/*
* EAP peer method: EAP-AKA (RFC 4187) and EAP-AKA' (draft-arkko-eap-aka-kdf)
* Copyright (c) 2004-2008, 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 "pcsc_funcs.h"
#include "crypto/crypto.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "crypto/milenage.h"
#include "eap_common/eap_sim_common.h"
#include "eap_config.h"
#include "eap_i.h"
struct eap_aka_data {
u8 ik[EAP_AKA_IK_LEN], ck[EAP_AKA_CK_LEN], res[EAP_AKA_RES_MAX_LEN];
size_t res_len;
u8 nonce_s[EAP_SIM_NONCE_S_LEN];
u8 mk[EAP_SIM_MK_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], autn[EAP_AKA_AUTN_LEN];
u8 auts[EAP_AKA_AUTS_LEN];
int num_id_req, num_notification;
u8 *pseudonym;
size_t pseudonym_len;
u8 *reauth_id;
size_t reauth_id_len;
int reauth;
unsigned int counter, counter_too_small;
u8 *last_eap_identity;
size_t last_eap_identity_len;
enum {
CONTINUE, RESULT_SUCCESS, RESULT_FAILURE, SUCCESS, FAILURE
} state;
struct wpabuf *id_msgs;
int prev_id;
int result_ind, use_result_ind;
u8 eap_method;
u8 *network_name;
size_t network_name_len;
u16 kdf;
int kdf_negotiation;
};
#ifndef CONFIG_NO_STDOUT_DEBUG
static const char * eap_aka_state_txt(int state)
{
switch (state) {
case CONTINUE:
return "CONTINUE";
case RESULT_SUCCESS:
return "RESULT_SUCCESS";
case RESULT_FAILURE:
return "RESULT_FAILURE";
case SUCCESS:
return "SUCCESS";
case FAILURE:
return "FAILURE";
default:
return "?";
}
}
#endif /* CONFIG_NO_STDOUT_DEBUG */
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 void * eap_aka_init(struct eap_sm *sm)
{
struct eap_aka_data *data;
const char *phase1 = eap_get_config_phase1(sm);
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->eap_method = EAP_TYPE_AKA;
eap_aka_state(data, CONTINUE);
data->prev_id = -1;
data->result_ind = phase1 && os_strstr(phase1, "result_ind=1") != NULL;
return data;
}
#ifdef EAP_AKA_PRIME
static void * eap_aka_prime_init(struct eap_sm *sm)
{
struct eap_aka_data *data = eap_aka_init(sm);
if (data == NULL)
return NULL;
data->eap_method = EAP_TYPE_AKA_PRIME;
return data;
}
#endif /* EAP_AKA_PRIME */
static void eap_aka_deinit(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
if (data) {
os_free(data->pseudonym);
os_free(data->reauth_id);
os_free(data->last_eap_identity);
wpabuf_free(data->id_msgs);
os_free(data->network_name);
os_free(data);
}
}
static int eap_aka_umts_auth(struct eap_sm *sm, struct eap_aka_data *data)
{
struct eap_peer_config *conf;
wpa_printf(MSG_DEBUG, "EAP-AKA: UMTS authentication algorithm");
conf = eap_get_config(sm);
if (conf == NULL)
return -1;
if (conf->pcsc) {
return scard_umts_auth(sm->scard_ctx, data->rand,
data->autn, data->res, &data->res_len,
data->ik, data->ck, data->auts);
}
#ifdef CONFIG_USIM_SIMULATOR
if (conf->password) {
u8 opc[16], k[16], sqn[6];
const char *pos;
wpa_printf(MSG_DEBUG, "EAP-AKA: Use internal Milenage "
"implementation for UMTS authentication");
if (conf->password_len < 78) {
wpa_printf(MSG_DEBUG, "EAP-AKA: invalid Milenage "
"password");
return -1;
}
pos = (const char *) conf->password;
if (hexstr2bin(pos, k, 16))
return -1;
pos += 32;
if (*pos != ':')
return -1;
pos++;
if (hexstr2bin(pos, opc, 16))
return -1;
pos += 32;
if (*pos != ':')
return -1;
pos++;
if (hexstr2bin(pos, sqn, 6))
return -1;
return milenage_check(opc, k, sqn, data->rand, data->autn,
data->ik, data->ck,
data->res, &data->res_len, data->auts);
}
#endif /* CONFIG_USIM_SIMULATOR */
#ifdef CONFIG_USIM_HARDCODED
wpa_printf(MSG_DEBUG, "EAP-AKA: Use hardcoded Kc and SRES values for "
"testing");
/* These hardcoded Kc and SRES values are used for testing.
