mirror of
https://github.com/vanhoefm/fragattacks.git
synced 2024-12-04 21:28:27 -05:00
7650f9e7d8
The l2_packet instances were not freed on some of the rsn_preauth_init() error paths. Signed-off-by: Jouni Malinen <j@w1.fi>
542 lines
15 KiB
C
542 lines
15 KiB
C
/*
|
|
* RSN pre-authentication (supplicant)
|
|
* Copyright (c) 2003-2015, 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 "wpa.h"
|
|
#include "eloop.h"
|
|
#include "l2_packet/l2_packet.h"
|
|
#include "eapol_supp/eapol_supp_sm.h"
|
|
#include "preauth.h"
|
|
#include "pmksa_cache.h"
|
|
#include "wpa_i.h"
|
|
|
|
|
|
#ifdef IEEE8021X_EAPOL
|
|
|
|
#define PMKID_CANDIDATE_PRIO_SCAN 1000
|
|
|
|
|
|
struct rsn_pmksa_candidate {
|
|
struct dl_list list;
|
|
u8 bssid[ETH_ALEN];
|
|
int priority;
|
|
};
|
|
|
|
|
|
/**
|
|
* pmksa_candidate_free - Free all entries in PMKSA candidate list
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
*/
|
|
void pmksa_candidate_free(struct wpa_sm *sm)
|
|
{
|
|
struct rsn_pmksa_candidate *entry, *n;
|
|
|
|
if (sm == NULL)
|
|
return;
|
|
|
|
dl_list_for_each_safe(entry, n, &sm->pmksa_candidates,
|
|
struct rsn_pmksa_candidate, list) {
|
|
dl_list_del(&entry->list);
|
|
os_free(entry);
|
|
}
|
|
}
|
|
|
|
|
|
static void rsn_preauth_receive(void *ctx, const u8 *src_addr,
|
|
const u8 *buf, size_t len)
|
|
{
|
|
struct wpa_sm *sm = ctx;
|
|
|
|
wpa_printf(MSG_DEBUG, "RX pre-auth from " MACSTR, MAC2STR(src_addr));
|
|
wpa_hexdump(MSG_MSGDUMP, "RX pre-auth", buf, len);
|
|
|
|
if (sm->preauth_eapol == NULL ||
|
|
is_zero_ether_addr(sm->preauth_bssid) ||
|
|
os_memcmp(sm->preauth_bssid, src_addr, ETH_ALEN) != 0) {
|
|
wpa_printf(MSG_WARNING, "RSN pre-auth frame received from "
|
|
"unexpected source " MACSTR " - dropped",
|
|
MAC2STR(src_addr));
|
|
return;
|
|
}
|
|
|
|
eapol_sm_rx_eapol(sm->preauth_eapol, src_addr, buf, len);
|
|
}
|
|
|
|
|
|
static void rsn_preauth_eapol_cb(struct eapol_sm *eapol,
|
|
enum eapol_supp_result result,
|
|
void *ctx)
|
|
{
|
|
struct wpa_sm *sm = ctx;
|
|
u8 pmk[PMK_LEN];
|
|
|
|
if (result == EAPOL_SUPP_RESULT_SUCCESS) {
|
|
int res, pmk_len;
|
|
pmk_len = PMK_LEN;
|
|
res = eapol_sm_get_key(eapol, pmk, PMK_LEN);
|
|
if (res) {
|
|
/*
|
|
* EAP-LEAP is an exception from other EAP methods: it
|
|
* uses only 16-byte PMK.
