fragattacks/hostapd/wps_hostapd.c

/*
 * hostapd / WPS integration
 * Copyright (c) 2008, 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 "hostapd.h"
#include "driver.h"
#include "eloop.h"
#include "uuid.h"
#include "wpa_ctrl.h"
#include "ctrl_iface.h"
#include "ieee802_11_defs.h"
#include "wps/wps.h"
#include "wps/wps_defs.h"
#include "wps/wps_dev_attr.h"
#include "wps_hostapd.h"


static int hostapd_wps_new_psk_cb(void *ctx, const u8 *mac_addr, const u8 *psk,
				  size_t psk_len)
{
	struct hostapd_data *hapd = ctx;
	struct hostapd_wpa_psk *p;
	struct hostapd_ssid *ssid = &hapd->conf->ssid;

	wpa_printf(MSG_DEBUG, "Received new WPA/WPA2-PSK from WPS for STA "
		   MACSTR, MAC2STR(mac_addr));
	wpa_hexdump_key(MSG_DEBUG, "Per-device PSK", psk, psk_len);

	if (psk_len != PMK_LEN) {
		wpa_printf(MSG_DEBUG, "Unexpected PSK length %lu",
			   (unsigned long) psk_len);
		return -1;
	}

	/* Add the new PSK to runtime PSK list */
	p = os_zalloc(sizeof(*p));
	if (p == NULL)
		return -1;
	os_memcpy(p->addr, mac_addr, ETH_ALEN);
	os_memcpy(p->psk, psk, PMK_LEN);

	p->next = ssid->wpa_psk;
	ssid->wpa_psk = p;

	if (ssid->wpa_psk_file) {
		FILE *f;
		char hex[PMK_LEN * 2 + 1];
		/* Add the new PSK to PSK list file */
		f = fopen(ssid->wpa_psk_file, "a");
		if (f == NULL) {
			wpa_printf(MSG_DEBUG, "Failed to add the PSK to "
				   "'%s'", ssid->wpa_psk_file);
			return -1;
		}

		wpa_snprintf_hex(hex, sizeof(hex), psk, psk_len);
		fprintf(f, MACSTR " %s\n", MAC2STR(mac_addr), hex);
		fclose(f);
	}

	return 0;
}


static int hostapd_wps_set_ie_cb(void *ctx, const u8 *beacon_ie,
				 size_t beacon_ie_len, const u8 *probe_resp_ie,
				 size_t probe_resp_ie_len)
{
	struct hostapd_data *hapd = ctx;

	os_free(hapd->wps_beacon_ie);
	if (beacon_ie_len == 0) {
		hapd->wps_beacon_ie = NULL;
		hapd->wps_beacon_ie_len = 0;
	} else {
		hapd->wps_beacon_ie = os_malloc(beacon_ie_len);
		if (hapd->wps_beacon_ie == NULL) {
			hapd->wps_beacon_ie_len = 0;
			return -1;
		}
		os_memcpy(hapd->wps_beacon_ie, beacon_ie, beacon_ie_len);
		hapd->wps_beacon_ie_len = beacon_ie_len;
	}
	hostapd_set_wps_beacon_ie(hapd, hapd->wps_beacon_ie,
				  hapd->wps_beacon_ie_len);

	os_free(hapd->wps_probe_resp_ie);
	if (probe_resp_ie_len == 0) {
		hapd->wps_probe_resp_ie = NULL;
		hapd->wps_probe_resp_ie_len = 0;
	} else {
		hapd->wps_probe_resp_ie = os_malloc(probe_resp_ie_len);
		if (hapd->wps_probe_resp_ie == NULL) {
			hapd->wps_probe_resp_ie_len = 0;
			return -1;
		}
		os_memcpy(hapd->wps_probe_resp_ie, probe_resp_ie,
			  probe_resp_ie_len);
		hapd->wps_probe_resp_ie_len = probe_resp_ie_len;
	}
	hostapd_set_wps_probe_resp_ie(hapd, hapd->wps_probe_resp_ie,
				      hapd->wps_probe_resp_ie_len);

