source4/kdc/mit_samba.c

   1 /*
   2    MIT-Samba4 library
   3
   4    Copyright (c) 2010, Simo Sorce <idra@samba.org>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #define TEVENT_DEPRECATED 1
  21
  22 #include "includes.h"
  23 #include "param/param.h"
  24 #include "dsdb/samdb/samdb.h"
  25 #include "system/kerberos.h"
  26 #include <hdb.h>
  27 #include "mit_samba_interface.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "kdc/samba_kdc.h"
  30 #include "kdc/pac-glue.h"
  31 #include "kdc/db-glue.h"
  32
  33 const int mit_samba_interface_version = MIT_SAMBA_INTERFACE_VERSION;
  34
  35 struct mit_samba_context {
  36         struct auth_session_info *session_info;
  37
  38         /* for compat with hdb plugin common code */
  39         krb5_context context;
  40         struct samba_kdc_db_context *db_ctx;
  41 };
  42
  43 static void mit_samba_context_free(struct mit_samba_context *ctx)
  44 {
  45         /* free heimdal's krb5_context */
  46         if (ctx->context) {
  47                 krb5_free_context(ctx->context);
  48         }
  49
  50         /* then free everything else */
  51         talloc_free(ctx);
  52 }
  53
  54 static int mit_samba_context_init(struct mit_samba_context **_ctx)
  55 {
  56         NTSTATUS status;
  57         struct mit_samba_context *ctx;
  58         const char *s4_conf_file;
  59         int ret;
  60         struct samba_kdc_base_context base_ctx;
  61
  62         ctx = talloc(NULL, struct mit_samba_context);
  63         if (!ctx) {
  64                 ret = ENOMEM;
  65                 goto done;
  66         }
  67
  68         base_ctx.ev_ctx = tevent_context_init(ctx);
  69         if (!base_ctx.ev_ctx) {
  70                 ret = ENOMEM;
  71                 goto done;
  72         }
  73         tevent_loop_allow_nesting(base_ctx.ev_ctx);
  74         base_ctx.lp_ctx = loadparm_init_global(false);
  75         if (!base_ctx.lp_ctx) {
  76                 ret = ENOMEM;
  77                 goto done;
  78         }
  79         /* init s4 configuration */
  80         s4_conf_file = lpcfg_configfile(base_ctx.lp_ctx);
  81         if (s4_conf_file) {
  82                 lpcfg_load(base_ctx.lp_ctx, s4_conf_file);
  83         } else {
  84                 lpcfg_load_default(base_ctx.lp_ctx);
  85         }
  86
  87         status = samba_kdc_setup_db_ctx(ctx, &base_ctx, &ctx->db_ctx);
  88         if (!NT_STATUS_IS_OK(status)) {
  89                 ret = EINVAL;
  90                 goto done;
  91         }
  92
  93         /* init heimdal's krb_context and log facilities */
  94         ret = smb_krb5_init_context_basic(ctx,
  95                                           ctx->db_ctx->lp_ctx,
  96                                           &ctx->context);
  97         if (ret) {
  98                 goto done;
  99         }
 100
 101         ret = 0;
 102
 103 done:
 104         if (ret) {
 105                 mit_samba_context_free(ctx);
 106         } else {
 107                 *_ctx = ctx;
 108         }
 109         return ret;
 110 }
 111
 112
 113 static int mit_samba_get_principal(struct mit_samba_context *ctx,
 114                                    char *principal_string,
 115                                    unsigned int flags,
 116                                    hdb_entry_ex **_hentry)
 117 {
 118         krb5_principal principal;
 119         hdb_entry_ex *hentry;
 120         int ret;
 121
 122         hentry = talloc(ctx, hdb_entry_ex);
 123         if (!hentry) {
 124                 return ENOMEM;
 125         }
 126
 127         ret = krb5_parse_name(ctx->context, principal_string, &principal);
 128         if (ret) {
 129                 goto done;
 130         }
 131
 132         ret = samba_kdc_fetch(ctx->context, ctx->db_ctx,
 133                               principal, flags, 0, hentry);
 134
 135         krb5_free_principal(ctx->context, principal);
 136
 137 done:
 138         if (ret) {
 139                 talloc_free(hentry);
