/*
* hostapd / EAP-AKA (RFC 4187) and EAP-AKA' (RFC 5448)
* Copyright (c) 2005-2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "crypto/sha256.h"
#include "crypto/crypto.h"
#include "crypto/random.h"
#include "eap_common/eap_sim_common.h"
#include "eap_server/eap_i.h"
#include "eap_server/eap_sim_db.h"
struct eap_aka_data {
u8 mk[EAP_SIM_MK_LEN];
u8 nonce_s[EAP_SIM_NONCE_S_LEN];
u8 k_aut[EAP_AKA_PRIME_K_AUT_LEN];
u8 k_encr[EAP_SIM_K_ENCR_LEN];
u8 k_re[EAP_AKA_PRIME_K_RE_LEN]; /* EAP-AKA' only */
u8 msk[EAP_SIM_KEYING_DATA_LEN];
u8 emsk[EAP_EMSK_LEN];
u8 rand[EAP_AKA_RAND_LEN];
u8 autn[EAP_AKA_AUTN_LEN];
u8 ck[EAP_AKA_CK_LEN];
u8 ik[EAP_AKA_IK_LEN];
u8 res[EAP_AKA_RES_MAX_LEN];
size_t res_len;
enum {
IDENTITY, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
} state;
char *next_pseudonym;
char *next_reauth_id;
u16 counter;
struct eap_sim_reauth *reauth;
int auts_reported; /* whether the current AUTS has been reported to the
* eap_sim_db */
u16 notification;
int use_result_ind;
struct wpabuf *id_msgs;
int pending_id;
u8 eap_method;
u8 *network_name;
size_t network_name_len;
u16 kdf;
int identity_round;
char permanent[20]; /* Permanent username */
};
static void eap_aka_fullauth(struct eap_sm *sm, struct eap_aka_data *data);
static const char * eap_aka_state_txt(int state)
{
switch (state) {
case IDENTITY:
return "IDENTITY";
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_aka_state(struct eap_aka_data *data, int state)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: %s -> %s",
eap_aka_state_txt(data->state),
eap_aka_state_txt(state));
data->state = state;
}
static int eap_aka_check_identity_reauth(struct eap_sm *sm,
struct eap_aka_data *data,
const char *username)
{
if (data->eap_method == EAP_TYPE_AKA_PRIME &&
username[0] != EAP_AKA_PRIME_REAUTH_ID_PREFIX)
return 0;
if (data->eap_method == EAP_TYPE_AKA &&
username[0] != EAP_AKA_REAUTH_ID_PREFIX)
return 0;
wpa_printf(MSG_DEBUG, "EAP-AKA: Reauth username '%s'", username);
data->reauth = eap_sim_db_get_reauth_entry(sm->eap_sim_db_priv,
username);
if (data->reauth == NULL) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown reauth identity - "
"request full auth identity");
/* Remain in IDENTITY state for another round */
return 0;
}
wpa_printf(MSG_DEBUG, "EAP-AKA: Using fast re-authentication");
os_strlcpy(data->permanent, data->reauth->permanent,
sizeof(data->permanent));
data->counter = data->reauth->counter;
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
os_memcpy(data->k_encr, data->reauth->k_encr,
EAP_SIM_K_ENCR_LEN);
os_memcpy(data->k_aut, data->reauth->k_aut,
EAP_AKA_PRIME_K_AUT_LEN);
os_memcpy(data->k_re, data->reauth->k_re,
EAP_AKA_PRIME_K_RE_LEN);
} else {
os_memcpy(data->mk, data->reauth->mk, EAP_SIM_MK_LEN);
}
eap_aka_state(data, REAUTH);
return 1;
}
static void eap_aka_check_identity(struct eap_sm *sm,
struct eap_aka_data *data)
{
char *username;
/* Check if we already know the identity from EAP-Response/Identity */
username = sim_get_username(sm->identity, sm->identity_len);
if (username == NULL)
return;
if (eap_aka_check_identity_reauth(sm, data, username) > 0) {
os_free(username);
/*
* Since re-auth username was recognized, skip AKA/Identity
* exchange.
