src/libpts/plugins/imv_attestation/imv_attestation_process.c

   1 /*
   2  * Copyright (C) 2011 Sansar Choinyambuu
   3  * HSR Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 #include "imv_attestation_process.h"
  17
  18 #include <ietf/ietf_attr_pa_tnc_error.h>
  19
  20 #include <pts/pts.h>
  21
  22 #include <tcg/tcg_pts_attr_aik.h>
  23 #include <tcg/tcg_pts_attr_dh_nonce_params_resp.h>
  24 #include <tcg/tcg_pts_attr_file_meas.h>
  25 #include <tcg/tcg_pts_attr_meas_algo.h>
  26 #include <tcg/tcg_pts_attr_proto_caps.h>
  27 #include <tcg/tcg_pts_attr_simple_comp_evid.h>
  28 #include <tcg/tcg_pts_attr_simple_evid_final.h>
  29 #include <tcg/tcg_pts_attr_tpm_version_info.h>
  30 #include <tcg/tcg_pts_attr_unix_file_meta.h>
  31
  32 #include <debug.h>
  33 #include <crypto/hashers/hasher.h>
  34
  35 #include <inttypes.h>
  36
  37 bool imv_attestation_process(pa_tnc_attr_t *attr, linked_list_t *attr_list,
  38                                                          imv_attestation_state_t *attestation_state,
  39                                                          pts_meas_algorithms_t supported_algorithms,
  40                                                          pts_dh_group_t supported_dh_groups,
  41                                                          pts_database_t *pts_db,
  42                                                          credential_manager_t *pts_credmgr)
  43 {
  44         pts_t *pts;
  45
  46         pts = attestation_state->get_pts(attestation_state);
  47
  48         switch (attr->get_type(attr))
  49         {
  50                 case TCG_PTS_PROTO_CAPS:
  51                 {
  52                         tcg_pts_attr_proto_caps_t *attr_cast;
  53                         pts_proto_caps_flag_t flags;
  54
  55                         attr_cast = (tcg_pts_attr_proto_caps_t*)attr;
  56                         flags = attr_cast->get_flags(attr_cast);
  57                         pts->set_proto_caps(pts, flags);
  58                         break;
  59                 }
  60                 case TCG_PTS_MEAS_ALGO_SELECTION:
  61                 {
  62                         tcg_pts_attr_meas_algo_t *attr_cast;
  63                         pts_meas_algorithms_t selected_algorithm;
  64
  65                         attr_cast = (tcg_pts_attr_meas_algo_t*)attr;
  66                         selected_algorithm = attr_cast->get_algorithms(attr_cast);
  67                         if (!(selected_algorithm & supported_algorithms))
  68                         {
  69                                 DBG1(DBG_IMV, "PTS-IMC selected unsupported"
  70                                                           " measurement algorithm");
  71                                 return FALSE;
  72                         }
  73                         pts->set_meas_algorithm(pts, selected_algorithm);
  74                         break;
  75                 }
  76                 case TCG_PTS_DH_NONCE_PARAMS_RESP:
  77                 {
  78                         tcg_pts_attr_dh_nonce_params_resp_t *attr_cast;
  79                         int nonce_len, min_nonce_len;
  80                         pts_dh_group_t dh_group;
  81                         pts_meas_algorithms_t offered_algorithms, selected_algorithm;
  82                         chunk_t responder_value, responder_nonce;
  83
  84                         attr_cast = (tcg_pts_attr_dh_nonce_params_resp_t*)attr;
  85                         responder_nonce = attr_cast->get_responder_nonce(attr_cast);
  86
  87                         /* check compliance of responder nonce length */
  88                         min_nonce_len = lib->settings->get_int(lib->settings,
  89                                                 "libimcv.plugins.imv-attestation.min_nonce_len", 0);
  90                         nonce_len = responder_nonce.len;
  91                         if (nonce_len < PTS_MIN_NONCE_LEN ||
  92                            (min_nonce_len > 0 && nonce_len < min_nonce_len))
  93                         {
  94                                 attr = pts_dh_nonce_error_create(
  95                                                                         max(PTS_MIN_NONCE_LEN, min_nonce_len),
  96                                                                                 PTS_MAX_NONCE_LEN);
  97                                 attr_list->insert_last(attr_list, attr);
  98                                 break;
  99                         }
 100
 101                         dh_group = attr_cast->get_dh_group(attr_cast);
 102                         if (!(dh_group & supported_dh_groups))
 103                         {
 104                                 DBG1(DBG_IMV, "PTS-IMC selected unsupported DH group");
 105                                 return FALSE;
 106                         }
 107
 108                         offered_algorithms = attr_cast->get_hash_algo_set(attr_cast);
 109                         selected_algorithm = pts_meas_algo_select(supported_algorithms,
 110                                                                                                           offered_algorithms);
 111                         if (selected_algorithm == PTS_MEAS_ALGO_NONE)