 140         } else {
 141                 talloc_steal(hentry->ctx, hentry);
 142                 *_hentry = hentry;
 143         }
 144         return ret;
 145 }
 146
 147 static int mit_samba_get_firstkey(struct mit_samba_context *ctx,
 148                                   hdb_entry_ex **_hentry)
 149 {
 150         hdb_entry_ex *hentry;
 151         int ret;
 152
 153         hentry = talloc(ctx, hdb_entry_ex);
 154         if (!hentry) {
 155                 return ENOMEM;
 156         }
 157
 158         ret = samba_kdc_firstkey(ctx->context, ctx->db_ctx, hentry);
 159
 160         if (ret) {
 161                 talloc_free(hentry);
 162         } else {
 163                 talloc_steal(hentry->ctx, hentry);
 164                 *_hentry = hentry;
 165         }
 166         return ret;
 167 }
 168
 169 static int mit_samba_get_nextkey(struct mit_samba_context *ctx,
 170                                  hdb_entry_ex **_hentry)
 171 {
 172         hdb_entry_ex *hentry;
 173         int ret;
 174
 175         hentry = talloc(ctx, hdb_entry_ex);
 176         if (!hentry) {
 177                 return ENOMEM;
 178         }
 179
 180         ret = samba_kdc_nextkey(ctx->context, ctx->db_ctx, hentry);
 181
 182         if (ret) {
 183                 talloc_free(hentry);
 184         } else {
 185                 talloc_steal(hentry->ctx, hentry);
 186                 *_hentry = hentry;
 187         }
 188         return ret;
 189 }
 190
 191 static int mit_samba_get_pac_data(struct mit_samba_context *ctx,
 192                                   hdb_entry_ex *client,
 193                                   DATA_BLOB *data)
 194 {
 195         TALLOC_CTX *tmp_ctx;
 196         DATA_BLOB *pac_blob;
 197         NTSTATUS nt_status;
 198
 199         tmp_ctx = talloc_named(ctx, 0, "mit_samba_get_pac_data context");
 200         if (!tmp_ctx) {
 201                 return ENOMEM;
 202         }
 203
 204         nt_status = samba_kdc_get_pac_blob(tmp_ctx, client, &pac_blob);
 205         if (!NT_STATUS_IS_OK(nt_status)) {
 206                 talloc_free(tmp_ctx);
 207                 return EINVAL;
 208         }
 209
 210         data->data = (uint8_t *)malloc(pac_blob->length);
 211         if (!data->data) {
 212                 talloc_free(tmp_ctx);
 213                 return ENOMEM;
 214         }
 215         memcpy(data->data, pac_blob->data, pac_blob->length);
 216         data->length = pac_blob->length;
 217
 218         talloc_free(tmp_ctx);
 219         return 0;
 220 }
 221
 222 static int mit_samba_update_pac_data(struct mit_samba_context *ctx,
 223                                      hdb_entry_ex *client,
 224                                      DATA_BLOB *pac_data,
 225                                      DATA_BLOB *logon_data)
 226 {
 227         TALLOC_CTX *tmp_ctx;
 228         DATA_BLOB *logon_blob;
 229         krb5_error_code code;
 230         NTSTATUS nt_status;
 231         krb5_pac pac = NULL;
 232         int ret;
 233
 234         /* The user account may be set not to want the PAC */
 235         if (client && !samba_princ_needs_pac(client)) {
 236                 return EINVAL;
 237         }
 238
 239         tmp_ctx = talloc_named(ctx, 0, "mit_samba_update_pac_data context");
 240         if (!tmp_ctx) {
 241                 return ENOMEM;
 242         }
 243
 244         logon_blob = talloc_zero(tmp_ctx, DATA_BLOB);
 245         if (!logon_blob) {
 246                 ret = ENOMEM;
 247                 goto done;
 248         }
 249
 250         code = krb5_pac_parse(ctx->context,
 251                               pac_data->data, pac_data->length, &pac);
 252         if (code) {
 253                 ret = EINVAL;
 254                 goto done;
 255         }
 256
 257         /* TODO: An implementation-specific decision will need to be
 258          * made as to when to check the KDC pac signature, and how to
 259          * untrust untrusted RODCs */
