/*
* Copyright (C) 2011-2012 Sansar Choinyambuu
* Copyright (C) 2011-2014 Andreas Steffen
* HSR Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include "imv_attestation_build.h"
#include "imv_attestation_state.h"
#include <tcg/pts/tcg_pts_attr_dh_nonce_params_req.h>
#include <tcg/pts/tcg_pts_attr_dh_nonce_finish.h>
#include <tcg/pts/tcg_pts_attr_get_tpm_version_info.h>
#include <tcg/pts/tcg_pts_attr_get_aik.h>
#include <tcg/pts/tcg_pts_attr_req_func_comp_evid.h>
#include <tcg/pts/tcg_pts_attr_gen_attest_evid.h>
#include <utils/debug.h>
bool imv_attestation_build(imv_msg_t *out_msg, imv_state_t *state,
pts_dh_group_t supported_dh_groups,
pts_database_t *pts_db)
{
imv_attestation_state_t *attestation_state;
imv_attestation_handshake_state_t handshake_state;
pts_t *pts;
pa_tnc_attr_t *attr = NULL;
attestation_state = (imv_attestation_state_t*)state;
handshake_state = attestation_state->get_handshake_state(attestation_state);
pts = attestation_state->get_pts(attestation_state);
switch (handshake_state)
{
case IMV_ATTESTATION_STATE_NONCE_REQ:
{
int min_nonce_len;
/* Send DH nonce parameters request attribute */
min_nonce_len = lib->settings->get_int(lib->settings,
"%s.plugins.imv-attestation.min_nonce_len", 0, lib->ns);
attr = tcg_pts_attr_dh_nonce_params_req_create(min_nonce_len,
supported_dh_groups);
attr->set_noskip_flag(attr, TRUE);
out_msg->add_attribute(out_msg, attr);
attestation_state->set_handshake_state(attestation_state,
IMV_ATTESTATION_STATE_TPM_INIT);
break;
}
case IMV_ATTESTATION_STATE_TPM_INIT:
{
pts_meas_algorithms_t selected_algorithm;
chunk_t initiator_value, initiator_nonce;
if (!(state->get_action_flags(state) & IMV_ATTESTATION_DH_NONCE))
{
break;
}
/* Send DH nonce finish attribute */
selected_algorithm = pts->get_meas_algorithm(pts);
if (!pts->get_my_public_value(pts, &initiator_value,
&initiator_nonce))
{
return FALSE;
}
attr = tcg_pts_attr_dh_nonce_finish_create(selected_algorithm,
initiator_value, initiator_nonce);
attr->set_noskip_flag(attr, TRUE);
out_msg->add_attribute(out_msg, attr);
/* Send Get TPM Version attribute */
attr = tcg_pts_attr_get_tpm_version_info_create();
attr->set_noskip_flag(attr, TRUE);
out_msg->add_attribute(out_msg, attr);
/* Send Get AIK attribute */
attr = tcg_pts_attr_get_aik_create();
attr->set_noskip_flag(attr, TRUE);
out_msg->add_attribute(out_msg, attr);
attestation_state->set_handshake_state(attestation_state,
IMV_ATTESTATION_STATE_COMP_EVID);
break;
}
case IMV_ATTESTATION_STATE_COMP_EVID:
{
tcg_pts_attr_req_func_comp_evid_t *attr_cast;
enumerator_t *enumerator;
pts_comp_func_name_t *name;
uint8_t flags;
uint32_t depth;
bool first_component = TRUE;
if (!(state->get_action_flags(state) & IMV_ATTESTATION_AIK))
{
break;
}
attestation_state->set_handshake_state(attestation_state,
IMV_ATTESTATION_STATE_END);
if (!pts->get_aik_id(pts))
{
attestation_state->set_measurement_error(attestation_state,
IMV_ATTESTATION_ERROR_NO_TRUSTED_AIK);
return FALSE;
}
enumerator = attestation_state->create_component_enumerator(
attestation_state);
while (enumerator->enumerate(enumerator, &flags, &depth, &name))
{
if (first_component)
{
attr = tcg_pts_attr_req_func_comp_evid_create();
attr->set_noskip_flag(attr, TRUE);
first_component = FALSE;
DBG2(DBG_IMV, "evidence request by");
}
name->log(name, " ");
/* TODO check flags against negotiated_caps */
attr_cast = (tcg_pts_attr_req_func_comp_evid_t *)attr;
attr_cast->add_component(attr_cast, flags, depth, name);
}
enumerator->destroy(enumerator);
if (attr)
{
/* Send Request Functional Component Evidence attribute */
out_msg->add_attribute(out_msg, attr);
/* Send Generate Attestation Evidence attribute */
attr = tcg_pts_attr_gen_attest_evid_create();
attr->set_noskip_flag(attr, TRUE);
out_msg->add_attribute(out_msg, attr);
attestation_state->set_handshake_state(attestation_state,
IMV_ATTESTATION_STATE_EVID_FINAL);
}
break;
}
default:
break;
}
return TRUE;
}
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