*/
return;
}
if ((data->eap_method == EAP_TYPE_AKA_PRIME &&
username[0] == EAP_AKA_PRIME_PSEUDONYM_PREFIX) ||
(data->eap_method == EAP_TYPE_AKA &&
username[0] == EAP_AKA_PSEUDONYM_PREFIX)) {
const char *permanent;
wpa_printf(MSG_DEBUG, "EAP-AKA: Pseudonym username '%s'",
username);
permanent = eap_sim_db_get_permanent(
sm->eap_sim_db_priv, username);
if (permanent == NULL) {
os_free(username);
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown pseudonym "
"identity - request permanent identity");
/* Remain in IDENTITY state for another round */
return;
}
os_strlcpy(data->permanent, permanent,
sizeof(data->permanent));
/*
* Since pseudonym username was recognized, skip AKA/Identity
* exchange.
*/
eap_aka_fullauth(sm, data);
}
os_free(username);
}
static void * eap_aka_init(struct eap_sm *sm)
{
struct eap_aka_data *data;
if (sm->eap_sim_db_priv == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: eap_sim_db not configured");
return NULL;
}
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->eap_method = EAP_TYPE_AKA;
data->state = IDENTITY;
data->pending_id = -1;
eap_aka_check_identity(sm, data);
return data;
}
#ifdef EAP_SERVER_AKA_PRIME
static void * eap_aka_prime_init(struct eap_sm *sm)
{
struct eap_aka_data *data;
/* TODO: make ANID configurable; see 3GPP TS 24.302 */
char *network_name = "WLAN";
if (sm->eap_sim_db_priv == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: eap_sim_db not configured");
return NULL;
}
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->eap_method = EAP_TYPE_AKA_PRIME;
data->network_name = (u8 *) os_strdup(network_name);
if (data->network_name == NULL) {
os_free(data);
return NULL;
}
data->network_name_len = os_strlen(network_name);
data->state = IDENTITY;
data->pending_id = -1;
eap_aka_check_identity(sm, data);
return data;
}
#endif /* EAP_SERVER_AKA_PRIME */
static void eap_aka_reset(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
os_free(data->next_pseudonym);
os_free(data->next_reauth_id);
wpabuf_free(data->id_msgs);
os_free(data->network_name);
bin_clear_free(data, sizeof(*data));
}
static int eap_aka_add_id_msg(struct eap_aka_data *data,
const struct wpabuf *msg)
{
if (msg == NULL)
return -1;
if (data->id_msgs == NULL) {
data->id_msgs = wpabuf_dup(msg);
return data->id_msgs == NULL ? -1 : 0;
}
if (wpabuf_resize(&data->id_msgs, wpabuf_len(msg)) < 0)
return -1;
wpabuf_put_buf(data->id_msgs, msg);
return 0;
}
static void eap_aka_add_checkcode(struct eap_aka_data *data,
struct eap_sim_msg *msg)
{
const u8 *addr;
size_t len;
u8 hash[SHA256_MAC_LEN];
wpa_printf(MSG_DEBUG, " AT_CHECKCODE");
if (data->id_msgs == NULL) {
/*
* No EAP-AKA/Identity packets were exchanged - send empty
* checkcode.
*/
eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, NULL, 0);
return;
}
/* Checkcode is SHA1 hash over all EAP-AKA/Identity packets. */
addr = wpabuf_head(data->id_msgs);
len = wpabuf_len(data->id_msgs);
wpa_hexdump(MSG_MSGDUMP, "EAP-AKA: AT_CHECKCODE data", addr, len);
if (data->eap_method == EAP_TYPE_AKA_PRIME)
sha256_vector(1, &addr, &len, hash);
else
sha1_vector(1, &addr, &len, hash);
eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, hash,
data->eap_method == EAP_TYPE_AKA_PRIME ?
EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN);
}
static int eap_aka_verify_checkcode(struct eap_aka_data *data,
const u8 *checkcode, size_t checkcode_len)
{
const u8 *addr;
size_t len;
u8 hash[SHA256_MAC_LEN];
size_t hash_len;
if (checkcode == NULL)
return -1;
if (data->id_msgs == NULL) {
if (checkcode_len != 0) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from peer "
"indicates that AKA/Identity messages were "
"used, but they were not");
return -1;
}
return 0;
}
hash_len = data->eap_method == EAP_TYPE_AKA_PRIME ?
EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN;
if (checkcode_len != hash_len) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from peer indicates "
"that AKA/Identity message were not used, but they "
"were");
return -1;
}
/* Checkcode is SHA1 hash over all EAP-AKA/Identity packets. */
addr = wpabuf_head(data->id_msgs);
len = wpabuf_len(data->id_msgs);
if (data->eap_method == EAP_TYPE_AKA_PRIME)
sha256_vector(1, &addr, &len, hash);
else
sha1_vector(1, &addr, &len, hash);
if (os_memcmp_const(hash, checkcode, hash_len) != 0) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Mismatch in AT_CHECKCODE");
return -1;
}
return 0;
}
static struct wpabuf * eap_aka_build_identity(struct eap_sm *sm,
struct eap_aka_data *data, u8 id)
{
struct eap_sim_msg *msg;
struct wpabuf *buf;
wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Identity");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
EAP_AKA_SUBTYPE_IDENTITY);
data->identity_round++;
if (data->identity_round == 1) {
/*
* RFC 4187, Chap. 4.1.4 recommends that identity from EAP is
* ignored and the AKA/Identity 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);
} else if (data->identity_round > 3) {
/* Cannot use more than three rounds of Identity messages */
eap_sim_msg_free(msg);
return NULL;
} else if (sm->identity && sm->identity_len > 0 &&
(sm->identity[0] == EAP_AKA_REAUTH_ID_PREFIX ||
sm->identity[0] == EAP_AKA_PRIME_REAUTH_ID_PREFIX)) {
/* Reauth id may have expired - try fullauth */
wpa_printf(MSG_DEBUG, " AT_FULLAUTH_ID_REQ");
eap_sim_msg_add(msg, EAP_SIM_AT_FULLAUTH_ID_REQ, 0, NULL, 0);
} else {
wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ");
eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
}
buf = eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
if (eap_aka_add_id_msg(data, buf) < 0) {
wpabuf_free(buf);
return NULL;
}
data->pending_id = id;
return buf;
}
static int eap_aka_build_encr(struct eap_sm *sm, struct eap_aka_data *data,
struct eap_sim_msg *msg, u16 counter,
const u8 *nonce_s)
{
os_free(data->next_pseudonym);
if (nonce_s == NULL) {
data->next_pseudonym =
eap_sim_db_get_next_pseudonym(
sm->eap_sim_db_priv,
data->eap_method == EAP_TYPE_AKA_PRIME ?
EAP_SIM_DB_AKA_PRIME : EAP_SIM_DB_AKA);
} else {
/* Do not update pseudonym during re-authentication */
data->next_pseudonym = NULL;
}
os_free(data->next_reauth_id);
if (data->counter <= EAP_AKA_MAX_FAST_REAUTHS) {
data->next_reauth_id =
eap_sim_db_get_next_reauth_id(
sm->eap_sim_db_priv,
data->eap_method == EAP_TYPE_AKA_PRIME ?