 260         nt_status = samba_kdc_update_pac_blob(tmp_ctx, ctx->context,
 261                                               pac, logon_blob, NULL, NULL);
 262         if (!NT_STATUS_IS_OK(nt_status)) {
 263                 DEBUG(0, ("Building PAC failed: %s\n",
 264                           nt_errstr(nt_status)));
 265                 ret = EINVAL;
 266                 goto done;
 267         }
 268
 269         logon_data->data = (uint8_t *)malloc(logon_blob->length);
 270         if (!logon_data->data) {
 271                 ret = ENOMEM;
 272                 goto done;
 273         }
 274         memcpy(logon_data->data, logon_blob->data, logon_blob->length);
 275         logon_data->length = logon_blob->length;
 276
 277         ret = 0;
 278
 279 done:
 280         if (pac) krb5_pac_free(ctx->context, pac);
 281         talloc_free(tmp_ctx);
 282         return ret;
 283 }
 284
 285 static int mit_samba_check_client_access(struct mit_samba_context *ctx,
 286                                          hdb_entry_ex *client,
 287                                          const char *client_name,
 288                                          hdb_entry_ex *server,
 289                                          const char *server_name,
 290                                          const char *netbios_name,
 291                                          bool password_change,
 292                                          DATA_BLOB *e_data)
 293 {
 294         struct samba_kdc_entry *kdc_entry;
 295         NTSTATUS nt_status;
 296
 297         kdc_entry = talloc_get_type(client->ctx, struct samba_kdc_entry);
 298
 299         nt_status = samba_kdc_check_client_access(kdc_entry,
 300                                                   client_name,
 301                                                   netbios_name,
 302                                                   password_change);
 303
 304         if (!NT_STATUS_IS_OK(nt_status)) {
 305                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
 306                         return ENOMEM;
 307                 }
 308
 309                 samba_kdc_build_edata_reply(nt_status, e_data);
 310
 311                 return samba_kdc_map_policy_err(nt_status);
 312         }
 313
 314         return 0;
 315 }
 316
 317 static int mit_samba_check_s4u2proxy(struct mit_samba_context *ctx,
 318                                      hdb_entry_ex *entry,
 319                                      const char *target_name,
 320                                      bool is_nt_enterprise_name)
 321 {
 322 #if 1
 323         /*
 324          * This is disabled because mit_samba_update_pac_data() does not handle
 325          * S4U_DELEGATION_INFO
 326          */
 327
 328         return KRB5KDC_ERR_BADOPTION;
 329 #else
 330         krb5_principal target_principal;
 331         int flags = 0;
 332         int ret;
 333
 334         if (is_nt_enterprise_name) {
 335                 flags = KRB5_PRINCIPAL_PARSE_ENTERPRISE;
 336         }
 337
 338         ret = krb5_parse_name_flags(ctx->context, target_name,
 339                                     flags, &target_principal);
 340         if (ret) {
 341                 return ret;
 342         }
 343
 344         ret = samba_kdc_check_s4u2proxy(ctx->context,
 345                                         ctx->db_ctx,
 346                                         entry,
 347                                         target_principal);
 348
 349         krb5_free_principal(ctx->context, target_principal);
 350
 351         return ret;
 352 #endif
 353 }
 354
 355 struct mit_samba_function_table mit_samba_function_table = {
 356         mit_samba_context_init,
 357         mit_samba_context_free,
 358         mit_samba_get_principal,
 359         mit_samba_get_firstkey,
 360         mit_samba_get_nextkey,
 361         mit_samba_get_pac_data,
 362         mit_samba_update_pac_data,
 363         mit_samba_check_client_access,
 364         mit_samba_check_s4u2proxy
 365 };