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    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 "lib/ldb/include/ldb.h"
  27 #include "librpc/gen_ndr/ndr_krb5pac.h"
  28 #include "librpc/gen_ndr/krb5pac.h"
  29 #include "auth/auth.h"
  30 #include "auth/auth_sam.h"
  31 #include "auth/auth_sam_reply.h"
  32 #include "kdc/kdc.h"
  33 #include "param/param.h"
  34
  35 struct krb5_dh_moduli;
  36 struct _krb5_krb_auth_data;
  37
  38 static krb5_error_code  samba_kdc_plugin_init(krb5_context context, void **ptr)
  39 {
  40         *ptr = NULL;
  41         return 0;
  42 }
  43
  44 static void     samba_kdc_plugin_fini(void *ptr)
  45 {
  46         return;
  47 }
  48
  49 static NTSTATUS
  50 get_logon_info_pac_blob(TALLOC_CTX *mem_ctx,
  51                         struct smb_iconv_convenience *ic,
  52                         struct auth_serversupplied_info *info,
  53                         DATA_BLOB *pac_data)
  54 {
  55         struct netr_SamInfo3 *info3;
  56         union PAC_INFO pac_info;
  57         enum ndr_err_code ndr_err;
  58         NTSTATUS nt_status;
  59
  60         ZERO_STRUCT(pac_info);
  61
  62         nt_status = auth_convert_server_info_saminfo3(mem_ctx, info, &info3);
  63         if (!NT_STATUS_IS_OK(nt_status)) {
  64                 DEBUG(1, ("Getting Samba info failed: %s\n",
  65                           nt_errstr(nt_status)));
  66                 return nt_status;
  67         }
  68
  69         pac_info.logon_info.info = talloc_zero(mem_ctx, struct PAC_LOGON_INFO);
  70         if (!mem_ctx) {
  71                 return NT_STATUS_NO_MEMORY;
  72         }
  73
  74         pac_info.logon_info.info->info3 = *info3;
  75
  76         ndr_err = ndr_push_union_blob(pac_data, mem_ctx, ic, &pac_info,
  77                                       PAC_TYPE_LOGON_INFO,
  78                                       (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
  79         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  80                 nt_status = ndr_map_error2ntstatus(ndr_err);
  81                 DEBUG(1, ("PAC (presig) push failed: %s\n",
  82                           nt_errstr(nt_status)));
  83                 return nt_status;
  84         }
  85
  86         return NT_STATUS_OK;
  87 }
  88
  89 static krb5_error_code make_krb5_pac(krb5_context context,
  90                                      DATA_BLOB *pac_blob,
  91                                      krb5_pac *pac)
  92 {
  93         krb5_data pac_data;
  94         krb5_error_code ret;
  95
  96         ret = krb5_data_copy(&pac_data, pac_blob->data, pac_blob->length);
  97         if (ret != 0) {
  98                 return ret;
  99         }
 100
 101         ret = krb5_pac_init(context, pac);
 102         if (ret != 0) {
 103                 krb5_data_free(&pac_data);
 104                 return ret;
 105         }
 106
 107         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
 108         krb5_data_free(&pac_data);
 109         if (ret != 0) {
 110                 return ret;
 111         }
 112
 113         return ret;
 114 }
 115
 116 static bool princ_needs_pac(struct hdb_entry_ex *princ)
 117 {
 118
 119         struct hdb_samba4_private *p = talloc_get_type(princ->ctx, struct hdb_samba4_private);
 120         unsigned int userAccountControl;
 121
 122
 123         /* The service 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                 return false;
 127         }
 128
 129         return true;
 130 }
 131
 132 static NTSTATUS samba_kdc_get_pac_blob(TALLOC_CTX *mem_ctx,
 133                                        struct hdb_entry_ex *client,
 134                                        DATA_BLOB **_pac_blob)
 135 {
 136         struct hdb_samba4_private *p = talloc_get_type(client->ctx, struct hdb_samba4_private);
 137         struct auth_serversupplied_info *server_info;
 138         DATA_BLOB *pac_blob;
 139         NTSTATUS nt_status;
 140
 141         /* The user account may be set not to want the PAC */
 142         if ( ! princ_needs_pac(client)) {
 143                 *_pac_blob = NULL;
 144                 return NT_STATUS_OK;
 145         }
 146
 147         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
 148         if (!pac_blob) {
 149                 return NT_STATUS_NO_MEMORY;
 150         }
 151
 152         nt_status = authsam_make_server_info(mem_ctx, p->samdb,
 153                                              lp_netbios_name(p->lp_ctx),
 154                                              lp_sam_name(p->lp_ctx),
 155                                              p->realm_dn,
 156                                              p->msg,
 157                                              data_blob(NULL, 0),
 158                                              data_blob(NULL, 0),
 159                                              &server_info);
 160         if (!NT_STATUS_IS_OK(nt_status)) {
 161                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 162                           nt_errstr(nt_status)));