* Could consider making them configurable. */
os_memset(data->res, '2', EAP_AKA_RES_MAX_LEN);
data->res_len = EAP_AKA_RES_MAX_LEN;
os_memset(data->ik, '3', EAP_AKA_IK_LEN);
os_memset(data->ck, '4', EAP_AKA_CK_LEN);
{
u8 autn[EAP_AKA_AUTN_LEN];
os_memset(autn, '1', EAP_AKA_AUTN_LEN);
if (os_memcmp(autn, data->autn, EAP_AKA_AUTN_LEN) != 0) {
wpa_printf(MSG_WARNING, "EAP-AKA: AUTN did not match "
"with expected value");
return -1;
}
}
#if 0
{
static int test_resync = 1;
if (test_resync) {
/* Test Resynchronization */
test_resync = 0;
return -2;
}
}
#endif
return 0;
#else /* CONFIG_USIM_HARDCODED */
wpa_printf(MSG_DEBUG, "EAP-AKA: No UMTS authentication algorith "
"enabled");
return -1;
#endif /* CONFIG_USIM_HARDCODED */
}
#define CLEAR_PSEUDONYM 0x01
#define CLEAR_REAUTH_ID 0x02
#define CLEAR_EAP_ID 0x04
static void eap_aka_clear_identities(struct eap_aka_data *data, int id)
{
if (id & CLEAR_PSEUDONYM) {
wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old pseudonym");
os_free(data->pseudonym);
data->pseudonym = NULL;
data->pseudonym_len = 0;
}
if (id & CLEAR_REAUTH_ID) {
wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old reauth_id");
os_free(data->reauth_id);
data->reauth_id = NULL;
data->reauth_id_len = 0;
}
if (id & CLEAR_EAP_ID) {
wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old eap_id");
os_free(data->last_eap_identity);
data->last_eap_identity = NULL;
data->last_eap_identity_len = 0;
}
}
static int eap_aka_learn_ids(struct eap_sm *sm, struct eap_aka_data *data,
struct eap_sim_attrs *attr)
{
if (attr->next_pseudonym) {
const u8 *identity = NULL;
size_t identity_len = 0;
const u8 *realm = NULL;
size_t realm_len = 0;
wpa_hexdump_ascii(MSG_DEBUG,
"EAP-AKA: (encr) AT_NEXT_PSEUDONYM",
attr->next_pseudonym,
attr->next_pseudonym_len);
os_free(data->pseudonym);
/* Look for the realm of the permanent identity */
identity = eap_get_config_identity(sm, &identity_len);
if (identity) {
for (realm = identity, realm_len = identity_len;
realm_len > 0; realm_len--, realm++) {
if (*realm == '@')
break;
}
}
data->pseudonym = os_malloc(attr->next_pseudonym_len +
realm_len);
if (data->pseudonym == NULL) {
wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
"next pseudonym");
data->pseudonym_len = 0;
return -1;
}
os_memcpy(data->pseudonym, attr->next_pseudonym,
attr->next_pseudonym_len);
if (realm_len) {
os_memcpy(data->pseudonym + attr->next_pseudonym_len,
realm, realm_len);
}
data->pseudonym_len = attr->next_pseudonym_len + realm_len;
}
if (attr->next_reauth_id) {
os_free(data->reauth_id);
data->reauth_id = os_malloc(attr->next_reauth_id_len);
if (data->reauth_id == NULL) {
wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
"next reauth_id");
data->reauth_id_len = 0;
return -1;
}
os_memcpy(data->reauth_id, attr->next_reauth_id,
attr->next_reauth_id_len);
data->reauth_id_len = attr->next_reauth_id_len;
wpa_hexdump_ascii(MSG_DEBUG,
"EAP-AKA: (encr) AT_NEXT_REAUTH_ID",
data->reauth_id,
data->reauth_id_len);
}
return 0;
}
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/SHA256 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);
#ifdef EAP_AKA_PRIME
if (data->eap_method == EAP_TYPE_AKA_PRIME)
sha256_vector(1, &addr, &len, hash);
else
#endif /* EAP_AKA_PRIME */
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 server "
"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 server "
"indicates that AKA/Identity message were not "
"used, but they were");
return -1;
}
/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
addr = wpabuf_head(data->id_msgs);
len = wpabuf_len(data->id_msgs);
#ifdef EAP_AKA_PRIME
if (data->eap_method == EAP_TYPE_AKA_PRIME)
sha256_vector(1, &addr, &len, hash);
else
#endif /* EAP_AKA_PRIME */
sha1_vector(1, &addr, &len, hash);
if (os_memcmp(hash, checkcode, hash_len) != 0) {
wpa_printf(MSG_DEBUG, "EAP-AKA: Mismatch in AT_CHECKCODE");
return -1;
}
return 0;
}
static struct wpabuf * eap_aka_client_error(struct eap_aka_data *data, u8 id,
int err)
{
struct eap_sim_msg *msg;
eap_aka_state(data, FAILURE);
data->num_id_req = 0;
