static u8 * eap_sim_process_challenge(struct eap_sm *sm,
struct eap_sim_data *data,
struct eap_hdr *req, size_t reqDataLen,
size_t *respDataLen,
struct eap_sim_attrs *attr)
{
struct wpa_ssid *config = eap_get_config(sm);
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(sm, data, req, respDataLen,
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(sm, data, req, respDataLen,
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(sm, data, req, respDataLen,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
/* Verify that RANDs are different */
if (memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
GSM_RAND_LEN) == 0 ||
(attr->num_chal > 2 &&
(memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
GSM_RAND_LEN) == 0 ||
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(sm, data, req, respDataLen,
EAP_SIM_RAND_NOT_FRESH);
}
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(sm, data, req, respDataLen,
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 = config->identity;
identity_len = config->identity_len;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
"derivation", identity, identity_len);
eap_sim_derive_mk(data, identity, identity_len);
eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk);
if (eap_sim_verify_mac(data->k_aut, (u8 *) req, reqDataLen, 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(sm, data, req, respDataLen,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
/* Old reauthentication and pseudonym identities must not be used
* anymore. In other words, if no new identities are received, full
* authentication will be used on next reauthentication. */
eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
CLEAR_EAP_ID);
if (attr->encr_data) {
if (eap_sim_parse_encr(data->k_encr, attr->encr_data,
attr->encr_data_len, attr->iv, &eattr,
0)) {
return eap_sim_client_error(
sm, data, req, respDataLen,
EAP_SIM_UNABLE_TO_PROCESS_PACKET);
}
eap_sim_learn_ids(data, &eattr);
}
if (data->state != FAILURE)
data->state = SUCCESS;
data->num_id_req = 0;
data->num_notification = 0;
/* draft-haverinen-pppext-eap-sim-13.txt 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(sm, data, req, respDataLen);
}
static void eap_sim_process_start(struct eap_sm *sm,
struct eap_sim_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
const u8 *identity;
size_t identity_len;
u8 ver_list[2];
wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
if (attr->identity) {
os_free(sm->identity);
sm->identity = os_malloc(attr->identity_len);
if (sm->identity) {
os_memcpy(sm->identity, attr->identity,
attr->identity_len);
sm->identity_len = attr->identity_len;
}
}
identity = NULL;
identity_len = 0;
if (sm->identity && sm->identity_len > 0 &&
sm->identity[0] == EAP_SIM_PERMANENT_PREFIX) {
identity = sm->identity;
identity_len = sm->identity_len;
} else {
identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv,
sm->identity,
sm->identity_len,
&identity_len);
if (identity == NULL) {
data->reauth = eap_sim_db_get_reauth_entry(
sm->eap_sim_db_priv, sm->identity,
sm->identity_len);
if (data->reauth) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast "
"re-authentication");
identity = data->reauth->identity;
identity_len = data->reauth->identity_len;
data->counter = data->reauth->counter;
os_memcpy(data->mk, data->reauth->mk,
EAP_SIM_MK_LEN);
}
}
}
if (identity == NULL) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Could not get proper permanent"
" user name");
eap_sim_state(data, FAILURE);
return;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
identity, identity_len);
if (data->reauth) {
eap_sim_state(data, REAUTH);
return;
}
if (attr->nonce_mt == NULL || attr->selected_version < 0) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
"required attributes");
eap_sim_state(data, FAILURE);
return;
}
if (!eap_sim_supported_ver(data, attr->selected_version)) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
"version %d", attr->selected_version);
eap_sim_state(data, FAILURE);
return;
}
data->counter = 0; /* reset re-auth counter since this is full auth */
data->reauth = NULL;
data->num_chal = eap_sim_db_get_gsm_triplets(
sm->eap_sim_db_priv, identity, identity_len,
EAP_SIM_MAX_CHAL,
(u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
if (data->num_chal == EAP_SIM_DB_PENDING) {
wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
"not yet available - pending request");
sm->method_pending = METHOD_PENDING_WAIT;
return;
}
if (data->num_chal < 2) {
wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
"authentication triplets for the peer");
eap_sim_state(data, FAILURE);
return;
}
identity_len = sm->identity_len;
while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
"character from identity");
identity_len--;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
sm->identity, identity_len);
os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
attr->selected_version, ver_list, sizeof(ver_list),
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);
eap_sim_state(data, CHALLENGE);
}
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(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 void eap_sim_process_start(struct eap_sm *sm,
struct eap_sim_data *data,
struct wpabuf *respData,
struct eap_sim_attrs *attr)
{
size_t identity_len;
u8 ver_list[2];
u8 *new_identity;
char *username;
wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
if (data->start_round == 0) {
/*
* Special case for AT_COUNTER_TOO_SMALL recovery - no identity
* was requested since we already know it.