|
|
*/
|
|
res = eapol_sm_get_key(eapol, pmk, 16);
|
|
pmk_len = 16;
|
|
}
|
|
if (res == 0) {
|
|
wpa_hexdump_key(MSG_DEBUG, "RSN: PMK from pre-auth",
|
|
pmk, pmk_len);
|
|
sm->pmk_len = pmk_len;
|
|
pmksa_cache_add(sm->pmksa, pmk, pmk_len,
|
|
NULL, 0,
|
|
sm->preauth_bssid, sm->own_addr,
|
|
sm->network_ctx,
|
|
WPA_KEY_MGMT_IEEE8021X);
|
|
} else {
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
|
|
"RSN: failed to get master session key from "
|
|
"pre-auth EAPOL state machines");
|
|
result = EAPOL_SUPP_RESULT_FAILURE;
|
|
}
|
|
}
|
|
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_INFO, "RSN: pre-authentication with "
|
|
MACSTR " %s", MAC2STR(sm->preauth_bssid),
|
|
result == EAPOL_SUPP_RESULT_SUCCESS ? "completed successfully" :
|
|
"failed");
|
|
|
|
rsn_preauth_deinit(sm);
|
|
rsn_preauth_candidate_process(sm);
|
|
}
|
|
|
|
|
|
static void rsn_preauth_timeout(void *eloop_ctx, void *timeout_ctx)
|
|
{
|
|
struct wpa_sm *sm = eloop_ctx;
|
|
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_INFO, "RSN: pre-authentication with "
|
|
MACSTR " timed out", MAC2STR(sm->preauth_bssid));
|
|
rsn_preauth_deinit(sm);
|
|
rsn_preauth_candidate_process(sm);
|
|
}
|
|
|
|
|
|
static int rsn_preauth_eapol_send(void *ctx, int type, const u8 *buf,
|
|
size_t len)
|
|
{
|
|
struct wpa_sm *sm = ctx;
|
|
u8 *msg;
|
|
size_t msglen;
|
|
int res;
|
|
|
|
/* TODO: could add l2_packet_sendmsg that allows fragments to avoid
|
|
* extra copy here */
|
|
|
|
if (sm->l2_preauth == NULL)
|
|
return -1;
|
|
|
|
msg = wpa_sm_alloc_eapol(sm, type, buf, len, &msglen, NULL);
|
|
if (msg == NULL)
|
|
return -1;
|
|
|
|
wpa_hexdump(MSG_MSGDUMP, "TX EAPOL (preauth)", msg, msglen);
|
|
res = l2_packet_send(sm->l2_preauth, sm->preauth_bssid,
|
|
ETH_P_RSN_PREAUTH, msg, msglen);
|
|
os_free(msg);
|
|
return res;
|
|
}
|
|
|
|
|
|
/**
|
|
* rsn_preauth_init - Start new RSN pre-authentication
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
* @dst: Authenticator address (BSSID) with which to preauthenticate
|
|
* @eap_conf: Current EAP configuration
|
|
* Returns: 0 on success, -1 on another pre-authentication is in progress,
|
|
* -2 on layer 2 packet initialization failure, -3 on EAPOL state machine
|
|
* initialization failure, -4 on memory allocation failure
|
|
*
|
|
* This function request an RSN pre-authentication with a given destination
|
|
* address. This is usually called for PMKSA candidates found from scan results
|
|
* or from driver reports. In addition, ctrl_iface PREAUTH command can trigger
|
|
* pre-authentication.
|
|
*/
|
|
int rsn_preauth_init(struct wpa_sm *sm, const u8 *dst,
|
|
struct eap_peer_config *eap_conf)
|
|
{
|
|
struct eapol_config eapol_conf;
|
|
struct eapol_ctx *ctx;
|
|
int ret;
|
|
|
|
if (sm->preauth_eapol)
|
|
return -1;
|
|
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG,
|
|
"RSN: starting pre-authentication with " MACSTR, MAC2STR(dst));
|
|
|
|
sm->l2_preauth = l2_packet_init(sm->ifname, sm->own_addr,
|
|
ETH_P_RSN_PREAUTH,
|
|
rsn_preauth_receive, sm, 0);
|
|
if (sm->l2_preauth == NULL) {
|
|
wpa_printf(MSG_WARNING, "RSN: Failed to initialize L2 packet "
|
|
"processing for pre-authentication");
|
|
return -2;
|
|
}
|
|
|
|
if (sm->bridge_ifname) {
|
|
sm->l2_preauth_br = l2_packet_init(sm->bridge_ifname,
