fragattacks/src/eap_common/eap_ikev2_common.c
Jouni Malinen 675ddad1c2 EAP-IKEv2: 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 12:38:47 +03:00

117 lines
2.8 KiB
C

/*
* EAP-IKEv2 common routines
* Copyright (c) 2007, 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_defs.h"
#include "eap_common.h"
#include "ikev2_common.h"
#include "eap_ikev2_common.h"
int eap_ikev2_derive_keymat(int prf, struct ikev2_keys *keys,
const u8 *i_nonce, size_t i_nonce_len,
const u8 *r_nonce, size_t r_nonce_len,
u8 *keymat)
{
u8 *nonces;
size_t nlen;
/* KEYMAT = prf+(SK_d, Ni | Nr) */
if (keys->SK_d == NULL || i_nonce == NULL || r_nonce == NULL)
return -1;
nlen = i_nonce_len + r_nonce_len;
nonces = os_malloc(nlen);
if (nonces == NULL)
return -1;
os_memcpy(nonces, i_nonce, i_nonce_len);
os_memcpy(nonces + i_nonce_len, r_nonce, r_nonce_len);
if (ikev2_prf_plus(prf, keys->SK_d, keys->SK_d_len, nonces, nlen,
keymat, EAP_MSK_LEN + EAP_EMSK_LEN)) {
os_free(nonces);
return -1;
}
os_free(nonces);
wpa_hexdump_key(MSG_DEBUG, "EAP-IKEV2: KEYMAT",
keymat, EAP_MSK_LEN + EAP_EMSK_LEN);
return 0;
}
struct wpabuf * eap_ikev2_build_frag_ack(u8 id, u8 code)
{
struct wpabuf *msg;
msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 0, code, id);
if (msg == NULL) {
wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
"for fragment ack");
return NULL;
}
wpa_printf(MSG_DEBUG, "EAP-IKEV2: Send fragment ack");
return msg;
}
int eap_ikev2_validate_icv(int integ_alg, struct ikev2_keys *keys,
int initiator, const struct wpabuf *msg,
const u8 *pos, const u8 *end)
{
const struct ikev2_integ_alg *integ;
size_t icv_len;
u8 icv[IKEV2_MAX_HASH_LEN];
const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
integ = ikev2_get_integ(integ_alg);
if (integ == NULL) {
wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
"transform / cannot validate ICV");
return -1;
}
icv_len = integ->hash_len;
if (end - pos < (int) icv_len) {
wpa_printf(MSG_DEBUG, "EAP-IKEV2: Not enough room in the "
"message for Integrity Checksum Data");
return -1;
}
if (SK_a == NULL) {
wpa_printf(MSG_DEBUG, "EAP-IKEV2: No SK_a for ICV validation");
return -1;
}
if (ikev2_integ_hash(integ_alg, SK_a, keys->SK_integ_len,
wpabuf_head(msg),
wpabuf_len(msg) - icv_len, icv) < 0) {
wpa_printf(MSG_INFO, "EAP-IKEV2: Could not calculate ICV");
return -1;
}
if (os_memcmp_const(icv, end - icv_len, icv_len) != 0) {
wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid ICV");
wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Calculated ICV",
icv, icv_len);
wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Received ICV",
end - icv_len, icv_len);
return -1;
}
wpa_printf(MSG_DEBUG, "EAP-IKEV2: Valid Integrity Checksum Data in "
"the received message");
return icv_len;
}