*/
goto skip_id_update;
}
/*
* We always request identity in SIM/Start, so the peer is required to
* have replied with one.
*/
if (!attr->identity || attr->identity_len == 0) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Peer did not provide any "
"identity");
goto failed;
}
new_identity = os_malloc(attr->identity_len);
if (new_identity == NULL)
goto failed;
os_free(sm->identity);
sm->identity = new_identity;
os_memcpy(sm->identity, attr->identity, attr->identity_len);
sm->identity_len = attr->identity_len;
wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
sm->identity, sm->identity_len);
username = sim_get_username(sm->identity, sm->identity_len);
if (username == NULL)
goto failed;
if (username[0] == EAP_SIM_REAUTH_ID_PREFIX) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Reauth username '%s'",
username);
data->reauth = eap_sim_db_get_reauth_entry(
sm->eap_sim_db_priv, username);
os_free(username);
if (data->reauth == NULL) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown reauth "
"identity - request full auth identity");
/* Remain in START state for another round */
return;
}
wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast re-authentication");
os_strlcpy(data->permanent, data->reauth->permanent,
sizeof(data->permanent));
data->counter = data->reauth->counter;
os_memcpy(data->mk, data->reauth->mk, EAP_SIM_MK_LEN);
eap_sim_state(data, REAUTH);
return;
}
if (username[0] == EAP_SIM_PSEUDONYM_PREFIX) {
const char *permanent;
wpa_printf(MSG_DEBUG, "EAP-SIM: 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-SIM: Unknown pseudonym "
"identity - request permanent identity");
/* Remain in START state for another round */
return;
}
os_strlcpy(data->permanent, permanent,
sizeof(data->permanent));
} else if (username[0] == EAP_SIM_PERMANENT_PREFIX) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Permanent username '%s'",
username);
os_strlcpy(data->permanent, username, sizeof(data->permanent));
os_free(username);
} else {
wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized username '%s'",
username);
os_free(username);
goto failed;
}
skip_id_update:
/* Full authentication */
if (attr->nonce_mt == NULL || attr->selected_version < 0) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
"required attributes");
goto failed;
}
if (!eap_sim_supported_ver(data, attr->selected_version)) {
wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
"version %d", attr->selected_version);
goto failed;
}
data->counter = 0; /* reset re-auth counter since this is full auth */
data->reauth = NULL;
data->num_chal = eap_sim_db_get_gsm_triplets(
sm->eap_sim_db_priv, data->permanent, EAP_SIM_MAX_CHAL,
(u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
if (data->num_chal == EAP_SIM_DB_PENDING) {
wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
"not yet available - pending request");
sm->method_pending = METHOD_PENDING_WAIT;
return;
}
if (data->num_chal < 2) {
wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
"authentication triplets for the peer");
goto failed;
}
identity_len = sm->identity_len;
while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
"character from identity");
identity_len--;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
sm->identity, identity_len);
os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
attr->selected_version, ver_list, sizeof(ver_list),
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);
eap_sim_state(data, CHALLENGE);
return;
failed:
data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
eap_sim_state(data, NOTIFICATION);
}