source3/auth/auth_netlogond.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Authenticate against a netlogon pipe listening on a unix domain socket
   4    Copyright (C) Volker Lendecke 2008
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "../libcli/auth/libcli_auth.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_AUTH
  25
  26 static NTSTATUS netlogond_validate(TALLOC_CTX *mem_ctx,
  27                                    const struct auth_context *auth_context,
  28                                    const char *ncalrpc_sockname,
  29                                    uint8_t schannel_key[16],
  30                                    const auth_usersupplied_info *user_info,
  31                                    struct netr_SamInfo3 **pinfo3,
  32                                    NTSTATUS *schannel_bind_result)
  33 {
  34         struct rpc_pipe_client *p = NULL;
  35         struct cli_pipe_auth_data *auth = NULL;
  36         struct netr_SamInfo3 *info3 = NULL;
  37         NTSTATUS status;
  38
  39         *schannel_bind_result = NT_STATUS_OK;
  40
  41         status = rpc_pipe_open_ncalrpc(talloc_tos(), ncalrpc_sockname,
  42                                        &ndr_table_netlogon.syntax_id, &p);
  43         if (!NT_STATUS_IS_OK(status)) {
  44                 DEBUG(10, ("rpc_pipe_open_ncalrpc failed: %s\n",
  45                            nt_errstr(status)));
  46                 return status;
  47         }
  48
  49         /*
  50          * We have to fake a struct dcinfo, so that
  51          * rpccli_netlogon_sam_network_logon_ex can decrypt the session keys.
  52          */
  53
  54         p->dc = netlogon_creds_client_init_session_key(p, schannel_key);
  55         if (p->dc == NULL) {
  56                 DEBUG(0, ("talloc failed\n"));
  57                 TALLOC_FREE(p);
  58                 return NT_STATUS_NO_MEMORY;
  59         }
  60
  61         status = rpccli_schannel_bind_data(p, lp_workgroup(),
  62                                            DCERPC_AUTH_LEVEL_PRIVACY,
  63                                            p->dc, &auth);
  64         if (!NT_STATUS_IS_OK(status)) {
  65                 DEBUG(10, ("rpccli_schannel_bind_data failed: %s\n",
  66                            nt_errstr(status)));
  67                 TALLOC_FREE(p);
  68                 return status;
  69         }
  70
  71         status = rpc_pipe_bind(p, auth);
  72         if (!NT_STATUS_IS_OK(status)) {
  73                 DEBUG(10, ("rpc_pipe_bind failed: %s\n", nt_errstr(status)));
  74                 TALLOC_FREE(p);
  75                 *schannel_bind_result = status;
  76                 return status;
  77         }
  78
  79         status = rpccli_netlogon_sam_network_logon_ex(
  80                 p, p,
  81                 user_info->logon_parameters,/* flags such as 'allow
  82                                              * workstation logon' */
  83                 global_myname(),            /* server name */
  84                 user_info->smb_name,        /* user name logging on. */
  85                 user_info->client_domain,   /* domain name */
  86                 user_info->wksta_name,      /* workstation name */
  87                 (uchar *)auth_context->challenge.data, /* 8 byte challenge. */
  88                 user_info->lm_resp,         /* lanman 24 byte response */
  89                 user_info->nt_resp,         /* nt 24 byte response */
  90                 &info3);                    /* info3 out */
  91
  92         DEBUG(10, ("rpccli_netlogon_sam_network_logon_ex returned %s\n",
  93                    nt_errstr(status)));
  94
  95         if (!NT_STATUS_IS_OK(status)) {
  96                 TALLOC_FREE(p);
  97                 return status;
  98         }
  99
 100         *pinfo3 = talloc_move(mem_ctx, &info3);
 101
 102         TALLOC_FREE(p);