|
|
sm->own_addr,
|
|
ETH_P_RSN_PREAUTH,
|
|
rsn_preauth_receive, sm, 0);
|
|
if (sm->l2_preauth_br == NULL) {
|
|
wpa_printf(MSG_WARNING, "RSN: Failed to initialize L2 "
|
|
"packet processing (bridge) for "
|
|
"pre-authentication");
|
|
ret = -2;
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
ctx = os_zalloc(sizeof(*ctx));
|
|
if (ctx == NULL) {
|
|
wpa_printf(MSG_WARNING, "Failed to allocate EAPOL context.");
|
|
ret = -4;
|
|
goto fail;
|
|
}
|
|
ctx->ctx = sm->ctx->ctx;
|
|
ctx->msg_ctx = sm->ctx->ctx;
|
|
ctx->preauth = 1;
|
|
ctx->cb = rsn_preauth_eapol_cb;
|
|
ctx->cb_ctx = sm;
|
|
ctx->scard_ctx = sm->scard_ctx;
|
|
ctx->eapol_send = rsn_preauth_eapol_send;
|
|
ctx->eapol_send_ctx = sm;
|
|
ctx->set_config_blob = sm->ctx->set_config_blob;
|
|
ctx->get_config_blob = sm->ctx->get_config_blob;
|
|
|
|
sm->preauth_eapol = eapol_sm_init(ctx);
|
|
if (sm->preauth_eapol == NULL) {
|
|
os_free(ctx);
|
|
wpa_printf(MSG_WARNING, "RSN: Failed to initialize EAPOL "
|
|
"state machines for pre-authentication");
|
|
ret = -3;
|
|
goto fail;
|
|
}
|
|
os_memset(&eapol_conf, 0, sizeof(eapol_conf));
|
|
eapol_conf.accept_802_1x_keys = 0;
|
|
eapol_conf.required_keys = 0;
|
|
eapol_conf.fast_reauth = sm->fast_reauth;
|
|
eapol_conf.workaround = sm->eap_workaround;
|
|
eapol_sm_notify_config(sm->preauth_eapol, eap_conf, &eapol_conf);
|
|
/*
|
|
* Use a shorter startPeriod with preauthentication since the first
|
|
* preauth EAPOL-Start frame may end up being dropped due to race
|
|
* condition in the AP between the data receive and key configuration
|
|
* after the 4-Way Handshake.
|
|
*/
|
|
eapol_sm_configure(sm->preauth_eapol, -1, -1, 5, 6);
|
|
os_memcpy(sm->preauth_bssid, dst, ETH_ALEN);
|
|
|
|
eapol_sm_notify_portValid(sm->preauth_eapol, TRUE);
|
|
/* 802.1X::portControl = Auto */
|
|
eapol_sm_notify_portEnabled(sm->preauth_eapol, TRUE);
|
|
|
|
eloop_register_timeout(sm->dot11RSNAConfigSATimeout, 0,
|
|
rsn_preauth_timeout, sm, NULL);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
if (sm->l2_preauth_br) {
|
|
l2_packet_deinit(sm->l2_preauth_br);
|
|
sm->l2_preauth_br = NULL;
|
|
}
|
|
l2_packet_deinit(sm->l2_preauth);
|
|
sm->l2_preauth = NULL;
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* rsn_preauth_deinit - Abort RSN pre-authentication
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
*
|
|
* This function aborts the current RSN pre-authentication (if one is started)
|
|
* and frees resources allocated for it.
|
|
*/
|
|
void rsn_preauth_deinit(struct wpa_sm *sm)
|
|
{
|
|
if (sm == NULL || !sm->preauth_eapol)
|
|
return;
|
|
|
|
eloop_cancel_timeout(rsn_preauth_timeout, sm, NULL);
|
|
eapol_sm_deinit(sm->preauth_eapol);
|
|
sm->preauth_eapol = NULL;
|
|
os_memset(sm->preauth_bssid, 0, ETH_ALEN);
|
|
|
|
l2_packet_deinit(sm->l2_preauth);
|
|
sm->l2_preauth = NULL;
|
|
if (sm->l2_preauth_br) {
|
|
l2_packet_deinit(sm->l2_preauth_br);
|
|
sm->l2_preauth_br = NULL;
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* rsn_preauth_candidate_process - Process PMKSA candidates
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
*
|
|
* Go through the PMKSA candidates and start pre-authentication if a candidate
|
|
* without an existing PMKSA cache entry is found. Processed candidates will be
|
|
* removed from the list.
