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,
  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                 nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
  88                 if (!NT_STATUS_IS_OK(nt_status)) {
  89                         talloc_free(mem_ctx);
  90                         return EINVAL;
  91                 }
  92         } else {
  93                 pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
  94                 if (!pac_blob) {
  95                         talloc_free(mem_ctx);
  96                         return ENOMEM;
  97                 }
  98
  99                 nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
 100                                                       pac, pac_blob);
 101                 if (!NT_STATUS_IS_OK(nt_status)) {
 102                         DEBUG(0, ("Building PAC failed: %s\n",
 103                                   nt_errstr(nt_status)));
 104                         talloc_free(mem_ctx);
 105                         return EINVAL;
 106                 }
 107         }
 108         /* We now completely regenerate this pac */
 109         krb5_pac_free(context, *pac);
 110
 111         ret = samba_make_krb5_pac(context, pac_blob, pac);
 112
 113         talloc_free(mem_ctx);
 114         return ret;
 115 }
 116
 117 static char *get_netbios_name(TALLOC_CTX *mem_ctx, HostAddresses *addrs)
 118 {
 119         char *nb_name = NULL;
 120         size_t len;
 121         unsigned int i;
 122
 123         for (i = 0; addrs && i < addrs->len; i++) {
 124                 if (addrs->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
 125                         continue;
 126                 }
 127                 len = MIN(addrs->val[i].address.length, 15);
 128                 nb_name = talloc_strndup(mem_ctx,
 129                                          addrs->val[i].address.data, len);
 130                 if (nb_name) {
 131                         break;
 132                 }
 133         }
 134
 135         if (nb_name == NULL) {
 136                 return NULL;
 137         }
 138
 139         /* Strip space padding */
 140         i = strlen(nb_name) - 1;
 141         while (i > 0 && nb_name[i] == ' ') {
 142                 nb_name[i] = '\0';
 143         }
 144
 145         return nb_name;
 146 }
 147
 148 static krb5_data fill_krb5_data(void *data, size_t length)
 149 {
 150         krb5_data kdata;
 151
 152         kdata.data = data;
 153         kdata.length = length;
 154
 155         return kdata;
 156 }
 157
 158 static krb5_error_code samba_wdc_check_client_access(void *priv,
 159                                                      krb5_context context,
 160                                                      krb5_kdc_configuration *config,
 161                                                      hdb_entry_ex *client_ex, const char *client_name,
 162                                                      hdb_entry_ex *server_ex, const char *server_name,
 163                                                      KDC_REQ *req,
 164                                                      krb5_data *e_data)
 165 {
 166         struct samba_kdc_entry *kdc_entry;
 167         bool password_change;
 168         char *workstation;
 169         NTSTATUS nt_status;
 170
 171         kdc_entry = talloc_get_type(client_ex->ctx, struct samba_kdc_entry);
 172         password_change = (server_ex && server_ex->entry.flags.change_pw);
 173         workstation = get_netbios_name((TALLOC_CTX *)client_ex->ctx,
 174                                         req->req_body.addresses);
 175
 176         nt_status = samba_kdc_check_client_access(kdc_entry,
 177                                                   client_name,
 178                                                   workstation,
 179                                                   password_change);
 180
 181         if (!NT_STATUS_IS_OK(nt_status)) {
 182                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
 183                         return ENOMEM;
 184                 }
 185
 186                 if (e_data) {
 187                         DATA_BLOB data;
 188
 189                         samba_kdc_build_edata_reply(nt_status, &data);
 190                         *e_data = fill_krb5_data(data.data, data.length);
 191                 }
 192
 193                 return samba_kdc_map_policy_err(nt_status);
 194         }
 195
 196         /* Now do the standard Heimdal check */
 197         return kdc_check_flags(context, config,
 198                                client_ex, client_name,
 199                                server_ex, server_name,
 200                                req->msg_type == krb_as_req);
 201 }
 202
 203 static krb5_error_code samba_wdc_plugin_init(krb5_context context, void **ptr)
 204 {
 205         *ptr = NULL;
 206         return 0;
 207 }
 208
 209 static void samba_wdc_plugin_fini(void *ptr)
 210 {
 211         return;
 212 }
 213
 214 struct krb5plugin_windc_ftable windc_plugin_table = {
 215         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 216         .init = samba_wdc_plugin_init,
 217         .fini = samba_wdc_plugin_fini,
 218         .pac_generate = samba_wdc_get_pac,
 219         .pac_verify = samba_wdc_reget_pac,
 220         .client_access = samba_wdc_check_client_access,
 221 };
 222
 223