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 "kdc/kdc-glue.h"
  26 #include "kdc/pac-glue.h"
  27
  28 /* Given the right private pointer from hdb_samba4, get a PAC from the attached ldb messages */
  29 static krb5_error_code samba_wdc_get_pac(void *priv, krb5_context context,
  30                                          struct hdb_entry_ex *client,
  31                                          krb5_pac *pac)
  32 {
  33         TALLOC_CTX *mem_ctx;
  34         DATA_BLOB *pac_blob;
  35         krb5_error_code ret;
  36         NTSTATUS nt_status;
  37
  38         mem_ctx = talloc_named(client->ctx, 0, "samba_get_pac context");
  39         if (!mem_ctx) {
  40                 return ENOMEM;
  41         }
  42
  43         nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
  44         if (!NT_STATUS_IS_OK(nt_status)) {
  45                 talloc_free(mem_ctx);
  46                 return EINVAL;
  47         }
  48
  49         ret = samba_make_krb5_pac(context, pac_blob, NULL, pac);
  50
  51         talloc_free(mem_ctx);
  52         return ret;
  53 }
  54
  55 /* Resign (and reform, including possibly new groups) a PAC */
  56
  57 static krb5_error_code samba_wdc_reget_pac(void *priv, krb5_context context,
  58                                            const krb5_principal client_principal,
  59                                            const krb5_principal delegated_proxy_principal,
  60                                            struct hdb_entry_ex *client,
  61                                            struct hdb_entry_ex *server,
  62                                            struct hdb_entry_ex *krbtgt,
  63                                            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         DATA_BLOB *deleg_blob = NULL;
  69         krb5_error_code ret;
  70         NTSTATUS nt_status;
  71
  72         if (!mem_ctx) {
  73                 return ENOMEM;
  74         }
  75
  76         /* The user account may be set not to want the PAC */
  77         if (!samba_princ_needs_pac(server)) {
  78                 talloc_free(mem_ctx);
  79                 return EINVAL;
  80         }
  81
  82         /* If the krbtgt was generated by an RODC, and we are not that
  83          * RODC, then we need to regenerate the PAC - we can't trust
  84          * it */
  85         if (samba_krbtgt_was_untrusted_rodc(krbtgt)) {
  86                 if (client == NULL) {
  87                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
  88                 }
  89                 nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
  90                 if (!NT_STATUS_IS_OK(nt_status)) {
  91                         talloc_free(mem_ctx);
  92                         return EINVAL;
  93                 }
  94         } else {
  95                 pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
  96                 if (!pac_blob) {
  97                         talloc_free(mem_ctx);
  98                         return ENOMEM;
  99                 }
 100
 101                 nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
 102                                                       *pac, pac_blob);
 103                 if (!NT_STATUS_IS_OK(nt_status)) {
 104                         DEBUG(0, ("Building PAC failed: %s\n",
 105                                   nt_errstr(nt_status)));
 106                         talloc_free(mem_ctx);
 107                         return EINVAL;
 108                 }
 109         }
 110
 111         if (delegated_proxy_principal) {
 112                 deleg_blob = talloc_zero(mem_ctx, DATA_BLOB);
 113                 if (!deleg_blob) {
 114                         talloc_free(mem_ctx);
 115                         return ENOMEM;
 116                 }
 117
 118                 nt_status = samba_kdc_update_delegation_info_blob(mem_ctx,
 119                                         context, *pac,
 120                                         server->entry.principal,
 121                                         delegated_proxy_principal,
 122                                         deleg_blob);
 123                 if (!NT_STATUS_IS_OK(nt_status)) {
 124                         DEBUG(0, ("Building PAC failed: %s\n",
 125                                   nt_errstr(nt_status)));
 126                         talloc_free(mem_ctx);