|
|
*/
|
|
void rsn_preauth_candidate_process(struct wpa_sm *sm)
|
|
{
|
|
struct rsn_pmksa_candidate *candidate, *n;
|
|
|
|
if (dl_list_empty(&sm->pmksa_candidates))
|
|
return;
|
|
|
|
/* TODO: drop priority for old candidate entries */
|
|
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: processing PMKSA candidate "
|
|
"list");
|
|
if (sm->preauth_eapol ||
|
|
sm->proto != WPA_PROTO_RSN ||
|
|
wpa_sm_get_state(sm) != WPA_COMPLETED ||
|
|
(sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X &&
|
|
sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X_SHA256 &&
|
|
sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X_SUITE_B &&
|
|
sm->key_mgmt != WPA_KEY_MGMT_IEEE8021X_SUITE_B_192)) {
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: not in suitable "
|
|
"state for new pre-authentication");
|
|
return; /* invalid state for new pre-auth */
|
|
}
|
|
|
|
dl_list_for_each_safe(candidate, n, &sm->pmksa_candidates,
|
|
struct rsn_pmksa_candidate, list) {
|
|
struct rsn_pmksa_cache_entry *p = NULL;
|
|
p = pmksa_cache_get(sm->pmksa, candidate->bssid, NULL, NULL);
|
|
if (os_memcmp(sm->bssid, candidate->bssid, ETH_ALEN) != 0 &&
|
|
(p == NULL || p->opportunistic)) {
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: PMKSA "
|
|
"candidate " MACSTR
|
|
" selected for pre-authentication",
|
|
MAC2STR(candidate->bssid));
|
|
dl_list_del(&candidate->list);
|
|
rsn_preauth_init(sm, candidate->bssid,
|
|
sm->eap_conf_ctx);
|
|
os_free(candidate);
|
|
return;
|
|
}
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: PMKSA candidate "
|
|
MACSTR " does not need pre-authentication anymore",
|
|
MAC2STR(candidate->bssid));
|
|
/* Some drivers (e.g., NDIS) expect to get notified about the
|
|
* PMKIDs again, so report the existing data now. */
|
|
if (p) {
|
|
wpa_sm_add_pmkid(sm, candidate->bssid, p->pmkid);
|
|
}
|
|
|
|
dl_list_del(&candidate->list);
|
|
os_free(candidate);
|
|
}
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: no more pending PMKSA "
|
|
"candidates");
|
|
}
|
|
|
|
|
|
/**
|
|
* pmksa_candidate_add - Add a new PMKSA candidate
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
* @bssid: BSSID (authenticator address) of the candidate
|
|
* @prio: Priority (the smaller number, the higher priority)
|
|
* @preauth: Whether the candidate AP advertises support for pre-authentication
|
|
*
|
|
* This function is used to add PMKSA candidates for RSN pre-authentication. It
|
|
* is called from scan result processing and from driver events for PMKSA
|
|
* candidates, i.e., EVENT_PMKID_CANDIDATE events to wpa_supplicant_event().
|
|
*/
|
|
void pmksa_candidate_add(struct wpa_sm *sm, const u8 *bssid,
|
|
int prio, int preauth)
|
|
{
|
|
struct rsn_pmksa_candidate *cand, *pos;
|
|
|
|
if (sm->network_ctx && sm->proactive_key_caching)
|
|
pmksa_cache_get_opportunistic(sm->pmksa, sm->network_ctx,
|
|
bssid);
|
|
|
|
if (!preauth) {
|
|
wpa_printf(MSG_DEBUG, "RSN: Ignored PMKID candidate without "
|
|
"preauth flag");
|
|
return;
|
|
}
|
|
|
|
/* If BSSID already on candidate list, update the priority of the old
|
|
* entry. Do not override priority based on normal scan results. */
|
|
cand = NULL;
|
|
dl_list_for_each(pos, &sm->pmksa_candidates,
|
|
struct rsn_pmksa_candidate, list) {
|
|
if (os_memcmp(pos->bssid, bssid, ETH_ALEN) == 0) {
|
|
cand = pos;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (cand) {
|
|
dl_list_del(&cand->list);
|
|
if (prio < PMKID_CANDIDATE_PRIO_SCAN)
|
|
cand->priority = prio;
|
|
} else {
|
|
cand = os_zalloc(sizeof(*cand));
|
|
if (cand == NULL)
|
|
return;
|
|
os_memcpy(cand->bssid, bssid, ETH_ALEN);
|
|
cand->priority = prio;
|
|
}
|
|
|
|
/* Add candidate to the list; order by increasing priority value. i.e.,
|
|
* highest priority (smallest value) first. */
|
|
dl_list_for_each(pos, &sm->pmksa_candidates,
|
|
struct rsn_pmksa_candidate, list) {
|
|
if (cand->priority <= pos->priority) {
|
|
if (!pos->list.prev) {
|
|
/*
|
|
* This cannot really happen in pracrice since
|
|
* pos was fetched from the list and the prev
|
|
* pointer must be set. It looks like clang
|
|
* static analyzer gets confused with the
|
|
* dl_list_del(&cand->list) call above and ends
|
|
* up assuming pos->list.prev could be NULL.