 112                         {
 113                                 attr = pts_hash_alg_error_create(supported_algorithms);
 114                                 attr_list->insert_last(attr_list, attr);
 115                                 break;
 116                         }
 117                         pts->set_dh_hash_algorithm(pts, selected_algorithm);
 118
 119                         if (!pts->create_dh_nonce(pts, dh_group, nonce_len))
 120                         {
 121                                 return FALSE;
 122                         }
 123
 124                         responder_value = attr_cast->get_responder_value(attr_cast);
 125                         pts->set_peer_public_value(pts, responder_value,
 126                                                                                         responder_nonce);
 127
 128                         /* Calculate secret assessment value */
 129                         if (!pts->calculate_secret(pts))
 130                         {
 131                                 return FALSE;
 132                         }
 133                         break;
 134                 }
 135                 case TCG_PTS_TPM_VERSION_INFO:
 136                 {
 137                         tcg_pts_attr_tpm_version_info_t *attr_cast;
 138                         chunk_t tpm_version_info;
 139
 140                         attr_cast = (tcg_pts_attr_tpm_version_info_t*)attr;
 141                         tpm_version_info = attr_cast->get_tpm_version_info(attr_cast);
 142                         pts->set_tpm_version_info(pts, tpm_version_info);
 143                         break;
 144                 }
 145                 case TCG_PTS_AIK:
 146                 {
 147                         tcg_pts_attr_aik_t *attr_cast;
 148                         certificate_t *aik, *issuer;
 149                         public_key_t *public;
 150                         chunk_t keyid;
 151                         enumerator_t *e;
 152                         bool trusted = FALSE;
 153
 154                         attr_cast = (tcg_pts_attr_aik_t*)attr;
 155                         aik = attr_cast->get_aik(attr_cast);
 156                         if (!aik)
 157                         {
 158                                 DBG1(DBG_IMV, "AIK unavailable");
 159                                 return FALSE;
 160                         }
 161                         if (aik->get_type(aik) == CERT_X509)
 162                         {
 163                                 public = aik->get_public_key(aik);
 164                                 public->get_fingerprint(public, KEYID_PUBKEY_INFO_SHA1, &keyid);
 165                                 DBG1(DBG_IMV, "verifying AIK certificate with keyid %#B", &keyid);
 166                                 public->destroy(public);
 167
 168                                 e = pts_credmgr->create_trusted_enumerator(pts_credmgr,
 169                                                         KEY_ANY, aik->get_issuer(aik), FALSE);
 170                                 while (e->enumerate(e, &issuer))
 171                                 {
 172                                         if (aik->issued_by(aik, issuer))
 173                                         {
 174                                                 trusted = TRUE;
 175                                                 break;
 176                                         }
 177                                 }
 178                                 e->destroy(e);
 179                                 DBG1(DBG_IMV, "AIK certificate is %strusted",
 180                                                            trusted ? "" : "not ");
 181                         }
 182                         pts->set_aik(pts, aik);
 183                         break;
 184                 }
 185                 case TCG_PTS_FILE_MEAS:
 186                 {
 187                         tcg_pts_attr_file_meas_t *attr_cast;
 188                         u_int16_t request_id;
 189                         int file_count, file_id;
 190                         pts_meas_algorithms_t algo;
 191                         pts_file_meas_t *measurements;
 192                         char *platform_info;
 193                         enumerator_t *e_hash;
 194                         bool is_dir;
 195
 196                         platform_info = pts->get_platform_info(pts);
 197                         if (!pts_db || !platform_info)
 198                         {
 199                                 DBG1(DBG_IMV, "%s%s%s not available",
 200                                         (pts_db) ? "" : "pts database",
 201                                         (!pts_db && !platform_info) ? "and" : "",
 202                                         (platform_info) ? "" : "platform info");
 203                                 break;
 204                         }
 205
 206                         attr_cast = (tcg_pts_attr_file_meas_t*)attr;
 207                         measurements = attr_cast->get_measurements(attr_cast);
 208                         algo = pts->get_meas_algorithm(pts);
 209                         request_id = measurements->get_request_id(measurements);
