source4/kdc/pac-glue.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
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "../libds/common/flags.h"
  25 #include "lib/ldb/include/ldb.h"
  26 #include "librpc/gen_ndr/ndr_krb5pac.h"
  27 #include "librpc/gen_ndr/krb5pac.h"
  28 #include "auth/auth.h"
  29 #include "auth/auth_sam.h"
  30 #include "auth/auth_sam_reply.h"
  31 #include "kdc/kdc.h"
  32 #include "param/param.h"
  33
  34 struct krb5_dh_moduli;
  35 struct _krb5_krb_auth_data;
  36
  37 static krb5_error_code  samba_kdc_plugin_init(krb5_context context, void **ptr)
  38 {
  39         *ptr = NULL;
  40         return 0;
  41 }
  42
  43 static void     samba_kdc_plugin_fini(void *ptr)
  44 {
  45         return;
  46 }
  47
  48 static krb5_error_code make_pac(krb5_context context,
  49                                 TALLOC_CTX *mem_ctx,
  50                                 struct smb_iconv_convenience *iconv_convenience,
  51                                 struct auth_serversupplied_info *server_info,
  52                                 krb5_pac *pac)
  53 {
  54         union PAC_INFO info;
  55         struct netr_SamInfo3 *info3;
  56         krb5_data pac_data;
  57         NTSTATUS nt_status;
  58         enum ndr_err_code ndr_err;
  59         DATA_BLOB pac_out;
  60         krb5_error_code ret;
  61
  62         ZERO_STRUCT(info);
  63
  64         nt_status = auth_convert_server_info_saminfo3(mem_ctx, server_info, &info3);
  65         if (!NT_STATUS_IS_OK(nt_status)) {
  66                 DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
  67                 return EINVAL;
  68         }
  69
  70         info.logon_info.info = talloc_zero(mem_ctx, struct PAC_LOGON_INFO);
  71         if (!mem_ctx) {
  72                 return ENOMEM;
  73         }
  74
  75         info.logon_info.info->info3 = *info3;
  76
  77         ndr_err = ndr_push_union_blob(&pac_out, mem_ctx, iconv_convenience, &info,
  78                                       PAC_TYPE_LOGON_INFO,
  79                                       (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
  80         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  81                 nt_status = ndr_map_error2ntstatus(ndr_err);
  82                 DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
  83                 return EINVAL;
  84         }
  85
  86         ret = krb5_data_copy(&pac_data, pac_out.data, pac_out.length);
  87         if (ret != 0) {
  88                 return ret;
  89         }
  90
  91         ret = krb5_pac_init(context, pac);
  92         if (ret != 0) {
  93                 krb5_data_free(&pac_data);
  94                 return ret;
  95         }
  96
  97         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
  98         krb5_data_free(&pac_data);
  99         if (ret != 0) {
 100                 return ret;
 101         }
 102
 103         return ret;
 104 }
 105
 106 /* Given the right private pointer from hdb_samba4, get a PAC from the attached ldb messages */
 107 static krb5_error_code samba_kdc_get_pac(void *priv,
 108                                          krb5_context context,
 109                                          struct hdb_entry_ex *client,
 110                                          krb5_pac *pac)
 111 {
 112         krb5_error_code ret;
 113         NTSTATUS nt_status;
 114         struct auth_serversupplied_info *server_info;
 115         struct hdb_samba4_private *p = talloc_get_type(client->ctx, struct hdb_samba4_private);
 116         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_get_pac context");
 117         unsigned int userAccountControl;
 118
 119         if (!mem_ctx) {
 120                 return ENOMEM;
 121         }
 122
 123         /* The user account may be set not to want the PAC */
 124         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 125         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 126                 *pac = NULL;
 127                 return 0;
 128         }
 129
 130         nt_status = authsam_make_server_info(mem_ctx, p->samdb,
 131                                              lp_netbios_name(p->lp_ctx),
 132                                              lp_sam_name(p->lp_ctx),
 133                                              p->realm_dn,
 134                                              p->msg,
 135                                              data_blob(NULL, 0),
 136                                              data_blob(NULL, 0),
 137                                              &server_info);
 138         if (!NT_STATUS_IS_OK(nt_status)) {
 139                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 140                           nt_errstr(nt_status)));
 141                 return ENOMEM;
 142         }
 143
 144         ret = make_pac(context, mem_ctx, p->iconv_convenience, server_info, pac);
 145
 146         talloc_free(mem_ctx);
 147         return ret;
 148 }
 149
 150 /* Resign (and reform, including possibly new groups) a PAC */
 151
 152 static krb5_error_code samba_kdc_reget_pac(void *priv, krb5_context context,
 153                                            const krb5_principal client_principal,
 154                                            struct hdb_entry_ex *client,
 155                                            struct hdb_entry_ex *server, krb5_pac *pac)
 156 {
 157         krb5_error_code ret;
 158
 159         unsigned int userAccountControl;
 160
 161         struct hdb_samba4_private *p = talloc_get_type(server->ctx, struct hdb_samba4_private);
 162
 163         struct auth_serversupplied_info *server_info_out;
 164
 165         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_get_pac context");
 166
 167         if (!mem_ctx) {
 168                 return ENOMEM;
 169         }
 170
 171         /* The service account may be set not to want the PAC */
 172         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 173         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 174                 talloc_free(mem_ctx);
 175                 *pac = NULL;
 176                 return 0;
 177         }
 178
 179         ret = kerberos_pac_to_server_info(mem_ctx, p->iconv_convenience,
