source4/kdc/mit-kdb/kdb_samba_principals.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Samba KDB plugin for MIT Kerberos
   5
   6    Copyright (c) 2010      Simo Sorce <idra@samba.org>.
   7    Copyright (c) 2014      Andreas Schneider <asn@samba.org>
   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    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
  25 #include "system/kerberos.h"
  26
  27 #include <profile.h>
  28 #include <kdb.h>
  29
  30 #include "kdc/mit_samba.h"
  31 #include "kdb_samba.h"
  32
  33 #define ADMIN_LIFETIME 60*60*3 /* 3 hours */
  34 #define CHANGEPW_LIFETIME 60*5 /* 5 minutes */
  35
  36 static krb5_error_code ks_get_principal(krb5_context context,
  37                                         krb5_const_principal principal,
  38                                         unsigned int kflags,
  39                                         krb5_db_entry **kentry)
  40 {
  41         struct mit_samba_context *mit_ctx;
  42         krb5_error_code code;
  43
  44         mit_ctx = ks_get_context(context);
  45         if (mit_ctx == NULL) {
  46                 return KRB5_KDB_DBNOTINITED;
  47         }
  48
  49         code = mit_samba_get_principal(mit_ctx,
  50                                        principal,
  51                                        kflags,
  52                                        kentry);
  53         if (code != 0) {
  54                 goto cleanup;
  55         }
  56
  57 cleanup:
  58
  59         return code;
  60 }
  61
  62 static krb5_boolean ks_is_master_key_principal(krb5_context context,
  63                                                krb5_const_principal princ)
  64 {
  65         return krb5_princ_size(context, princ) == 2 &&
  66                ks_data_eq_string(princ->data[0], "K") &&
  67                ks_data_eq_string(princ->data[1], "M");
  68 }
  69
  70 static krb5_error_code ks_get_master_key_principal(krb5_context context,
  71                                                    krb5_const_principal princ,
  72                                                    krb5_db_entry **kentry_ptr)
  73 {
  74         krb5_error_code code;
  75         krb5_key_data *key_data;
  76         krb5_timestamp now;
  77         krb5_db_entry *kentry;
  78
  79         *kentry_ptr = NULL;
  80
  81         kentry = calloc(1, sizeof(krb5_db_entry));
  82         if (kentry == NULL) {
  83                 return ENOMEM;
  84         }
  85
  86         kentry->magic = KRB5_KDB_MAGIC_NUMBER;
  87         kentry->len = KRB5_KDB_V1_BASE_LENGTH;
  88         kentry->attributes = KRB5_KDB_DISALLOW_ALL_TIX;
  89
  90         if (princ == NULL) {
  91                 code = krb5_parse_name(context, KRB5_KDB_M_NAME, &kentry->princ);
  92         } else {
  93                 code = krb5_copy_principal(context, princ, &kentry->princ);
  94         }
  95         if (code != 0) {
  96                 krb5_db_free_principal(context, kentry);
  97                 return code;
  98         }
  99
 100         now = time(NULL);
 101
 102         code = krb5_dbe_update_mod_princ_data(context, kentry, now, kentry->princ);
 103         if (code != 0) {
 104                 krb5_db_free_principal(context, kentry);
 105                 return code;
 106         }
 107
 108         /* Return a dummy key */
 109         kentry->n_key_data = 1;
 110         kentry->key_data = calloc(1, sizeof(krb5_key_data));
 111         if (code != 0) {
 112                 krb5_db_free_principal(context, kentry);
 113                 return code;
 114         }
 115
 116         key_data = &kentry->key_data[0];
 117
 118         key_data->key_data_ver          = KRB5_KDB_V1_KEY_DATA_ARRAY;
 119         key_data->key_data_kvno         = 1;
 120         key_data->key_data_type[0]      = ENCTYPE_UNKNOWN;
 121         if (code != 0) {
 122                 krb5_db_free_principal(context, kentry);
 123                 return code;
 124         }
 125
 126         *kentry_ptr = kentry;
 127
 128         return 0;
 129 }
 130
 131 static krb5_error_code ks_create_principal(krb5_context context,