data->num_notification = 0;
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_CLIENT_ERROR);
eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static struct wpabuf * eap_aka_authentication_reject(struct eap_aka_data *data,
u8 id)
{
struct eap_sim_msg *msg;
eap_aka_state(data, FAILURE);
data->num_id_req = 0;
data->num_notification = 0;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Authentication-Reject "
"(id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT);
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static struct wpabuf * eap_aka_synchronization_failure(
struct eap_aka_data *data, u8 id)
{
struct eap_sim_msg *msg;
data->num_id_req = 0;
data->num_notification = 0;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Synchronization-Failure "
"(id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE);
wpa_printf(MSG_DEBUG, " AT_AUTS");
eap_sim_msg_add_full(msg, EAP_SIM_AT_AUTS, data->auts,
EAP_AKA_AUTS_LEN);
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static struct wpabuf * eap_aka_response_identity(struct eap_sm *sm,
struct eap_aka_data *data,
u8 id,
enum eap_sim_id_req id_req)
{
const u8 *identity = NULL;
size_t identity_len = 0;
struct eap_sim_msg *msg;
data->reauth = 0;
if (id_req == ANY_ID && data->reauth_id) {
identity = data->reauth_id;
identity_len = data->reauth_id_len;
data->reauth = 1;
} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
data->pseudonym) {
identity = data->pseudonym;
identity_len = data->pseudonym_len;
eap_aka_clear_identities(data, CLEAR_REAUTH_ID);
} else if (id_req != NO_ID_REQ) {
identity = eap_get_config_identity(sm, &identity_len);
if (identity) {
eap_aka_clear_identities(data, CLEAR_PSEUDONYM |
CLEAR_REAUTH_ID);
}
}
if (id_req != NO_ID_REQ)
eap_aka_clear_identities(data, CLEAR_EAP_ID);
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Identity (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_IDENTITY);
if (identity) {
wpa_hexdump_ascii(MSG_DEBUG, " AT_IDENTITY",
identity, identity_len);
eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
identity, identity_len);
}
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static struct wpabuf * eap_aka_response_challenge(struct eap_aka_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_CHALLENGE);
wpa_printf(MSG_DEBUG, " AT_RES");
eap_sim_msg_add(msg, EAP_SIM_AT_RES, data->res_len * 8,
data->res, data->res_len);
eap_aka_add_checkcode(data, msg);
if (data->use_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, (u8 *) "", 0);
}
static struct wpabuf * eap_aka_response_reauth(struct eap_aka_data *data,
u8 id, int counter_too_small,
const u8 *nonce_s)
{
struct eap_sim_msg *msg;
unsigned int counter;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Reauthentication (id=%d)",
id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_REAUTHENTICATION);
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_too_small) {
wpa_printf(MSG_DEBUG, " *AT_COUNTER_TOO_SMALL");
eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
counter = data->counter_too_small;
} else
counter = data->counter;
wpa_printf(MSG_DEBUG, " *AT_COUNTER %d", counter);
eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, 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;
}
eap_aka_add_checkcode(data, msg);
if (data->use_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, nonce_s,
EAP_SIM_NONCE_S_LEN);
}
static struct wpabuf * eap_aka_response_notification(struct eap_aka_data *data,
u8 id, u16 notification)
{
struct eap_sim_msg *msg;
u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Notification (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_NOTIFICATION);
if (k_aut && 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 %d", 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;
}
}
if (k_aut) {
wpa_printf(MSG_DEBUG, " AT_MAC");
eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
}
return eap_sim_msg_finish(msg, k_aut, (u8 *) "", 0);
}
static struct wpabuf * eap_aka_process_identity(struct eap_sm *sm,
struct eap_aka_data *data,