	return 0;
}


static void hostapd_wps_pin_needed_cb(void *ctx, const u8 *uuid_e,
				      const struct wps_device_data *dev)
{
	struct hostapd_data *hapd = ctx;
	char uuid[40], txt[400];
	int len;
	if (uuid_bin2str(uuid_e, uuid, sizeof(uuid)))
		return;
	wpa_printf(MSG_DEBUG, "WPS: PIN needed for E-UUID %s", uuid);
	len = os_snprintf(txt, sizeof(txt), WPS_EVENT_PIN_NEEDED
			  "%s " MACSTR " [%s|%s|%s|%s|%s|%d-%08X-%d]",
			  uuid, MAC2STR(dev->mac_addr), dev->device_name,
			  dev->manufacturer, dev->model_name,
			  dev->model_number, dev->serial_number,
			  dev->categ, dev->oui, dev->sub_categ);
	if (len > 0 && len < (int) sizeof(txt))
		hostapd_ctrl_iface_send(hapd, MSG_INFO, txt, len);

	if (hapd->conf->wps_pin_requests) {
		FILE *f;
		struct os_time t;
		f = fopen(hapd->conf->wps_pin_requests, "a");
		if (f == NULL)
			return;
		os_get_time(&t);
		fprintf(f, "%ld\t%s\t" MACSTR "\t%s\t%s\t%s\t%s\t%s"
			"\t%d-%08X-%d\n",
			t.sec, uuid, MAC2STR(dev->mac_addr), dev->device_name,
			dev->manufacturer, dev->model_name, dev->model_number,
			dev->serial_number,
			dev->categ, dev->oui, dev->sub_categ);
		fclose(f);
	}
}


static int str_starts(const char *str, const char *start)
{
	return os_strncmp(str, start, os_strlen(start)) == 0;
}


static void wps_reload_config(void *eloop_data, void *user_ctx)
{
	struct hostapd_iface *iface = eloop_data;

	wpa_printf(MSG_DEBUG, "WPS: Reload configuration data");
	if (hostapd_reload_config(iface) < 0) {
		wpa_printf(MSG_WARNING, "WPS: Failed to reload the updated "
			   "configuration");
	}
}


static int hostapd_wps_cred_cb(void *ctx, const struct wps_credential *cred)
{
	struct hostapd_data *hapd = ctx;
	FILE *oconf, *nconf;
	size_t len, i;
	char *tmp_fname;
	char buf[1024];
	int multi_bss;
	int wpa;

	wpa_printf(MSG_DEBUG, "WPS: Received new AP Settings");
	wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID", cred->ssid, cred->ssid_len);
	wpa_printf(MSG_DEBUG, "WPS: Authentication Type 0x%x",
		   cred->auth_type);
	wpa_printf(MSG_DEBUG, "WPS: Encryption Type 0x%x", cred->encr_type);
	wpa_printf(MSG_DEBUG, "WPS: Network Key Index %d", cred->key_idx);
	wpa_hexdump_key(MSG_DEBUG, "WPS: Network Key",
			cred->key, cred->key_len);
	wpa_printf(MSG_DEBUG, "WPS: MAC Address " MACSTR,
		   MAC2STR(cred->mac_addr));

	hostapd_ctrl_iface_send(hapd, MSG_INFO, WPS_EVENT_NEW_AP_SETTINGS,
				os_strlen(WPS_EVENT_NEW_AP_SETTINGS));

	len = os_strlen(hapd->iface->config_fname) + 5;
	tmp_fname = os_malloc(len);
	if (tmp_fname == NULL)
		return -1;
	os_snprintf(tmp_fname, len, "%s-new", hapd->iface->config_fname);

