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