hostap/src/eap_server/eap_server_gtc.c
Jouni Malinen 3e4b77c9bd EAP-GTC: Use os_memcmp_const() for hash/password comparisons
This makes the implementation less likely to provide useful timing
information to potential attackers from comparisons of information
received from a remote device and private material known only by the
authorized devices.

Signed-off-by: Jouni Malinen <j@w1.fi>
2014-07-02 12:38:48 +03:00

224 lines
5 KiB
C

/*
* hostapd / EAP-GTC (RFC 3748)
* Copyright (c) 2004-2006, 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"
struct eap_gtc_data {
enum { CONTINUE, SUCCESS, FAILURE } state;
int prefix;
};
static void * eap_gtc_init(struct eap_sm *sm)
{
struct eap_gtc_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = CONTINUE;
#ifdef EAP_SERVER_FAST
if (sm->m && sm->m->vendor == EAP_VENDOR_IETF &&
sm->m->method == EAP_TYPE_FAST) {
wpa_printf(MSG_DEBUG, "EAP-GTC: EAP-FAST tunnel - use prefix "
"with challenge/response");
data->prefix = 1;
}
#endif /* EAP_SERVER_FAST */
return data;
}
static void eap_gtc_reset(struct eap_sm *sm, void *priv)
{
struct eap_gtc_data *data = priv;
os_free(data);
}
static struct wpabuf * eap_gtc_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
struct eap_gtc_data *data = priv;
struct wpabuf *req;
char *msg;
size_t msg_len;
msg = data->prefix ? "CHALLENGE=Password" : "Password";
msg_len = os_strlen(msg);
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GTC, msg_len,
EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-GTC: Failed to allocate memory for "
"request");
data->state = FAILURE;
return NULL;
}
wpabuf_put_data(req, msg, msg_len);
data->state = CONTINUE;
return req;
}
static Boolean eap_gtc_check(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
const u8 *pos;
size_t len;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GTC, respData, &len);
if (pos == NULL || len < 1) {
wpa_printf(MSG_INFO, "EAP-GTC: Invalid frame");
return TRUE;
}
return FALSE;
}
static void eap_gtc_process(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_gtc_data *data = priv;
const u8 *pos;
size_t rlen;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GTC, respData, &rlen);
if (pos == NULL || rlen < 1)
return; /* Should not happen - frame already validated */
wpa_hexdump_ascii_key(MSG_MSGDUMP, "EAP-GTC: Response", pos, rlen);
#ifdef EAP_SERVER_FAST
if (data->prefix) {
const u8 *pos2, *end;
/* "RESPONSE=<user>\0<password>" */
if (rlen < 10) {
wpa_printf(MSG_DEBUG, "EAP-GTC: Too short response "
"for EAP-FAST prefix");
data->state = FAILURE;
return;
}
end = pos + rlen;
pos += 9;
pos2 = pos;
while (pos2 < end && *pos2)
pos2++;
if (pos2 == end) {
wpa_printf(MSG_DEBUG, "EAP-GTC: No password in "
"response to EAP-FAST prefix");
data->state = FAILURE;
return;
}
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-GTC: Response user",
pos, pos2 - pos);
if (sm->identity && sm->require_identity_match &&
(pos2 - pos != (int) sm->identity_len ||
os_memcmp(pos, sm->identity, sm->identity_len))) {
wpa_printf(MSG_DEBUG, "EAP-GTC: Phase 2 Identity did "
"not match with required Identity");
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-GTC: Expected "
"identity",
sm->identity, sm->identity_len);
data->state = FAILURE;
return;
} else {
os_free(sm->identity);
sm->identity_len = pos2 - pos;
sm->identity = os_malloc(sm->identity_len);
if (sm->identity == NULL) {
data->state = FAILURE;
return;
}
os_memcpy(sm->identity, pos, sm->identity_len);
}
if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
wpa_hexdump_ascii(MSG_DEBUG, "EAP-GTC: Phase2 "
"Identity not found in the user "
"database",
sm->identity, sm->identity_len);
data->state = FAILURE;
return;
}
pos = pos2 + 1;
rlen = end - pos;
wpa_hexdump_ascii_key(MSG_MSGDUMP,
"EAP-GTC: Response password",
pos, rlen);
}
#endif /* EAP_SERVER_FAST */
if (sm->user == NULL || sm->user->password == NULL ||
sm->user->password_hash) {
wpa_printf(MSG_INFO, "EAP-GTC: Plaintext password not "
"configured");
data->state = FAILURE;
return;
}
if (rlen != sm->user->password_len ||
os_memcmp_const(pos, sm->user->password, rlen) != 0) {
wpa_printf(MSG_DEBUG, "EAP-GTC: Done - Failure");
data->state = FAILURE;
} else {
wpa_printf(MSG_DEBUG, "EAP-GTC: Done - Success");
data->state = SUCCESS;
}
}
static Boolean eap_gtc_isDone(struct eap_sm *sm, void *priv)
{
struct eap_gtc_data *data = priv;
return data->state != CONTINUE;
}
static Boolean eap_gtc_isSuccess(struct eap_sm *sm, void *priv)
{
struct eap_gtc_data *data = priv;
return data->state == SUCCESS;
}
int eap_server_gtc_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_GTC, "GTC");
if (eap == NULL)
return -1;
eap->init = eap_gtc_init;
eap->reset = eap_gtc_reset;
eap->buildReq = eap_gtc_buildReq;
eap->check = eap_gtc_check;
eap->process = eap_gtc_process;
eap->isDone = eap_gtc_isDone;
eap->isSuccess = eap_gtc_isSuccess;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}