 163                 return nt_status;
 164         }
 165
 166         nt_status = get_logon_info_pac_blob(mem_ctx,
 167                                             p->iconv_convenience,
 168                                             server_info, pac_blob);
 169         if (!NT_STATUS_IS_OK(nt_status)) {
 170                 DEBUG(0, ("Building PAC failed: %s\n",
 171                           nt_errstr(nt_status)));
 172                 return nt_status;
 173         }
 174
 175         *_pac_blob = pac_blob;
 176         return NT_STATUS_OK;
 177 }
 178
 179 static NTSTATUS samba_kdc_update_pac_blob(TALLOC_CTX *mem_ctx,
 180                                           krb5_context context,
 181                                           struct smb_iconv_convenience *ic,
 182                                           krb5_pac *pac, DATA_BLOB *pac_blob)
 183 {
 184         struct auth_serversupplied_info *server_info;
 185         krb5_error_code ret;
 186         NTSTATUS nt_status;
 187
 188         ret = kerberos_pac_to_server_info(mem_ctx, ic, *pac,
 189                                           context, &server_info);
 190         if (ret) {
 191                 return NT_STATUS_UNSUCCESSFUL;
 192         }
 193
 194         nt_status = samba_get_logon_info_pac_blob(mem_ctx, ic,
 195                                                   server_info, pac_blob);
 196
 197         return nt_status;
 198 }
 199
 200 /* Given the right private pointer from hdb_samba4, get a PAC from the attached ldb messages */
 201 static krb5_error_code samba_kdc_get_pac(void *priv, krb5_context context,
 202                                          struct hdb_entry_ex *client,
 203                                          krb5_pac *pac)
 204 {
 205         TALLOC_CTX *mem_ctx;
 206         DATA_BLOB *pac_blob;
 207         krb5_error_code ret;
 208         NTSTATUS nt_status;
 209
 210         mem_ctx = talloc_named(client->ctx, 0, "samba_get_pac context");
 211         if (!mem_ctx) {
 212                 return ENOMEM;
 213         }
 214
 215         nt_status = samba_kdc_get_pac_blob(mem_ctx, client, &pac_blob);
 216         if (!NT_STATUS_IS_OK(nt_status)) {
 217                 talloc_free(mem_ctx);
 218                 return EINVAL;
 219         }
 220
 221         ret = make_krb5_pac(context, pac_blob, pac);
 222
 223         talloc_free(mem_ctx);
 224         return ret;
 225 }
 226
 227 /* Resign (and reform, including possibly new groups) a PAC */
 228
 229 static krb5_error_code samba_kdc_reget_pac(void *priv, krb5_context context,
 230                                            const krb5_principal client_principal,
 231                                            struct hdb_entry_ex *client,
 232                                            struct hdb_entry_ex *server, krb5_pac *pac)
 233 {
 234         struct hdb_samba4_private *p = talloc_get_type(server->ctx, struct hdb_samba4_private);
 235         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_kdc_reget_pac context");
 236         DATA_BLOB *pac_blob;
 237         krb5_error_code ret;
 238         NTSTATUS nt_status;
 239
 240         if (!mem_ctx) {
 241                 return ENOMEM;
 242         }
 243
 244         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
 245         if (!pac_blob) {
 246                 talloc_free(mem_ctx);
 247                 return ENOMEM;
 248         }
 249
 250         /* The user account may be set not to want the PAC */
 251         if ( ! princ_needs_pac(server)) {
 252                 talloc_free(mem_ctx);
 253                 return EINVAL;
 254         }
 255
 256         nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
 257                                               p->iconv_convenience,
 258                                               pac, pac_blob);
 259         if (!NT_STATUS_IS_OK(nt_status)) {
 260                 DEBUG(0, ("Building PAC failed: %s\n",
 261                           nt_errstr(nt_status)));
 262                 talloc_free(mem_ctx);
 263                 return EINVAL;
 264         }
 265
 266         /* We now completly regenerate this pac */
 267         krb5_pac_free(context, *pac);
 268
 269         ret = make_krb5_pac(context, pac_blob, pac);
 270
 271         talloc_free(mem_ctx);
 272         return ret;
 273 }
 274
 275 static void samba_kdc_build_edata_reply(TALLOC_CTX *tmp_ctx, krb5_data *e_data,
 276                                        NTSTATUS nt_status)
 277 {
 278         PA_DATA pa;
 279         unsigned char *buf;
 280         size_t len;
 281         krb5_error_code ret = 0;
 282
 283         if (!e_data)
 284                 return;
 285
 286         pa.padata_type          = KRB5_PADATA_PW_SALT;
 287         pa.padata_value.length  = 12;
 288         pa.padata_value.data    = malloc(pa.padata_value.length);
 289         if (!pa.padata_value.data) {
 290                 e_data->length = 0;
 291                 e_data->data = NULL;
 292                 return;
 293         }
 294
