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.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, krb5_pac *pac)
  64 {
  65         struct samba_kdc_entry *p = talloc_get_type(server->ctx, struct samba_kdc_entry);
  66         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_kdc_reget_pac context");
  67         DATA_BLOB *pac_blob;
  68         krb5_error_code ret;
  69         NTSTATUS nt_status;
  70
  71         if (!mem_ctx) {
  72                 return ENOMEM;
  73         }
  74
  75         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
  76         if (!pac_blob) {
  77                 talloc_free(mem_ctx);
  78                 return ENOMEM;
  79         }
  80
  81         /* The user account may be set not to want the PAC */
  82         if (!samba_princ_needs_pac(server)) {
  83                 talloc_free(mem_ctx);
  84                 return EINVAL;
  85         }
  86
  87         nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
  88                                               p->kdc_db_ctx->ic_ctx,
  89                                               pac, pac_blob);
  90         if (!NT_STATUS_IS_OK(nt_status)) {
  91                 DEBUG(0, ("Building PAC failed: %s\n",
  92                           nt_errstr(nt_status)));
  93                 talloc_free(mem_ctx);
  94                 return EINVAL;
  95         }
  96
  97         /* We now completely regenerate this pac */
  98         krb5_pac_free(context, *pac);
  99
 100         ret = samba_make_krb5_pac(context, pac_blob, pac);
 101
 102         talloc_free(mem_ctx);
 103         return ret;
 104 }
 105
 106 static char *get_netbios_name(TALLOC_CTX *mem_ctx, HostAddresses *addrs)
 107 {
 108         char *nb_name = NULL;
 109         int len, i;
 110
 111         for (i = 0; addrs && i < addrs->len; i++) {
 112                 if (addrs->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
 113                         continue;
 114                 }
 115                 len = MIN(addrs->val[i].address.length, 15);
 116                 nb_name = talloc_strndup(mem_ctx,
 117                                          addrs->val[i].address.data, len);
 118                 if (nb_name) {
 119                         break;
 120                 }
 121         }
 122
 123         if (nb_name == NULL) {
 124                 return NULL;
 125         }
 126
 127         /* Strip space padding */
 128         i = strlen(nb_name) - 1;
 129         while (i > 0 && nb_name[i] == ' ') {
 130                 nb_name[i] = '\0';
 131         }
 132
 133         return nb_name;
 134 }
 135
 136 static krb5_data fill_krb5_data(void *data, size_t length)
 137 {
 138         krb5_data kdata;
 139
 140         kdata.data = data;
 141         kdata.length = length;
 142
 143         return kdata;
 144 }
 145
 146 static krb5_error_code samba_wdc_check_client_access(void *priv,
 147                                                      krb5_context context,
 148                                                      krb5_kdc_configuration *config,
 149                                                      hdb_entry_ex *client_ex, const char *client_name,
 150                                                      hdb_entry_ex *server_ex, const char *server_name,
 151                                                      KDC_REQ *req,
 152                                                      krb5_data *e_data)
 153 {
 154         struct samba_kdc_entry *kdc_entry;
 155         bool password_change;
 156         char *workstation;
 157         NTSTATUS nt_status;
 158
 159         kdc_entry = talloc_get_type(client_ex->ctx, struct samba_kdc_entry);
 160         password_change = (server_ex && server_ex->entry.flags.change_pw);
 161         workstation = get_netbios_name((TALLOC_CTX *)client_ex->ctx,
 162                                         req->req_body.addresses);
 163
 164         nt_status = samba_kdc_check_client_access(kdc_entry,
 165                                                   client_name,
 166                                                   workstation,
 167                                                   password_change);
 168
 169         if (!NT_STATUS_IS_OK(nt_status)) {
 170                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
 171                         return ENOMEM;
 172                 }
 173
 174                 if (e_data) {
 175                         DATA_BLOB data;
 176
 177                         samba_kdc_build_edata_reply(nt_status, &data);
 178                         *e_data = fill_krb5_data(data.data, data.length);
 179                 }
 180
 181                 return samba_kdc_map_policy_err(nt_status);
 182         }
 183
 184         /* Now do the standard Heimdal check */
 185         return kdc_check_flags(context, config,
 186                                client_ex, client_name,
 187                                server_ex, server_name,
 188                                req->msg_type == krb_as_req);
 189 }
 190
 191 static krb5_error_code samba_wdc_plugin_init(krb5_context context, void **ptr)
 192 {
 193         *ptr = NULL;
 194         return 0;
 195 }
 196
 197 static void samba_wdc_plugin_fini(void *ptr)
 198 {
 199         return;
 200 }
 201
 202 struct krb5plugin_windc_ftable windc_plugin_table = {
 203         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 204         .init = samba_wdc_plugin_init,
 205         .fini = samba_wdc_plugin_fini,
 206         .pac_generate = samba_wdc_get_pac,
 207         .pac_verify = samba_wdc_reget_pac,
 208         .client_access = samba_wdc_check_client_access,
 209 };
 210
 211