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authorJouni Malinen <j@w1.fi>2008-02-28 01:34:43 (GMT)
committerJouni Malinen <jm@jm.kir.nu>2008-02-28 01:34:43 (GMT)
commit6fc6879bd55a394f807cbbe927df736c190cb8ab (patch)
treecdf50da0c58f21510a808d53502a060d911ff243 /src/rsn_supp/preauth.c
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Re-initialize hostapd/wpa_supplicant git repository based on 0.6.3 release
Diffstat (limited to 'src/rsn_supp/preauth.c')
-rw-r--r--src/rsn_supp/preauth.c528
1 files changed, 528 insertions, 0 deletions
diff --git a/src/rsn_supp/preauth.c b/src/rsn_supp/preauth.c
new file mode 100644
index 0000000..e9bf7c6
--- /dev/null
+++ b/src/rsn_supp/preauth.c
@@ -0,0 +1,528 @@
+/*
+ * WPA Supplicant - RSN pre-authentication
+ * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "wpa.h"
+#include "drivers/driver.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"
+#include "ieee802_11_defs.h"
+
+
+#if defined(IEEE8021X_EAPOL) && !defined(CONFIG_NO_WPA2)
+
+#define PMKID_CANDIDATE_PRIO_SCAN 1000
+
+
+struct rsn_pmksa_candidate {
+ struct rsn_pmksa_candidate *next;
+ 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, *prev;
+
+ if (sm == NULL)
+ return;
+
+ entry = sm->pmksa_candidates;
+ sm->pmksa_candidates = NULL;
+ while (entry) {
+ prev = entry;
+ entry = entry->next;
+ os_free(prev);
+ }
+}
+
+
+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 ||
+ os_memcmp(sm->preauth_bssid, "\x00\x00\x00\x00\x00\x00",
+ ETH_ALEN) == 0 ||
+ 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, int success,
+ void *ctx)
+{
+ struct wpa_sm *sm = ctx;
+ u8 pmk[PMK_LEN];
+
+ if (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,
+ sm->preauth_bssid, sm->own_addr,
+ sm->network_ctx);
+ } else {
+ wpa_msg(sm->ctx->ctx, MSG_INFO, "RSN: failed to get "
+ "master session key from pre-auth EAPOL state "
+ "machines");
+ success = 0;
+ }
+ }
+
+ wpa_msg(sm->ctx->ctx, MSG_INFO, "RSN: pre-authentication with " MACSTR
+ " %s", MAC2STR(sm->preauth_bssid),
+ 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->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;
+
+ if (sm->preauth_eapol)
+ return -1;
+
+ wpa_msg(sm->ctx->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");
+ return -2;
+ }
+ }
+
+ ctx = os_zalloc(sizeof(*ctx));
+ if (ctx == NULL) {
+ wpa_printf(MSG_WARNING, "Failed to allocate EAPOL context.");
+ return -4;
+ }
+ 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");
+ return -3;
+ }
+ 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;
+}
+
+
+/**
+ * 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;
+
+ if (sm->pmksa_candidates == NULL)
+ return;
+
+ /* TODO: drop priority for old candidate entries */
+
+ wpa_msg(sm->ctx->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) {
+ wpa_msg(sm->ctx->ctx, MSG_DEBUG, "RSN: not in suitable state "
+ "for new pre-authentication");
+ return; /* invalid state for new pre-auth */
+ }
+
+ while (sm->pmksa_candidates) {
+ struct rsn_pmksa_cache_entry *p = NULL;
+ candidate = sm->pmksa_candidates;
+ p = pmksa_cache_get(sm->pmksa, candidate->bssid, NULL);
+ if (os_memcmp(sm->bssid, candidate->bssid, ETH_ALEN) != 0 &&
+ (p == NULL || p->opportunistic)) {
+ wpa_msg(sm->ctx->ctx, MSG_DEBUG, "RSN: PMKSA "
+ "candidate " MACSTR
+ " selected for pre-authentication",
+ MAC2STR(candidate->bssid));
+ sm->pmksa_candidates = candidate->next;
+ rsn_preauth_init(sm, candidate->bssid,
+ sm->eap_conf_ctx);
+ os_free(candidate);
+ return;
+ }
+ wpa_msg(sm->ctx->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);
+ }
+
+ sm->pmksa_candidates = candidate->next;
+ os_free(candidate);
+ }
+ wpa_msg(sm->ctx->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, *prev, *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. */
+ prev = NULL;
+ cand = sm->pmksa_candidates;
+ while (cand) {
+ if (os_memcmp(cand->bssid, bssid, ETH_ALEN) == 0) {
+ if (prev)
+ prev->next = cand->next;
+ else
+ sm->pmksa_candidates = cand->next;
+ break;
+ }
+ prev = cand;
+ cand = cand->next;
+ }
+
+ if (cand) {
+ 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. */
+ prev = NULL;
+ pos = sm->pmksa_candidates;
+ while (pos) {
+ if (cand->priority <= pos->priority)
+ break;
+ prev = pos;
+ pos = pos->next;
+ }
+ cand->next = pos;
+ if (prev)
+ prev->next = cand;
+ else
+ sm->pmksa_candidates = cand;
+
+ wpa_msg(sm->ctx->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 - Process scan results to find PMKSA candidates
+ * @sm: Pointer to WPA state machine data from wpa_sm_init()
+ * @results: Scan results
+ *
+ * This functions goes through the scan results and adds all suitable APs
+ * (Authenticators) into PMKSA candidate list.
+ */
+void rsn_preauth_scan_results(struct wpa_sm *sm,
+ struct wpa_scan_results *results)
+{
+ struct wpa_scan_res *r;
+ struct wpa_ie_data ie;
+ int i;
+ struct rsn_pmksa_cache_entry *pmksa;
+
+ if (sm->ssid_len == 0)
+ return;
+
+ /*
+ * TODO: is it ok to free all candidates? What about the entries
+ * received from EVENT_PMKID_CANDIDATE?
+ */
+ pmksa_candidate_free(sm);
+
+ for (i = results->num - 1; i >= 0; i--) {
+ const u8 *ssid, *rsn;
+
+ r = results->res[i];
+
+ ssid = wpa_scan_get_ie(r, WLAN_EID_SSID);
+ if (ssid == NULL || ssid[1] != sm->ssid_len ||
+ os_memcmp(ssid + 2, sm->ssid, ssid[1]) != 0)
+ continue;
+
+ if (os_memcmp(r->bssid, sm->bssid, ETH_ALEN) == 0)
+ continue;
+
+ rsn = wpa_scan_get_ie(r, WLAN_EID_RSN);
+ if (rsn == NULL || wpa_parse_wpa_ie(rsn, 2 + rsn[1], &ie))
+ continue;
+
+ pmksa = pmksa_cache_get(sm->pmksa, r->bssid, NULL);
+ if (pmksa &&
+ (!pmksa->opportunistic ||
+ !(ie.capabilities & WPA_CAPABILITY_PREAUTH)))
+ continue;
+
+ /*
+ * Give less priority to candidates found from normal
+ * scan results.
+ */
+ pmksa_candidate_add(sm, r->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 (ret < 0 || ret >= end - pos)
+ 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 and !CONFIG_NO_WPA2 */