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hostap/src/eap_peer/eap_sim.c
Jouni Malinen e026159a8e EAP-SIM/AKA: Store pseudonym identity in configuration 
Use the anonymous_identity field to store EAP-SIM/AKA pseudonym identity
so that this can be maintained between EAP sessions (e.g., after
wpa_supplicant restart) even if fast re-authentication data was cleared.

Signed-hostap: Jouni Malinen <j@w1.fi>
2012-09-02 13:04:18 +03:00

1131 lines
31 KiB
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/*
* EAP peer method: EAP-SIM (RFC 4186)
* Copyright (c) 2004-2012, 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 "pcsc_funcs.h"
#include "crypto/milenage.h"
#include "crypto/random.h"
#include "eap_peer/eap_i.h"
#include "eap_config.h"
#include "eap_common/eap_sim_common.h"
struct eap_sim_data {
u8 *ver_list;
size_t ver_list_len;
int selected_version;
size_t min_num_chal, num_chal;
u8 kc[3][EAP_SIM_KC_LEN];
u8 sres[3][EAP_SIM_SRES_LEN];
u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
u8 mk[EAP_SIM_MK_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 rand[3][GSM_RAND_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;
int result_ind, use_result_ind;
};
#ifndef CONFIG_NO_STDOUT_DEBUG
static const char * eap_sim_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_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;
struct eap_peer_config *config = eap_get_config(sm);
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
"for NONCE_MT");
os_free(data);
return NULL;
}
data->min_num_chal = 2;
if (config && config->phase1) {
char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
if (pos) {
data->min_num_chal = atoi(pos + 17);
if (data->min_num_chal < 2 || data->min_num_chal > 3) {
wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
"sim_min_num_chal configuration "
"(%lu, expected 2 or 3)",
(unsigned long) data->min_num_chal);
os_free(data);
return NULL;
}
wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
"challenges to %lu",
(unsigned long) data->min_num_chal);
}
data->result_ind = os_strstr(config->phase1, "result_ind=1") !=
NULL;
}
if (config && config->anonymous_identity) {
data->pseudonym = os_malloc(config->anonymous_identity_len);
if (data->pseudonym) {
os_memcpy(data->pseudonym, config->anonymous_identity,
config->anonymous_identity_len);
data->pseudonym_len = config->anonymous_identity_len;
}
}
eap_sim_state(data, CONTINUE);
return data;
}
static void eap_sim_deinit(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
if (data) {
os_free(data->ver_list);
os_free(data->pseudonym);
os_free(data->reauth_id);
os_free(data->last_eap_identity);
os_free(data);
}
}
static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
{
struct eap_peer_config *conf;
wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
conf = eap_get_config(sm);
if (conf == NULL)
return -1;
if (conf->pcsc) {
if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
data->sres[0], data->kc[0]) ||
scard_gsm_auth(sm->scard_ctx, data->rand[1],
data->sres[1], data->kc[1]) ||
(data->num_chal > 2 &&
scard_gsm_auth(sm->scard_ctx, data->rand[2],
data->sres[2], data->kc[2]))) {
wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM "
"authentication could not be completed");
return -1;
}
return 0;
}
#ifdef CONFIG_SIM_SIMULATOR
if (conf->password) {
u8 opc[16], k[16];
const char *pos;
size_t i;
wpa_printf(MSG_DEBUG, "EAP-SIM: Use internal GSM-Milenage "
"implementation for authentication");
if (conf->password_len < 65) {
wpa_printf(MSG_DEBUG, "EAP-SIM: invalid GSM-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;
for (i = 0; i < data->num_chal; i++) {
if (gsm_milenage(opc, k, data->rand[i],
data->sres[i], data->kc[i])) {
wpa_printf(MSG_DEBUG, "EAP-SIM: "
"GSM-Milenage authentication "
"could not be completed");
return -1;
}
wpa_hexdump(MSG_DEBUG, "EAP-SIM: RAND",
data->rand[i], GSM_RAND_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: SRES",
data->sres[i], EAP_SIM_SRES_LEN);
wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: Kc",
data->kc[i], EAP_SIM_KC_LEN);
}
return 0;
}
#endif /* CONFIG_SIM_SIMULATOR */
#ifdef CONFIG_SIM_HARDCODED
/* These hardcoded Kc and SRES values are used for testing. RAND to
