static struct wpabuf * eap_aka_build_reauth(struct eap_sm *sm,
struct eap_aka_data *data, u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Re-authentication");
if (os_get_random(data->nonce_s, EAP_SIM_NONCE_S_LEN))
return NULL;
wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA: NONCE_S",
data->nonce_s, EAP_SIM_NONCE_S_LEN);
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
sm->identity,
sm->identity_len,
data->nonce_s,
data->msk, data->emsk);
} else {
eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
data->msk, data->emsk);
eap_sim_derive_keys_reauth(data->counter, sm->identity,
sm->identity_len, data->nonce_s,
data->mk, data->msk, data->emsk);
}
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
EAP_AKA_SUBTYPE_REAUTHENTICATION);
if (eap_aka_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
eap_sim_msg_free(msg);
return NULL;
}
eap_aka_add_checkcode(data, msg);
if (sm->eap_sim_aka_result_ind) {
wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
}
wpa_printf(MSG_DEBUG, " AT_MAC");
eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}
static struct wpabuf * eap_aka_process_reauthentication(
struct eap_sm *sm, struct eap_aka_data *data, u8 id,
const struct wpabuf *reqData, struct eap_sim_attrs *attr)
{
struct eap_sim_attrs eattr;
u8 *decrypted;
wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Reauthentication");
if (attr->checkcode &&
eap_aka_verify_checkcode(data, attr->checkcode,
attr->checkcode_len)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
"message");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
if (data->reauth_id == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Server is trying "
"reauthentication, but no reauth_id available");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
data->reauth = 1;
if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
"did not have valid AT_MAC");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
if (attr->encr_data == NULL || attr->iv == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
"message did not include encrypted data");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
attr->encr_data_len, attr->iv, &eattr,
0);
if (decrypted == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
"data from reauthentication message");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
if (eattr.nonce_s == NULL || eattr.counter < 0) {
wpa_printf(MSG_INFO, "EAP-AKA: (encr) No%s%s in reauth packet",
!eattr.nonce_s ? " AT_NONCE_S" : "",
eattr.counter < 0 ? " AT_COUNTER" : "");
os_free(decrypted);
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
struct wpabuf *res;
wpa_printf(MSG_INFO, "EAP-AKA: (encr) Invalid counter "
"(%d <= %d)", eattr.counter, data->counter);
data->counter_too_small = eattr.counter;
/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
* reauth_id must not be used to start a new reauthentication.
* However, since it was used in the last EAP-Response-Identity
* packet, it has to saved for the following fullauth to be
* used in MK derivation. */
os_free(data->last_eap_identity);
data->last_eap_identity = data->reauth_id;
data->last_eap_identity_len = data->reauth_id_len;
data->reauth_id = NULL;
data->reauth_id_len = 0;
res = eap_aka_response_reauth(data, id, 1, eattr.nonce_s);
os_free(decrypted);
return res;
}
data->counter = eattr.counter;
os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-AKA: (encr) AT_NONCE_S",
data->nonce_s, EAP_SIM_NONCE_S_LEN);
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
data->reauth_id,
data->reauth_id_len,
data->nonce_s,
data->msk, data->emsk);
} else {
eap_sim_derive_keys_reauth(data->counter, data->reauth_id,
data->reauth_id_len,
data->nonce_s, data->mk,
data->msk, data->emsk);
}
eap_aka_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
eap_aka_learn_ids(sm, data, &eattr);
if (data->result_ind && attr->result_ind)
data->use_result_ind = 1;
if (data->state != FAILURE && data->state != RESULT_FAILURE) {
eap_aka_state(data, data->use_result_ind ?
RESULT_SUCCESS : SUCCESS);
}
data->num_id_req = 0;
data->num_notification = 0;
if (data->counter > EAP_AKA_MAX_FAST_REAUTHS) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Maximum number of "
"fast reauths performed - force fullauth");
eap_aka_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
}
os_free(decrypted);
return eap_aka_response_reauth(data, id, 0, data->nonce_s);
}