u8 id,
const struct wpabuf *reqData,
struct eap_sim_attrs *attr)
{
int id_error;
struct wpabuf *buf;
wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Identity");
id_error = 0;
switch (attr->id_req) {
case NO_ID_REQ:
break;
case ANY_ID:
if (data->num_id_req > 0)
id_error++;
data->num_id_req++;
break;
case FULLAUTH_ID:
if (data->num_id_req > 1)
id_error++;
data->num_id_req++;
break;
case PERMANENT_ID:
if (data->num_id_req > 2)
id_error++;
data->num_id_req++;
break;
}
if (id_error) {
wpa_printf(MSG_INFO, "EAP-AKA: Too many ID requests "
"used within one authentication");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
buf = eap_aka_response_identity(sm, data, id, attr->id_req);
if (data->prev_id != id) {
eap_aka_add_id_msg(data, reqData);
eap_aka_add_id_msg(data, buf);
data->prev_id = id;
}
return buf;
}
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);
}
#ifdef EAP_AKA_PRIME
static struct wpabuf * eap_aka_prime_kdf_select(struct eap_aka_data *data,
u8 id, u16 kdf)
{
struct eap_sim_msg *msg;
data->kdf_negotiation = 1;
data->kdf = kdf;
wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d) (KDF "
"select)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
EAP_AKA_SUBTYPE_CHALLENGE);
wpa_printf(MSG_DEBUG, " AT_KDF");
eap_sim_msg_add(msg, EAP_SIM_AT_KDF, kdf, NULL, 0);
return eap_sim_msg_finish(msg, NULL, NULL, 0);
}
static struct wpabuf * eap_aka_prime_kdf_neg(struct eap_aka_data *data,
u8 id, struct eap_sim_attrs *attr)
{
size_t i;
for (i = 0; i < attr->kdf_count; i++) {
if (attr->kdf[i] == EAP_AKA_PRIME_KDF)
return eap_aka_prime_kdf_select(data, id,
EAP_AKA_PRIME_KDF);
}
/* No matching KDF found - fail authentication as if AUTN had been
* incorrect */
return eap_aka_authentication_reject(data, id);
}
static int eap_aka_prime_kdf_valid(struct eap_aka_data *data,
struct eap_sim_attrs *attr)
{
size_t i, j;
if (attr->kdf_count == 0)
return 0;
/* The only allowed (and required) duplication of a KDF is the addition
* of the selected KDF into the beginning of the list. */
if (data->kdf_negotiation) {
if (attr->kdf[0] != data->kdf) {
wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
"accept the selected KDF");
return 0;
}
for (i = 1; i < attr->kdf_count; i++) {
if (attr->kdf[i] == data->kdf)
break;
}
if (i == attr->kdf_count &&
attr->kdf_count < EAP_AKA_PRIME_KDF_MAX) {
wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
"duplicate the selected KDF");
return 0;
}
/* TODO: should check that the list is identical to the one
* used in the previous Challenge message apart from the added
* entry in the beginning. */
}
for (i = data->kdf ? 1 : 0; i < attr->kdf_count; i++) {
for (j = i + 1; j < attr->kdf_count; j++) {
if (attr->kdf[i] == attr->kdf[j]) {
wpa_printf(MSG_WARNING, "EAP-AKA': The server "
"included a duplicated KDF");
return 0;
}
}
}
return 1;
}
#endif /* EAP_AKA_PRIME */
static struct wpabuf * eap_aka_process_challenge(struct eap_sm *sm,
struct eap_aka_data *data,
u8 id,
const struct wpabuf *reqData,
struct eap_sim_attrs *attr)
{
const u8 *identity;
size_t identity_len;
int res;
struct eap_sim_attrs eattr;
wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Challenge");
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);
}
#ifdef EAP_AKA_PRIME
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
if (!attr->kdf_input || attr->kdf_input_len == 0) {
wpa_printf(MSG_WARNING, "EAP-AKA': Challenge message "
"did not include non-empty AT_KDF_INPUT");
/* Fail authentication as if AUTN had been incorrect */
return eap_aka_authentication_reject(data, id);
}
os_free(data->network_name);
data->network_name = os_malloc(attr->kdf_input_len);
if (data->network_name == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA': No memory for "
"storing Network Name");
return eap_aka_authentication_reject(data, id);
}
os_memcpy(data->network_name, attr->kdf_input,
attr->kdf_input_len);
data->network_name_len = attr->kdf_input_len;
wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': Network Name "
"(AT_KDF_INPUT)",
