libcli/auth/krb5_wrap.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    simple kerberos5 routines for active directory
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Luke Howard 2002-2003
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2011
   7    Copyright (C) Guenther Deschner 2005-2009
   8    Copyright (C) Simo Sorce 2010.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  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 #ifdef HAVE_KRB5
  26
  27 #include "libcli/auth/krb5_wrap.h"
  28 #include "librpc/gen_ndr/krb5pac.h"
  29
  30 #if defined(HAVE_KRB5_PRINCIPAL2SALT) && defined(HAVE_KRB5_USE_ENCTYPE) && defined(HAVE_KRB5_STRING_TO_KEY) && defined(HAVE_KRB5_ENCRYPT_BLOCK)
  31 int create_kerberos_key_from_string_direct(krb5_context context,
  32                                                   krb5_principal host_princ,
  33                                                   krb5_data *password,
  34                                                   krb5_keyblock *key,
  35                                                   krb5_enctype enctype)
  36 {
  37         int ret = 0;
  38         krb5_data salt;
  39         krb5_encrypt_block eblock;
  40
  41         ret = krb5_principal2salt(context, host_princ, &salt);
  42         if (ret) {
  43                 DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
  44                 return ret;
  45         }
  46         krb5_use_enctype(context, &eblock, enctype);
  47         ret = krb5_string_to_key(context, &eblock, key, password, &salt);
  48         SAFE_FREE(salt.data);
  49
  50         return ret;
  51 }
  52 #elif defined(HAVE_KRB5_GET_PW_SALT) && defined(HAVE_KRB5_STRING_TO_KEY_SALT)
  53 int create_kerberos_key_from_string_direct(krb5_context context,
  54                                                   krb5_principal host_princ,
  55                                                   krb5_data *password,
  56                                                   krb5_keyblock *key,
  57                                                   krb5_enctype enctype)
  58 {
  59         int ret;
  60         krb5_salt salt;
  61
  62         ret = krb5_get_pw_salt(context, host_princ, &salt);
  63         if (ret) {
  64                 DEBUG(1,("krb5_get_pw_salt failed (%s)\n", error_message(ret)));
  65                 return ret;
  66         }
  67
  68         ret = krb5_string_to_key_salt(context, enctype, (const char *)password->data, salt, key);
  69         krb5_free_salt(context, salt);
  70
  71         return ret;
  72 }
  73 #else
  74 #error UNKNOWN_CREATE_KEY_FUNCTIONS
  75 #endif
  76
  77  void kerberos_free_data_contents(krb5_context context, krb5_data *pdata)
  78 {
  79 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
  80         if (pdata->data) {
  81                 krb5_free_data_contents(context, pdata);
  82         }
  83 #elif defined(HAVE_KRB5_DATA_FREE)
  84         krb5_data_free(context, pdata);
  85 #else
  86         SAFE_FREE(pdata->data);
  87 #endif
  88 }
  89
  90
  91  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
  92 {
  93 /* Try krb5_free_keytab_entry_contents first, since
  94  * MIT Kerberos >= 1.7 has both krb5_free_keytab_entry_contents and
  95  * krb5_kt_free_entry but only has a prototype for the first, while the
  96  * second is considered private.
  97  */
  98 #if defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
  99         return krb5_free_keytab_entry_contents(context, kt_entry);
 100 #elif defined(HAVE_KRB5_KT_FREE_ENTRY)
 101         return krb5_kt_free_entry(context, kt_entry);
 102 #else
 103 #error UNKNOWN_KT_FREE_FUNCTION
 104 #endif
 105 }
 106
 107 /**************************************************************
 108  Wrappers around kerberos string functions that convert from
 109  utf8 -> unix charset and vica versa.
 110 **************************************************************/
 111
 112 /**************************************************************
 113  krb5_parse_name that takes a UNIX charset.
 114 **************************************************************/
 115
 116  krb5_error_code smb_krb5_parse_name(krb5_context context,
 117                                 const char *name, /* in unix charset */
 118                                 krb5_principal *principal)
 119 {
 120         krb5_error_code ret;
 121         char *utf8_name;
 122         size_t converted_size;
 123
 124         if (!push_utf8_talloc(talloc_tos(), &utf8_name, name, &converted_size)) {
 125                 return ENOMEM;
 126         }
 127
 128         ret = krb5_parse_name(context, utf8_name, principal);
 129         TALLOC_FREE(utf8_name);
 130         return ret;
 131 }
 132
 133 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 134 static void krb5_free_unparsed_name(krb5_context context, char *val)
 135 {
 136         SAFE_FREE(val);
 137 }
 138 #endif
 139
 140 /**************************************************************
 141  krb5_parse_name that returns a UNIX charset name. Must
 142  be freed with talloc_free() call.