EAP_SIM_DB_AKA_PRIME : EAP_SIM_DB_AKA);
} else {
wpa_printf(MSG_DEBUG, "EAP-AKA: 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-AKA: Failed to encrypt "
"AT_ENCR_DATA");
return -1;
}
return 0;
}
static struct wpabuf * eap_aka_build_challenge(struct eap_sm *sm,
struct eap_aka_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Challenge");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
EAP_AKA_SUBTYPE_CHALLENGE);
wpa_printf(MSG_DEBUG, " AT_RAND");
eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, data->rand, EAP_AKA_RAND_LEN);
wpa_printf(MSG_DEBUG, " AT_AUTN");
eap_sim_msg_add(msg, EAP_SIM_AT_AUTN, 0, data->autn, EAP_AKA_AUTN_LEN);
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
if (data->kdf) {
/* Add the selected KDF into the beginning */
wpa_printf(MSG_DEBUG, " AT_KDF");
eap_sim_msg_add(msg, EAP_SIM_AT_KDF, data->kdf,
NULL, 0);
}
wpa_printf(MSG_DEBUG, " AT_KDF");
eap_sim_msg_add(msg, EAP_SIM_AT_KDF, EAP_AKA_PRIME_KDF,
NULL, 0);
wpa_printf(MSG_DEBUG, " AT_KDF_INPUT");
eap_sim_msg_add(msg, EAP_SIM_AT_KDF_INPUT,
data->network_name_len,
data->network_name, data->network_name_len);
}
if (eap_aka_build_encr(sm, data, msg, 0, NULL)) {
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);
}
#ifdef EAP_SERVER_AKA_PRIME
if (data->eap_method == EAP_TYPE_AKA) {
u16 flags = 0;
int i;
int aka_prime_preferred = 0;
i = 0;
while (sm->user && i < EAP_MAX_METHODS &&
(sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
sm->user->methods[i].method != EAP_TYPE_NONE)) {
if (sm->user->methods[i].vendor == EAP_VENDOR_IETF) {
if (sm->user->methods[i].method ==
EAP_TYPE_AKA)
break;
if (sm->user->methods[i].method ==
EAP_TYPE_AKA_PRIME) {
aka_prime_preferred = 1;
break;
}
}
i++;
}
if (aka_prime_preferred)
flags |= EAP_AKA_BIDDING_FLAG_D;
eap_sim_msg_add(msg, EAP_SIM_AT_BIDDING, flags, NULL, 0);
}
#endif /* EAP_SERVER_AKA_PRIME */
wpa_printf(MSG_DEBUG, " AT_MAC");
eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, NULL, 0);
}
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 (random_get_bytes(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->eap_method, data->k_aut, NULL, 0);
}
static struct wpabuf * eap_aka_build_notification(struct eap_sm *sm,
struct eap_aka_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Notification");
msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
EAP_AKA_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-AKA: Failed to "
"encrypt AT_ENCR_DATA");
eap_sim_msg_free(msg);
return NULL;
}
}
wpa_printf(MSG_DEBUG, " AT_MAC");
eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
}
return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, NULL, 0);
}
static struct wpabuf * eap_aka_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
struct eap_aka_data *data = priv;
data->auts_reported = 0;
switch (data->state) {
case IDENTITY:
return eap_aka_build_identity(sm, data, id);
case CHALLENGE:
return eap_aka_build_challenge(sm, data, id);
case REAUTH:
return eap_aka_build_reauth(sm, data, id);
case NOTIFICATION:
return eap_aka_build_notification(sm, data, id);
default:
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown state %d in "
"buildReq", data->state);
break;
}
return NULL;
}
static Boolean eap_aka_check(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_aka_data *data = priv;
const u8 *pos;
size_t len;
pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, respData,
&len);
if (pos == NULL || len < 3) {
wpa_printf(MSG_INFO, "EAP-AKA: Invalid frame");
return TRUE;
}
return FALSE;
}
static Boolean eap_aka_subtype_ok(struct eap_aka_data *data, u8 subtype)
{
if (subtype == EAP_AKA_SUBTYPE_CLIENT_ERROR ||
subtype == EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT)