 103         return NT_STATUS_OK;
 104 }
 105
 106 static char *mymachinepw(TALLOC_CTX *mem_ctx)
 107 {
 108         fstring pwd;
 109         const char *script;
 110         char *to_free = NULL;
 111         ssize_t nread;
 112         int ret, fd;
 113
 114         script = lp_parm_const_string(
 115                 GLOBAL_SECTION_SNUM, "auth_netlogond", "machinepwscript",
 116                 NULL);
 117
 118         if (script == NULL) {
 119                 to_free = talloc_asprintf(talloc_tos(), "%s/%s",
 120                                           get_dyn_SBINDIR(), "mymachinepw");
 121                 script = to_free;
 122         }
 123         if (script == NULL) {
 124                 return NULL;
 125         }
 126
 127         ret = smbrun(script, &fd);
 128         DEBUG(ret ? 0 : 3, ("mymachinepw: Running the command `%s' gave %d\n",
 129                             script, ret));
 130         TALLOC_FREE(to_free);
 131
 132         if (ret != 0) {
 133                 return NULL;
 134         }
 135
 136         nread = read(fd, pwd, sizeof(pwd)-1);
 137         close(fd);
 138
 139         if (nread <= 0) {
 140                 DEBUG(3, ("mymachinepwd: Could not read password\n"));
 141                 return NULL;
 142         }
 143
 144         pwd[nread] = '\0';
 145
 146         if (pwd[nread-1] == '\n') {
 147                 pwd[nread-1] = '\0';
 148         }
 149
 150         return talloc_strdup(mem_ctx, pwd);
 151 }
 152
 153 static NTSTATUS check_netlogond_security(const struct auth_context *auth_context,
 154                                          void *my_private_data,
 155                                          TALLOC_CTX *mem_ctx,
 156                                          const auth_usersupplied_info *user_info,
 157                                          auth_serversupplied_info **server_info)
 158 {
 159         TALLOC_CTX *frame = talloc_stackframe();
 160         struct netr_SamInfo3 *info3 = NULL;
 161         struct rpc_pipe_client *p = NULL;
 162         struct cli_pipe_auth_data *auth = NULL;
 163         uint32_t neg_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 164         char *plaintext_machinepw = NULL;
 165         uint8_t machine_password[16];
 166         uint8_t schannel_key[16];
 167         NTSTATUS schannel_bind_result, status;
 168         struct named_mutex *mutex = NULL;
 169         const char *ncalrpcsock;
 170
 171         ncalrpcsock = lp_parm_const_string(
 172                 GLOBAL_SECTION_SNUM, "auth_netlogond", "socket", NULL);
 173
 174         if (ncalrpcsock == NULL) {
 175                 ncalrpcsock = talloc_asprintf(talloc_tos(), "%s/%s",
 176                                               get_dyn_NCALRPCDIR(), "DEFAULT");
 177         }
 178
 179         if (ncalrpcsock == NULL) {
 180                 status = NT_STATUS_NO_MEMORY;
 181                 goto done;
 182         }
 183
 184         if (!secrets_fetch_local_schannel_key(schannel_key)) {
 185                 goto new_key;
 186         }
 187
 188         status = netlogond_validate(talloc_tos(), auth_context, ncalrpcsock,
 189                                     schannel_key, user_info, &info3,
 190                                     &schannel_bind_result);
 191
 192         DEBUG(10, ("netlogond_validate returned %s\n", nt_errstr(status)));
 193
 194         if (NT_STATUS_IS_OK(status)) {
 195                 goto okay;
 196         }
 197
 198         if (NT_STATUS_IS_OK(schannel_bind_result)) {
 199                 /*
 200                  * This is a real failure from the DC
 201                  */
 202                 goto done;
 203         }
 204
 205  new_key:
 206
 207         mutex = grab_named_mutex(talloc_tos(), "LOCAL_SCHANNEL_KEY", 60);
 208         if (mutex == NULL) {
 209                 DEBUG(10, ("Could not get mutex LOCAL_SCHANNEL_KEY\n"));