 295         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
 296         SIVAL(pa.padata_value.data, 4, 0);
 297         SIVAL(pa.padata_value.data, 8, 1);
 298
 299         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
 300         free(pa.padata_value.data);
 301
 302         e_data->data   = buf;
 303         e_data->length = len;
 304
 305         return;
 306 }
 307
 308 /* Given an hdb entry (and in particular it's private member), consult
 309  * the account_ok routine in auth/auth_sam.c for consistancy */
 310
 311
 312 static krb5_error_code samba_kdc_check_client_access(void *priv,
 313                                                      krb5_context context,
 314                                                      krb5_kdc_configuration *config,
 315                                                      hdb_entry_ex *client_ex, const char *client_name,
 316                                                      hdb_entry_ex *server_ex, const char *server_name,
 317                                                      KDC_REQ *req,
 318                                                      krb5_data *e_data)
 319 {
 320         krb5_error_code ret;
 321         NTSTATUS nt_status;
 322         TALLOC_CTX *tmp_ctx;
 323         struct hdb_samba4_private *p;
 324         char *workstation = NULL;
 325         HostAddresses *addresses = req->req_body.addresses;
 326         int i;
 327         bool password_change;
 328
 329         tmp_ctx = talloc_new(client_ex->ctx);
 330         p = talloc_get_type(client_ex->ctx, struct hdb_samba4_private);
 331
 332         if (!tmp_ctx) {
 333                 return ENOMEM;
 334         }
 335
 336         if (addresses) {
 337                 for (i=0; i < addresses->len; i++) {
 338                         if (addresses->val->addr_type == KRB5_ADDRESS_NETBIOS) {
 339                                 workstation = talloc_strndup(tmp_ctx, addresses->val->address.data, MIN(addresses->val->address.length, 15));
 340                                 if (workstation) {
 341                                         break;
 342                                 }
 343                         }
 344                 }
 345         }
 346
 347         /* Strip space padding */
 348         if (workstation) {
 349                 i = MIN(strlen(workstation), 15);
 350                 for (; i > 0 && workstation[i - 1] == ' '; i--) {
 351                         workstation[i - 1] = '\0';
 352                 }
 353         }
 354
 355         password_change = (server_ex && server_ex->entry.flags.change_pw);
 356
 357         /* we allow all kinds of trusts here */
 358         nt_status = authsam_account_ok(tmp_ctx,
 359                                        p->samdb,
 360                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 361                                        p->realm_dn,
 362                                        p->msg,
 363                                        workstation,
 364                                        client_name, true, password_change);
 365
 366         if (NT_STATUS_IS_OK(nt_status)) {
 367                 /* Now do the standard Heimdal check */
 368                 ret = kdc_check_flags(context, config,
 369                                       client_ex, client_name,
 370                                       server_ex, server_name,
 371                                       req->msg_type == krb_as_req);
 372         } else {
 373                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 374                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 375                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 376                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 377                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 378                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 379                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 380                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 381                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 382                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 383                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 384                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 385                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 386                         ret = KRB5KDC_ERR_POLICY;
 387                 else
 388                         ret = KRB5KDC_ERR_POLICY;
 389
 390                 samba_kdc_build_edata_reply(tmp_ctx, e_data, nt_status);
 391         }
 392
 393         return ret;
 394 }
 395
 396 struct krb5plugin_windc_ftable windc_plugin_table = {
 397         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 398         .init = samba_kdc_plugin_init,
 399         .fini = samba_kdc_plugin_fini,
 400         .pac_generate = samba_kdc_get_pac,
 401         .pac_verify = samba_kdc_reget_pac,
 402         .client_access = samba_kdc_check_client_access,
 403 };
 404