return FALSE;
switch (data->state) {
case IDENTITY:
if (subtype != EAP_AKA_SUBTYPE_IDENTITY) {
wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
"subtype %d", subtype);
return TRUE;
}
break;
case CHALLENGE:
if (subtype != EAP_AKA_SUBTYPE_CHALLENGE &&
subtype != EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE) {
wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
"subtype %d", subtype);
return TRUE;
}
break;
case REAUTH:
if (subtype != EAP_AKA_SUBTYPE_REAUTHENTICATION) {
wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
"subtype %d", subtype);
return TRUE;
}
break;
case NOTIFICATION:
if (subtype != EAP_AKA_SUBTYPE_NOTIFICATION) {
wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
"subtype %d", subtype);
return TRUE;
}
break;
default:
wpa_printf(MSG_INFO, "EAP-AKA: Unexpected state (%d) for "
"processing a response", data->state);
return TRUE;
}
return FALSE;
}
static void eap_aka_determine_identity(struct eap_sm *sm,
struct eap_aka_data *data)
{
char *username;
wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Identity",
sm->identity, sm->identity_len);
username = sim_get_username(sm->identity, sm->identity_len);
if (username == NULL) {
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
if (eap_aka_check_identity_reauth(sm, data, username) > 0) {
os_free(username);
return;
}
if (((data->eap_method == EAP_TYPE_AKA_PRIME &&
username[0] == EAP_AKA_PRIME_REAUTH_ID_PREFIX) ||
(data->eap_method == EAP_TYPE_AKA &&
username[0] == EAP_AKA_REAUTH_ID_PREFIX)) &&
data->identity_round == 1) {
/* Remain in IDENTITY state for another round to request full
* auth identity since we did not recognize reauth id */
os_free(username);
return;
}
if ((data->eap_method == EAP_TYPE_AKA_PRIME &&
username[0] == EAP_AKA_PRIME_PSEUDONYM_PREFIX) ||
(data->eap_method == EAP_TYPE_AKA &&
username[0] == EAP_AKA_PSEUDONYM_PREFIX)) {
const char *permanent;
wpa_printf(MSG_DEBUG, "EAP-AKA: Pseudonym username '%s'",
username);
permanent = eap_sim_db_get_permanent(
sm->eap_sim_db_priv, username);
os_free(username);
if (permanent == NULL) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown pseudonym "
"identity - request permanent identity");
/* Remain in IDENTITY state for another round */
return;
}
os_strlcpy(data->permanent, permanent,
sizeof(data->permanent));
} else if ((data->eap_method == EAP_TYPE_AKA_PRIME &&
username[0] == EAP_AKA_PRIME_PERMANENT_PREFIX) ||
(data->eap_method == EAP_TYPE_AKA &&
username[0] == EAP_AKA_PERMANENT_PREFIX)) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Permanent username '%s'",
username);
os_strlcpy(data->permanent, username, sizeof(data->permanent));
os_free(username);
} else {
wpa_printf(MSG_DEBUG, "EAP-AKA: Unrecognized username '%s'",
username);
os_free(username);
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
eap_aka_fullauth(sm, data);
}
static void eap_aka_fullauth(struct eap_sm *sm, struct eap_aka_data *data)
{
size_t identity_len;
int res;
res = eap_sim_db_get_aka_auth(sm->eap_sim_db_priv, data->permanent,
data->rand, data->autn, data->ik,
data->ck, data->res, &data->res_len, sm);
if (res == EAP_SIM_DB_PENDING) {
wpa_printf(MSG_DEBUG, "EAP-AKA: AKA authentication data "
"not yet available - pending request");
sm->method_pending = METHOD_PENDING_WAIT;
return;
}
#ifdef EAP_SERVER_AKA_PRIME
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
/* Note: AUTN = (SQN ^ AK) || AMF || MAC which gives us the
* needed 6-octet SQN ^AK for CK',IK' derivation */
eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
data->autn,
data->network_name,
data->network_name_len);
}
#endif /* EAP_SERVER_AKA_PRIME */
data->reauth = NULL;
data->counter = 0; /* reset re-auth counter since this is full auth */
