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