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;
  35         struct cli_pipe_auth_data *auth;
  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         status = rpccli_schannel_bind_data(p, lp_workgroup(),
  50                                            PIPE_AUTH_LEVEL_PRIVACY,
  51                                            schannel_key, &auth);
  52         if (!NT_STATUS_IS_OK(status)) {
  53                 DEBUG(10, ("rpccli_schannel_bind_data failed: %s\n",
  54                            nt_errstr(status)));
  55                 TALLOC_FREE(p);
  56                 return status;
  57         }
  58
  59         status = rpc_pipe_bind(p, auth);
  60         if (!NT_STATUS_IS_OK(status)) {
  61                 DEBUG(10, ("rpc_pipe_bind failed: %s\n", nt_errstr(status)));
  62                 TALLOC_FREE(p);
  63                 *schannel_bind_result = status;
  64                 return status;
  65         }
  66
  67         /*
  68          * We have to fake a struct dcinfo, so that
  69          * rpccli_netlogon_sam_network_logon_ex can decrypt the session keys.
  70          */
  71
  72         p->dc = talloc(p, struct dcinfo);
  73         if (p->dc == NULL) {
  74                 DEBUG(0, ("talloc failed\n"));
  75                 TALLOC_FREE(p);
  76                 return NT_STATUS_NO_MEMORY;
  77         }
  78
  79         memcpy(p->dc->sess_key, schannel_key, 16);
  80
  81         status = rpccli_netlogon_sam_network_logon_ex(
  82                 p, p,
  83                 user_info->logon_parameters,/* flags such as 'allow
  84                                              * workstation logon' */
  85                 global_myname(),            /* server name */
  86                 user_info->smb_name,        /* user name logging on. */
  87                 user_info->client_domain,   /* domain name */
  88                 user_info->wksta_name,      /* workstation name */
  89                 (uchar *)auth_context->challenge.data, /* 8 byte challenge. */
  90                 user_info->lm_resp,         /* lanman 24 byte response */
  91                 user_info->nt_resp,         /* nt 24 byte response */
  92                 &info3);                    /* info3 out */
  93
  94         DEBUG(10, ("rpccli_netlogon_sam_network_logon_ex returned %s\n",
  95                    nt_errstr(status)));
  96
  97         if (!NT_STATUS_IS_OK(status)) {
  98                 TALLOC_FREE(p);
  99                 return status;
 100         }
 101
 102         *pinfo3 = talloc_move(mem_ctx, &info3);
 103
 104         TALLOC_FREE(p);
 105         return NT_STATUS_OK;
 106 }
 107
 108 static char *mymachinepw(TALLOC_CTX *mem_ctx)
 109 {
 110         fstring pwd;
 111         const char *script;
 112         char *to_free = NULL;
 113         ssize_t nread;
 114         int ret, fd;
 115
 116         script = lp_parm_const_string(
 117                 GLOBAL_SECTION_SNUM, "auth_netlogond", "machinepwscript",
 118                 NULL);
 119
 120         if (script == NULL) {
 121                 to_free = talloc_asprintf(talloc_tos(), "%s/%s",
 122                                           get_dyn_SBINDIR(), "mymachinepw");
 123                 script = to_free;
 124         }
 125         if (script == NULL) {
 126                 return NULL;
 127         }
 128
 129         ret = smbrun(script, &fd);
 130         DEBUG(ret ? 0 : 3, ("mymachinepw: Running the command `%s' gave %d\n",
 131                             script, ret));
 132         TALLOC_FREE(to_free);
 133
 134         if (ret != 0) {
 135                 return NULL;
 136         }
 137
 138         nread = read(fd, pwd, sizeof(pwd)-1);
 139         close(fd);
 140
 141         if (nread <= 0) {
 142                 DEBUG(3, ("mymachinepwd: Could not read password\n"));
 143                 return NULL;
 144         }
 145
 146         pwd[nread] = '\0';
 147
 148         if (pwd[nread-1] == '\n') {
 149                 pwd[nread-1] = '\0';
 150         }
 151
 152         return talloc_strdup(mem_ctx, pwd);
 153 }
 154
 155 static NTSTATUS check_netlogond_security(const struct auth_context *auth_context,
 156                                          void *my_private_data,
 157                                          TALLOC_CTX *mem_ctx,
 158                                          const auth_usersupplied_info *user_info,
 159                                          auth_serversupplied_info **server_info)
 160 {
 161         TALLOC_CTX *frame = talloc_stackframe();
 162         struct netr_SamInfo3 *info3 = NULL;
 163         struct rpc_pipe_client *p;
 164         struct cli_pipe_auth_data *auth;
 165         uint32_t neg_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 166         char *plaintext_machinepw;
 167         uint8_t machine_password[16];
 168         uint8_t schannel_key[16];
 169         NTSTATUS schannel_bind_result, status;
 170         struct named_mutex *mutex;
 171         const char *ncalrpcsock;
 172
 173         ncalrpcsock = lp_parm_const_string(
 174                 GLOBAL_SECTION_SNUM, "auth_netlogond", "socket", NULL);
 175
 176         if (ncalrpcsock == NULL) {
