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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "auth/auth.h"
  25 #include "lib/ldb/include/ldb.h"
  26 #include "lib/ldb/include/ldb_errors.h"
  27 #include "dsdb/samdb/samdb.h"
  28
  29 /*
  30   connect to the schannel ldb
  31 */
  32 struct ldb_context *schannel_db_connect(TALLOC_CTX *mem_ctx)
  33 {
  34         char *path;
  35         struct ldb_context *ldb;
  36         BOOL existed;
  37         const char *init_ldif =
  38                 "dn: @ATTRIBUTES\n" \
  39                 "computerName: CASE_INSENSITIVE\n" \
  40                 "flatname: CASE_INSENSITIVE\n";
  41
  42         path = smbd_tmp_path(mem_ctx, "schannel.ldb");
  43         if (!path) {
  44                 return NULL;
  45         }
  46
  47         existed = file_exists(path);
  48
  49         ldb = ldb_wrap_connect(mem_ctx, path, system_session(mem_ctx),
  50                                NULL, LDB_FLG_NOSYNC, NULL);
  51         talloc_free(path);
  52         if (!ldb) {
  53                 return NULL;
  54         }
  55
  56         if (!existed) {
  57                 gendb_add_ldif(ldb, init_ldif);
  58         }
  59
  60         return ldb;
  61 }
  62
  63 /*
  64   remember an established session key for a netr server authentication
  65   use a simple ldb structure
  66 */
  67 NTSTATUS schannel_store_session_key_ldb(TALLOC_CTX *mem_ctx,
  68                                         struct ldb_context *ldb,
  69                                         struct creds_CredentialState *creds)
  70 {
  71         struct ldb_message *msg;
  72         struct ldb_val val, seed, client_state, server_state;
  73         char *f;
  74         char *sct;
  75         int ret;
  76
  77         f = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->negotiate_flags);
  78
  79         if (f == NULL) {
  80                 return NT_STATUS_NO_MEMORY;
  81         }
  82
  83         sct = talloc_asprintf(mem_ctx, "%u", (unsigned int)creds->secure_channel_type);
  84
  85         if (sct == NULL) {
  86                 return NT_STATUS_NO_MEMORY;
  87         }
  88
  89         msg = ldb_msg_new(ldb);
  90         if (msg == NULL) {
  91                 return NT_STATUS_NO_MEMORY;
  92         }
  93
  94         msg->dn = ldb_dn_build_child(msg, "computerName", creds->computer_name, NULL);
  95         if (msg->dn == NULL) {
  96                 return NT_STATUS_NO_MEMORY;
  97         }
  98
  99         val.data = creds->session_key;
 100         val.length = sizeof(creds->session_key);
 101
 102         seed.data = creds->seed.data;
 103         seed.length = sizeof(creds->seed.data);
 104
 105         client_state.data = creds->client.data;
 106         client_state.length = sizeof(creds->client.data);
 107         server_state.data = creds->server.data;
 108         server_state.length = sizeof(creds->server.data);
 109
 110         ldb_msg_add_string(msg, "objectClass", "schannelState");
 111         ldb_msg_add_value(msg, "sessionKey", &val);
 112         ldb_msg_add_value(msg, "seed", &seed);
 113         ldb_msg_add_value(msg, "clientState", &client_state);
 114         ldb_msg_add_value(msg, "serverState", &server_state);
 115         ldb_msg_add_string(msg, "negotiateFlags", f);
 116         ldb_msg_add_string(msg, "secureChannelType", sct);
 117         ldb_msg_add_string(msg, "accountName", creds->account_name);
 118         ldb_msg_add_string(msg, "computerName", creds->computer_name);
 119         ldb_msg_add_string(msg, "flatname", creds->domain);
 120         samdb_msg_add_dom_sid(ldb, mem_ctx, msg, "objectSid", creds->sid);
 121
 122         ldb_delete(ldb, msg->dn);
 123
 124         ret = ldb_add(ldb, msg);
 125
 126         if (ret != 0) {
 127                 DEBUG(0,("Unable to add %s to session key db - %s\n",
 128                          ldb_dn_linearize(msg, msg->dn), ldb_errstring(ldb)));
 129                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 130         }
 131
 132         return NT_STATUS_OK;
 133 }
 134
 135 NTSTATUS schannel_store_session_key(TALLOC_CTX *mem_ctx,
 136                                     struct creds_CredentialState *creds)
 137 {
 138         struct ldb_context *ldb;
 139         NTSTATUS nt_status;
 140         int ret;
 141
 142         ldb = schannel_db_connect(mem_ctx);
 143         if (!ldb) {
 144                 return NT_STATUS_ACCESS_DENIED;
 145         }
 146
 147         ret = ldb_transaction_start(ldb);
 148         if (ret != 0) {
 149                 talloc_free(ldb);
 150                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 151         }
 152
 153         nt_status = schannel_store_session_key_ldb(mem_ctx, ldb, creds);
 154
 155         if (NT_STATUS_IS_OK(nt_status)) {
 156                 ret = ldb_transaction_commit(ldb);
 157         } else {