 132                                            krb5_const_principal princ,
 133                                            int attributes,
 134                                            int max_life,
 135                                            const char *password,
 136                                            krb5_db_entry **kentry_ptr)
 137 {
 138         krb5_error_code code;
 139         krb5_key_data *key_data;
 140         krb5_timestamp now;
 141         krb5_db_entry *kentry;
 142         krb5_keyblock key;
 143         krb5_data salt;
 144         krb5_data pwd;
 145         int enctype = ENCTYPE_AES256_CTS_HMAC_SHA1_96;
 146         int sts = KRB5_KDB_SALTTYPE_SPECIAL;
 147
 148         if (princ == NULL) {
 149                 return KRB5_KDB_NOENTRY;
 150         }
 151
 152         *kentry_ptr = NULL;
 153
 154         kentry = calloc(1, sizeof(krb5_db_entry));
 155         if (kentry == NULL) {
 156                 return ENOMEM;
 157         }
 158
 159         kentry->magic = KRB5_KDB_MAGIC_NUMBER;
 160         kentry->len = KRB5_KDB_V1_BASE_LENGTH;
 161
 162         if (attributes > 0) {
 163                 kentry->attributes = attributes;
 164         }
 165
 166         if (max_life > 0) {
 167                 kentry->max_life = max_life;
 168         }
 169
 170         code = krb5_copy_principal(context, princ, &kentry->princ);
 171         if (code != 0) {
 172                 krb5_db_free_principal(context, kentry);
 173                 return code;
 174         }
 175
 176         now = time(NULL);
 177
 178         code = krb5_dbe_update_mod_princ_data(context, kentry, now, kentry->princ);
 179         if (code != 0) {
 180                 krb5_db_free_principal(context, kentry);
 181                 return code;
 182         }
 183
 184         code = mit_samba_generate_salt(&salt);
 185         if (code != 0) {
 186                 krb5_db_free_principal(context, kentry);
 187                 return code;
 188         }
 189
 190         if (password != NULL) {
 191                 pwd.data = strdup(password);
 192                 pwd.length = strlen(password);
 193         } else {
 194                 /* create a random password */
 195                 code = mit_samba_generate_random_password(&pwd);
 196                 if (code != 0) {
 197                         krb5_db_free_principal(context, kentry);
 198                         return code;
 199                 }
 200         }
 201
 202         code = krb5_c_string_to_key(context, enctype, &pwd, &salt, &key);
 203         SAFE_FREE(pwd.data);
 204         if (code != 0) {
 205                 krb5_db_free_principal(context, kentry);
 206                 return code;
 207         }
 208
 209         kentry->n_key_data = 1;
 210         kentry->key_data = calloc(1, sizeof(krb5_key_data));
 211         if (code != 0) {
 212                 krb5_db_free_principal(context, kentry);
 213                 return code;
 214         }
 215
 216         key_data = &kentry->key_data[0];
 217
 218         key_data->key_data_ver          = KRB5_KDB_V1_KEY_DATA_ARRAY;
 219         key_data->key_data_kvno         = 1;
 220         key_data->key_data_type[0]      = key.enctype;
 221         key_data->key_data_length[0]    = key.length;
 222         key_data->key_data_contents[0]  = key.contents;
 223         key_data->key_data_type[1]      = sts;
 224         key_data->key_data_length[1]    = salt.length;
 225         key_data->key_data_contents[1]  = (krb5_octet*)salt.data;
 226
 227         *kentry_ptr = kentry;
 228
 229         return 0;
 230 }
 231
 232 static krb5_error_code ks_get_admin_principal(krb5_context context,
 233                                               krb5_const_principal princ,
 234                                               krb5_db_entry **kentry_ptr)
 235 {
 236         krb5_error_code code = EINVAL;
 237
 238         code = ks_create_principal(context,
 239                                    princ,
 240                                    KRB5_KDB_DISALLOW_TGT_BASED,
 241                                    ADMIN_LIFETIME,
 242                                    NULL,
