/** Set the next section type if it's not already set
*
* @param[in] request The current request.
* @param[in] type_da to use. Usually attr_auth_type.
* @param[in] enumv Enumeration value of the specified type_da.
*/
bool module_section_type_set(REQUEST *request, fr_dict_attr_t const *type_da, fr_dict_enum_t const *enumv)
{
VALUE_PAIR *vp;
switch (pair_update_control(&vp, type_da)) {
case 0:
fr_value_box_copy(vp, &vp->data, enumv->value);
vp->data.enumv = vp->da; /* So we get the correct string alias */
RDEBUG2("Setting &control:%pP", vp);
return true;
case 1:
RDEBUG2("&control:%s already set. Not setting to %s", vp->da->name, enumv->alias);
return false;
default:
MEM(0);
return false;
}
}
/** Send the challenge itself
*
* Challenges will come from one of three places eventually:
*
* 1 from attributes like FR_EAP_AKA_RANDx
* (these might be retrieved from a database)
*
* 2 from internally implemented SIM authenticators
* (a simple one based upon XOR will be provided)
*
* 3 from some kind of SS7 interface.
*
* For now, they only come from attributes.
* It might be that the best way to do 2/3 will be with a different
* module to generate/calculate things.
*/
static int eap_aka_send_challenge(eap_session_t *eap_session)
{
REQUEST *request = eap_session->request;
eap_aka_session_t *eap_aka_session = talloc_get_type_abort(eap_session->opaque, eap_aka_session_t);
VALUE_PAIR **to_peer, *vp;
RADIUS_PACKET *packet;
fr_sim_vector_src_t src = SIM_VECTOR_SRC_AUTO;
rad_assert(request);
rad_assert(request->reply);
/*
* to_peer is the data to the client
*/
packet = eap_session->request->reply;
to_peer = &packet->vps;
RDEBUG2("Acquiring UMTS vector(s)");
/*
* Toggle the AMF high bit to indicate we're doing AKA'
*/
if (eap_aka_session->type == FR_EAP_AKA_PRIME) {
uint8_t amf_buff[2] = { 0x80, 0x00 }; /* Set the AMF separation bit high */
MEM(pair_update_control(&vp, attr_sim_amf) >= 0);
fr_pair_value_memcpy(vp, amf_buff, sizeof(amf_buff));
}
/*
* Get vectors from attribute or generate
* them using COMP128-* or Milenage.
*/
if (fr_sim_vector_umts_from_attrs(eap_session, request->control, &eap_aka_session->keys, &src) != 0) {
REDEBUG("Failed retrieving UMTS vectors");
return RLM_MODULE_FAIL;
}
/*
* Don't leave the AMF hanging around
*/
if (eap_aka_session->type == FR_EAP_AKA_PRIME) pair_delete_control(attr_sim_amf);
/*
* All set, calculate keys!
*/
switch (eap_aka_session->kdf) {
case FR_EAP_AKA_KDF_VALUE_EAP_AKA_PRIME_WITH_CK_PRIME_IK_PRIME:
fr_sim_crypto_kdf_1_umts(&eap_aka_session->keys);
break;
default:
fr_sim_crypto_kdf_0_umts(&eap_aka_session->keys);
break;
}
if (RDEBUG_ENABLED3) fr_sim_crypto_keys_log(request, &eap_aka_session->keys);
RDEBUG2("Sending AKA-Challenge");
eap_session->this_round->request->code = FR_EAP_CODE_REQUEST;
/*
* Set the subtype to challenge
*/
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_subtype));
vp->vp_uint16 = FR_EAP_AKA_SUBTYPE_VALUE_AKA_CHALLENGE;
fr_pair_replace(to_peer, vp);
/*
* Indicate we'd like to use protected success messages
*/
if (eap_aka_session->send_result_ind) {
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_result_ind));
vp->vp_bool = true;
fr_pair_replace(to_peer, vp);
}
/*
* We support EAP-AKA' and the peer should use that
* if it's able to...
*/
if (eap_aka_session->send_at_bidding) {
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_bidding));
vp->vp_uint16 = FR_EAP_AKA_BIDDING_VALUE_PREFER_AKA_PRIME;
fr_pair_replace(to_peer, vp);
}
/*
* Send the network name and KDF to the peer
*/
if (eap_aka_session->type == FR_EAP_AKA_PRIME) {
if (!eap_aka_session->keys.network_len) {
REDEBUG2("No network name available, can't set EAP-AKA-KDF-Input");
failure:
fr_pair_list_free(&packet->vps);
return -1;
}
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_kdf_input));
fr_pair_value_bstrncpy(vp, eap_aka_session->keys.network, eap_aka_session->keys.network_len);
fr_pair_replace(to_peer, vp);
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_kdf));
vp->vp_uint16 = eap_aka_session->kdf;
fr_pair_replace(to_peer, vp);
}
/*
* Okay, we got the challenge! Put it into an attribute.
*/
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_rand));
fr_pair_value_memcpy(vp, eap_aka_session->keys.umts.vector.rand, SIM_VECTOR_UMTS_RAND_SIZE);
fr_pair_replace(to_peer, vp);
/*
* Send the AUTN value to the client, so it can authenticate
* whoever has knowledge of the Ki.
*/
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_autn));
fr_pair_value_memcpy(vp, eap_aka_session->keys.umts.vector.autn, SIM_VECTOR_UMTS_AUTN_SIZE);
fr_pair_replace(to_peer, vp);
/*
* need to include an AT_MAC attribute so that it will get
* calculated.
*/
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_mac));
fr_pair_replace(to_peer, vp);
/*
* If we have checkcode data, send that to the peer
* for validation.
*/
if (eap_aka_session->checkcode_state) {
ssize_t slen;
slen = fr_sim_crypto_finalise_checkcode(eap_aka_session->checkcode, &eap_aka_session->checkcode_state);
if (slen < 0) {
RPEDEBUG("Failed calculating checkcode");
goto failure;
}
eap_aka_session->checkcode_len = slen;
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_checkcode));
fr_pair_value_memcpy(vp, eap_aka_session->checkcode, slen);
/*
* If we don't have checkcode data, then we exchanged
* no identity packets, so checkcode is zero.
*/
} else {
MEM(vp = fr_pair_afrom_da(packet, attr_eap_aka_checkcode));
eap_aka_session->checkcode_len = 0;
}
fr_pair_replace(to_peer, vp);
/*
* We've sent the challenge so the peer should now be able
* to accept encrypted attributes.
*/
eap_aka_session->allow_encrypted = true;
/*
* Encode the packet
*/
if (eap_aka_compose(eap_session) < 0) goto failure;
return 0;
}