 210                         file_count = measurements->get_file_count(measurements);
 211
 212                         DBG1(DBG_IMV, "measurement request %d returned %d file%s:",
 213                                  request_id, file_count, (file_count == 1) ? "":"s");
 214
 215                         if (!attestation_state->check_off_file_meas_request(attestation_state,
 216                                 request_id, &file_id, &is_dir))
 217                         {
 218                                 DBG1(DBG_IMV, "  no entry found for file measurement request %d",
 219                                          request_id);
 220                                 break;
 221                         }
 222
 223                         /* check hashes from database against measurements */
 224                         e_hash = pts_db->create_file_hash_enumerator(pts_db,
 225                                                         platform_info, algo, file_id, is_dir);
 226                         if (!measurements->verify(measurements, e_hash, is_dir))
 227                         {
 228                                 attestation_state->set_measurement_error(attestation_state);
 229                         }
 230                         e_hash->destroy(e_hash);
 231                         break;
 232                 }
 233                 case TCG_PTS_UNIX_FILE_META:
 234                 {
 235                         tcg_pts_attr_file_meta_t *attr_cast;
 236                         int file_count;
 237                         pts_file_meta_t *metadata;
 238                         pts_file_metadata_t *entry;
 239                         time_t created, modified, accessed;
 240                         bool utc = FALSE;
 241                         enumerator_t *e;
 242
 243                         attr_cast = (tcg_pts_attr_file_meta_t*)attr;
 244                         metadata = attr_cast->get_metadata(attr_cast);
 245                         file_count = metadata->get_file_count(metadata);
 246
 247                         DBG1(DBG_IMV, "metadata request returned %d file%s:",
 248                                  file_count, (file_count == 1) ? "":"s");
 249
 250                         e = metadata->create_enumerator(metadata);
 251                         while (e->enumerate(e, &entry))
 252                         {
 253                                 DBG1(DBG_IMV, " '%s' (%"PRIu64" bytes)"
 254                                                           " owner %"PRIu64", group %"PRIu64", type %N",
 255                                          entry->filename, entry->filesize, entry->owner,
 256                                          entry->group, pts_file_type_names, entry->type);
 257
 258                                 created = entry->created;
 259                                 modified = entry->modified;
 260                                 accessed = entry->accessed;
 261
 262                                 DBG1(DBG_IMV, "    created %T, modified %T, accessed %T",
 263                                          &created, utc, &modified, utc, &accessed, utc);
 264                         }
 265                         e->destroy(e);
 266                         break;
 267                 }
 268                 case TCG_PTS_SIMPLE_COMP_EVID:
 269                 {
 270                         tcg_pts_attr_simple_comp_evid_t *attr_cast;
 271                         pts_comp_func_name_t *name;
 272                         pts_comp_evidence_t *evidence;
 273                         pts_component_t *comp;
 274                         u_int32_t depth;
 275                         status_t status;
 276
 277                         attr_cast = (tcg_pts_attr_simple_comp_evid_t*)attr;
 278                         evidence = attr_cast->get_comp_evidence(attr_cast);
 279                         name = evidence->get_comp_func_name(evidence, &depth);
 280
 281                         comp = attestation_state->check_off_component(attestation_state, name);
 282                         if (!comp)
 283                         {
 284                                 DBG1(DBG_IMV, "  no entry found for component evidence request");
 285                                 break;
 286                         }
 287                         status = comp->verify(comp, pts, evidence);
 288
 289                         switch (status)
 290                         {
 291                                 default:
 292                                 case FAILED:
 293                                         attestation_state->set_measurement_error(attestation_state);
 294                                         comp->destroy(comp);
 295                                         break;
 296                                 case SUCCESS:
 297                                         name->log(name, "  successfully measured ");
 298                                         comp->destroy(comp);
 299                                         break;
 300                                 case NEED_MORE:
 301                                         /* re-enter component into list */
 302                                         attestation_state->add_component(attestation_state, comp);