|
|
*/
|
|
os_free(cand);
|
|
return;
|
|
}
|
|
dl_list_add(pos->list.prev, &cand->list);
|
|
cand = NULL;
|
|
break;
|
|
}
|
|
}
|
|
if (cand)
|
|
dl_list_add_tail(&sm->pmksa_candidates, &cand->list);
|
|
|
|
wpa_msg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: added PMKSA cache "
|
|
"candidate " MACSTR " prio %d", MAC2STR(bssid), prio);
|
|
rsn_preauth_candidate_process(sm);
|
|
}
|
|
|
|
|
|
/* TODO: schedule periodic scans if current AP supports preauth */
|
|
|
|
/**
|
|
* rsn_preauth_scan_results - Start processing scan results for canditates
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
* Returns: 0 if ready to process results or -1 to skip processing
|
|
*
|
|
* This functions is used to notify RSN code about start of new scan results
|
|
* processing. The actual scan results will be provided by calling
|
|
* rsn_preauth_scan_result() for each BSS if this function returned 0.
|
|
*/
|
|
int rsn_preauth_scan_results(struct wpa_sm *sm)
|
|
{
|
|
if (sm->ssid_len == 0)
|
|
return -1;
|
|
|
|
/*
|
|
* TODO: is it ok to free all candidates? What about the entries
|
|
* received from EVENT_PMKID_CANDIDATE?
|
|
*/
|
|
pmksa_candidate_free(sm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* rsn_preauth_scan_result - Processing scan result for PMKSA canditates
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
*
|
|
* Add all suitable APs (Authenticators) from scan results into PMKSA
|
|
* candidate list.
|
|
*/
|
|
void rsn_preauth_scan_result(struct wpa_sm *sm, const u8 *bssid,
|
|
const u8 *ssid, const u8 *rsn)
|
|
{
|
|
struct wpa_ie_data ie;
|
|
struct rsn_pmksa_cache_entry *pmksa;
|
|
|
|
if (ssid[1] != sm->ssid_len ||
|
|
os_memcmp(ssid + 2, sm->ssid, sm->ssid_len) != 0)
|
|
return; /* Not for the current SSID */
|
|
|
|
if (os_memcmp(bssid, sm->bssid, ETH_ALEN) == 0)
|
|
return; /* Ignore current AP */
|
|
|
|
if (wpa_parse_wpa_ie(rsn, 2 + rsn[1], &ie))
|
|
return;
|
|
|
|
pmksa = pmksa_cache_get(sm->pmksa, bssid, NULL, NULL);
|
|
if (pmksa && (!pmksa->opportunistic ||
|
|
!(ie.capabilities & WPA_CAPABILITY_PREAUTH)))
|
|
return;
|
|
|
|
/* Give less priority to candidates found from normal scan results. */
|
|
pmksa_candidate_add(sm, bssid, PMKID_CANDIDATE_PRIO_SCAN,
|
|
ie.capabilities & WPA_CAPABILITY_PREAUTH);
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_CTRL_IFACE
|
|
/**
|
|
* rsn_preauth_get_status - Get pre-authentication status
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
* @buf: Buffer for status information
|
|
* @buflen: Maximum buffer length
|
|
* @verbose: Whether to include verbose status information
|
|
* Returns: Number of bytes written to buf.
|
|
*
|
|
* Query WPA2 pre-authentication for status information. This function fills in
|
|
* a text area with current status information. If the buffer (buf) is not
|
|
* large enough, status information will be truncated to fit the buffer.
|
|
*/
|
|
int rsn_preauth_get_status(struct wpa_sm *sm, char *buf, size_t buflen,
|
|
int verbose)
|
|
{
|
|
char *pos = buf, *end = buf + buflen;
|
|
int res, ret;
|
|
|
|
if (sm->preauth_eapol) {
|
|
ret = os_snprintf(pos, end - pos, "Pre-authentication "
|
|
"EAPOL state machines:\n");
|
|
if (os_snprintf_error(end - pos, ret))
|
|
return pos - buf;
|
|
pos += ret;
|
|
res = eapol_sm_get_status(sm->preauth_eapol,
|
|
pos, end - pos, verbose);
|
|
if (res >= 0)
|
|
pos += res;
|
|
}
|
|
|
|
return pos - buf;
|
|
}
|
|
#endif /* CONFIG_CTRL_IFACE */
|
|
|
|
|
|
/**
|
|
* rsn_preauth_in_progress - Verify whether pre-authentication is in progress
|
|
* @sm: Pointer to WPA state machine data from wpa_sm_init()
|
|
*/
|
|
int rsn_preauth_in_progress(struct wpa_sm *sm)
|
|
{
|
|
return sm->preauth_eapol != NULL;
|
|
}
|
|
|
|
#endif /* IEEE8021X_EAPOL */
|