if (res != 0) {
wpa_printf(MSG_INFO, "EAP-AKA: Failed to get AKA "
"authentication data for the peer");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
if (sm->method_pending == METHOD_PENDING_WAIT) {
wpa_printf(MSG_DEBUG, "EAP-AKA: AKA authentication data "
"available - abort pending wait");
sm->method_pending = METHOD_PENDING_NONE;
}
identity_len = sm->identity_len;
while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
wpa_printf(MSG_DEBUG, "EAP-AKA: Workaround - drop last null "
"character from identity");
identity_len--;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Identity for MK derivation",
sm->identity, identity_len);
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
eap_aka_prime_derive_keys(sm->identity, identity_len, data->ik,
data->ck, data->k_encr, data->k_aut,
data->k_re, data->msk, data->emsk);
} else {
eap_aka_derive_mk(sm->identity, identity_len, data->ik,
data->ck, data->mk);
eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
data->msk, data->emsk);
}
eap_aka_state(data, CHALLENGE);
}
static void eap_aka_process_identity(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
u8 *new_identity;
wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Identity");
if (attr->mac || attr->iv || attr->encr_data) {
wpa_printf(MSG_WARNING, "EAP-AKA: Unexpected attribute "
"received in EAP-Response/AKA-Identity");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
/*
* We always request identity with AKA/Identity, so the peer is
* required to have replied with one.
*/
if (!attr->identity || attr->identity_len == 0) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Peer did not provide any "
"identity");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
new_identity = os_malloc(attr->identity_len);
if (new_identity == NULL) {
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
os_free(sm->identity);
sm->identity = new_identity;
os_memcpy(sm->identity, attr->identity, attr->identity_len);
sm->identity_len = attr->identity_len;
eap_aka_determine_identity(sm, data);
if (eap_get_id(respData) == data->pending_id) {
data->pending_id = -1;
eap_aka_add_id_msg(data, respData);
}
}
static int eap_aka_verify_mac(struct eap_aka_data *data,
const struct wpabuf *req,
const u8 *mac, const u8 *extra,
size_t extra_len)
{
if (data->eap_method == EAP_TYPE_AKA_PRIME)
return eap_sim_verify_mac_sha256(data->k_aut, req, mac, extra,
extra_len);
return eap_sim_verify_mac(data->k_aut, req, mac, extra, extra_len);
}
static void eap_aka_process_challenge(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Challenge");
#ifdef EAP_SERVER_AKA_PRIME
#if 0
/* KDF negotiation; to be enabled only after more than one KDF is
* supported */
if (data->eap_method == EAP_TYPE_AKA_PRIME &&
attr->kdf_count == 1 && attr->mac == NULL) {
if (attr->kdf[0] != EAP_AKA_PRIME_KDF) {
wpa_printf(MSG_WARNING, "EAP-AKA': Peer selected "
"unknown KDF");
data->notification =
EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
data->kdf = attr->kdf[0];
/* Allow negotiation to continue with the selected KDF by
* sending another Challenge message */
wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
return;
}
#endif
#endif /* EAP_SERVER_AKA_PRIME */
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");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
if (attr->mac == NULL ||
eap_aka_verify_mac(data, respData, attr->mac, NULL, 0)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
"did not include valid AT_MAC");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
/*
* AT_RES is padded, so verify that there is enough room for RES and
* that the RES length in bits matches with the expected RES.
