source4/kdc/wdc-samba4.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    PAC Glue between Samba and the KDC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2009
   7    Copyright (C) Simo Sorce <idra@samba.org> 2010
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "../libds/common/flags.h"
  26 #include "auth/auth.h"
  27 #include "kdc/kdc-glue.h"
  28 #include "param/param.h"
  29 #include "kdc/pac-glue.h"
  30
  31 /* Given the right private pointer from hdb_samba4, get a PAC from the attached ldb messages */
  32 static krb5_error_code samba_wdc_get_pac(void *priv, krb5_context context,
  33                                          struct hdb_entry_ex *client,
  34                                          krb5_pac *pac)
  35 {
  36         TALLOC_CTX *mem_ctx;
  37         DATA_BLOB *pac_blob;
  38         krb5_error_code ret;
  39         NTSTATUS nt_status;
  40
  41         mem_ctx = talloc_named(client->ctx, 0, "samba_get_pac context");
  42         if (!mem_ctx) {
  43                 return ENOMEM;
  44         }
  45
  46         nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
  47         if (!NT_STATUS_IS_OK(nt_status)) {
  48                 talloc_free(mem_ctx);
  49                 return EINVAL;
  50         }
  51
  52         ret = samba_make_krb5_pac(context, pac_blob, pac);
  53
  54         talloc_free(mem_ctx);
  55         return ret;
  56 }
  57
  58 /* Resign (and reform, including possibly new groups) a PAC */
  59
  60 static krb5_error_code samba_wdc_reget_pac(void *priv, krb5_context context,
  61                                            const krb5_principal client_principal,
  62                                            struct hdb_entry_ex *client,
  63                                            struct hdb_entry_ex *server,
  64                                            struct hdb_entry_ex *krbtgt,
  65                                            krb5_pac *pac)
  66 {
  67         struct samba_kdc_entry *p = talloc_get_type(server->ctx, struct samba_kdc_entry);
  68         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_kdc_reget_pac context");
  69         DATA_BLOB *pac_blob;
  70         krb5_error_code ret;
  71         NTSTATUS nt_status;
  72
  73         if (!mem_ctx) {
  74                 return ENOMEM;
  75         }
  76
  77         /* The user account may be set not to want the PAC */
  78         if (!samba_princ_needs_pac(server)) {
  79                 talloc_free(mem_ctx);
  80                 return EINVAL;
  81         }
  82
  83         /* If the krbtgt was generated by an RODC, and we are not that
  84          * RODC, then we need to regenerate the PAC - we can't trust
  85          * it */
  86         if (samba_krbtgt_was_untrusted_rodc(krbtgt)) {
  87                 if (client == NULL) {
  88                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
  89                 }
  90                 nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
  91                 if (!NT_STATUS_IS_OK(nt_status)) {
  92                         talloc_free(mem_ctx);
  93                         return EINVAL;
  94                 }
  95         } else {
  96                 pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
  97                 if (!pac_blob) {
  98                         talloc_free(mem_ctx);
  99                         return ENOMEM;
 100                 }
 101
 102                 nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
 103                                                       pac, pac_blob);
 104                 if (!NT_STATUS_IS_OK(nt_status)) {
 105                         DEBUG(0, ("Building PAC failed: %s\n",
 106                                   nt_errstr(nt_status)));
 107                         talloc_free(mem_ctx);
 108                         return EINVAL;
 109                 }
 110         }
 111         /* We now completely regenerate this pac */
 112         krb5_pac_free(context, *pac);
 113
 114         ret = samba_make_krb5_pac(context, pac_blob, pac);
 115
 116         talloc_free(mem_ctx);
 117         return ret;
 118 }
 119
 120 static char *get_netbios_name(TALLOC_CTX *mem_ctx, HostAddresses *addrs)
 121 {
 122         char *nb_name = NULL;
 123         size_t len;
 124         unsigned int i;
 125
 126         for (i = 0; addrs && i < addrs->len; i++) {
 127                 if (addrs->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
 128                         continue;
 129                 }
 130                 len = MIN(addrs->val[i].address.length, 15);
 131                 nb_name = talloc_strndup(mem_ctx,
 132                                          addrs->val[i].address.data, len);
 133                 if (nb_name) {
 134                         break;
 135                 }
 136         }
 137
 138         if (nb_name == NULL) {
 139                 return NULL;
 140         }
 141
 142         /* Strip space padding */
 143         i = strlen(nb_name) - 1;
 144         while (i > 0 && nb_name[i] == ' ') {
 145                 nb_name[i] = '\0';
 146         }
 147
 148         return nb_name;
 149 }
 150
 151 static krb5_data fill_krb5_data(void *data, size_t length)
 152 {
 153         krb5_data kdata;
 154
 155         kdata.data = data;
 156         kdata.length = length;
 157
 158         return kdata;
 159 }
 160
 161 static krb5_error_code samba_wdc_check_client_access(void *priv,
 162                                                      krb5_context context,
 163                                                      krb5_kdc_configuration *config,
 164                                                      hdb_entry_ex *client_ex, const char *client_name,
 165                                                      hdb_entry_ex *server_ex, const char *server_name,
 166                                                      KDC_REQ *req,
 167                                                      krb5_data *e_data)
 168 {
 169         struct samba_kdc_entry *kdc_entry;
 170         bool password_change;
 171         char *workstation;
 172         NTSTATUS nt_status;
 173
 174         kdc_entry = talloc_get_type(client_ex->ctx, struct samba_kdc_entry);
 175         password_change = (server_ex && server_ex->entry.flags.change_pw);
 176         workstation = get_netbios_name((TALLOC_CTX *)client_ex->ctx,
 177                                         req->req_body.addresses);
 178
 179         nt_status = samba_kdc_check_client_access(kdc_entry,
 180                                                   client_name,
 181                                                   workstation,
 182                                                   password_change);
 183
 184         if (!NT_STATUS_IS_OK(nt_status)) {
 185                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
 186                         return ENOMEM;
 187                 }
 188
 189                 if (e_data) {
 190                         DATA_BLOB data;
 191
 192                         samba_kdc_build_edata_reply(nt_status, &data);
 193                         *e_data = fill_krb5_data(data.data, data.length);
 194                 }
 195
 196                 return samba_kdc_map_policy_err(nt_status);
 197         }
 198
 199         /* Now do the standard Heimdal check */
 200         return kdc_check_flags(context, config,
 201                                client_ex, client_name,
 202                                server_ex, server_name,
 203                                req->msg_type == krb_as_req);
 204 }
 205
 206 static krb5_error_code samba_wdc_plugin_init(krb5_context context, void **ptr)
 207 {
 208         *ptr = NULL;
 209         return 0;
 210 }
 211
 212 static void samba_wdc_plugin_fini(void *ptr)
 213 {
 214         return;
 215 }
 216
 217 struct krb5plugin_windc_ftable windc_plugin_table = {
 218         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 219         .init = samba_wdc_plugin_init,
 220         .fini = samba_wdc_plugin_fini,
 221         .pac_generate = samba_wdc_get_pac,
 222         .pac_verify = samba_wdc_reget_pac,
 223         .client_access = samba_wdc_check_client_access,
 224 };
 225
 226