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refactored DH group nonce exchange

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This commit is contained in:
Andreas Steffen
2011-11-28 14:39:50 +01:00
parent 6728e09d39
commit cc1406d6fa
10 changed files with 364 additions and 398 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libimcv/plugins/imv_attestation/imv_attestation.c
+53 -64
View File
@@ -60,23 +60,19 @@ static const char imv_name[] = "Attestation";
#define IMV_VENDOR_ID PEN_TCG
#define IMV_SUBTYPE PA_SUBTYPE_TCG_PTS
#define NONCE_LEN_LIMIT 16
static imv_agent_t *imv_attestation;
/**
* Supported PTS measurement algorithms
*/
static pts_meas_algorithms_t supported_algorithms = 0;
static pts_meas_algorithms_t supported_algorithms = PTS_MEAS_ALGO_NONE;
/**
* Supported PTS Diffie Hellman Groups
*/
static pts_dh_group_t supported_dh_groups = 0;
/**
* High Entropy Random Data
* used in calculation of shared secret for the assessment session
*/
static char *initiator_nonce = NULL;
static pts_dh_group_t supported_dh_groups = PTS_DH_GROUP_NONE;
/**
* PTS file measurement database
@@ -107,18 +103,14 @@ TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
TNC_Version *actual_version)
{
char *hash_alg, *dh_group, *uri, *cadir;
rng_t *rng;
if (imv_attestation)
{
DBG1(DBG_IMV, "IMV \"%s\" has already been initialized", imv_name);
return TNC_RESULT_ALREADY_INITIALIZED;
}
if (!pts_meas_probe_algorithms(&supported_algorithms))
{
return TNC_RESULT_FATAL;
}
if (!pts_probe_dh_groups(&supported_dh_groups))
if (!pts_meas_algo_probe(&supported_algorithms) ||
!pts_dh_group_probe(&supported_dh_groups))
{
return TNC_RESULT_FATAL;
}
@@ -131,15 +123,6 @@ TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
libpts_init();
/* Create a initiator nonce */
initiator_nonce = (char*)malloc(NONCE_LEN);
rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
if (rng)
{
rng->get_bytes(rng, NONCE_LEN, initiator_nonce);
rng->destroy(rng);
}
if (min_version > TNC_IFIMV_VERSION_1 || max_version < TNC_IFIMV_VERSION_1)
{
DBG1(DBG_IMV, "no common IF-IMV version");
@@ -157,17 +140,7 @@ TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
*/
hash_alg = lib->settings->get_str(lib->settings,
"libimcv.plugins.imv-attestation.hash_algorithm", "sha256");
if (!strcaseeq(hash_alg, "sha384") && !strcaseeq(hash_alg, "sha2_384"))
{
/* remove SHA384 algorithm */
supported_algorithms &= ~PTS_MEAS_ALGO_SHA384;
}
if (strcaseeq(hash_alg, "sha1"))
{
/* remove SHA256 algorithm */
supported_algorithms &= ~PTS_MEAS_ALGO_SHA256;
}
/**
* Specify supported PTS Diffie-Hellman groups
*
@@ -183,7 +156,9 @@ TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
*/
dh_group = lib->settings->get_str(lib->settings,
"libimcv.plugins.imv-attestation.dh_group", "ecp256");
if (!pts_update_supported_dh_groups(dh_group, &supported_dh_groups))
if (!pts_meas_algo_update(hash_alg, &supported_algorithms) ||
!pts_dh_group_update(dh_group, &supported_dh_groups))
{
return TNC_RESULT_FATAL;
}
@@ -304,8 +279,13 @@ static TNC_Result send_message(TNC_ConnectionID connection_id)
{
if (!dh_nonce_req_sent)
{
int min_nonce_len;
/* Send DH nonce parameters request attribute */
attr = tcg_pts_attr_dh_nonce_params_req_create(0, supported_dh_groups);
min_nonce_len = lib->settings->get_int(lib->settings,
"libimcv.plugins.imv-attestation.min_nonce_len", 0);
attr = tcg_pts_attr_dh_nonce_params_req_create(min_nonce_len,
supported_dh_groups);
attr->set_noskip_flag(attr, TRUE);
msg->add_attribute(msg, attr);
dh_nonce_req_sent = TRUE;
@@ -313,16 +293,13 @@ static TNC_Result send_message(TNC_ConnectionID connection_id)
else
{
pts_meas_algorithms_t selected_algorithm;
chunk_t initiator_pub_val;
chunk_t initiator_value, initiator_nonce;
/* Send DH nonce finish attribute */
