source3/auth/user_krb5.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Authentication utility functions
   4    Copyright (C) Simo Sorce 2010
   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 "auth.h"
  22 #include "librpc/gen_ndr/krb5pac.h"
  23 #include "nsswitch/libwbclient/wbclient.h"
  24 #include "passdb.h"
  25 #include "lib/param/loadparm.h"
  26
  27 #undef DBGC_CLASS
  28 #define DBGC_CLASS DBGC_AUTH
  29
  30 #ifdef HAVE_KRB5
  31 NTSTATUS get_user_from_kerberos_info(TALLOC_CTX *mem_ctx,
  32                                      const char *cli_name,
  33                                      const char *princ_name,
  34                                      bool *is_mapped,
  35                                      bool *mapped_to_guest,
  36                                      char **ntuser,
  37                                      char **ntdomain,
  38                                      char **username,
  39                                      struct passwd **_pw)
  40 {
  41         NTSTATUS status;
  42         const char *domain = NULL;
  43         const char *realm = NULL;
  44         char *user = NULL;
  45         char *p;
  46         char *fuser = NULL;
  47         char *unixuser = NULL;
  48         struct passwd *pw = NULL;
  49         bool may_retry = false;
  50
  51         DEBUG(3, ("Kerberos ticket principal name is [%s]\n", princ_name));
  52
  53         p = strchr_m(princ_name, '@');
  54         if (!p) {
  55                 DEBUG(3, ("[%s] Doesn't look like a valid principal\n",
  56                           princ_name));
  57                 return NT_STATUS_LOGON_FAILURE;
  58         }
  59
  60         user = talloc_strndup(mem_ctx, princ_name, p - princ_name);
  61         if (!user) {
  62                 return NT_STATUS_NO_MEMORY;
  63         }
  64
  65         realm = p + 1;
  66
  67         if (!strequal(realm, lp_realm())) {
  68                 DEBUG(3, ("Ticket for foreign realm %s@%s\n", user, realm));
  69                 if (!lp_allow_trusted_domains()) {
  70                         return NT_STATUS_LOGON_FAILURE;
  71                 }
  72                 domain = realm;
  73         } else {
  74                 domain = lp_workgroup();
  75                 may_retry = true;
  76         }
  77
  78         fuser = talloc_asprintf(mem_ctx,
  79                                 "%s%c%s",
  80                                 domain,
  81                                 *lp_winbind_separator(),
  82                                 user);
  83         if (!fuser) {
  84                 return NT_STATUS_NO_MEMORY;
  85         }
  86
  87         *is_mapped = map_username(mem_ctx, fuser, &fuser);
  88         if (!fuser) {
  89                 return NT_STATUS_NO_MEMORY;
  90         }
  91         *mapped_to_guest = false;
  92
  93         pw = smb_getpwnam(mem_ctx, fuser, &unixuser, true);
  94         if (may_retry && pw == NULL && !*is_mapped) {
  95                 fuser = talloc_strdup(mem_ctx, user);
  96                 if (!fuser) {
  97                         return NT_STATUS_NO_MEMORY;
  98                 }
  99                 pw = smb_getpwnam(mem_ctx, fuser, &unixuser, true);
 100         }
 101         if (pw) {
 102                 if (!unixuser) {
 103                         return NT_STATUS_NO_MEMORY;
 104                 }
 105                 /* if a real user check pam account restrictions */
 106                 /* only really performed if "obey pam restriction" is true */
 107                 /* do this before an eventual mapping to guest occurs */
 108                 status = smb_pam_accountcheck(pw->pw_name, cli_name);
 109                 if (!NT_STATUS_IS_OK(status)) {
 110                         DEBUG(1, ("PAM account restrictions prevent user "
 111                                   "[%s] login\n", unixuser));
 112                         return status;
 113                 }
 114         }
 115         if (!pw) {
 116
 117                 /* this was originally the behavior of Samba 2.2, if a user
 118                    did not have a local uid but has been authenticated, then
 119                    map them to a guest account */
 120
 121                 if (lp_map_to_guest() == MAP_TO_GUEST_ON_BAD_UID) {
 122                         *mapped_to_guest = true;
 123                         fuser = talloc_strdup(mem_ctx, lp_guest_account());
 124                         if (!fuser) {
 125                                 return NT_STATUS_NO_MEMORY;
 126                         }
 127                         pw = smb_getpwnam(mem_ctx, fuser, &unixuser, false);
 128                 }
 129
 130                 /* extra sanity check that the guest account is valid */
 131                 if (!pw) {
 132                         DBG_NOTICE("Username %s is invalid on this system\n",
 133                                   fuser);
 134                         return NT_STATUS_LOGON_FAILURE;
 135                 }
 136         }
 137
 138         if (!unixuser) {
 139                 return NT_STATUS_NO_MEMORY;
 140         }
 141
 142         *username = talloc_strdup(mem_ctx, unixuser);
 143         if (!*username) {
