source3/libnet/libnet_keytab.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    dump the remote SAM using rpc samsync operations
   4
   5    Copyright (C) Guenther Deschner 2008.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "libnet/libnet.h"
  23
  24 #ifdef HAVE_KRB5
  25
  26 /****************************************************************
  27 ****************************************************************/
  28
  29 static int keytab_close(struct libnet_keytab_context *ctx)
  30 {
  31         if (!ctx) {
  32                 return 0;
  33         }
  34
  35         if (ctx->keytab && ctx->context) {
  36                 krb5_kt_close(ctx->context, ctx->keytab);
  37         }
  38
  39         if (ctx->context) {
  40                 krb5_free_context(ctx->context);
  41         }
  42
  43         if (ctx->ads) {
  44                 ads_destroy(&ctx->ads);
  45         }
  46
  47         TALLOC_FREE(ctx);
  48
  49         return 0;
  50 }
  51
  52 /****************************************************************
  53 ****************************************************************/
  54
  55 krb5_error_code libnet_keytab_init(TALLOC_CTX *mem_ctx,
  56                                    const char *keytab_name,
  57                                    struct libnet_keytab_context **ctx)
  58 {
  59         krb5_error_code ret = 0;
  60         krb5_context context = NULL;
  61         krb5_keytab keytab = NULL;
  62         const char *keytab_string = NULL;
  63
  64         struct libnet_keytab_context *r;
  65
  66         r = TALLOC_ZERO_P(mem_ctx, struct libnet_keytab_context);
  67         if (!r) {
  68                 return ENOMEM;
  69         }
  70
  71         talloc_set_destructor(r, keytab_close);
  72
  73         initialize_krb5_error_table();
  74         ret = krb5_init_context(&context);
  75         if (ret) {
  76                 DEBUG(1,("keytab_init: could not krb5_init_context: %s\n",
  77                         error_message(ret)));
  78                 return ret;
  79         }
  80
  81         ret = smb_krb5_open_keytab(context, keytab_name, true, &keytab);
  82         if (ret) {
  83                 DEBUG(1,("keytab_init: smb_krb5_open_keytab failed (%s)\n",
  84                         error_message(ret)));
  85                 krb5_free_context(context);
  86                 return ret;
  87         }
  88
  89         ret = smb_krb5_keytab_name(mem_ctx, context, keytab, &keytab_string);
  90         if (ret) {
  91                 krb5_kt_close(context, keytab);
  92                 krb5_free_context(context);
  93                 return ret;
  94         }
  95
  96         r->context = context;
  97         r->keytab = keytab;
  98         r->keytab_name = keytab_string;
  99
 100         *ctx = r;
 101
 102         return 0;
 103 }
 104
 105 /****************************************************************
 106 ****************************************************************/
 107
 108 /**
 109  * Remove all entries that have the given principal, kvno and enctype.
 110  */
 111 static krb5_error_code libnet_keytab_remove_entries(krb5_context context,
 112                                                     krb5_keytab keytab,
 113                                                     const char *principal,
 114                                                     int kvno,
 115                                                     const krb5_enctype enctype)
 116 {
 117         krb5_error_code ret;
 118         krb5_kt_cursor cursor;
 119         krb5_keytab_entry kt_entry;
 120
 121         ZERO_STRUCT(kt_entry);
 122         ZERO_STRUCT(cursor);
 123
 124         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 125         if (ret) {
 126                 return 0;
 127         }
 128
 129         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0)
 130         {
 131                 char *princ_s = NULL;
 132
 133                 if (kt_entry.vno != kvno) {
 134                         goto cont;
 135                 }
 136
 137                 if (kt_entry.key.enctype != enctype) {
 138                         goto cont;
 139                 }
 140
 141                 ret = smb_krb5_unparse_name(context, kt_entry.principal,
 142                                             &princ_s);
 143                 if (ret) {
 144                         DEBUG(5, ("smb_krb5_unparse_name failed (%s)\n",
 145                                   error_message(ret)));
 146                         goto cont;
 147                 }
 148
