source/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
   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 2 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, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "kdc/kdc.h"
  26 #include "dsdb/common/flags.h"
  27 #include "lib/ldb/include/ldb.h"
  28 #include "librpc/gen_ndr/krb5pac.h"
  29 #include "auth/auth.h"
  30 #include "auth/auth_sam.h"
  31
  32 struct krb5_dh_moduli;
  33 struct _krb5_krb_auth_data;
  34
  35 #include "heimdal/lib/krb5/krb5_locl.h"
  36
  37 /* Given the right private pointer from hdb_ldb, get a PAC from the attached ldb messages */
  38 static krb5_error_code samba_get_pac(krb5_context context,
  39                                      struct hdb_ldb_private *private,
  40                                      krb5_principal client,
  41                                      const krb5_keyblock *krbtgt_keyblock,
  42                                      const krb5_keyblock *server_keyblock,
  43                                      time_t tgs_authtime,
  44                                      krb5_data *pac)
  45 {
  46         krb5_error_code ret;
  47         NTSTATUS nt_status;
  48         struct auth_serversupplied_info *server_info;
  49         DATA_BLOB tmp_blob;
  50         TALLOC_CTX *mem_ctx = talloc_named(private, 0, "samba_get_pac context");
  51
  52         if (!mem_ctx) {
  53                 return ENOMEM;
  54         }
  55
  56         nt_status = authsam_make_server_info(mem_ctx, private->samdb,
  57                                              private->msg,
  58                                              private->realm_ref_msg,
  59                                              data_blob(NULL, 0),
  60                                              data_blob(NULL, 0),
  61                                              &server_info);
  62         if (!NT_STATUS_IS_OK(nt_status)) {
  63                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
  64                           nt_errstr(nt_status)));
  65                 return ENOMEM;
  66         }
  67
  68         ret = kerberos_create_pac(mem_ctx, server_info,
  69                                   context,
  70                                   krbtgt_keyblock,
  71                                   server_keyblock,
  72                                   client,
  73                                   tgs_authtime,
  74                                   &tmp_blob);
  75
  76         if (ret) {
  77                 DEBUG(1, ("PAC encoding failed: %s\n",
  78                           smb_get_krb5_error_message(context, ret, mem_ctx)));
  79                 talloc_free(mem_ctx);
  80                 return ret;
  81         }
  82
  83         ret = krb5_data_copy(pac, tmp_blob.data, tmp_blob.length);
  84         talloc_free(mem_ctx);
  85         return ret;
  86 }
  87
  88 /* Wrap the PAC in the right ASN.1.  Will always free 'pac', on success or failure */
  89 static krb5_error_code wrap_pac(krb5_context context, krb5_data *pac, AuthorizationData **out)
  90 {
  91         krb5_error_code ret;
  92
  93         unsigned char *buf;
  94         size_t buf_size;
  95         size_t len;
  96
  97         AD_IF_RELEVANT if_relevant;
  98         AuthorizationData *auth_data;
  99
 100         if_relevant.len = 1;
 101         if_relevant.val = malloc(sizeof(*if_relevant.val));
 102         if (!if_relevant.val) {
 103                 krb5_data_free(pac);
 104                 *out = NULL;
 105                 return ENOMEM;
 106         }
 107
 108         if_relevant.val[0].ad_type = KRB5_AUTHDATA_WIN2K_PAC;
 109         if_relevant.val[0].ad_data.data = NULL;
 110         if_relevant.val[0].ad_data.length = 0;
 111
 112         /* pac.data will be freed with this */
 113         if_relevant.val[0].ad_data.data = pac->data;
 114         if_relevant.val[0].ad_data.length = pac->length;
 115
 116         ASN1_MALLOC_ENCODE(AuthorizationData, buf, buf_size, &if_relevant, &len, ret);
 117         free_AuthorizationData(&if_relevant);
 118         if (ret) {
 119                 *out = NULL;
 120                 return ret;
 121         }
 122
 123         auth_data = malloc(sizeof(*auth_data));
 124         if (!auth_data) {
 125                 free(buf);
 126                 *out = NULL;
 127                 return ret;
 128         }
 129         auth_data->len = 1;
 130         auth_data->val = malloc(sizeof(*auth_data->val));
 131         if (!auth_data->val) {
 132                 free(buf);
 133                 free(auth_data);
 134                 *out = NULL;
 135                 return ret;
 136         }
 137         auth_data->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
 138         auth_data->val[0].ad_data.length = len;
 139         auth_data->val[0].ad_data.data = buf;
 140
 141         *out = auth_data;
 142         return 0;
 143 }
 144
 145
 146 /* Given a hdb_entry, create a PAC out of the private data
 147
 148    Don't create it if the client has the UF_NO_AUTH_DATA_REQUIRED bit
 149    set, or if they specificaly asked not to get it.
