8) {
 240                 DEBUG(1,("schannel: record in schannel DB must contain a vaid serverState of length 8, when searching for client: %s\n", computer_name));
 241                 talloc_free(res);
 242                 return NT_STATUS_INTERNAL_ERROR;
 243         }
 244         memcpy((*creds)->server.data, val->data, 8);
 245
 246         (*creds)->negotiate_flags = ldb_msg_find_attr_as_int(res->msgs[0], "negotiateFlags", 0);
 247
 248         (*creds)->secure_channel_type = ldb_msg_find_attr_as_int(res->msgs[0], "secureChannelType", 0);
 249
 250         (*creds)->account_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "accountName", NULL));
 251         if ((*creds)->account_name == NULL) {
 252                 talloc_free(res);
 253                 return NT_STATUS_NO_MEMORY;
 254         }
 255
 256         (*creds)->computer_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "computerName", NULL));
 257         if ((*creds)->computer_name == NULL) {
 258                 talloc_free(res);
 259                 return NT_STATUS_NO_MEMORY;
 260         }
 261
 262         (*creds)->domain = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "flatname", NULL));
 263         if ((*creds)->domain == NULL) {
 264                 talloc_free(res);
 265                 return NT_STATUS_NO_MEMORY;
 266         }
 267
 268         (*creds)->sid = samdb_result_dom_sid(*creds, res->msgs[0], "objectSid");
 269
 270         talloc_free(res);
 271         return NT_STATUS_OK;
 272 }
 273
 274 NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
 275                                     struct tevent_context *ev_ctx,
 276                                     struct loadparm_context *lp_ctx,
 277                                         const char *computer_name,
 278                                         const char *domain,
 279                                         struct creds_CredentialState **creds)
 280 {
 281         NTSTATUS nt_status;
 282         struct ldb_context *ldb;
 283
 284         ldb = schannel_db_connect(mem_ctx, ev_ctx, lp_ctx);
 285         if (!ldb) {
 286                 return NT_STATUS_ACCESS_DENIED;
 287         }
 288
 289         nt_status = schannel_fetch_session_key_ldb(mem_ctx, ldb,
 290                                                    computer_name, domain,
 291                                                    creds);
 292         talloc_free(ldb);
 293         return nt_status;
 294 }