/*
* hostapd / EAP-SIM (RFC 4186)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#include "eap_server/eap_i.h"
#include "eap_common/eap_sim_common.h"
#include "eap_server/eap_sim_db.h"
struct eap_sim_data {
u8 mk[EAP_SIM_MK_LEN];
u8 nonce_mt[EAP_SIM_NONCE_MT_LEN];
u8 nonce_s[EAP_SIM_NONCE_S_LEN];
u8 k_aut[EAP_SIM_K_AUT_LEN];
u8 k_encr[EAP_SIM_K_ENCR_LEN];
u8 msk[EAP_SIM_KEYING_DATA_LEN];
u8 emsk[EAP_EMSK_LEN];
u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN];
u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN];
u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN];
int num_chal;
enum {
START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
} state;
char *next_pseudonym;
char *next_reauth_id;
u16 counter;
struct eap_sim_reauth *reauth;
u16 notification;
int use_result_ind;
};
static const char * eap_sim_state_txt(int state)
{
switch (state) {
case START:
return "START";
case CHALLENGE:
return "CHALLENGE";
case REAUTH:
return "REAUTH";
case SUCCESS:
return "SUCCESS";
case FAILURE:
return "FAILURE";
case NOTIFICATION:
return "NOTIFICATION";
default:
return "Unknown?!";
}
}
static void eap_sim_state(struct eap_sim_data *data, int state)
{
wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
eap_sim_state_txt(data->state),
eap_sim_state_txt(state));
data->state = state;
}
static void * eap_sim_init(struct eap_sm *sm)
{
struct eap_sim_data *data;
if (sm->eap_sim_db_priv == NULL) {
wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
return NULL;
}
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = START;
return data;
}
static void eap_sim_reset(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
os_free(data->next_pseudonym);
os_free(data->next_reauth_id);
os_free(data);
}
static struct wpabuf * eap_sim_build_start(struct eap_sm *sm,
struct eap_sim_data *data, u8 id)
{
struct eap_sim_msg *msg;
u8 ver[2];
wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
EAP_SIM_SUBTYPE_START);
if (eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity,
sm->identity_len)) {
wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ");
eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
} else {
/*
* RFC 4186, Chap. 4.2.4 recommends that identity from EAP is
* ignored and the SIM/Start is used to request the identity.
*/
wpa_printf(MSG_DEBUG, " AT_ANY_ID_REQ");
eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0);
}
wpa_printf(MSG_DEBUG, " AT_VERSION_LIST");
ver[0] = 0;
ver[1] = EAP_SIM_VERSION;
eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
ver, sizeof(ver));
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
struct eap_sim_msg *msg, u16 counter,
const u8 *nonce_s)
{
os_free(data->next_pseudonym);
data->next_pseudonym =
eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv, 0);
os_free(data->next_reauth_id);
if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
data->next_reauth_id =
eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv, 0);
} else {
wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
"count exceeded - force full authentication");
data->next_reauth_id = NULL;
}
if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
counter == 0 && nonce_s == NULL)
return 0;
wpa_printf(MSG_DEBUG, " AT_IV");
wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
if (counter > 0) {
wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", counter);
eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
}
if (nonce_s) {
wpa_printf(MSG_DEBUG, " *AT_NONCE_S");
eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
EAP_SIM_NONCE_S_LEN);
}
if (data->next_pseudonym) {
wpa_printf(MSG_DEBUG, " *AT_NEXT_PSEUDONYM (%s)",
data->next_pseudonym);
eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
os_strlen(data->next_pseudonym),
(u8 *) data->next_pseudonym,
os_strlen(data->next_pseudonym));
}
if (data->next_reauth_id) {
wpa_printf(MSG_DEBUG, " *AT_NEXT_REAUTH_ID (%s)",
data->next_reauth_id);
eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
os_strlen(data->next_reauth_id),
(u8 *) data->next_reauth_id,
os_strlen(data->next_reauth_id));
}
if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
"AT_ENCR_DATA");
return -1;
}
return 0;
}
static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm,
struct eap_sim_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
EAP_SIM_SUBTYPE_CHALLENGE);
wpa_printf(MSG_DEBUG, " AT_RAND");
eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
data->num_chal * GSM_RAND_LEN);
if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
eap_sim_msg_free(msg);
return NULL;
}
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, data->nonce_mt,
EAP_SIM_NONCE_MT_LEN);
}
static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
struct eap_sim_data *data, u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");
if (os_get_random(data->nonce_s, EAP_SIM_NONCE_S_LEN))
return NULL;
wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
data->nonce_s, EAP_SIM_NONCE_S_LEN);
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, EAP_TYPE_SIM,
EAP_SIM_SUBTYPE_REAUTHENTICATION);
if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
eap_sim_msg_free(msg);
return NULL;
}
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_sim_build_notification(struct eap_sm *sm,
struct eap_sim_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
EAP_SIM_SUBTYPE_NOTIFICATION);
wpa_printf(MSG_DEBUG, " AT_NOTIFICATION (%d)", data->notification);
eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
NULL, 0);
if (data->use_result_ind) {
if (data->reauth) {
wpa_printf(MSG_DEBUG, " AT_IV");
wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
EAP_SIM_AT_ENCR_DATA);
wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)",
data->counter);
eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
NULL, 0);
if (eap_sim_msg_add_encr_end(msg, data->k_encr,
EAP_SIM_AT_PADDING)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Failed to "
"encrypt AT_ENCR_DATA");
eap_sim_msg_free(msg);
return NULL;
}
}
wpa_printf(MSG_DE