data->network_name, data->network_name_len);
/* TODO: check Network Name per 3GPP.33.402 */
if (!eap_aka_prime_kdf_valid(data, attr))
return eap_aka_authentication_reject(data, id);
if (attr->kdf[0] != EAP_AKA_PRIME_KDF)
return eap_aka_prime_kdf_neg(data, id, attr);
data->kdf = EAP_AKA_PRIME_KDF;
wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
}
if (data->eap_method == EAP_TYPE_AKA && attr->bidding) {
u16 flags = WPA_GET_BE16(attr->bidding);
if ((flags & EAP_AKA_BIDDING_FLAG_D) &&
eap_allowed_method(sm, EAP_VENDOR_IETF,
EAP_TYPE_AKA_PRIME)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Bidding down from "
"AKA' to AKA detected");
/* Fail authentication as if AUTN had been incorrect */
return eap_aka_authentication_reject(data, id);
}
}
#endif /* EAP_AKA_PRIME */
data->reauth = 0;
if (!attr->mac || !attr->rand || !attr->autn) {
wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
"did not include%s%s%s",
!attr->mac ? " AT_MAC" : "",
!attr->rand ? " AT_RAND" : "",
!attr->autn ? " AT_AUTN" : "");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
os_memcpy(data->rand, attr->rand, EAP_AKA_RAND_LEN);
os_memcpy(data->autn, attr->autn, EAP_AKA_AUTN_LEN);
res = eap_aka_umts_auth(sm, data);
if (res == -1) {
wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
"failed (AUTN)");
return eap_aka_authentication_reject(data, id);
} else if (res == -2) {
wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
"failed (AUTN seq# -> AUTS)");
return eap_aka_synchronization_failure(data, id);
} else if (res) {
wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication failed");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
#ifdef EAP_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 */
u16 amf = WPA_GET_BE16(data->autn + 6);
if (!(amf & 0x8000)) {
wpa_printf(MSG_WARNING, "EAP-AKA': AMF separation bit "
"not set (AMF=0x%4x)", amf);
return eap_aka_authentication_reject(data, id);
}
eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
data->autn,
data->network_name,
data->network_name_len);
}
#endif /* EAP_AKA_PRIME */
if (data->last_eap_identity) {
identity = data->last_eap_identity;
identity_len = data->last_eap_identity_len;
} else if (data->pseudonym) {
identity = data->pseudonym;
identity_len = data->pseudonym_len;
} else
identity = eap_get_config_identity(sm, &identity_len);
wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Selected identity for MK "
"derivation", identity, identity_len);
if (data->eap_method == EAP_TYPE_AKA_PRIME) {
eap_aka_prime_derive_keys(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(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);
}
if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
"used invalid AT_MAC");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
/* Old reauthentication identity must not be used anymore. In
* other words, if no new identities are received, full
* authentication will be used on next reauthentication (using
* pseudonym identity or permanent identity). */
eap_aka_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
if (attr->encr_data) {
u8 *decrypted;
decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
attr->encr_data_len, attr->iv,
&eattr, 0);
if (decrypted == NULL) {
return eap_aka_client_error(
data, id, EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
eap_aka_learn_ids(sm, data, &eattr);
os_free(decrypted);
}
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;
/* RFC 4187 specifies that counter is initialized to one after
* fullauth, but initializing it to zero makes it easier to implement
* reauth verification. */
data->counter = 0;
return eap_aka_response_challenge(data, id);
}
static int eap_aka_process_notification_reauth(struct eap_aka_data *data,
struct eap_sim_attrs *attr)
{
struct eap_sim_attrs eattr;
u8 *decrypted;
if (attr->encr_data == NULL || attr->iv == NULL) {
wpa_printf(MSG_WARNING, "EAP-AKA: Notification message after "
"reauth did not include encrypted data");
return -1;
}
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 notification message");