 150 */
 151
 152 krb5_error_code hdb_ldb_authz_data_as_req(krb5_context context, struct hdb_entry_ex *entry_ex,
 153                                           METHOD_DATA* pa_data_seq,
 154                                           time_t authtime,
 155                                           const EncryptionKey *tgtkey,
 156                                           const EncryptionKey *sessionkey,
 157                                           AuthorizationData **out)
 158 {
 159         krb5_error_code ret;
 160         int i;
 161         krb5_data pac;
 162         krb5_boolean pac_wanted = TRUE;
 163         unsigned int userAccountControl;
 164         struct PA_PAC_REQUEST pac_request;
 165         struct hdb_ldb_private *private = talloc_get_type(entry_ex->ctx, struct hdb_ldb_private);
 166
 167         /* The user account may be set not to want the PAC */
 168         userAccountControl = ldb_msg_find_attr_as_uint(private->msg, "userAccountControl", 0);
 169         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 170                 *out = NULL;
 171                 return 0;
 172         }
 173
 174         /* The user may not want a PAC */
 175         for (i=0; i<pa_data_seq->len; i++) {
 176                 if (pa_data_seq->val[i].padata_type == KRB5_PADATA_PA_PAC_REQUEST) {
 177                         ret = decode_PA_PAC_REQUEST(pa_data_seq->val[i].padata_value.data,
 178                                                     pa_data_seq->val[i].padata_value.length,
 179                                                     &pac_request, NULL);
 180                         if (ret == 0) {
 181                                 pac_wanted = !!pac_request.include_pac;
 182                         }
 183                         free_PA_PAC_REQUEST(&pac_request);
 184                         break;
 185                 }
 186         }
 187
 188         if (!pac_wanted) {
 189                 *out = NULL;
 190                 return 0;
 191         }
 192
 193         /* Get PAC from Samba */
 194         ret = samba_get_pac(context,
 195                             private,
 196                             entry_ex->entry.principal,
 197                             tgtkey,
 198                             tgtkey,
 199                             authtime,
 200                             &pac);
 201
 202         if (ret) {
 203                 *out = NULL;
 204                 return ret;
 205         }
 206
 207         return wrap_pac(context, &pac, out);
 208 }
 209
 210 /* Resign (and reform, including possibly new groups) a PAC */
 211
 212 krb5_error_code hdb_ldb_authz_data_tgs_req(krb5_context context, struct hdb_entry_ex *entry_ex,
 213                                            krb5_principal client,
 214                                            AuthorizationData *in,
 215                                            time_t authtime,
 216                                            const EncryptionKey *tgtkey,
 217                                            const EncryptionKey *servicekey,
 218                                            const EncryptionKey *sessionkey,
 219                                            AuthorizationData **out)
 220 {
 221         NTSTATUS nt_status;
 222         krb5_error_code ret;
 223
 224         unsigned int userAccountControl;
 225
 226         struct hdb_ldb_private *private = talloc_get_type(entry_ex->ctx, struct hdb_ldb_private);
 227         krb5_data k5pac_in, k5pac_out;
 228         DATA_BLOB pac_in, pac_out;
 229
 230         struct PAC_LOGON_INFO *logon_info;
 231         union netr_Validation validation;
 232         struct auth_serversupplied_info *server_info_out;
 233
 234         krb5_boolean found = FALSE;
 235         TALLOC_CTX *mem_ctx;
 236
 237         /* The service account may be set not to want the PAC */
 238         userAccountControl = ldb_msg_find_attr_as_uint(private->msg, "userAccountControl", 0);
 239         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 240                 *out = NULL;
 241                 return 0;
 242         }
 243
 244         ret = _krb5_find_type_in_ad(context, KRB5_AUTHDATA_WIN2K_PAC,
 245                                     &k5pac_in, &found, sessionkey, in);
 246         if (ret || !found) {
 247                 *out = NULL;
 248                 return 0;
 249         }
 250
 251         mem_ctx = talloc_new(private);
 252         if (!mem_ctx) {
 253                 krb5_data_free(&k5pac_in);
 254                 *out = NULL;
 255                 return ENOMEM;
 256         }
 257
 258         pac_in = data_blob_talloc(mem_ctx, k5pac_in.data, k5pac_in.length);
 259         krb5_data_free(&k5pac_in);
 260         if (!pac_in.data) {
 261                 talloc_free(mem_ctx);
 262                 *out = NULL;
