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, lp_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 loadparm_context *lp_ctx,
 141                                     struct creds_CredentialState *creds)
 142 {
 143         struct ldb_context *ldb;
 144         NTSTATUS nt_status;
 145         int ret;
 146
 147         ldb = schannel_db_connect(mem_ctx, lp_ctx);
 148         if (!ldb) {
 149                 return NT_STATUS_ACCESS_DENIED;
 150         }
 151
 152         ret = ldb_transaction_start(ldb);
 153         if (ret != 0) {
 154                 talloc_free(ldb);
 155                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 156         }
 157
 158         nt_status = schannel_store_session_key_ldb(mem_ctx, ldb, creds);
 159
 160         if (NT_STATUS_IS_OK(nt_status)) {
 161                 ret = ldb_transaction_commit(ldb);
 162         } else {
 163                 ret = ldb_transaction_cancel(ldb);
 164         }
 165
 166         if (ret != 0) {
 167                 DEBUG(0,("Unable to commit adding credentials for %s to schannel key db - %s\n",
 168                          creds->computer_name, ldb_errstring(ldb)));
 169                 talloc_free(ldb);
 170                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 171         }
 172
 173         talloc_free(ldb);
 174         return nt_status;
 175 }
 176
 177 /*
 178   read back a credentials back for a computer
 179 */
 180 NTSTATUS schannel_fetch_session_key_ldb(TALLOC_CTX *mem_ctx,
 181                                         struct ldb_context *ldb,
 182                                         const char *computer_name,
 183                                         const char *domain,
 184                                         struct creds_CredentialState **creds)
 185 {
 186         struct ldb_result *res;
 187         int ret;
 188         const struct ldb_val *val;
 189
 190         *creds = talloc_zero(mem_ctx, struct creds_CredentialState);
 191         if (!*creds) {
 192                 return NT_STATUS_NO_MEMORY;
 193         }
 194
 195         ret = ldb_search_exp_fmt(ldb, mem_ctx, &res,
 196                                  NULL, LDB_SCOPE_SUBTREE, NULL,
 197                                 "(&(computerName=%s)(flatname=%s))", computer_name, domain);
 198         if (ret != LDB_SUCCESS) {
 199                 DEBUG(3,("schannel: Failed to find a record for client %s: %s\n", computer_name, ldb_errstring(ldb)));
 200                 return NT_STATUS_INVALID_HANDLE;
 201         }
 202         if (res->count != 1) {
 203                 DEBUG(3,("schannel: Failed to find a record for client: %s (found %d records)\n", computer_name, res->count));
 204                 talloc_free(res);
 205                 return NT_STATUS_INVALID_HANDLE;
 206         }
 207
 208         val = ldb_msg_find_ldb_val(res->msgs[0], "sessionKey");
 209         if (val == NULL || val->length != 16) {
 210                 DEBUG(1,("schannel: record in schannel DB must contain a sessionKey of length 16, when searching for client: %s\n", computer_name));
 211                 talloc_free(res);
 212                 return NT_STATUS_INTERNAL_ERROR;
 213         }
 214
 215         memcpy((*creds)->session_key, val->data, 16);
 216
 217         val = ldb_msg_find_ldb_val(res->msgs[0], "seed");
 218         if (val == NULL || val->length != 8) {
 219                 DEBUG(1,("schannel: record in schannel DB must contain a vaid seed of length 8, when searching for client: %s\n", computer_name));
 220                 talloc_free(res);
 221                 return NT_STATUS_INTERNAL_ERROR;
 222         }
 223
 224         memcpy((*creds)->seed.data, val->data, 8);
 225
 226         val = ldb_msg_find_ldb_val(res->msgs[0], "clientState");
 227         if (val == NULL || val->length != 8) {
 228                 DEBUG(1,("schannel: record in schannel DB must contain a vaid clientState of length 8, when searching for client: %s\n", computer_name));
 229                 talloc_free(res);
 230                 return NT_STATUS_INTERNAL_ERROR;
 231         }
 232         memcpy((*creds)->client.data, val->data, 8);
 233
 234         val = ldb_msg_find_ldb_val(res->msgs[0], "serverState");
 235         if (val == NULL || val->length != 8) {
 236                 DEBUG(1,("schannel: record in schannel DB must contain a vaid serverState of length 8, when searching for client: %s\n", computer_name));
 237                 talloc_free(res);
 238                 return NT_STATUS_INTERNAL_ERROR;
 239         }
 240         memcpy((*creds)->server.data, val->data, 8);
 241
 242         (*creds)->negotiate_flags = ldb_msg_find_attr_as_int(res->msgs[0], "negotiateFlags", 0);
 243
 244         (*creds)->secure_channel_type = ldb_msg_find_attr_as_int(res->msgs[0], "secureChannelType", 0);
 245
 246         (*creds)->account_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "accountName", NULL));
 247         if ((*creds)->account_name == NULL) {
 248                 talloc_free(res);
 249                 return NT_STATUS_NO_MEMORY;
 250         }
 251
 252         (*creds)->computer_name = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "computerName", NULL));
 253         if ((*creds)->computer_name == NULL) {
 254                 talloc_free(res);
 255                 return NT_STATUS_NO_MEMORY;
 256         }
 257
 258         (*creds)->domain = talloc_strdup(*creds, ldb_msg_find_attr_as_string(res->msgs[0], "flatname", NULL));
 259         if ((*creds)->domain == NULL) {
 260                 talloc_free(res);
 261                 return NT_STATUS_NO_MEMORY;
 262         }
 263
 264         (*creds)->sid = samdb_result_dom_sid(*creds, res->msgs[0], "objectSid");
 265
 266         talloc_free(res);
 267         return NT_STATUS_OK;
 268 }
 269
 270 NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
 271                                     struct loadparm_context *lp_ctx,
 272                                         const char *computer_name,
 273                                         const char *domain,
 274                                         struct creds_CredentialState **creds)
 275 {
 276         NTSTATUS nt_status;
 277         struct ldb_context *ldb;
 278
 279         ldb = schannel_db_connect(mem_ctx, lp_ctx);
 280         if (!ldb) {
 281                 return NT_STATUS_ACCESS_DENIED;
 282         }
 283
 284         nt_status = schannel_fetch_session_key_ldb(mem_ctx, ldb,
 285                                                    computer_name, domain,
 286                                                    creds);
 287         talloc_free(ldb);
 288         return nt_status;
 289 }