*/
if (attr->res == NULL || attr->res_len < data->res_len ||
attr->res_len_bits != data->res_len * 8 ||
os_memcmp_const(attr->res, data->res, data->res_len) != 0) {
wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message did not "
"include valid AT_RES (attr len=%lu, res len=%lu "
"bits, expected %lu bits)",
(unsigned long) attr->res_len,
(unsigned long) attr->res_len_bits,
(unsigned long) data->res_len * 8);
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
wpa_printf(MSG_DEBUG, "EAP-AKA: Challenge response includes the "
"correct AT_MAC");
if (sm->eap_sim_aka_result_ind && attr->result_ind) {
data->use_result_ind = 1;
data->notification = EAP_SIM_SUCCESS;
eap_aka_state(data, NOTIFICATION);
} else
eap_aka_state(data, SUCCESS);
if (data->next_pseudonym) {
eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, data->permanent,
data->next_pseudonym);
data->next_pseudonym = NULL;
}
if (data->next_reauth_id) {
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
#ifdef EAP_SERVER_AKA_PRIME
eap_sim_db_add_reauth_prime(sm->eap_sim_db_priv,
data->permanent,
data->next_reauth_id,
data->counter + 1,
data->k_encr, data->k_aut,
data->k_re);
#endif /* EAP_SERVER_AKA_PRIME */
} else {
eap_sim_db_add_reauth(sm->eap_sim_db_priv,
data->permanent,
data->next_reauth_id,
data->counter + 1,
data->mk);
}
data->next_reauth_id = NULL;
}
}
static void eap_aka_process_sync_failure(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Synchronization-Failure");
if (attr->auts == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Synchronization-Failure "
"message did not include valid AT_AUTS");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
/* Avoid re-reporting AUTS when processing pending EAP packet by
* maintaining a local flag stating whether this AUTS has already been
* reported. */
if (!data->auts_reported &&
eap_sim_db_resynchronize(sm->eap_sim_db_priv, data->permanent,
attr->auts, data->rand)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Resynchronization failed");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
data->auts_reported = 1;
/* Remain in CHALLENGE state to re-try after resynchronization */
eap_aka_fullauth(sm, data);
}
static void eap_aka_process_reauth(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
struct eap_sim_attrs eattr;
u8 *decrypted = NULL;
wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Reauthentication");
if (attr->mac == NULL ||
eap_aka_verify_mac(data, respData, attr->mac, data->nonce_s,
EAP_SIM_NONCE_S_LEN)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Re-authentication message "
"did not include valid AT_MAC");
goto fail;
}
if (attr->encr_data == NULL || attr->iv == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
"message did not include encrypted data");
goto fail;
}
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");
goto fail;
}
if (eattr.counter != data->counter) {
wpa_printf(MSG_WARNING, "EAP-AKA: Re-authentication message "
"used incorrect counter %u, expected %u",
eattr.counter, data->counter);
goto fail;
}
os_free(decrypted);
decrypted = NULL;
wpa_printf(MSG_DEBUG, "EAP-AKA: Re-authentication response includes "
"the correct AT_MAC");
if (eattr.counter_too_small) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Re-authentication response "
"included AT_COUNTER_TOO_SMALL - starting full "
"authentication");
eap_aka_fullauth(sm, data);
return;
}
if (sm->eap_sim_aka_result_ind && attr->result_ind) {
data->use_result_ind = 1;
data->notification = EAP_SIM_SUCCESS;
eap_aka_state(data, NOTIFICATION);
} else
eap_aka_state(data, SUCCESS);
if (data->next_reauth_id) {
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
#ifdef EAP_SERVER_AKA_PRIME
eap_sim_db_add_reauth_prime(sm->eap_sim_db_priv,
data->permanent,
data->next_reauth_id,
data->counter + 1,
data->k_encr, data->k_aut,
data->k_re);
#endif /* EAP_SERVER_AKA_PRIME */
} else {
eap_sim_db_add_reauth(sm->eap_sim_db_priv,
data->permanent,
data->next_reauth_id,
data->counter + 1,
data->mk);
}
data->next_reauth_id = NULL;
} else {
eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
data->reauth = NULL;
}
return;
fail:
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
data->reauth = NULL;
os_free(decrypted);
}
