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eapol: Add utility to find GTK KDEs

This commit is contained in:
Denis Kenzior 2015-02-24 17:11:56 -06:00
parent b1ca41b476
commit 7f9b8117fd
2 changed files with 45 additions and 0 deletions

View File

@ -136,6 +136,7 @@ unit_test_mpdu_LDADD = ell/libell-internal.la
unit_test_eapol_SOURCES = unit/test-eapol.c \
src/sha1.h src/sha1.c \
src/crypto.h src/crypto.c \
src/ie.h src/ie.c \
src/eapol.h src/eapol.c
unit_test_eapol_LDADD = ell/libell-internal.la

View File

@ -30,6 +30,7 @@
#include "sha1.h"
#include "crypto.h"
#include "eapol.h"
#include "ie.h"
struct l_hashmap *state_machines;
eapol_tx_packet_func_t tx_packet = NULL;
@ -531,6 +532,38 @@ fail:
l_free(step2);
}
static const uint8_t *eapol_find_gtk_kde(const uint8_t *data, size_t data_len,
size_t *out_gtk_len)
{
static const unsigned char gtk_oui[] = { 0x00, 0x0f, 0xac, 0x01 };
struct ie_tlv_iter iter;
const uint8_t *gtk;
unsigned int len;
ie_tlv_iter_init(&iter, data, data_len);
while (ie_tlv_iter_next(&iter)) {
if (ie_tlv_iter_get_tag(&iter) != IE_TYPE_VENDOR_SPECIFIC)
continue;
len = ie_tlv_iter_get_length(&iter);
if (len < 4) /* Take care of padding */
return NULL;
/* Check OUI */
gtk = ie_tlv_iter_get_data(&iter);
if (memcmp(gtk, gtk_oui, 4))
continue;
if (out_gtk_len)
*out_gtk_len = len - 4;
return gtk + 4;
}
return NULL;
}
static void eapol_handle_ptk_3_of_4(int ifindex, struct eapol_sm *sm,
const struct eapol_key *ek,
const uint8_t *decrypted_key_data,
@ -539,6 +572,8 @@ static void eapol_handle_ptk_3_of_4(int ifindex, struct eapol_sm *sm,
struct crypto_ptk *ptk = (struct crypto_ptk *) sm->ptk;
struct eapol_key *step4;
uint8_t mic[16];
const uint8_t *gtk;
size_t gtk_len;
if (!eapol_verify_ptk_3_of_4(ek))
return;
@ -565,6 +600,15 @@ static void eapol_handle_ptk_3_of_4(int ifindex, struct eapol_sm *sm,
* Supplicant uses the pairwise cipher suite specified in the second
* RSNE or deauthenticates."
*/
/*
* TODO: If group_cipher was negotiated, find the GTK and install it
*/
gtk = eapol_find_gtk_kde(decrypted_key_data, decrypted_key_data_size,
&gtk_len);
if (!gtk)
return;
step4 = eapol_create_ptk_4_of_4(protocol_version,
ek->key_descriptor_version,
sm->replay_counter);