 243                                    kentry_ptr);
 244
 245         return code;
 246 }
 247
 248 krb5_error_code kdb_samba_db_get_principal(krb5_context context,
 249                                            krb5_const_principal princ,
 250                                            unsigned int kflags,
 251                                            krb5_db_entry **kentry)
 252 {
 253         struct mit_samba_context *mit_ctx;
 254         krb5_error_code code;
 255
 256         mit_ctx = ks_get_context(context);
 257         if (mit_ctx == NULL) {
 258                 return KRB5_KDB_DBNOTINITED;
 259         }
 260
 261         if (ks_is_master_key_principal(context, princ)) {
 262                 return ks_get_master_key_principal(context, princ, kentry);
 263         }
 264
 265         /*
 266          * Fake a kadmin/admin and kadmin/history principal so that kadmindd can
 267          * start
 268          */
 269         if (ks_is_kadmin_admin(context, princ) ||
 270             ks_is_kadmin_history(context, princ)) {
 271                 return ks_get_admin_principal(context, princ, kentry);
 272         }
 273
 274         code = ks_get_principal(context, princ, kflags, kentry);
 275
 276         /*
 277          * This restricts the changepw account so it isn't able to request a
 278          * service ticket. It also marks the principal as the changepw service.
 279          */
 280         if (ks_is_kadmin_changepw(context, princ)) {
 281                 /* FIXME: shouldn't we also set KRB5_KDB_DISALLOW_TGT_BASED ?
 282                  * testing showed that setpw kpasswd command fails then on the
 283                  * server though... */
 284                 (*kentry)->attributes |= KRB5_KDB_PWCHANGE_SERVICE;
 285                 (*kentry)->max_life = CHANGEPW_LIFETIME;
 286         }
 287
 288         return code;
 289 }
 290
 291 krb5_error_code kdb_samba_db_put_principal(krb5_context context,
 292                                            krb5_db_entry *entry,
 293                                            char **db_args)
 294 {
 295
 296         /* NOTE: deferred, samba does not allow the KDC to store
 297          * principals for now. We should not return KRB5_KDB_DB_INUSE as this
 298          * would result in confusing error messages after password changes. */
 299         return 0;
 300 }
 301
 302 krb5_error_code kdb_samba_db_delete_principal(krb5_context context,
 303                                               krb5_const_principal princ)
 304 {
 305
 306         /* NOTE: deferred, samba does not allow the KDC to delete
 307          * principals for now */
 308         return KRB5_KDB_DB_INUSE;
 309 }
 310
 311 #if KRB5_KDB_API_VERSION >= 8
 312 krb5_error_code kdb_samba_db_iterate(krb5_context context,
 313                                      char *match_entry,
 314                                      int (*func)(krb5_pointer, krb5_db_entry *),
 315                                      krb5_pointer func_arg,
 316                                      krb5_flags iterflags)
 317 #else
 318 krb5_error_code kdb_samba_db_iterate(krb5_context context,
 319                                      char *match_entry,
 320                                      int (*func)(krb5_pointer, krb5_db_entry *),
 321                                      krb5_pointer func_arg)
 322 #endif
 323 {
 324         struct mit_samba_context *mit_ctx;
 325         krb5_db_entry *kentry = NULL;
 326         krb5_error_code code;
 327
 328
 329         mit_ctx = ks_get_context(context);
 330         if (mit_ctx == NULL) {
 331                 return KRB5_KDB_DBNOTINITED;
 332         }
 333
 334         code = mit_samba_get_firstkey(mit_ctx, &kentry);
 335         while (code == 0) {
 336                 code = (*func)(func_arg, kentry);
 337                 if (code != 0) {
 338                         break;
 339                 }
 340
 341                 code = mit_samba_get_nextkey(mit_ctx, &kentry);
 342         }
 343
 344         if (code == KRB5_KDB_NOENTRY) {
 345                 code = 0;
 346         }
 347
 348         return code;
 349 }