	oconf = fopen(hapd->iface->config_fname, "r");
	if (oconf == NULL) {
		wpa_printf(MSG_WARNING, "WPS: Could not open current "
			   "configuration file");
		os_free(tmp_fname);
		return -1;
	}

	nconf = fopen(tmp_fname, "w");
	if (nconf == NULL) {
		wpa_printf(MSG_WARNING, "WPS: Could not write updated "
			   "configuration file");
		os_free(tmp_fname);
		fclose(oconf);
		return -1;
	}

	fprintf(nconf, "# WPS configuration - START\n");

	fprintf(nconf, "wps_state=2\n");

	fprintf(nconf, "ssid=");
	for (i = 0; i < cred->ssid_len; i++)
		fputc(cred->ssid[i], nconf);
	fprintf(nconf, "\n");

	if ((cred->auth_type & (WPS_AUTH_WPA2 | WPS_AUTH_WPA2PSK)) &&
	    (cred->auth_type & (WPS_AUTH_WPA | WPS_AUTH_WPAPSK)))
		wpa = 3;
	else if (cred->auth_type & (WPS_AUTH_WPA2 | WPS_AUTH_WPA2PSK))
		wpa = 2;
	else if (cred->auth_type & (WPS_AUTH_WPA | WPS_AUTH_WPAPSK))
		wpa = 1;
	else
		wpa = 0;

	if (wpa) {
		char *prefix;
		fprintf(nconf, "wpa=%d\n", wpa);

		fprintf(nconf, "wpa_key_mgmt=");
		prefix = "";
		if (cred->auth_type & (WPS_AUTH_WPA2 | WPS_AUTH_WPA)) {
			fprintf(nconf, "WPA-EAP");
			prefix = " ";
		}
		if (cred->auth_type & (WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK))
			fprintf(nconf, "%sWPA-PSK", prefix);
		fprintf(nconf, "\n");

		fprintf(nconf, "wpa_pairwise=");
		prefix = "";
		if (cred->encr_type & WPS_ENCR_AES) {
			fprintf(nconf, "CCMP");
			prefix = " ";
		}
		if (cred->encr_type & WPS_ENCR_TKIP) {
			fprintf(nconf, "%sTKIP", prefix);
		}
		fprintf(nconf, "\n");

		if (cred->key_len >= 8 && cred->key_len < 64) {
			fprintf(nconf, "wpa_passphrase=");
			for (i = 0; i < cred->key_len; i++)
				fputc(cred->key[i], nconf);
			fprintf(nconf, "\n");
		} else if (cred->key_len == 64) {
			fprintf(nconf, "wpa_psk=");
			for (i = 0; i < cred->key_len; i++)
				fputc(cred->key[i], nconf);
			fprintf(nconf, "\n");
		} else {
			wpa_printf(MSG_WARNING, "WPS: Invalid key length %lu "
				   "for WPA/WPA2",
				   (unsigned long) cred->key_len);
		}

		fprintf(nconf, "auth_algs=1\n");
	} else {
		if ((cred->auth_type & WPS_AUTH_OPEN) &&
		    (cred->auth_type & WPS_AUTH_SHARED))
			fprintf(nconf, "auth_algs=3\n");
		else if (cred->auth_type & WPS_AUTH_SHARED)
			fprintf(nconf, "auth_algs=2\n");
		else
			fprintf(nconf, "auth_algs=1\n");

		if (cred->encr_type & WPS_ENCR_WEP && cred->key_idx < 4) {
			fprintf(nconf, "wep_default_key=%d\n", cred->key_idx);
			fprintf(nconf, "wep_key%d=", cred->key_idx);
			if (cred->key_len != 10 && cred->key_len != 26)
				fputc('"', nconf);
			for (i = 0; i < cred->key_len; i++)
				fputc(cred->key[i], nconf);
			if (cred->key_len != 10 && cred->key_len != 26)
				fputc('"', nconf);
			fprintf(nconf, "\n");
		}
	}

	fprintf(nconf, "# WPS configuration - END\n");

