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_pac(krb5_context context,
  90                                 TALLOC_CTX *mem_ctx,
  91                                 struct smb_iconv_convenience *iconv_convenience,
  92                                 struct auth_serversupplied_info *server_info,
  93                                 krb5_pac *pac)
  94 {
  95         krb5_data pac_data;
  96         DATA_BLOB pac_out;
  97         NTSTATUS nt_status;
  98         krb5_error_code ret;
  99
 100         nt_status = get_logon_info_pac_blob(mem_ctx,
 101                                             iconv_convenience,
 102                                             server_info, pac_out);
 103         if (!NT_STATUS_IS_OK(nt_status)) {
 104                 return EINVAL;
 105         }
 106
 107         ret = krb5_data_copy(&pac_data, pac_out.data, pac_out.length);
 108         if (ret != 0) {
 109                 return ret;
 110         }
 111
 112         ret = krb5_pac_init(context, pac);
 113         if (ret != 0) {
 114                 krb5_data_free(&pac_data);
 115                 return ret;
 116         }
 117
 118         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
 119         krb5_data_free(&pac_data);
 120         if (ret != 0) {
 121                 return ret;
 122         }
 123
 124         return ret;
 125 }
 126
 127 /* Given the right private pointer from hdb_samba4, get a PAC from the attached ldb messages */
 128 static krb5_error_code samba_kdc_get_pac(void *priv,
 129                                          krb5_context context,
 130                                          struct hdb_entry_ex *client,
 131                                          krb5_pac *pac)
 132 {
 133         krb5_error_code ret;
 134         NTSTATUS nt_status;
 135         struct auth_serversupplied_info *server_info;
 136         struct hdb_samba4_private *p = talloc_get_type(client->ctx, struct hdb_samba4_private);
 137         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_get_pac context");
 138         unsigned int userAccountControl;
 139
 140         if (!mem_ctx) {
 141                 return ENOMEM;
 142         }
 143
 144         /* The user account may be set not to want the PAC */
 145         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 146         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 147                 *pac = NULL;
 148                 return 0;
 149         }
 150
 151         nt_status = authsam_make_server_info(mem_ctx, p->samdb,
 152                                              lp_netbios_name(p->lp_ctx),
 153                                              lp_sam_name(p->lp_ctx),
 154                                              p->realm_dn,
 155                                              p->msg,
 156                                              data_blob(NULL, 0),
 157                                              data_blob(NULL, 0),
 158                                              &server_info);
 159         if (!NT_STATUS_IS_OK(nt_status)) {
 160                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 161                           nt_errstr(nt_status)));
 162                 return ENOMEM;
 163         }
 164
 165         ret = make_pac(context, mem_ctx, p->iconv_convenience, server_info, pac);
 166
 167         talloc_free(mem_ctx);
 168         return ret;
 169 }
 170
 171 /* Resign (and reform, including possibly new groups) a PAC */
 172
 173 static krb5_error_code samba_kdc_reget_pac(void *priv, krb5_context context,
 174                                            const krb5_principal client_principal,
 175                                            struct hdb_entry_ex *client,
 176                                            struct hdb_entry_ex *server, krb5_pac *pac)
 177 {
 178         krb5_error_code ret;
 179
 180         unsigned int userAccountControl;
 181
 182         struct hdb_samba4_private *p = talloc_get_type(server->ctx, struct hdb_samba4_private);
 183
 184         struct auth_serversupplied_info *server_info_out;
 185
 186         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_get_pac context");
 187
 188         if (!mem_ctx) {
 189                 return ENOMEM;
 190         }
 191
 192         /* The service account may be set not to want the PAC */
 193         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 194         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 195                 talloc_free(mem_ctx);
 196                 *pac = NULL;
 197                 return 0;
 198         }
 199
 200         ret = kerberos_pac_to_server_info(mem_ctx, p->iconv_convenience,
 201                                           *pac, context, &server_info_out);
 202
 203         /* We will compleatly regenerate this pac */
 204         krb5_pac_free(context, *pac);
 205
 206         if (ret) {
 207                 talloc_free(mem_ctx);
 208                 return ret;
 209         }
 210
 211         ret = make_pac(context, mem_ctx, p->iconv_convenience, server_info_out, pac);
 212
 213         talloc_free(mem_ctx);
 214         return ret;
 215 }
 216
 217 static void samba_kdc_build_edata_reply(TALLOC_CTX *tmp_ctx, krb5_data *e_data,
 218                                        NTSTATUS nt_status)
 219 {
 220         PA_DATA pa;
 221         unsigned char *buf;
 222         size_t len;
 223         krb5_error_code ret = 0;
 224
 225         if (!e_data)
 226                 return;