 210                 status = NT_STATUS_ACCESS_DENIED;
 211                 goto done;
 212         }
 213
 214         DEBUG(10, ("schannel bind failed, setting up new key\n"));
 215
 216         status = rpc_pipe_open_ncalrpc(talloc_tos(), ncalrpcsock,
 217                                        &ndr_table_netlogon.syntax_id, &p);
 218
 219         if (!NT_STATUS_IS_OK(status)) {
 220                 DEBUG(10, ("rpc_pipe_open_ncalrpc failed: %s\n",
 221                            nt_errstr(status)));
 222                 goto done;
 223         }
 224
 225         status = rpccli_anon_bind_data(p, &auth);
 226         if (!NT_STATUS_IS_OK(status)) {
 227                 DEBUG(10, ("rpccli_anon_bind_data failed: %s\n",
 228                            nt_errstr(status)));
 229                 goto done;
 230         }
 231
 232         status = rpc_pipe_bind(p, auth);
 233         if (!NT_STATUS_IS_OK(status)) {
 234                 DEBUG(10, ("rpc_pipe_bind failed: %s\n", nt_errstr(status)));
 235                 goto done;
 236         }
 237
 238         plaintext_machinepw = mymachinepw(talloc_tos());
 239         if (plaintext_machinepw == NULL) {
 240                 status = NT_STATUS_NO_MEMORY;
 241                 goto done;
 242         }
 243
 244         E_md4hash(plaintext_machinepw, machine_password);
 245
 246         TALLOC_FREE(plaintext_machinepw);
 247
 248         status = rpccli_netlogon_setup_creds(
 249                 p, global_myname(), lp_workgroup(), global_myname(),
 250                 global_myname(), machine_password, SEC_CHAN_BDC, &neg_flags);
 251
 252         if (!NT_STATUS_IS_OK(status)) {
 253                 DEBUG(10, ("rpccli_netlogon_setup_creds failed: %s\n",
 254                            nt_errstr(status)));
 255                 goto done;
 256         }
 257
 258         memcpy(schannel_key, p->dc->session_key, 16);
 259         secrets_store_local_schannel_key(schannel_key);
 260
 261         TALLOC_FREE(p);
 262
 263         /*
 264          * Retry the authentication with the mutex held. This way nobody else
 265          * can step on our toes.
 266          */
 267
 268         status = netlogond_validate(talloc_tos(), auth_context, ncalrpcsock,
 269                                     schannel_key, user_info, &info3,
 270                                     &schannel_bind_result);
 271
 272         DEBUG(10, ("netlogond_validate returned %s\n", nt_errstr(status)));
 273
 274         if (!NT_STATUS_IS_OK(status)) {
 275                 goto done;
 276         }
 277
 278  okay:
 279
 280         status = make_server_info_info3(mem_ctx, user_info->smb_name,
 281                                         user_info->domain, server_info,
 282                                         info3);
 283         if (!NT_STATUS_IS_OK(status)) {
 284                 DEBUG(10, ("make_server_info_info3 failed: %s\n",
 285                            nt_errstr(status)));
 286                 TALLOC_FREE(frame);
 287                 return status;
 288         }
 289
 290         status = NT_STATUS_OK;
 291
 292  done:
 293         TALLOC_FREE(frame);
 294         return status;
 295 }
 296
 297 /* module initialisation */
 298 static NTSTATUS auth_init_netlogond(struct auth_context *auth_context,
 299                                     const char *param,
 300                                     auth_methods **auth_method)
 301 {
 302         if (!make_auth_methods(auth_context, auth_method)) {
 303                 return NT_STATUS_NO_MEMORY;
 304         }
 305
 306         (*auth_method)->name = "netlogond";
 307         (*auth_method)->auth = check_netlogond_security;
 308         return NT_STATUS_OK;
 309 }
 310
 311 NTSTATUS auth_netlogond_init(void)
 312 {
 313         smb_register_auth(AUTH_INTERFACE_VERSION, "netlogond",
 314                           auth_init_netlogond);
 315         return NT_STATUS_OK;
 316 }