	multi_bss = 0;
	while (fgets(buf, sizeof(buf), oconf)) {
		if (os_strncmp(buf, "bss=", 4) == 0)
			multi_bss = 1;
		if (!multi_bss &&
		    (str_starts(buf, "ssid=") ||
		     str_starts(buf, "auth_algs=") ||
		     str_starts(buf, "wps_state=") ||
		     str_starts(buf, "wpa=") ||
		     str_starts(buf, "wpa_psk=") ||
		     str_starts(buf, "wpa_pairwise=") ||
		     str_starts(buf, "rsn_pairwise=") ||
		     str_starts(buf, "wpa_key_mgmt=") ||
		     str_starts(buf, "wpa_passphrase="))) {
			fprintf(nconf, "#WPS# %s", buf);
		} else
			fprintf(nconf, "%s", buf);
	}

	fclose(nconf);
	fclose(oconf);

	if (rename(tmp_fname, hapd->iface->config_fname) < 0) {
		wpa_printf(MSG_WARNING, "WPS: Failed to rename the updated "
			   "configuration file: %s", strerror(errno));
		os_free(tmp_fname);
		return -1;
	}

	os_free(tmp_fname);

	/* Schedule configuration reload after short period of time to allow
	 * EAP-WSC to be finished.
	 */
	eloop_register_timeout(0, 100000, wps_reload_config, hapd->iface,
			       NULL);

	/* TODO: dualband AP may need to update multiple configuration files */

	wpa_printf(MSG_DEBUG, "WPS: AP configuration updated");

	return 0;
}


static void hostapd_wps_clear_ies(struct hostapd_data *hapd)
{
	os_free(hapd->wps_beacon_ie);
	hapd->wps_beacon_ie = NULL;
	hapd->wps_beacon_ie_len = 0;
	hostapd_set_wps_beacon_ie(hapd, NULL, 0);

	os_free(hapd->wps_probe_resp_ie);
	hapd->wps_probe_resp_ie = NULL;
	hapd->wps_probe_resp_ie_len = 0;
	hostapd_set_wps_probe_resp_ie(hapd, NULL, 0);
}


int hostapd_init_wps(struct hostapd_data *hapd,
		     struct hostapd_bss_config *conf)
{
	struct wps_context *wps;
	struct wps_registrar_config cfg;

	if (conf->wps_state == 0) {
		hostapd_wps_clear_ies(hapd);
		return 0;
	}

	wps = os_zalloc(sizeof(*wps));
	if (wps == NULL)
		return -1;

	wps->cred_cb = hostapd_wps_cred_cb;
	wps->cb_ctx = hapd;

	os_memset(&cfg, 0, sizeof(cfg));
	wps->wps_state = hapd->conf->wps_state;
	wps->ap_setup_locked = hapd->conf->ap_setup_locked;
	os_memcpy(wps->uuid, hapd->conf->uuid, UUID_LEN);
	wps->ssid_len = hapd->conf->ssid.ssid_len;
	os_memcpy(wps->ssid, hapd->conf->ssid.ssid, wps->ssid_len);
	wps->ap = 1;
	os_memcpy(wps->dev.mac_addr, hapd->own_addr, ETH_ALEN);
	wps->dev.device_name = hapd->conf->device_name;
	wps->dev.manufacturer = hapd->conf->manufacturer;
	wps->dev.model_name = hapd->conf->model_name;
	wps->dev.model_number = hapd->conf->model_number;
	wps->dev.serial_number = hapd->conf->serial_number;
	if (hapd->conf->config_methods) {
		char *m = hapd->conf->config_methods;
		if (os_strstr(m, "label"))
			wps->config_methods |= WPS_CONFIG_LABEL;
		if (os_strstr(m, "display"))
			wps->config_methods |= WPS_CONFIG_DISPLAY;
		if (os_strstr(m, "push_button"))
			wps->config_methods |= WPS_CONFIG_PUSHBUTTON;
		if (os_strstr(m, "keypad"))
			wps->config_methods |= WPS_CONFIG_KEYPAD;
	}
	if (hapd->conf->device_type) {
		char *pos;
		u8 oui[4];
		/* <categ>-<OUI>-<subcateg> */
		wps->dev.categ = atoi(hapd->conf->device_type);
		pos = os_strchr(hapd->conf->device_type, '-');
		if (pos == NULL) {
			wpa_printf(MSG_ERROR, "WPS: Invalid device_type");
			os_free(wps);
			return -1;
		}
		pos++;
		if (hexstr2bin(pos, oui, 4)) {
			wpa_printf(MSG_ERROR, "WPS: Invalid device_type OUI");
			os_free(wps);
			return -1;
		}
		wps->dev.oui = WPA_GET_BE32(oui);
		pos = os_strchr(pos, '-');
		if (pos == NULL) {
			wpa_printf(MSG_ERROR, "WPS: Invalid device_type");
			os_free(wps);
			return -1;
		}
		pos++;
		wps->dev.sub_categ = atoi(pos);
	}
	wps->dev.os_version = WPA_GET_BE32(hapd->conf->os_version);