 127                         return EINVAL;
 128                 }
 129         }
 130
 131         /* We now completely regenerate this pac */
 132         krb5_pac_free(context, *pac);
 133
 134         ret = samba_make_krb5_pac(context, pac_blob, deleg_blob, pac);
 135
 136         talloc_free(mem_ctx);
 137         return ret;
 138 }
 139
 140 static char *get_netbios_name(TALLOC_CTX *mem_ctx, HostAddresses *addrs)
 141 {
 142         char *nb_name = NULL;
 143         size_t len;
 144         unsigned int i;
 145
 146         for (i = 0; addrs && i < addrs->len; i++) {
 147                 if (addrs->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
 148                         continue;
 149                 }
 150                 len = MIN(addrs->val[i].address.length, 15);
 151                 nb_name = talloc_strndup(mem_ctx,
 152                                          addrs->val[i].address.data, len);
 153                 if (nb_name) {
 154                         break;
 155                 }
 156         }
 157
 158         if (nb_name == NULL) {
 159                 return NULL;
 160         }
 161
 162         /* Strip space padding */
 163         i = strlen(nb_name) - 1;
 164         while (i > 0 && nb_name[i] == ' ') {
 165                 nb_name[i] = '\0';
 166         }
 167
 168         return nb_name;
 169 }
 170
 171 static krb5_data fill_krb5_data(void *data, size_t length)
 172 {
 173         krb5_data kdata;
 174
 175         kdata.data = data;
 176         kdata.length = length;
 177
 178         return kdata;
 179 }
 180
 181 static krb5_error_code samba_wdc_check_client_access(void *priv,
 182                                                      krb5_context context,
 183                                                      krb5_kdc_configuration *config,
 184                                                      hdb_entry_ex *client_ex, const char *client_name,
 185                                                      hdb_entry_ex *server_ex, const char *server_name,
 186                                                      KDC_REQ *req,
 187                                                      krb5_data *e_data)
 188 {
 189         struct samba_kdc_entry *kdc_entry;
 190         bool password_change;
 191         char *workstation;
 192         NTSTATUS nt_status;
 193
 194         kdc_entry = talloc_get_type(client_ex->ctx, struct samba_kdc_entry);
 195         password_change = (server_ex && server_ex->entry.flags.change_pw);
 196         workstation = get_netbios_name((TALLOC_CTX *)client_ex->ctx,
 197                                         req->req_body.addresses);
 198
 199         nt_status = samba_kdc_check_client_access(kdc_entry,
 200                                                   client_name,
 201                                                   workstation,
 202                                                   password_change);
 203
 204         if (!NT_STATUS_IS_OK(nt_status)) {
 205                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
 206                         return ENOMEM;
 207                 }
 208
 209                 if (e_data) {
 210                         DATA_BLOB data;
 211
 212                         samba_kdc_build_edata_reply(nt_status, &data);
 213                         *e_data = fill_krb5_data(data.data, data.length);
 214                 }
 215
 216                 return samba_kdc_map_policy_err(nt_status);
 217         }
 218
 219         /* Now do the standard Heimdal check */
 220         return kdc_check_flags(context, config,
 221                                client_ex, client_name,
 222                                server_ex, server_name,
 223                                req->msg_type == krb_as_req);
 224 }
 225
 226 static krb5_error_code samba_wdc_plugin_init(krb5_context context, void **ptr)
 227 {
 228         *ptr = NULL;
 229         return 0;
 230 }
 231
 232 static void samba_wdc_plugin_fini(void *ptr)
 233 {
 234         return;
 235 }
 236
 237 struct krb5plugin_windc_ftable windc_plugin_table = {
 238         .minor_version = KRB5_WINDC_PLUGIN_MINOR,
 239         .init = samba_wdc_plugin_init,
 240         .fini = samba_wdc_plugin_fini,
 241         .pac_generate = samba_wdc_get_pac,
 242         .pac_verify = samba_wdc_reget_pac,
 243         .client_access = samba_wdc_check_client_access,
 244 };
 245
 246