 303                         }
 304                         break;
 305                 }
 306                 case TCG_PTS_SIMPLE_EVID_FINAL:
 307                 {
 308                         tcg_pts_attr_simple_evid_final_t *attr_cast;
 309                         u_int8_t flags;
 310                         pts_meas_algorithms_t comp_hash_algorithm;
 311                         chunk_t pcr_comp, tpm_quote_sig, evid_sig;
 312                         chunk_t pcr_composite, quote_info;
 313                         bool use_quote2, use_ver_info;
 314
 315                         attr_cast = (tcg_pts_attr_simple_evid_final_t*)attr;
 316                         flags = attr_cast->get_quote_info(attr_cast, &comp_hash_algorithm,
 317                                                                                           &pcr_comp, &tpm_quote_sig);
 318
 319                         if (flags != PTS_SIMPLE_EVID_FINAL_NO)
 320                         {
 321                                 use_quote2   = (flags == PTS_SIMPLE_EVID_FINAL_QUOTE_INFO2 ||
 322                                                             flags == PTS_SIMPLE_EVID_FINAL_QUOTE_INFO2_CAP_VER);
 323                                 use_ver_info = (flags == PTS_SIMPLE_EVID_FINAL_QUOTE_INFO2_CAP_VER);
 324
 325                                 /* Construct PCR Composite and TPM Quote Info structures */
 326                                 if (!pts->get_quote_info(pts, use_quote2, use_ver_info,
 327                                                 comp_hash_algorithm, &pcr_composite, &quote_info))
 328                                 {
 329                                         DBG1(DBG_IMV, "unable to construct TPM Quote Info");
 330                                         return FALSE;
 331                                 }
 332
 333                                 if (!chunk_equals(pcr_comp, pcr_composite))
 334                                 {
 335                                         DBG1(DBG_IMV, "received PCR Composite does not match "
 336                                                                   "constructed one");
 337                                         free(pcr_composite.ptr);
 338                                         free(quote_info.ptr);
 339                                         return FALSE;
 340                                 }
 341                                 DBG2(DBG_IMV, "received PCR Composite matches constructed one");
 342                                 free(pcr_composite.ptr);
 343
 344                                 if (!pts->verify_quote_signature(pts, quote_info, tpm_quote_sig))
 345                                 {
 346                                         free(quote_info.ptr);
 347                                         return FALSE;
 348                                 }
 349                                 DBG2(DBG_IMV, "TPM Quote Info signature verification successful");
 350                                 free(quote_info.ptr);
 351
 352                                 /* Finalize any pending measurement registrations */
 353                                 attestation_state->check_off_registrations(attestation_state);
 354                         }
 355
 356                         if (attr_cast->get_evid_sig(attr_cast, &evid_sig))
 357                         {
 358                                 /** TODO: What to do with Evidence Signature */
 359                                 DBG1(DBG_IMV, "this version of the Attestation IMV can not "
 360                                                           "handle Evidence Signatures");
 361                         }
 362                         break;
 363                 }
 364
 365                 /* TODO: Not implemented yet */
 366                 case TCG_PTS_INTEG_MEAS_LOG:
 367                 /* Attributes using XML */
 368                 case TCG_PTS_TEMPL_REF_MANI_SET_META:
 369                 case TCG_PTS_VERIFICATION_RESULT:
 370                 case TCG_PTS_INTEG_REPORT:
 371                 /* On Windows only*/
 372                 case TCG_PTS_WIN_FILE_META:
 373                 case TCG_PTS_REGISTRY_VALUE:
 374                 /* Received on IMC side only*/
 375                 case TCG_PTS_REQ_PROTO_CAPS:
 376                 case TCG_PTS_DH_NONCE_PARAMS_REQ:
 377                 case TCG_PTS_DH_NONCE_FINISH:
 378                 case TCG_PTS_MEAS_ALGO:
 379                 case TCG_PTS_GET_TPM_VERSION_INFO:
 380                 case TCG_PTS_REQ_TEMPL_REF_MANI_SET_META:
 381                 case TCG_PTS_UPDATE_TEMPL_REF_MANI:
 382                 case TCG_PTS_GET_AIK:
 383                 case TCG_PTS_REQ_FUNC_COMP_EVID:
 384                 case TCG_PTS_GEN_ATTEST_EVID:
 385                 case TCG_PTS_REQ_FILE_META:
 386                 case TCG_PTS_REQ_FILE_MEAS:
 387                 case TCG_PTS_REQ_INTEG_MEAS_LOG:
 388                 default:
 389                         DBG1(DBG_IMV, "received unsupported attribute '%N'",
 390                                  tcg_attr_names, attr->get_type(attr));
 391                         break;
 392         }
 393         return TRUE;
 394 }
 395