static void eap_aka_process_client_error(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: Client reported error %d",
attr->client_error_code);
if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
eap_aka_state(data, SUCCESS);
else
eap_aka_state(data, FAILURE);
}
static void eap_aka_process_authentication_reject(
struct eap_sm *sm, struct eap_aka_data *data,
struct wpabuf *respData, struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: Client rejected authentication");
eap_aka_state(data, FAILURE);
}
static void eap_aka_process_notification(struct eap_sm *sm,
struct eap_aka_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: Client replied to notification");
if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
eap_aka_state(data, SUCCESS);
else
eap_aka_state(data, FAILURE);
}
static void eap_aka_process(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_aka_data *data = priv;
const u8 *pos, *end;
u8 subtype;
size_t len;
struct eap_sim_attrs attr;
pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, respData,
&len);
if (pos == NULL || len < 3)
return;
end = pos + len;
subtype = *pos;
pos += 3;
if (eap_aka_subtype_ok(data, subtype)) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Unrecognized or unexpected "
"EAP-AKA Subtype in EAP Response");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
if (eap_sim_parse_attr(pos, end, &attr,
data->eap_method == EAP_TYPE_AKA_PRIME ? 2 : 1,
0)) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Failed to parse attributes");
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_aka_state(data, NOTIFICATION);
return;
}
if (subtype == EAP_AKA_SUBTYPE_CLIENT_ERROR) {
eap_aka_process_client_error(sm, data, respData, &attr);
return;
}
if (subtype == EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT) {
eap_aka_process_authentication_reject(sm, data, respData,
&attr);
return;
}
switch (data->state) {
case IDENTITY:
eap_aka_process_identity(sm, data, respData, &attr);
break;
case CHALLENGE:
if (subtype == EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE) {
eap_aka_process_sync_failure(sm, data, respData,
&attr);
} else {
eap_aka_process_challenge(sm, data, respData, &attr);
}
break;
case REAUTH:
eap_aka_process_reauth(sm, data, respData, &attr);
break;
case NOTIFICATION:
eap_aka_process_notification(sm, data, respData, &attr);
break;
default:
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown state %d in "
"process", data->state);
break;
}
}
static Boolean eap_aka_isDone(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
return data->state == SUCCESS || data->state == FAILURE;
}
static u8 * eap_aka_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_aka_data *data = priv;
u8 *key;
if (data->state != SUCCESS)
return NULL;
key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
if (key == NULL)
return NULL;
os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
*len = EAP_SIM_KEYING_DATA_LEN;
return key;
}
static u8 * eap_aka_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_aka_data *data = priv;
u8 *key;
if (data->state != SUCCESS)
return NULL;
key = os_malloc(EAP_EMSK_LEN);
if (key == NULL)
return NULL;
os_memcpy(key, data->emsk, EAP_EMSK_LEN);
*len = EAP_EMSK_LEN;
return key;
}
static Boolean eap_aka_isSuccess(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
return data->state == SUCCESS;
}
int eap_server_aka_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
if (eap == NULL)
return -1;
eap->init = eap_aka_init;
eap->reset = eap_aka_reset;
eap->buildReq = eap_aka_buildReq;
eap->check = eap_aka_check;
eap->process = eap_aka_process;
eap->isDone = eap_aka_isDone;
eap->getKey = eap_aka_getKey;
eap->isSuccess = eap_aka_isSuccess;
eap->get_emsk = eap_aka_get_emsk;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}
#ifdef EAP_SERVER_AKA_PRIME
int eap_server_aka_prime_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
"AKA'");
if (eap == NULL)
return -1;
eap->init = eap_aka_prime_init;
eap->reset = eap_aka_reset;
eap->buildReq = eap_aka_buildReq;
eap->check = eap_aka_check;
eap->process = eap_aka_process;
eap->isDone = eap_aka_isDone;
eap->getKey = eap_aka_getKey;
eap->isSuccess = eap_aka_isSuccess;
eap->get_emsk = eap_aka_get_emsk;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}
#endif /* EAP_SERVER_AKA_PRIME */