 149                 if (strcmp(principal, princ_s) != 0) {
 150                         goto cont;
 151                 }
 152
 153                 /* match found - remove */
 154
 155                 DEBUG(10, ("found entry for principal %s, kvno %d, "
 156                            "enctype %d - trying to remove it\n",
 157                            princ_s, kt_entry.vno, kt_entry.key.enctype));
 158
 159                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 160                 ZERO_STRUCT(cursor);
 161                 if (ret) {
 162                         DEBUG(5, ("krb5_kt_end_seq_get failed (%s)\n",
 163                                   error_message(ret)));
 164                         goto cont;
 165                 }
 166
 167                 ret = krb5_kt_remove_entry(context, keytab,
 168                                            &kt_entry);
 169                 if (ret) {
 170                         DEBUG(5, ("krb5_kt_remove_entry failed (%s)\n",
 171                                   error_message(ret)));
 172                         goto cont;
 173                 }
 174                 DEBUG(10, ("removed entry for principal %s, kvno %d, "
 175                            "enctype %d\n", princ_s, kt_entry.vno,
 176                            kt_entry.key.enctype));
 177
 178                 ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 179                 if (ret) {
 180                         DEBUG(5, ("krb5_kt_start_seq_get failed (%s)\n",
 181                                   error_message(ret)));
 182                         goto cont;
 183                 }
 184
 185 cont:
 186                 smb_krb5_kt_free_entry(context, &kt_entry);
 187                 SAFE_FREE(princ_s);
 188         }
 189
 190         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 191         if (ret) {
 192                 DEBUG(5, ("krb5_kt_end_seq_get failed (%s)\n",
 193                           error_message(ret)));
 194         }
 195
 196         return ret;
 197 }
 198
 199 static krb5_error_code libnet_keytab_add_entry(krb5_context context,
 200                                                krb5_keytab keytab,
 201                                                krb5_kvno kvno,
 202                                                const char *princ_s,
 203                                                krb5_enctype enctype,
 204                                                krb5_data password)
 205 {
 206         krb5_keyblock *keyp;
 207         krb5_keytab_entry kt_entry;
 208         krb5_error_code ret;
 209
 210         /* remove duplicates first ... */
 211         ret = libnet_keytab_remove_entries(context, keytab, princ_s, kvno,
 212                                            enctype);
 213         if (ret) {
 214                 DEBUG(1, ("libnet_keytab_remove_entries failed: %s\n",
 215                           error_message(ret)));
 216         }
 217
 218         ZERO_STRUCT(kt_entry);
 219
 220         kt_entry.vno = kvno;
 221
 222         ret = smb_krb5_parse_name(context, princ_s, &kt_entry.principal);
 223         if (ret) {
 224                 DEBUG(1, ("smb_krb5_parse_name(%s) failed (%s)\n",
 225                           princ_s, error_message(ret)));
 226                 return ret;
 227         }
 228
 229 #if !defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) && !defined(HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK)
 230 #error krb5_keytab_entry has no key or keyblock member
 231 #endif
 232 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEY               /* MIT */
 233         keyp = &kt_entry.key;
 234 #endif
 235 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK          /* Heimdal */
 236         keyp = &kt_entry.keyblock;
 237 #endif
 238
 239         if (create_kerberos_key_from_string(context, kt_entry.principal,
 240                                             &password, keyp, enctype, true))
 241         {
 242                 ret = KRB5KRB_ERR_GENERIC;
 243                 goto done;
 244         }
 245
 246         ret = krb5_kt_add_entry(context, keytab, &kt_entry);
 247         if (ret) {
 248                 DEBUG(1, ("adding entry to keytab failed (%s)\n",
 249                           error_message(ret)));
 250         }
 251
 252 done:
 253         krb5_free_keyblock_contents(context, keyp);
 254         krb5_free_principal(context, kt_entry.principal);
 255         ZERO_STRUCT(kt_entry);
 256         smb_krb5_kt_free_entry(context, &kt_entry);
 257
 258         return ret;
 259 }
 260