 263                 return ENOMEM;
 264         }
 265
 266         /* Parse the PAC again, for the logon info */
 267         nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info,
 268                                             pac_in,
 269                                             context,
 270                                             tgtkey,
 271                                             tgtkey,
 272                                             client, authtime,
 273                                             &ret);
 274
 275         if (!NT_STATUS_IS_OK(nt_status)) {
 276                 DEBUG(1, ("Failed to parse PAC in TGT: %s/%s\n",
 277                           nt_errstr(nt_status), error_message(ret)));
 278                 talloc_free(mem_ctx);
 279                 *out = NULL;
 280                 return ret;
 281         }
 282
 283         /* Pull this right into the normal auth sysstem structures */
 284         validation.sam3 = &logon_info->info3;
 285         nt_status = make_server_info_netlogon_validation(mem_ctx,
 286                                                          "",
 287                                                          3, &validation,
 288                                                          &server_info_out);
 289         if (!NT_STATUS_IS_OK(nt_status)) {
 290                 talloc_free(mem_ctx);
 291                 *out = NULL;
 292                 return ENOMEM;
 293         }
 294
 295         /* And make a new PAC, possibly containing new groups */
 296         ret = kerberos_create_pac(mem_ctx,
 297                                   server_info_out,
 298                                   context,
 299                                   tgtkey,
 300                                   servicekey,
 301                                   client,
 302                                   authtime,
 303                                   &pac_out);
 304
 305         if (ret != 0) {
 306                 talloc_free(mem_ctx);
 307                 *out = NULL;
 308                 return ret;
 309         }
 310
 311         ret = krb5_data_copy(&k5pac_out, pac_out.data, pac_out.length);
 312         if (ret != 0) {
 313                 talloc_free(mem_ctx);
 314                 *out = NULL;
 315                 return ret;
 316         }
 317
 318         return wrap_pac(context, &k5pac_out, out);
 319 }
 320
 321 /* Given an hdb entry (and in particular it's private member), consult
 322  * the account_ok routine in auth/auth_sam.c for consistancy */
 323
 324 krb5_error_code hdb_ldb_check_client_access(krb5_context context, hdb_entry_ex *entry_ex,
 325                                             HostAddresses *addresses)
 326 {
 327         krb5_error_code ret;
 328         NTSTATUS nt_status;
 329         TALLOC_CTX *tmp_ctx = talloc_new(entry_ex->ctx);
 330         struct hdb_ldb_private *private = talloc_get_type(entry_ex->ctx, struct hdb_ldb_private);
 331         char *name, *workstation = NULL;
 332         int i;
 333
 334         if (!tmp_ctx) {
 335                 return ENOMEM;
 336         }
 337
 338         ret = krb5_unparse_name(context, entry_ex->entry.principal, &name);
 339         if (ret != 0) {
 340                 talloc_free(tmp_ctx);
 341                 return ret;
 342         }
 343
 344         if (addresses) {
 345                 for (i=0; i < addresses->len; i++) {
 346                         if (addresses->val->addr_type == KRB5_ADDRESS_NETBIOS) {
 347                                 workstation = talloc_strndup(tmp_ctx, addresses->val->address.data, MIN(addresses->val->address.length, 15));
 348                                 if (workstation) {
 349                                         break;
 350                                 }
 351                         }
 352                 }
 353         }
 354
 355         /* Strip space padding */
 356         if (workstation) {
 357                 i = MIN(strlen(workstation), 15);
 358                 for (; i > 0 && workstation[i - 1] == ' '; i--) {
 359                         workstation[i - 1] = '\0';
 360                 }
 361         }
 362
 363         nt_status = authsam_account_ok(tmp_ctx,
 364                                        private->samdb,
 365                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 366                                        private->msg,
 367                                        private->realm_ref_msg,
 368                                        workstation,
 369                                        name);
 370         free(name);
 371
 372         /* TODO:  Need a more complete mapping of NTSTATUS to krb5kdc errors */
 373
 374         if (!NT_STATUS_IS_OK(nt_status)) {
 375                 return KRB5KDC_ERR_POLICY;
 376         }
 377         return 0;
 378 }
 379