	if (conf->wpa & WPA_PROTO_RSN) {
		if (conf->wpa_key_mgmt & WPA_KEY_MGMT_PSK)
			wps->auth_types |= WPS_AUTH_WPA2PSK;
		if (conf->wpa_key_mgmt & WPA_KEY_MGMT_IEEE8021X)
			wps->auth_types |= WPS_AUTH_WPA2;

		if (conf->rsn_pairwise & WPA_CIPHER_CCMP)
			wps->encr_types |= WPS_ENCR_AES;
		if (conf->rsn_pairwise & WPA_CIPHER_TKIP)
			wps->encr_types |= WPS_ENCR_TKIP;
	}

	if (conf->wpa & WPA_PROTO_WPA) {
		if (conf->wpa_key_mgmt & WPA_KEY_MGMT_PSK)
			wps->auth_types |= WPS_AUTH_WPAPSK;
		if (conf->wpa_key_mgmt & WPA_KEY_MGMT_IEEE8021X)
			wps->auth_types |= WPS_AUTH_WPA;

		if (conf->wpa_pairwise & WPA_CIPHER_CCMP)
			wps->encr_types |= WPS_ENCR_AES;
		if (conf->wpa_pairwise & WPA_CIPHER_TKIP)
			wps->encr_types |= WPS_ENCR_TKIP;
	}

	if (conf->ssid.security_policy == SECURITY_PLAINTEXT) {
		wps->encr_types |= WPS_ENCR_NONE;
		wps->auth_types |= WPS_AUTH_OPEN;
	} else if (conf->ssid.security_policy == SECURITY_STATIC_WEP) {
		wps->encr_types |= WPS_ENCR_WEP;
		if (conf->auth_algs & WPA_AUTH_ALG_OPEN)
			wps->auth_types |= WPS_AUTH_OPEN;
		if (conf->auth_algs & WPA_AUTH_ALG_SHARED)
			wps->auth_types |= WPS_AUTH_SHARED;
	} else if (conf->ssid.security_policy == SECURITY_IEEE_802_1X) {
		wps->auth_types |= WPS_AUTH_OPEN;
		if (conf->default_wep_key_len)
			wps->encr_types |= WPS_ENCR_WEP;
		else
			wps->encr_types |= WPS_ENCR_NONE;
	}