 143 **************************************************************/
 144
 145 krb5_error_code smb_krb5_unparse_name(TALLOC_CTX *mem_ctx,
 146                                       krb5_context context,
 147                                       krb5_const_principal principal,
 148                                       char **unix_name)
 149 {
 150         krb5_error_code ret;
 151         char *utf8_name;
 152         size_t converted_size;
 153
 154         *unix_name = NULL;
 155         ret = krb5_unparse_name(context, principal, &utf8_name);
 156         if (ret) {
 157                 return ret;
 158         }
 159
 160         if (!pull_utf8_talloc(mem_ctx, unix_name, utf8_name, &converted_size)) {
 161                 krb5_free_unparsed_name(context, utf8_name);
 162                 return ENOMEM;
 163         }
 164         krb5_free_unparsed_name(context, utf8_name);
 165         return 0;
 166 }
 167
 168  krb5_error_code smb_krb5_parse_name_norealm(krb5_context context,
 169                                             const char *name,
 170                                             krb5_principal *principal)
 171 {
 172 #ifdef HAVE_KRB5_PARSE_NAME_NOREALM
 173         return smb_krb5_parse_name_norealm_conv(context, name, principal);
 174 #endif
 175
 176         /* we are cheating here because parse_name will in fact set the realm.
 177          * We don't care as the only caller of smb_krb5_parse_name_norealm
 178          * ignores the realm anyway when calling
 179          * smb_krb5_principal_compare_any_realm later - Guenther */
 180
 181         return smb_krb5_parse_name(context, name, principal);
 182 }
 183
 184  bool smb_krb5_principal_compare_any_realm(krb5_context context,
 185                                           krb5_const_principal princ1,
 186                                           krb5_const_principal princ2)
 187 {
 188 #ifdef HAVE_KRB5_PRINCIPAL_COMPARE_ANY_REALM
 189
 190         return krb5_principal_compare_any_realm(context, princ1, princ2);
 191
 192 /* krb5_princ_size is a macro in MIT */
 193 #elif defined(HAVE_KRB5_PRINC_SIZE) || defined(krb5_princ_size)
 194
 195         int i, len1, len2;
 196         const krb5_data *p1, *p2;
 197
 198         len1 = krb5_princ_size(context, princ1);
 199         len2 = krb5_princ_size(context, princ2);
 200
 201         if (len1 != len2)
 202                 return False;
 203
 204         for (i = 0; i < len1; i++) {
 205
 206                 p1 = krb5_princ_component(context, discard_const(krb5_principal, princ1), i);
 207                 p2 = krb5_princ_component(context, discard_const(krb5_principal, princ2), i);
 208
 209                 if (p1->length != p2->length || memcmp(p1->data, p2->data, p1->length))
 210                         return False;
 211         }
 212
 213         return True;
 214 #else
 215 #error NO_SUITABLE_PRINCIPAL_COMPARE_FUNCTION
 216 #endif
 217 }
 218
 219  void smb_krb5_checksum_from_pac_sig(krb5_checksum *cksum,
 220                                      struct PAC_SIGNATURE_DATA *sig)
 221 {
 222 #ifdef HAVE_CHECKSUM_IN_KRB5_CHECKSUM
 223         cksum->cksumtype        = (krb5_cksumtype)sig->type;
 224         cksum->checksum.length  = sig->signature.length;
 225         cksum->checksum.data    = sig->signature.data;
 226 #else
 227         cksum->checksum_type    = (krb5_cksumtype)sig->type;
 228         cksum->length           = sig->signature.length;
 229         cksum->contents         = sig->signature.data;
 230 #endif
 231 }
 232
 233  krb5_error_code smb_krb5_verify_checksum(krb5_context context,
 234                                           const krb5_keyblock *keyblock,
 235                                          krb5_keyusage usage,
 236                                          krb5_checksum *cksum,
 237                                          uint8_t *data,
 238                                          size_t length)
 239 {
 240         krb5_error_code ret;
 241
 242         /* verify the checksum */
 243
 244         /* welcome to the wonderful world of samba's kerberos abstraction layer:
 245          *
 246          * function                     heimdal 0.6.1rc3        heimdal 0.7     MIT krb 1.4.2
 247          * -----------------------------------------------------------------------------
 248          * krb5_c_verify_checksum       -                       works           works
 249          * krb5_verify_checksum         works (6 args)          works (6 args)  broken (7 args)
 250          */
 251
 252 #if defined(HAVE_KRB5_C_VERIFY_CHECKSUM)