 144                 return NT_STATUS_NO_MEMORY;
 145         }
 146         *ntuser = user;
 147         *ntdomain = talloc_strdup(mem_ctx, domain);
 148         if (*ntdomain == NULL) {
 149                 return NT_STATUS_NO_MEMORY;
 150         }
 151
 152         *_pw = pw;
 153
 154         return NT_STATUS_OK;
 155 }
 156
 157 NTSTATUS make_session_info_krb5(TALLOC_CTX *mem_ctx,
 158                                 char *ntuser,
 159                                 char *ntdomain,
 160                                 char *username,
 161                                 struct passwd *pw,
 162                                 bool mapped_to_guest, bool username_was_mapped,
 163                                 struct auth_session_info **session_info)
 164 {
 165         NTSTATUS status;
 166         struct auth_serversupplied_info *server_info;
 167
 168         if (mapped_to_guest) {
 169                 status = make_server_info_guest(mem_ctx, &server_info);
 170                 if (!NT_STATUS_IS_OK(status)) {
 171                         DEBUG(1, ("make_server_info_guest failed: %s!\n",
 172                                   nt_errstr(status)));
 173                         return status;
 174                 }
 175
 176         } else {
 177                 /*
 178                  * We didn't get a PAC, we have to make up the user
 179                  * ourselves. Try to ask the pdb backend to provide
 180                  * SID consistency with ntlmssp session setup
 181                  */
 182                 struct samu *sampass;
 183
 184                 sampass = samu_new(talloc_tos());
 185                 if (sampass == NULL) {
 186                         return NT_STATUS_NO_MEMORY;
 187                 }
 188
 189                 if (pdb_getsampwnam(sampass, username)) {
 190                         DEBUG(10, ("found user %s in passdb, calling "
 191                                    "make_server_info_sam\n", username));
 192                         status = make_server_info_sam(mem_ctx,
 193                                                       sampass,
 194                                                       &server_info);
 195                 } else {
 196                         /*
 197                          * User not in passdb, make it up artificially
 198                          */
 199                         DEBUG(10, ("didn't find user %s in passdb, calling "
 200                                    "make_server_info_pw\n", username));
 201                         status = make_server_info_pw(mem_ctx,
 202                                                      username,
 203                                                      pw,
 204                                                      &server_info);
 205                 }
 206
 207                 TALLOC_FREE(sampass);
 208
 209                 if (!NT_STATUS_IS_OK(status)) {
 210                         DEBUG(1, ("make_server_info_[sam|pw] failed: %s!\n",
 211                                   nt_errstr(status)));
 212                         return status;
 213                 }
 214
 215                 /* make_server_info_pw does not set the domain. Without this
 216                  * we end up with the local netbios name in substitutions for
 217                  * %D. */
 218
 219                 if (server_info->info3 != NULL) {
 220                         server_info->info3->base.logon_domain.string =
 221                                 talloc_strdup(server_info->info3, ntdomain);
 222                 }
 223         }
 224
 225         server_info->nss_token |= username_was_mapped;
 226
 227         status = create_local_token(mem_ctx, server_info, NULL, ntuser, session_info);
 228         talloc_free(server_info);
 229         if (!NT_STATUS_IS_OK(status)) {
 230                 DEBUG(10,("failed to create local token: %s\n",
 231                           nt_errstr(status)));
 232                 return status;
 233         }
 234
 235         return NT_STATUS_OK;
 236 }
 237
 238 #else /* HAVE_KRB5 */
 239 NTSTATUS get_user_from_kerberos_info(TALLOC_CTX *mem_ctx,
 240                                      const char *cli_name,
 241                                      const char *princ_name,
 242                                      bool *is_mapped,
 243                                      bool *mapped_to_guest,
 244                                      char **ntuser,
 245                                      char **ntdomain,
 246                                      char **username,
 247                                      struct passwd **_pw)
 248 {
 249         return NT_STATUS_NOT_IMPLEMENTED;
 250 }
 251
 252 NTSTATUS make_session_info_krb5(TALLOC_CTX *mem_ctx,
 253                                 char *ntuser,
 254                                 char *ntdomain,
 255                                 char *username,
 256                                 struct passwd *pw,
 257                                 bool mapped_to_guest, bool username_was_mapped,
 258                                 struct auth_session_info **session_info)
 259 {
 260         return NT_STATUS_NOT_IMPLEMENTED;
 261 }
 262
 263 #endif /* HAVE_KRB5 */