* KC/SREC mapping is very bogus as far as real authentication is
* concerned, but it is quite useful for cases where the AS is rotating
* the order of pre-configured values. */
{
size_t i;
wpa_printf(MSG_DEBUG, "EAP-SIM: Use hardcoded Kc and SRES "
"values for testing");
for (i = 0; i < data->num_chal; i++) {
if (data->rand[i][0] == 0xaa) {
os_memcpy(data->kc[i],
"\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
EAP_SIM_KC_LEN);
os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
EAP_SIM_SRES_LEN);
} else if (data->rand[i][0] == 0xbb) {
os_memcpy(data->kc[i],
"\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
EAP_SIM_KC_LEN);
os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
EAP_SIM_SRES_LEN);
} else {
os_memcpy(data->kc[i],
"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
EAP_SIM_KC_LEN);
os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
EAP_SIM_SRES_LEN);
}
}
}
return 0;
#else /* CONFIG_SIM_HARDCODED */
wpa_printf(MSG_DEBUG, "EAP-SIM: No GSM authentication algorithm "
"enabled");
return -1;
#endif /* CONFIG_SIM_HARDCODED */
}
static int eap_sim_supported_ver(int version)
{
return version == EAP_SIM_VERSION;
}
#define CLEAR_PSEUDONYM 0x01
#define CLEAR_REAUTH_ID 0x02
#define CLEAR_EAP_ID 0x04
static void eap_sim_clear_identities(struct eap_sm *sm,
struct eap_sim_data *data, int id)
{
if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old pseudonym");
os_free(data->pseudonym);
data->pseudonym = NULL;
data->pseudonym_len = 0;
eap_set_anon_id(sm, NULL, 0);
}
if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old reauth_id");
os_free(data->reauth_id);
data->reauth_id = NULL;
data->reauth_id_len = 0;
}
if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old eap_id");
os_free(data->last_eap_identity);
data->last_eap_identity = NULL;
data->last_eap_identity_len = 0;
}
}
static int eap_sim_learn_ids(struct eap_sm *sm, struct eap_sim_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-SIM: (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-SIM: (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;
eap_set_anon_id(sm, data->pseudonym, data->pseudonym_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-SIM: (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-SIM: (encr) AT_NEXT_REAUTH_ID",
data->reauth_id,
data->reauth_id_len);
}
return 0;
}
static struct wpabuf * eap_sim_client_error(struct eap_sim_data *data, u8 id,
int err)
{
struct eap_sim_msg *msg;
eap_sim_state(data, FAILURE);
data->num_id_req = 0;
data->num_notification = 0;
wpa_printf(MSG_DEBUG, "EAP-SIM: Send Client-Error (error code %d)",
err);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
EAP_SIM_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_sim_response_start(struct eap_sm *sm,
struct eap_sim_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_sim_clear_identities(sm, data, CLEAR_REAUTH_ID);
} else if (id_req != NO_ID_REQ) {
identity = eap_get_config_identity(sm, &identity_len);
if (identity) {
eap_sim_clear_identities(sm, data, CLEAR_PSEUDONYM |
CLEAR_REAUTH_ID);
}
}
if (id_req != NO_ID_REQ)
eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
if (!data->reauth) {
wpa_hexdump(MSG_DEBUG, " AT_NONCE_MT",
data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
wpa_printf(MSG_DEBUG, " AT_SELECTED_VERSION %d",
data->selected_version);
eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
data->selected_version, NULL, 0);
}
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_sim_response_challenge(struct eap_sim_data *data,
u8 id)
{
struct eap_sim_msg *msg;
wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
EAP_SIM_SUBTYPE_CHALLENGE);
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 *) data->sres,
data->num_chal * EAP_SIM_SRES_LEN);
}
static struct wpabuf * eap_sim_response_reauth(struct eap_sim_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-SIM Reauthentication (id=%d)",
id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
EAP_SIM_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-SIM: Failed to encrypt "
"AT_ENCR_DATA");
eap_sim_msg_free(msg);
return NULL;
}
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_sim_response_notification(struct eap_sim_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-SIM Notification (id=%d)", id);
msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
EAP_TYPE_SIM, EAP_SIM_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-SIM: 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_sim_process_start(struct eap_sm *sm,
struct eap_sim_data *data, u8 id,
struct eap_sim_attrs *attr)
{
int selected_version = -1, id_error;
size_t i;
u8 *pos;
wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
if (attr->version_list == NULL) {
wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
"SIM/Start");
return eap_sim_client_error(data, id,
EAP_SIM_UNSUPPORTED_VERSION);
}
os_free(data->ver_list);
data->ver_list = os_malloc(attr->version_list_len);
if (data->ver_list == NULL) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
"memory for version list");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
data->ver_list_len = attr->version_list_len;
pos = data->ver_list;
for (i = 0; i < data->ver_list_len / 2; i++) {
int ver = pos[0] * 256 + pos[1];
pos += 2;
if (eap_sim_supported_ver(ver)) {
selected_version = ver;
break;
}
}
if (selected_version < 0) {
wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
"version");
return eap_sim_client_error(data, id,
EAP_SIM_UNSUPPORTED_VERSION);
}
wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
selected_version);
data->selected_version = selected_version;
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-SIM: Too many ID requests "
"used within one authentication");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
return eap_sim_response_start(sm, data, id, attr->id_req);
}
static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
struct eap_sim_data *data,
u8 id,
const struct wpabuf *reqData,
struct eap_sim_attrs *attr)
{
const u8 *identity;
size_t identity_len;
struct eap_sim_attrs eattr;
wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
data->reauth = 0;
if (!attr->mac || !attr->rand) {
wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
"did not include%s%s",
!attr->mac ? " AT_MAC" : "",
!attr->rand ? " AT_RAND" : "");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
(unsigned long) attr->num_chal);
if (attr->num_chal < data->min_num_chal) {
wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
"challenges (%lu)", (unsigned long) attr->num_chal);
return eap_sim_client_error(data, id,
EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
}
if (attr->num_chal > 3) {
wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
"(%lu)", (unsigned long) attr->num_chal);
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
/* Verify that RANDs are different */
if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
GSM_RAND_LEN) == 0 ||
(attr->num_chal > 2 &&
(os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
GSM_RAND_LEN) == 0 ||
os_memcmp(attr->rand + GSM_RAND_LEN,
attr->rand + 2 * GSM_RAND_LEN,
GSM_RAND_LEN) == 0))) {
wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
return eap_sim_client_error(data, id,
EAP_SIM_RAND_NOT_FRESH);
}
os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
data->num_chal = attr->num_chal;
if (eap_sim_gsm_auth(sm, data)) {
wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
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-SIM: Selected identity for MK "
"derivation", identity, identity_len);
eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
data->selected_version, data->ver_list,
data->ver_list_len, data->num_chal,
(const u8 *) data->kc, data->mk);
eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
data->emsk);
if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
EAP_SIM_NONCE_MT_LEN)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
"used invalid AT_MAC");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
/* Old reauthentication identity must not be used anymore. In
* other words, if no new reauth identity is received, full
* authentication will be used on next reauthentication (using
* pseudonym identity or permanent identity). */
eap_sim_clear_identities(sm, 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_sim_client_error(
data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
eap_sim_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_sim_state(data, data->use_result_ind ?