 253         {
 254                 krb5_boolean checksum_valid = false;
 255                 krb5_data input;
 256
 257                 input.data = (char *)data;
 258                 input.length = length;
 259
 260                 ret = krb5_c_verify_checksum(context,
 261                                              keyblock,
 262                                              usage,
 263                                              &input,
 264                                              cksum,
 265                                              &checksum_valid);
 266                 if (ret) {
 267                         DEBUG(3,("smb_krb5_verify_checksum: krb5_c_verify_checksum() failed: %s\n",
 268                                 error_message(ret)));
 269                         return ret;
 270                 }
 271
 272                 if (!checksum_valid)
 273                         ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
 274         }
 275
 276 #elif KRB5_VERIFY_CHECKSUM_ARGS == 6 && defined(HAVE_KRB5_CRYPTO_INIT) && defined(HAVE_KRB5_CRYPTO) && defined(HAVE_KRB5_CRYPTO_DESTROY)
 277
 278         /* Warning: MIT's krb5_verify_checksum cannot be used as it will use a key
 279          * without enctype and it ignores any key_usage types - Guenther */
 280
 281         {
 282
 283                 krb5_crypto crypto;
 284                 ret = krb5_crypto_init(context,
 285                                        keyblock,
 286                                        0,
 287                                        &crypto);
 288                 if (ret) {
 289                         DEBUG(0,("smb_krb5_verify_checksum: krb5_crypto_init() failed: %s\n",
 290                                 error_message(ret)));
 291                         return ret;
 292                 }
 293
 294                 ret = krb5_verify_checksum(context,
 295                                            crypto,
 296                                            usage,
 297                                            data,
 298                                            length,
 299                                            cksum);
 300
 301                 krb5_crypto_destroy(context, crypto);
 302         }
 303
 304 #else
 305 #error UNKNOWN_KRB5_VERIFY_CHECKSUM_FUNCTION
 306 #endif
 307
 308         return ret;
 309 }
 310
 311 char *gssapi_error_string(TALLOC_CTX *mem_ctx,
 312                           OM_uint32 maj_stat, OM_uint32 min_stat,
 313                           const gss_OID mech)
 314 {
 315         OM_uint32 disp_min_stat, disp_maj_stat;
 316         gss_buffer_desc maj_error_message;
 317         gss_buffer_desc min_error_message;
 318         char *maj_error_string, *min_error_string;
 319         OM_uint32 msg_ctx = 0;
 320
 321         char *ret;
 322
 323         maj_error_message.value = NULL;
 324         min_error_message.value = NULL;
 325         maj_error_message.length = 0;
 326         min_error_message.length = 0;
 327
 328         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
 329                            mech, &msg_ctx, &maj_error_message);
 330         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
 331                            mech, &msg_ctx, &min_error_message);
 332
 333         maj_error_string = talloc_strndup(mem_ctx, (char *)maj_error_message.value, maj_error_message.length);
 334
 335         min_error_string = talloc_strndup(mem_ctx, (char *)min_error_message.value, min_error_message.length);
 336
 337         ret = talloc_asprintf(mem_ctx, "%s: %s", maj_error_string, min_error_string);
 338
 339         talloc_free(maj_error_string);
 340         talloc_free(min_error_string);
 341
 342         gss_release_buffer(&disp_min_stat, &maj_error_message);
 343         gss_release_buffer(&disp_min_stat, &min_error_message);
 344
 345         return ret;
 346 }
 347
 348
 349  char *smb_get_krb5_error_message(krb5_context context, krb5_error_code code, TALLOC_CTX *mem_ctx)
 350 {
 351         char *ret;
 352
 353 #if defined(HAVE_KRB5_GET_ERROR_MESSAGE) && defined(HAVE_KRB5_FREE_ERROR_MESSAGE)
 354         const char *context_error = krb5_get_error_message(context, code);
 355         if (context_error) {
 356                 ret = talloc_asprintf(mem_ctx, "%s: %s", error_message(code), context_error);
 357                 krb5_free_error_message(context, context_error);
 358                 return ret;
 359         }
 360 #endif
 361         ret = talloc_strdup(mem_ctx, error_message(code));
 362         return ret;
 363 }
 364
 365 #endif