	if (conf->ssid.wpa_psk_file) {
		/* Use per-device PSKs */
	} else if (conf->ssid.wpa_passphrase) {
		wps->network_key = (u8 *) os_strdup(conf->ssid.wpa_passphrase);
		wps->network_key_len = os_strlen(conf->ssid.wpa_passphrase);
	} else if (conf->ssid.wpa_psk) {
		wps->network_key = os_malloc(2 * PMK_LEN + 1);
		if (wps->network_key == NULL) {
			os_free(wps);
			return -1;
		}
		wpa_snprintf_hex((char *) wps->network_key, 2 * PMK_LEN + 1,
				 conf->ssid.wpa_psk->psk, PMK_LEN);
		wps->network_key_len = 2 * PMK_LEN;
	} else if (conf->ssid.wep.keys_set && conf->ssid.wep.key[0]) {
		wps->network_key = os_malloc(conf->ssid.wep.len[0]);
		if (wps->network_key == NULL) {
			os_free(wps);
			return -1;
		}
		os_memcpy(wps->network_key, conf->ssid.wep.key[0],
			  conf->ssid.wep.len[0]);
		wps->network_key_len = conf->ssid.wep.len[0];
	}

	if (conf->wps_state == WPS_STATE_NOT_CONFIGURED) {
		/* Override parameters to enable security by default */
		wps->auth_types = WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK;
		wps->encr_types = WPS_ENCR_AES | WPS_ENCR_TKIP;
	}

	cfg.new_psk_cb = hostapd_wps_new_psk_cb;
	cfg.set_ie_cb = hostapd_wps_set_ie_cb;
	cfg.pin_needed_cb = hostapd_wps_pin_needed_cb;
	cfg.cb_ctx = hapd;

	wps->registrar = wps_registrar_init(wps, &cfg);
	if (wps->registrar == NULL) {
		printf("Failed to initialize WPS Registrar\n");
		os_free(wps->network_key);
		os_free(wps);
		return -1;
	}

	hapd->wps = wps;

	return 0;
}


void hostapd_deinit_wps(struct hostapd_data *hapd)
{
	if (hapd->wps == NULL)
		return;
	wps_registrar_deinit(hapd->wps->registrar);
	os_free(hapd->wps->network_key);
	os_free(hapd->wps);
	hapd->wps = NULL;
	hostapd_wps_clear_ies(hapd);
}


int hostapd_wps_add_pin(struct hostapd_data *hapd, const char *uuid,
			const char *pin)
{
	u8 u[UUID_LEN];
	if (hapd->wps == NULL || uuid_str2bin(uuid, u))
		return -1;
	return wps_registrar_add_pin(hapd->wps->registrar, u,
				     (const u8 *) pin, os_strlen(pin));
}


int hostapd_wps_button_pushed(struct hostapd_data *hapd)
{
	if (hapd->wps == NULL)
		return -1;
	return wps_registrar_button_pushed(hapd->wps->registrar);
}


void hostapd_wps_probe_req_rx(struct hostapd_data *hapd, const u8 *addr,
			      const u8 *ie, size_t ie_len)
{
	struct wpabuf *wps_ie;
	const u8 *end, *pos, *wps;

	if (hapd->wps == NULL)
		return;

	pos = ie;
	end = ie + ie_len;
	wps = NULL;

	while (pos + 1 < end) {
		if (pos + 2 + pos[1] > end)
			return;
		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
		    WPA_GET_BE32(&pos[2]) == WPS_DEV_OUI_WFA) {
			wps = pos;
			break;
		}
		pos += 2 + pos[1];
	}

	if (wps == NULL)
		return; /* No WPS IE in Probe Request */

	wps_ie = wpabuf_alloc(ie_len);
	if (wps_ie == NULL)
		return;

	/* There may be multiple WPS IEs in the message, so need to concatenate
	 * their WPS Data fields */
	while (pos + 1 < end) {
		if (pos + 2 + pos[1] > end)
			break;
		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
		    WPA_GET_BE32(&pos[2]) == WPS_DEV_OUI_WFA)
			wpabuf_put_data(wps_ie, pos + 6, pos[1] - 4);
		pos += 2 + pos[1];
	}

	if (wpabuf_len(wps_ie) > 0)
		wps_registrar_probe_req_rx(hapd->wps->registrar, addr, wps_ie);

	wpabuf_free(wps_ie);
}