RESULT_SUCCESS : SUCCESS);
}
data->num_id_req = 0;
data->num_notification = 0;
/* RFC 4186 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_sim_response_challenge(data, id);
}
static int eap_sim_process_notification_reauth(struct eap_sim_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-SIM: 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-SIM: 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-SIM: 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_sim_process_notification_auth(struct eap_sim_data *data,
const struct wpabuf *reqData,
struct eap_sim_attrs *attr)
{
if (attr->mac == NULL) {
wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
"Notification message");
return -1;
}
if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
{
wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
"used invalid AT_MAC");
return -1;
}
if (data->reauth &&
eap_sim_process_notification_reauth(data, attr)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
"message after reauth");
return -1;
}
return 0;
}
static struct wpabuf * eap_sim_process_notification(
struct eap_sm *sm, struct eap_sim_data *data, u8 id,
const struct wpabuf *reqData, struct eap_sim_attrs *attr)
{
wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
if (data->num_notification > 0) {
wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
"rounds (only one allowed)");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
data->num_notification++;
if (attr->notification == -1) {
wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
"Notification message");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
if ((attr->notification & 0x4000) == 0 &&
eap_sim_process_notification_auth(data, reqData, attr)) {
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
if (attr->notification >= 0 && attr->notification < 32768) {
eap_sim_state(data, FAILURE);
} else if (attr->notification == EAP_SIM_SUCCESS &&
data->state == RESULT_SUCCESS)
eap_sim_state(data, SUCCESS);
return eap_sim_response_notification(data, id, attr->notification);
}
static struct wpabuf * eap_sim_process_reauthentication(
struct eap_sm *sm, struct eap_sim_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-SIM: subtype Reauthentication");
if (data->reauth_id == NULL) {
wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
"reauthentication, but no reauth_id available");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
data->reauth = 1;
if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
{
wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
"did not have valid AT_MAC");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
if (attr->encr_data == NULL || attr->iv == NULL) {
wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
"message did not include encrypted data");
return eap_sim_client_error(data, id,
EAP_SIM_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-SIM: Failed to parse encrypted "
"data from reauthentication message");
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
if (eattr.nonce_s == NULL || eattr.counter < 0) {
wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
!eattr.nonce_s ? " AT_NONCE_S" : "",
eattr.counter < 0 ? " AT_COUNTER" : "");
os_free(decrypted);
return eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
wpa_printf(MSG_INFO, "EAP-SIM: (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;
os_free(decrypted);
return eap_sim_response_reauth(data, id, 1, eattr.nonce_s);
}
data->counter = eattr.counter;
os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
data->nonce_s, EAP_SIM_NONCE_S_LEN);
eap_sim_derive_keys_reauth(data->counter,
data->reauth_id, data->reauth_id_len,
data->nonce_s, data->mk, data->msk,
data->emsk);
eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
eap_sim_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_sim_state(data, data->use_result_ind ?
RESULT_SUCCESS : SUCCESS);
}
data->num_id_req = 0;
data->num_notification = 0;
if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
"fast reauths performed - force fullauth");
eap_sim_clear_identities(sm, data,
CLEAR_REAUTH_ID | CLEAR_EAP_ID);
}
os_free(decrypted);
return eap_sim_response_reauth(data, id, 0, data->nonce_s);
}
static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
struct eap_sim_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-SIM: EAP data", reqData);
if (eap_get_config_identity(sm, &len) == NULL) {
wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
eap_sm_request_identity(sm);
ret->ignore = TRUE;
return NULL;
}
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, 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-SIM: Subtype=%d", subtype);
pos += 2; /* Reserved */
if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
0)) {
res = eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
goto done;
}
switch (subtype) {
case EAP_SIM_SUBTYPE_START:
res = eap_sim_process_start(sm, data, id, &attr);
break;
case EAP_SIM_SUBTYPE_CHALLENGE:
res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
break;
case EAP_SIM_SUBTYPE_NOTIFICATION:
res = eap_sim_process_notification(sm, data, id, reqData,
&attr);
break;
case EAP_SIM_SUBTYPE_REAUTHENTICATION:
res = eap_sim_process_reauthentication(sm, data, id, reqData,
&attr);
break;
case EAP_SIM_SUBTYPE_CLIENT_ERROR:
wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
res = eap_sim_client_error(data, id,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
break;
default:
wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
res = eap_sim_client_error(data, id,
EAP_SIM_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;
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_sim_has_reauth_data(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
return data->pseudonym || data->reauth_id;
}
static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
data->use_result_ind = 0;
}
static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
"for NONCE_MT");
os_free(data);
return NULL;
}
data->num_id_req = 0;
data->num_notification = 0;
eap_sim_state(data, CONTINUE);
return priv;
}
static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
size_t *len)
{
struct eap_sim_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_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
{
struct eap_sim_data *data = priv;
return data->state == SUCCESS;
}
static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_sim_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_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_sim_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_sim_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
if (eap == NULL)
return -1;
eap->init = eap_sim_init;
eap->deinit = eap_sim_deinit;
eap->process = eap_sim_process;
eap->isKeyAvailable = eap_sim_isKeyAvailable;
eap->getKey = eap_sim_getKey;
eap->has_reauth_data = eap_sim_has_reauth_data;
eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
eap->init_for_reauth = eap_sim_init_for_reauth;
eap->get_identity = eap_sim_get_identity;
eap->get_emsk = eap_sim_get_emsk;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}
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