 227
 228         pa.padata_type          = KRB5_PADATA_PW_SALT;
 229         pa.padata_value.length  = 12;
 230         pa.padata_value.data    = malloc(pa.padata_value.length);
 231         if (!pa.padata_value.data) {
 232                 e_data->length = 0;
 233                 e_data->data = NULL;
 234                 return;
 235         }
 236
 237         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
 238         SIVAL(pa.padata_value.data, 4, 0);
 239         SIVAL(pa.padata_value.data, 8, 1);
 240
 241         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
 242         free(pa.padata_value.data);
 243
 244         e_data->data   = buf;
 245         e_data->length = len;
 246
 247         return;
 248 }
 249
 250 /* Given an hdb entry (and in particular it's private member), consult
 251  * the account_ok routine in auth/auth_sam.c for consistancy */
 252
 253
 254 static krb5_error_code samba_kdc_check_client_access(void *priv,
 255                                                      krb5_context context,
 256                                                      krb5_kdc_configuration *config,
 257                                                      hdb_entry_ex *client_ex, const char *client_name,
 258                                                      hdb_entry_ex *server_ex, const char *server_name,
 259                                                      KDC_REQ *req,
 260                                                      krb5_data *e_data)
 261 {
 262         krb5_error_code ret;
 263         NTSTATUS nt_status;
 264         TALLOC_CTX *tmp_ctx;
 265         struct hdb_samba4_private *p;
 266         char *workstation = NULL;
 267         HostAddresses *addresses = req->req_body.addresses;
 268         int i;
 269         bool password_change;
 270
 271         tmp_ctx = talloc_new(client_ex->ctx);
 272         p = talloc_get_type(client_ex->ctx, struct hdb_samba4_private);
 273
 274         if (!tmp_ctx) {
 275                 return ENOMEM;
 276         }
 277
 278         if (addresses) {
 279                 for (i=0; i < addresses->len; i++) {
 280                         if (addresses->val->addr_type == KRB5_ADDRESS_NETBIOS) {
 281                                 workstation = talloc_strndup(tmp_ctx, addresses->val->address.data, MIN(addresses->val->address.length, 15));
 282                                 if (workstation) {
 283                                         break;
 284                                 }
 285                         }
 286                 }
 287         }
 288
 289         /* Strip space padding */
 290         if (workstation) {
 291                 i = MIN(strlen(workstation), 15);
 292                 for (; i > 0 && workstation[i - 1] == ' '; i--) {
 293                         workstation[i - 1] = '\0';
 294                 }
 295         }
 296
 297         password_change = (server_ex && server_ex->entry.flags.change_pw);
 298
 299         /* we allow all kinds of trusts here */
 300         nt_status = authsam_account_ok(tmp_ctx,
 301                                        p->samdb,
 302                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT | MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 303                                        p->realm_dn,
 304                                        p->msg,
 305                                        workstation,
 306                                        client_name, true, password_change);
 307
 308         if (NT_STATUS_IS_OK(nt_status)) {
 309                 /* Now do the standard Heimdal check */
 310                 ret = kdc_check_flags(context, config,
 311                                       client_ex, client_name,
 312                                       server_ex, server_name,
 313                                       req->msg_type == krb_as_req);
 314         } else {
 315                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 316                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 317                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 318                         ret = KRB5KDC_ERR_KEY_EXPIRED;
 319                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 320                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 321                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 322                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 323                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 324                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 325                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 326                         ret = KRB5KDC_ERR_CLIENT_REVOKED;
 327                 else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 328                         ret = KRB5KDC_ERR_POLICY;
 329                 else
 330                         ret = KRB5KDC_ERR_POLICY;
 331
 332                 samba_kdc_build_edata_reply(tmp_ctx, e_data, nt_status);
 333         }
 334
 335         return ret;
 336 }
 337
 338 struct krb5plugin_windc_ftable windc_plugin_table = {
 339         .minor_version = KRB5_WINDC_PLUGING_MINOR,
 340         .init = samba_kdc_plugin_init,
 341         .fini = samba_kdc_plugin_fini,
 342         .pac_generate = samba_kdc_get_pac,
 343         .pac_verify = samba_kdc_reget_pac,
 344         .client_access = samba_kdc_check_client_access,
 345 };
 346