return -1;
}
if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
wpa_printf(MSG_WARNING, "EAP-AKA: Counter in notification "
"message does not match with counter in reauth "
"message");
os_free(decrypted);
return -1;
}
os_free(decrypted);
return 0;
}
static int eap_aka_process_notification_auth(struct eap_aka_data *data,
const struct wpabuf *reqData,
struct eap_sim_attrs *attr)
{
if (attr->mac == NULL) {
wpa_printf(MSG_INFO, "EAP-AKA: no AT_MAC in after_auth "
"Notification message");
return -1;
}
if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Notification message "
"used invalid AT_MAC");
return -1;
}
if (data->reauth &&
eap_aka_process_notification_reauth(data, attr)) {
wpa_printf(MSG_WARNING, "EAP-AKA: Invalid notification "
"message after reauth");
return -1;
}
return 0;
}
static struct wpabuf * eap_aka_process_notification(
struct eap_sm *sm, struct eap_aka_data *data, u8 id,
const struct wpabuf *reqData, struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Notification");
if (data->num_notification > 0) {
wpa_printf(MSG_INFO, "EAP-AKA: too many notification "
"rounds (only one allowed)");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
data->num_notification++;
if (attr->notification == -1) {
wpa_printf(MSG_INFO, "EAP-AKA: no AT_NOTIFICATION in "
"Notification message");
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
if ((attr->notification & 0x4000) == 0 &&
eap_aka_process_notification_auth(data, reqData, attr)) {
return eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
}
eap_sim_report_notification(sm->msg_ctx, attr->notification, 1);
if (attr->notification >= 0 && attr->notification < 32768) {
eap_aka_state(data, FAILURE);
} else if (attr->notification == EAP_SIM_SUCCESS &&
data->state == RESULT_SUCCESS)
eap_aka_state(data, SUCCESS);
return eap_aka_response_notification(data, id, attr->notification);
}
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);
}
static struct wpabuf * eap_aka_process(struct eap_sm *sm, void *priv,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
struct eap_aka_data *data = priv;
const struct eap_hdr *req;
u8 subtype, id;
struct wpabuf *res;
const u8 *pos;
struct eap_sim_attrs attr;
size_t len;
wpa_hexdump_buf(MSG_DEBUG, "EAP-AKA: EAP data", reqData);
if (eap_get_config_identity(sm, &len) == NULL) {
wpa_printf(MSG_INFO, "EAP-AKA: Identity not configured");
eap_sm_request_identity(sm);
ret->ignore = TRUE;
return NULL;
}
pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, reqData,
&len);
if (pos == NULL || len < 1) {
ret->ignore = TRUE;
return NULL;
}
req = wpabuf_head(reqData);
id = req->identifier;
len = be_to_host16(req->length);
ret->ignore = FALSE;
ret->methodState = METHOD_MAY_CONT;
ret->decision = DECISION_FAIL;
ret->allowNotifications = TRUE;
subtype = *pos++;
wpa_printf(MSG_DEBUG, "EAP-AKA: Subtype=%d", subtype);
pos += 2; /* Reserved */
if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr,
data->eap_method == EAP_TYPE_AKA_PRIME ? 2 : 1,
0)) {
res = eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
goto done;
}
switch (subtype) {
case EAP_AKA_SUBTYPE_IDENTITY:
res = eap_aka_process_identity(sm, data, id, reqData, &attr);
break;
case EAP_AKA_SUBTYPE_CHALLENGE:
res = eap_aka_process_challenge(sm, data, id, reqData, &attr);
break;
case EAP_AKA_SUBTYPE_NOTIFICATION:
res = eap_aka_process_notification(sm, data, id, reqData,
&attr);
break;
case EAP_AKA_SUBTYPE_REAUTHENTICATION:
res = eap_aka_process_reauthentication(sm, data, id, reqData,
&attr);
break;
case EAP_AKA_SUBTYPE_CLIENT_ERROR:
wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Client-Error");
res = eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
break;
default:
wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown subtype=%d", subtype);
res = eap_aka_client_error(data, id,
EAP_AKA_UNABLE_TO_PROCESS_PACKET);
break;
}
done:
if (data->state == FAILURE) {
ret->decision = DECISION_FAIL;
ret->methodState = METHOD_DONE;
} else if (data->state == SUCCESS) {
ret->decision = data->use_result_ind ?
DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
/*
* It is possible for the server to reply with AKA
* Notification, so we must allow the method to continue and
* not only accept EAP-Success at this point.
*/
ret->methodState = data->use_result_ind ?
METHOD_DONE : METHOD_MAY_CONT;
} else if (data->state == RESULT_FAILURE)
ret->methodState = METHOD_CONT;
else if (data->state == RESULT_SUCCESS)
ret->methodState = METHOD_CONT;
if (ret->methodState == METHOD_DONE) {
ret->allowNotifications = FALSE;
}
return res;
}
static Boolean eap_aka_has_reauth_data(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
return data->pseudonym || data->reauth_id;
}
static void eap_aka_deinit_for_reauth(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
eap_aka_clear_identities(data, CLEAR_EAP_ID);
data->prev_id = -1;
wpabuf_free(data->id_msgs);
data->id_msgs = NULL;
data->use_result_ind = 0;
data->kdf_negotiation = 0;
}
static void * eap_aka_init_for_reauth(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
data->num_id_req = 0;
data->num_notification = 0;
eap_aka_state(data, CONTINUE);
return priv;
}
static const u8 * eap_aka_get_identity(struct eap_sm *sm, void *priv,
size_t *len)
{
struct eap_aka_data *data = priv;
if (data->reauth_id) {
*len = data->reauth_id_len;
return data->reauth_id;
}
if (data->pseudonym) {
*len = data->pseudonym_len;
return data->pseudonym;
}
return NULL;
}
static Boolean eap_aka_isKeyAvailable(struct eap_sm *sm, void *priv)
{
struct eap_aka_data *data = priv;
return data->state == SUCCESS;
}
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;
*len = EAP_SIM_KEYING_DATA_LEN;
os_memcpy(key, data->msk, 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;
*len = EAP_EMSK_LEN;
os_memcpy(key, data->emsk, EAP_EMSK_LEN);
return key;
}
int eap_peer_aka_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
if (eap == NULL)
return -1;
eap->init = eap_aka_init;
eap->deinit = eap_aka_deinit;
eap->process = eap_aka_process;
eap->isKeyAvailable = eap_aka_isKeyAvailable;
eap->getKey = eap_aka_getKey;
eap->has_reauth_data = eap_aka_has_reauth_data;
eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
eap->init_for_reauth = eap_aka_init_for_reauth;
eap->get_identity = eap_aka_get_identity;
eap->get_emsk = eap_aka_get_emsk;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}
#ifdef EAP_AKA_PRIME
int eap_peer_aka_prime_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
"AKA'");
if (eap == NULL)
return -1;
eap->init = eap_aka_prime_init;
eap->deinit = eap_aka_deinit;
eap->process = eap_aka_process;
eap->isKeyAvailable = eap_aka_isKeyAvailable;
eap->getKey = eap_aka_getKey;
eap->has_reauth_data = eap_aka_has_reauth_data;
eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
eap->init_for_reauth = eap_aka_init_for_reauth;
eap->get_identity = eap_aka_get_identity;
eap->get_emsk = eap_aka_get_emsk;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}
#endif /* EAP_AKA_PRIME */