 180                                           *pac, context, &server_info_out);
 181
 182         /* We will compleatly regenerate this pac */
 183         krb5_pac_free(context, *pac);
 184
 185         if (ret) {
 186                 talloc_free(mem_ctx);
 187                 return ret;
 188         }
 189
 190         ret = make_pac(context, mem_ctx, p->iconv_convenience, server_info_out, pac);
 191
 192         talloc_free(mem_ctx);
 193         return ret;
 194 }
 195
 196 static void samba_kdc_build_edata_reply(TALLOC_CTX *tmp_ctx, krb5_data *e_data,
 197                                        NTSTATUS nt_status)
 198 {
 199         PA_DATA pa;
 200         unsigned char *buf;
 201         size_t len;
 202         krb5_error_code ret = 0;
 203
 204         if (!e_data)
 205                 return;
 206
 207         pa.padata_type          = KRB5_PADATA_PW_SALT;
 208         pa.padata_value.length  = 12;
 209         pa.padata_value.data    = malloc(pa.padata_value.length);
 210         if (!pa.padata_value.data) {
 211                 e_data->length = 0;
 212                 e_data->data = NULL;
 213                 return;
 214         }
 215
 216         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
 217         SIVAL(pa.padata_value.data, 4, 0);
 218         SIVAL(pa.padata_value.data, 8, 1);
 219
 220         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
 221         free(pa.padata_value.data);
 222
 223         e_data->data   = buf;
 224         e_data->length = len;
 225
 226         return;
 227 }
 228
 229 /* Given an hdb entry (and in particular it's private member), consult
 230  * the account_ok routine in auth/auth_sam.c for consistancy */
 231
 232
 233 static krb5_error_code samba_kdc_check_client_access(void *priv,
 234                                                      krb5_context context,
 235                                                      krb5_kdc_configuration *config,
 236                                                      hdb_entry_ex *client_ex, const char *client_name,
 237                                                      hdb_entry_ex *server_ex, const char *server_name,
 238                                                      KDC_REQ *req,
 239                                                      krb5_data *e_data)
 240 {
 241         krb5_error_code ret;
 242         NTSTATUS nt_status;
 243         TALLOC_CTX *tmp_ctx;
 244         struct hdb_samba4_private *p;
 245         char *workstation = NULL;
 246         HostAddresses *addresses = req->req_body.addresses;
 247         int i;
 248         bool password_change;
 249
 250         tmp_ctx = talloc_new(client_ex->ctx);
 251         p = talloc_get_type(client_ex->ctx, struct hdb_samba4_private);
 252
 253         if (!tmp_ctx) {
 254                 return ENOMEM;
 255         }
 256
 257         if (addresses) {
 258                 for (i=0; i < addresses->len; i++) {
 259                         if (addresses->val->addr_type == KRB5_ADDRESS_NETBIOS) {
 260                                 workstation = talloc_strndup(tmp_ctx, addresses->val->address.data, MIN(addresses->val->address.length, 15));
 261                                 if (workstation) {
 262                                         break;
 263                                 }
 264                         }
 265                 }
 266         }
 267
 268         /* Strip space padding */
 269         if (workstation) {
 270                 i = MIN(strlen(workstation), 15);
 271                 for (; i > 0 && workstation[i - 1] == ' '; i--) {
 272                         workstation[i - 1] = '\0';
 273                 }
 274         }
 275
 276         password_change = (server_ex && server_ex->entry.flags.change_pw);
 277
 278         /* we allow all kinds of trusts here */
 279         nt_status = authsam_account_ok(tmp_ctx,
 280                                        p->samdb,
 281                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 282                                        p->realm_dn,
 283                                        p->msg,
 284                                        workstation,
 285                                        client_name, true, password_change);
 286
 287         if (NT_STATUS_IS_OK(nt_status)) {
 288                 /* Now do the standard Heimdal check */
 289                 ret = kdc_check_flags(context, config,
 290                                       client_ex, client_name,
 291                                       server_ex, server_name,
 292                                       req->msg_type == krb_as_req);
 293         } else {
 294                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 295                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 296                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 297                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 298                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 299                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 300                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 301                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 302                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 303                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 304                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 305                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 306                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 307                         ret = KRB5KDC_ERR_POLICY;
 308                 else
 309                         ret = KRB5KDC_ERR_POLICY;
 310
 311                 samba_kdc_build_edata_reply(tmp_ctx, e_data, nt_status);
 312         }
 313
 314         return ret;
 315 }
 316
 317 struct krb5plugin_windc_ftable windc_plugin_table = {
 318         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 319         .init = samba_kdc_plugin_init,
 320         .fini = samba_kdc_plugin_fini,
 321         .pac_generate = samba_kdc_get_pac,
 322         .pac_verify = samba_kdc_reget_pac,
 323         .client_access = samba_kdc_check_client_access,
 324 };
 325