hostap/src/eap_server/eap_server_tls.c

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/*
* hostapd / EAP-TLS (RFC 2716)
* 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 "eap_i.h"
#include "eap_tls_common.h"
#include "crypto/tls.h"
static void eap_tls_reset(struct eap_sm *sm, void *priv);
struct eap_tls_data {
struct eap_ssl_data ssl;
enum { START, CONTINUE, SUCCESS, FAILURE } state;
int established;
u8 eap_type;
};
static const char * eap_tls_state_txt(int state)
{
switch (state) {
case START:
return "START";
case CONTINUE:
return "CONTINUE";
case SUCCESS:
return "SUCCESS";
case FAILURE:
return "FAILURE";
default:
return "Unknown?!";
}
}
static void eap_tls_state(struct eap_tls_data *data, int state)
{
wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
eap_tls_state_txt(data->state),
eap_tls_state_txt(state));
data->state = state;
}
static void * eap_tls_init(struct eap_sm *sm)
{
struct eap_tls_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = START;
if (eap_server_tls_ssl_init(sm, &data->ssl, 1)) {
wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
eap_tls_reset(sm, data);
return NULL;
}
data->eap_type = EAP_TYPE_TLS;
return data;
}
#ifdef EAP_SERVER_UNAUTH_TLS
static void * eap_unauth_tls_init(struct eap_sm *sm)
{
struct eap_tls_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = START;
if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
eap_tls_reset(sm, data);
return NULL;
}
data->eap_type = EAP_UNAUTH_TLS_TYPE;
return data;
}
#endif /* EAP_SERVER_UNAUTH_TLS */
static void eap_tls_reset(struct eap_sm *sm, void *priv)
{
struct eap_tls_data *data = priv;
if (data == NULL)
return;
eap_server_tls_ssl_deinit(sm, &data->ssl);
os_free(data);
}
static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
struct eap_tls_data *data, u8 id)
{
struct wpabuf *req;
req = eap_tls_msg_alloc(data->eap_type, 1, EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
"request");
eap_tls_state(data, FAILURE);
return NULL;
}
wpabuf_put_u8(req, EAP_TLS_FLAGS_START);
eap_tls_state(data, CONTINUE);
return req;
}
static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
struct eap_tls_data *data = priv;
struct wpabuf *res;
if (data->ssl.state == FRAG_ACK) {
return eap_server_tls_build_ack(id, data->eap_type, 0);
}
if (data->ssl.state == WAIT_FRAG_ACK) {
res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0,
id);
goto check_established;
}
switch (data->state) {
case START:
return eap_tls_build_start(sm, data, id);
case CONTINUE:
if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
data->established = 1;
break;
default:
wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
__func__, data->state);
return NULL;
}
res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0, id);
check_established:
if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
/* TLS handshake has been completed and there are no more
* fragments waiting to be sent out. */
wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
eap_tls_state(data, SUCCESS);
}
return res;
}
static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_tls_data *data = priv;
const u8 *pos;
size_t len;
if (data->eap_type == EAP_UNAUTH_TLS_TYPE)
pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
&len);
else
pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_type,
respData, &len);
if (pos == NULL || len < 1) {
wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
return TRUE;
}
return FALSE;
}
static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
const struct wpabuf *respData)
{
struct eap_tls_data *data = priv;
if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
"handshake message");
return;
}
if (eap_server_tls_phase1(sm, &data->ssl) < 0)
eap_tls_state(data, FAILURE);
}
static void eap_tls_process(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_tls_data *data = priv;
if (eap_server_tls_process(sm, &data->ssl, respData, data,
data->eap_type, NULL, eap_tls_process_msg) <
0)
eap_tls_state(data, FAILURE);
}
static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
{
struct eap_tls_data *data = priv;
return data->state == SUCCESS || data->state == FAILURE;
}
static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_tls_data *data = priv;
u8 *eapKeyData;
if (data->state != SUCCESS)
return NULL;
eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
"client EAP encryption",
EAP_TLS_KEY_LEN);
if (eapKeyData) {
*len = EAP_TLS_KEY_LEN;
wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
eapKeyData, EAP_TLS_KEY_LEN);
} else {
wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
}
return eapKeyData;
}
static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_tls_data *data = priv;
u8 *eapKeyData, *emsk;
if (data->state != SUCCESS)
return NULL;
eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
"client EAP encryption",
EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
if (eapKeyData) {
emsk = os_malloc(EAP_EMSK_LEN);
if (emsk)
os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
EAP_EMSK_LEN);
os_free(eapKeyData);
} else
emsk = NULL;
if (emsk) {
*len = EAP_EMSK_LEN;
wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
emsk, EAP_EMSK_LEN);
} else {
wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
}
return emsk;
}
static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
{
struct eap_tls_data *data = priv;
return data->state == SUCCESS;
}
int eap_server_tls_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
if (eap == NULL)
return -1;
eap->init = eap_tls_init;
eap->reset = eap_tls_reset;
eap->buildReq = eap_tls_buildReq;
eap->check = eap_tls_check;
eap->process = eap_tls_process;
eap->isDone = eap_tls_isDone;
eap->getKey = eap_tls_getKey;
eap->isSuccess = eap_tls_isSuccess;
eap->get_emsk = eap_tls_get_emsk;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}
#ifdef EAP_SERVER_UNAUTH_TLS
int eap_server_unauth_tls_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_UNAUTH_TLS,
EAP_VENDOR_TYPE_UNAUTH_TLS,
"UNAUTH-TLS");
if (eap == NULL)
return -1;
eap->init = eap_unauth_tls_init;
eap->reset = eap_tls_reset;
eap->buildReq = eap_tls_buildReq;
eap->check = eap_tls_check;
eap->process = eap_tls_process;
eap->isDone = eap_tls_isDone;
eap->getKey = eap_tls_getKey;
eap->isSuccess = eap_tls_isSuccess;
eap->get_emsk = eap_tls_get_emsk;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}
#endif /* EAP_SERVER_UNAUTH_TLS */