selected_algorithm = pts->get_meas_algorithm(pts);
pts->get_my_public_value(pts, &initiator_pub_val);
attr = tcg_pts_attr_dh_nonce_finish_create(NONCE_LEN,
selected_algorithm,
chunk_create(initiator_nonce, NONCE_LEN),
initiator_pub_val);
pts->get_my_public_value(pts, &initiator_value, &initiator_nonce);
attr = tcg_pts_attr_dh_nonce_finish_create(selected_algorithm,
initiator_value, initiator_nonce);
attr->set_noskip_flag(attr, TRUE);
msg->add_attribute(msg, attr);
@@ -484,6 +461,7 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
}
attr_list = linked_list_create();
/* analyze PA-TNC attributes */
enumerator = pa_tnc_msg->create_attribute_enumerator(pa_tnc_msg);
while (enumerator->enumerate(enumerator, &attr))
@@ -564,21 +542,32 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
attr_cast = (tcg_pts_attr_meas_algo_t*)attr;
selected_algorithm = attr_cast->get_algorithms(attr_cast);
if (!(selected_algorithm & supported_algorithms))
{
DBG1(DBG_IMV, "PTS-IMC selected unsupported "
"measurement algorithm");
return TNC_RESULT_FATAL;
}
pts->set_meas_algorithm(pts, selected_algorithm);
break;
}
case TCG_PTS_DH_NONCE_PARAMS_RESP:
{
tcg_pts_attr_dh_nonce_params_resp_t *attr_cast;
u_int8_t nonce_len;
int nonce_len, min_nonce_len;
pts_dh_group_t dh_group;
pts_meas_algorithms_t offered_algorithms, selected_algorithm;
chunk_t responder_nonce, initiator_non, responder_pub_val;
chunk_t responder_value, responder_nonce;
attr_cast = (tcg_pts_attr_dh_nonce_params_resp_t*)attr;
responder_nonce = attr_cast->get_responder_nonce(attr_cast);
nonce_len = attr_cast->get_nonce_len(attr_cast);
if (nonce_len < 0 || nonce_len <= 16)
/* check compliance of responder nonce length */
min_nonce_len = lib->settings->get_int(lib->settings,
"libimcv.plugins.imv-attestation.min_nonce_len", 0);
nonce_len = responder_nonce.len;
if (nonce_len <= NONCE_LEN_LIMIT ||
(min_nonce_len > 0 && nonce_len < min_nonce_len))
{
attr_info = attr->get_value(attr);
attr = ietf_attr_pa_tnc_error_create(PEN_TCG,
@@ -588,33 +577,34 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
}
dh_group = attr_cast->get_dh_group(attr_cast);
if (!(dh_group & supported_dh_groups))
{
DBG1(DBG_IMV, "PTS-IMC selected unsupported DH group");
return TNC_RESULT_FATAL;
}
offered_algorithms = attr_cast->get_hash_algo_set(attr_cast);
if (!(offered_algorithms & PTS_MEAS_ALGO_SHA1) &&
!(offered_algorithms & PTS_MEAS_ALGO_SHA256) &&
!(offered_algorithms & PTS_MEAS_ALGO_SHA384))
selected_algorithm = pts_meas_algo_select(supported_algorithms,
offered_algorithms);
if (selected_algorithm == PTS_MEAS_ALGO_NONE)
{
attr = pts_hash_alg_error_create(supported_algorithms);
attr_list->insert_last(attr_list, attr);
break;
}
/* Use already negotiated measurement algorithm */
selected_algorithm = pts->get_meas_algorithm(pts);
responder_nonce = attr_cast->get_responder_nonce(attr_cast);
responder_pub_val = attr_cast->get_responder_pub_val(attr_cast);
initiator_non = chunk_create(initiator_nonce, NONCE_LEN);
/* Calculate secret assessment value */
if (!pts->create_dh(pts, dh_group))
pts->set_dh_hash_algorithm(pts, selected_algorithm);
if (!pts->create_dh_nonce(pts, dh_group, nonce_len))
{
return TNC_RESULT_FATAL;
}
pts->set_peer_public_value(pts, responder_pub_val);
DBG3(DBG_IMV, "Initiator nonce: %B", &initiator_non);
DBG3(DBG_IMV, "Responder nonce: %B", &responder_nonce);
if (!pts->calculate_secret(pts, initiator_non,
responder_nonce, selected_algorithm))
responder_value = attr_cast->get_responder_value(attr_cast);
pts->set_peer_public_value(pts, responder_value,
responder_nonce);
/* Calculate secret assessment value */
if (!pts->calculate_secret(pts))
{
return TNC_RESULT_FATAL;
}
@@ -1010,7 +1000,6 @@ TNC_Result TNC_IMV_Terminate(TNC_IMVID imv_id)
}
DESTROY_IF(pts_db);
DESTROY_IF(pts_credmgr);
free(initiator_nonce);
libpts_deinit();