 158                 ret = ldb_transaction_cancel(ldb);
 159         }
 160
 161         if (ret != 0) {
 162                 DEBUG(0,("Unable to commit adding credentials for %s to schannel key db - %s\n",
 163                          creds->computer_name, ldb_errstring(ldb)));
 164                 talloc_free(ldb);
 165                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 166         }
 167
 168         talloc_free(ldb);
 169         return nt_status;
 170 }
 171
 172 /*
 173   read back a credentials back for a computer
 174 */
 175 NTSTATUS schannel_fetch_session_key_ldb(TALLOC_CTX *mem_ctx,
 176                                         struct ldb_context *ldb,
 177                                         const char *computer_name,
 178                                         const char *domain,
 179                                         struct creds_CredentialState **creds)
 180 {
 181         struct ldb_result *res;
 182         int ret;
 183         const struct ldb_val *val;
 184         char *expr=NULL;
 185
 186         *creds = talloc_zero(mem_ctx, struct creds_CredentialState);
 187         if (!*creds) {
 188                 return NT_STATUS_NO_MEMORY;
 189         }
 190
 191         expr = talloc_asprintf(mem_ctx, "(&(computerName=%s)(flatname=%s))",
 192                                computer_name, domain);
 193         if (expr == NULL) {
 194                 return NT_STATUS_NO_MEMORY;
 195         }
 196
 197         ret = ldb_search(ldb, NULL, LDB_SCOPE_SUBTREE, expr, NULL, &res);
 198         if (ret != LDB_SUCCESS || res->count != 1) {
 199                 DEBUG(3,("schannel: Failed to find a record for client: %s\n", computer_name));
 200                 return NT_STATUS_INVALID_HANDLE;
 201         }
 202
 203         val = ldb_msg_find_ldb_val(res->msgs[0], "sessionKey");
 204         if (val == NULL || val->length != 16) {
 205                 DEBUG(1,("schannel: record in schannel DB must contain a sessionKey of length 16, when searching for client: %s\n", computer_name));
 206                 return NT_STATUS_INTERNAL_ERROR;
 207         }
 208
 209         memcpy((*creds)->session_key, val->data, 16);
 210
 211         val = ldb_msg_find_ldb_val(res->msgs[0], "seed");
 212         if (val == NULL || val->length != 8) {
 213                 DEBUG(1,("schannel: record in schannel DB must contain a vaid seed of length 8, when searching for client: %s\n", computer_name));
 214                 return NT_STATUS_INTERNAL_ERROR;
 215         }
 216
 217         memcpy((*creds)->seed.data, val->data, 8);
 218
 219         val = ldb_msg_find_ldb_val(res->msgs[0], "clientState");
 220         if (val == NULL || val->length != 8) {
 221                 DEBUG(1,("schannel: record in schannel DB must contain a vaid clientState of length 8, when searching for client: %s\n", computer_name));
 222                 return NT_STATUS_INTERNAL_ERROR;
 223         }
 224         memcpy((*creds)->client.data, val->data, 8);
 225
 226         val = ldb_msg_find_ldb_val(res->msgs[0], "serverState");
 227         if (val == NULL || val->length != 8) {
 228                 DEBUG(1,("schannel: record in schannel DB must contain a vaid serverState of length 8, when searching for client: %s\n", computer_name));
 229                 return NT_STATUS_INTERNAL_ERROR;
 230         }
 231         memcpy((*creds)->server.data, val->data, 8);
 232
 233         (*creds)->negotiate_flags = ldb_msg_find_int(res->msgs[0], "negotiateFlags", 0);
 234
 235         (*creds)->secure_channel_type = ldb_msg_find_int(res->msgs[0], "secureChannelType", 0);
 236
 237         (*creds)->account_name = talloc_reference(*creds, ldb_msg_find_string(res->msgs[0], "accountName", NULL));
 238
 239         (*creds)->computer_name = talloc_reference(*creds, ldb_msg_find_string(res->msgs[0], "computerName", NULL));
 240
 241         (*creds)->domain = talloc_reference(*creds, ldb_msg_find_string(res->msgs[0], "flatname", NULL));
 242
 243         (*creds)->sid = samdb_result_dom_sid(*creds, res->msgs[0], "objectSid");
 244
 245         return NT_STATUS_OK;
 246 }
 247
 248 NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
 249                                         const char *computer_name,
 250                                         const char *domain,
 251                                         struct creds_CredentialState **creds)
 252 {
 253         NTSTATUS nt_status;
 254         struct ldb_context *ldb;
 255
 256         ldb = schannel_db_connect(mem_ctx);
 257         if (!ldb) {
 258                 return NT_STATUS_ACCESS_DENIED;
 259         }
 260
 261         nt_status = schannel_fetch_session_key_ldb(mem_ctx, ldb,
 262                                                    computer_name, domain,
 263                                                    creds);
 264         talloc_free(ldb);
 265         return nt_status;
 266 }