 261 krb5_error_code libnet_keytab_add(struct libnet_keytab_context *ctx)
 262 {
 263         krb5_error_code ret = 0;
 264         int i;
 265
 266         for (i=0; i<ctx->count; i++) {
 267
 268                 struct libnet_keytab_entry *entry = &ctx->entries[i];
 269                 krb5_data password;
 270
 271                 password.data = (char *)entry->password.data;
 272                 password.length = entry->password.length;
 273
 274                 ret = libnet_keytab_add_entry(ctx->context,
 275                                               ctx->keytab,
 276                                               entry->kvno,
 277                                               entry->principal,
 278                                               entry->enctype,
 279                                               password);
 280                 if (ret) {
 281                         DEBUG(1,("libnet_keytab_add: "
 282                                 "Failed to add entry to keytab file\n"));
 283                         return ret;
 284                 }
 285         }
 286
 287         return ret;
 288 }
 289
 290 struct libnet_keytab_entry *libnet_keytab_search(struct libnet_keytab_context *ctx,
 291                                                  const char *principal,
 292                                                  int kvno,
 293                                                  const krb5_enctype enctype,
 294                                                  TALLOC_CTX *mem_ctx)
 295 {
 296         krb5_error_code ret = 0;
 297         krb5_kt_cursor cursor;
 298         krb5_keytab_entry kt_entry;
 299         struct libnet_keytab_entry *entry = NULL;
 300
 301         ZERO_STRUCT(kt_entry);
 302         ZERO_STRUCT(cursor);
 303
 304         ret = krb5_kt_start_seq_get(ctx->context, ctx->keytab, &cursor);
 305         if (ret) {
 306                 DEBUG(10, ("krb5_kt_start_seq_get failed: %s",
 307                           error_message(ret)));
 308                 return NULL;
 309         }
 310
 311         while (krb5_kt_next_entry(ctx->context, ctx->keytab, &kt_entry, &cursor) == 0)
 312         {
 313                 char *princ_s = NULL;
 314
 315                 if (kt_entry.vno != kvno) {
 316                         goto cont;
 317                 }
 318
 319                 if (kt_entry.key.enctype != enctype) {
 320                         goto cont;
 321                 }
 322
 323                 ret = smb_krb5_unparse_name(ctx->context, kt_entry.principal,
 324                                             &princ_s);
 325                 if (ret) {
 326                         goto cont;
 327                 }
 328
 329                 if (strcmp(principal, princ_s) != 0) {
 330                         goto cont;
 331                 }
 332
 333                 entry = talloc_zero(mem_ctx, struct libnet_keytab_entry);
 334                 if (!entry) {
 335                         DEBUG(3, ("talloc failed\n"));
 336                         goto fail;
 337                 }
 338
 339                 entry->name = talloc_strdup(entry, princ_s);
 340                 if (!entry->name) {
 341                         DEBUG(3, ("talloc_strdup_failed\n"));
 342                         goto fail;
 343                 }
 344
 345                 entry->principal = talloc_strdup(entry, princ_s);
 346                 if (!entry->principal) {
 347                         DEBUG(3, ("talloc_strdup_failed\n"));
 348                         goto fail;
 349                 }
 350
 351                 entry->password = data_blob_talloc(entry, kt_entry.key.contents,
 352                                                    kt_entry.key.length);
 353                 if (!entry->password.data) {
 354                         DEBUG(3, ("data_blob_talloc failed\n"));
 355                         goto fail;
 356                 }
 357
 358                 DEBUG(10, ("found entry\n"));
 359
 360                 smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 361                 SAFE_FREE(princ_s);
 362                 break;
 363
 364 fail:
 365                 smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 366                 SAFE_FREE(princ_s);
 367                 TALLOC_FREE(entry);
 368                 break;
 369
 370 cont:
 371                 smb_krb5_kt_free_entry(ctx->context, &kt_entry);
 372                 SAFE_FREE(princ_s);
 373                 continue;
 374         }
 375
 376         krb5_kt_end_seq_get(ctx->context, ctx->keytab, &cursor);
 377         return entry;
 378 }
 379
 380 #endif /* HAVE_KRB5 */