3
0
mirror of https://git.kernel.org/pub/scm/network/wireless/iwd.git synced 2024-12-28 20:22:43 +01:00
iwd/src/eapolutil.c
James Prestwood 374b367ba4 eapol: allow 16, 24 and 32 byte MIC lengths
The MIC length was hard coded to 16 bytes everywhere, and since several
AKMs require larger MIC's (24/32) this needed to change. The main issue
was that the MIC was hard coded to 16 bytes inside eapol_key. Instead
of doing this, the MIC, key_data_length, and key_data elements were all
bundled into key_data[0]. In order to retrieve the MIC, key_data_len,
or key_data several macros were introduced which account for the MIC
length provided.

A consequence of this is that all the verify functions inside eapol now
require the MIC length as a parameter because without it they cannot
determine the byte offset of key_data or key_data_length.

The MIC length for a given handshake is set inside the SM when starting
EAPoL. This length is determined by the AKM for the handshake.
2019-01-17 15:20:28 -06:00

82 lines
2.1 KiB
C

/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2013-2014 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <ell/ell.h>
#include "src/eapolutil.h"
const struct eapol_key *eapol_key_validate(const uint8_t *frame, size_t len,
size_t mic_len)
{
const struct eapol_key *ek;
/*
* Since EAPOL_KEY_DATA_LEN actually gets the key data length bytes we
* have to check this first, otherwise we could potentially overrun the
* frame buffer
*/
if (len < EAPOL_FRAME_LEN(mic_len))
return NULL;
ek = (const struct eapol_key *) frame;
if (len < EAPOL_FRAME_LEN(mic_len) + EAPOL_KEY_DATA_LEN(ek, mic_len))
return NULL;
switch (ek->header.protocol_version) {
case EAPOL_PROTOCOL_VERSION_2001:
case EAPOL_PROTOCOL_VERSION_2004:
break;
default:
return NULL;
}
if (ek->header.packet_type != 3)
return NULL;
switch (ek->descriptor_type) {
case EAPOL_DESCRIPTOR_TYPE_RC4:
case EAPOL_DESCRIPTOR_TYPE_80211:
case EAPOL_DESCRIPTOR_TYPE_WPA:
break;
default:
return NULL;
}
switch (ek->key_descriptor_version) {
case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_MD5_ARC4:
case EAPOL_KEY_DESCRIPTOR_VERSION_HMAC_SHA1_AES:
case EAPOL_KEY_DESCRIPTOR_VERSION_AES_128_CMAC_AES:
case EAPOL_KEY_DESCRIPTOR_VERSION_AKM_DEFINED:
break;
default:
return NULL;
}
return ek;
}