 177                 ncalrpcsock = talloc_asprintf(talloc_tos(), "%s/%s",
 178                                               get_dyn_NCALRPCDIR(), "DEFAULT");
 179         }
 180
 181         if (ncalrpcsock == NULL) {
 182                 status = NT_STATUS_NO_MEMORY;
 183                 goto done;
 184         }
 185
 186         if (!secrets_fetch_local_schannel_key(schannel_key)) {
 187                 goto new_key;
 188         }
 189
 190         status = netlogond_validate(talloc_tos(), auth_context, ncalrpcsock,
 191                                     schannel_key, user_info, &info3,
 192                                     &schannel_bind_result);
 193
 194         DEBUG(10, ("netlogond_validate returned %s\n", nt_errstr(status)));
 195
 196         if (NT_STATUS_IS_OK(status)) {
 197                 goto okay;
 198         }
 199
 200         if (NT_STATUS_IS_OK(schannel_bind_result)) {
 201                 /*
 202                  * This is a real failure from the DC
 203                  */
 204                 goto done;
 205         }
 206
 207  new_key:
 208
 209         mutex = grab_named_mutex(talloc_tos(), "LOCAL_SCHANNEL_KEY", 60);
 210         if (mutex == NULL) {
 211                 DEBUG(10, ("Could not get mutex LOCAL_SCHANNEL_KEY\n"));
 212                 status = NT_STATUS_ACCESS_DENIED;
 213                 goto done;
 214         }
 215
 216         DEBUG(10, ("schannel bind failed, setting up new key\n"));
 217
 218         status = rpc_pipe_open_ncalrpc(talloc_tos(), ncalrpcsock,
 219                                        &ndr_table_netlogon.syntax_id, &p);
 220
 221         if (!NT_STATUS_IS_OK(status)) {
 222                 DEBUG(10, ("rpc_pipe_open_ncalrpc failed: %s\n",
 223                            nt_errstr(status)));
 224                 goto done;
 225         }
 226
 227         status = rpccli_anon_bind_data(p, &auth);
 228         if (!NT_STATUS_IS_OK(status)) {
 229                 DEBUG(10, ("rpccli_anon_bind_data failed: %s\n",
 230                            nt_errstr(status)));
 231                 goto done;
 232         }
 233
 234         status = rpc_pipe_bind(p, auth);
 235         if (!NT_STATUS_IS_OK(status)) {
 236                 DEBUG(10, ("rpc_pipe_bind failed: %s\n", nt_errstr(status)));
 237                 goto done;
 238         }
 239
 240         plaintext_machinepw = mymachinepw(talloc_tos());
 241         if (plaintext_machinepw == NULL) {
 242                 status = NT_STATUS_NO_MEMORY;
 243                 goto done;
 244         }
 245
 246         E_md4hash(plaintext_machinepw, machine_password);
 247
 248         TALLOC_FREE(plaintext_machinepw);
 249
 250         status = rpccli_netlogon_setup_creds(
 251                 p, global_myname(), lp_workgroup(), global_myname(),
 252                 global_myname(), machine_password, SEC_CHAN_BDC, &neg_flags);
 253
 254         if (!NT_STATUS_IS_OK(status)) {
 255                 DEBUG(10, ("rpccli_netlogon_setup_creds failed: %s\n",
 256                            nt_errstr(status)));
 257                 goto done;
 258         }
 259
 260         memcpy(schannel_key, p->dc->sess_key, 16);
 261         secrets_store_local_schannel_key(schannel_key);
 262
 263         TALLOC_FREE(p);
 264
 265         /*
 266          * Retry the authentication with the mutex held. This way nobody else
 267          * can step on our toes.
 268          */
 269
 270         status = netlogond_validate(talloc_tos(), auth_context, ncalrpcsock,
 271                                     schannel_key, user_info, &info3,
 272                                     &schannel_bind_result);
 273
 274         DEBUG(10, ("netlogond_validate returned %s\n", nt_errstr(status)));
 275
 276         if (!NT_STATUS_IS_OK(status)) {
 277                 goto done;
 278         }
 279
 280  okay:
 281
 282         status = make_server_info_info3(mem_ctx, user_info->smb_name,
 283                                         user_info->domain, server_info,
 284                                         info3);
 285         if (!NT_STATUS_IS_OK(status)) {
 286                 DEBUG(10, ("make_server_info_info3 failed: %s\n",
 287                            nt_errstr(status)));
 288                 TALLOC_FREE(frame);
 289                 return status;
 290         }
 291
 292         status = NT_STATUS_OK;
 293
 294  done:
 295         TALLOC_FREE(frame);
 296         return status;
 297 }
 298
 299 /* module initialisation */
 300 static NTSTATUS auth_init_netlogond(struct auth_context *auth_context,
 301                                     const char *param,
 302                                     auth_methods **auth_method)
 303 {
 304         if (!make_auth_methods(auth_context, auth_method)) {
 305                 return NT_STATUS_NO_MEMORY;
 306         }
 307
 308         (*auth_method)->name = "netlogond";
 309         (*auth_method)->auth = check_netlogond_security;
 310         return NT_STATUS_OK;
 311 }
 312
 313 NTSTATUS auth_netlogond_init(void)
 314 {
 315         smb_register_auth(AUTH_INTERFACE_VERSION, "netlogond",
 316                           auth_init_netlogond);
 317         return NT_STATUS_OK;
 318 }