fragattacks/wpa_supplicant/dpp_supplicant.c

/*
 * wpa_supplicant - DPP
 * Copyright (c) 2017, Qualcomm Atheros, Inc.
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "common/dpp.h"
#include "wpa_supplicant_i.h"
#include "dpp_supplicant.h"


static unsigned int wpas_dpp_next_id(struct wpa_supplicant *wpa_s)
{
	struct dpp_bootstrap_info *bi;
	unsigned int max_id = 0;

	dl_list_for_each(bi, &wpa_s->dpp_bootstrap, struct dpp_bootstrap_info,
			 list) {
		if (bi->id > max_id)
			max_id = bi->id;
	}
	return max_id + 1;
}


/**
 * wpas_dpp_qr_code - Parse and add DPP bootstrapping info from a QR Code
 * @wpa_s: Pointer to wpa_supplicant data
 * @cmd: DPP URI read from a QR Code
 * Returns: Identifier of the stored info or -1 on failure
 */
int wpas_dpp_qr_code(struct wpa_supplicant *wpa_s, const char *cmd)
{
	struct dpp_bootstrap_info *bi;

	bi = dpp_parse_qr_code(cmd);
	if (!bi)
		return -1;

	bi->id = wpas_dpp_next_id(wpa_s);
	dl_list_add(&wpa_s->dpp_bootstrap, &bi->list);

	return bi->id;
}


static char * get_param(const char *cmd, const char *param)
{
	const char *pos, *end;
	char *val;
	size_t len;

	pos = os_strstr(cmd, param);
	if (!pos)
		return NULL;

	pos += os_strlen(param);
	end = os_strchr(pos, ' ');
	if (end)
		len = end - pos;
	else
		len = os_strlen(pos);
	val = os_malloc(len + 1);
	if (!val)
		return NULL;
	os_memcpy(val, pos, len);
	val[len] = '\0';
	return val;
}


int wpas_dpp_bootstrap_gen(struct wpa_supplicant *wpa_s, const char *cmd)
{
	char *chan = NULL, *mac = NULL, *info = NULL, *pk = NULL, *curve = NULL;
	char *key = NULL;
	u8 *privkey = NULL;
	size_t privkey_len = 0;
	size_t len;
	int ret = -1;
	struct dpp_bootstrap_info *bi;

	bi = os_zalloc(sizeof(*bi));
	if (!bi)
		goto fail;

	if (os_strstr(cmd, "type=qrcode"))
		bi->type = DPP_BOOTSTRAP_QR_CODE;
	else
		goto fail;

	chan = get_param(cmd, " chan=");
	mac = get_param(cmd, " mac=");
	info = get_param(cmd, " info=");
	curve = get_param(cmd, " curve=");
	key = get_param(cmd, " key=");

	if (key) {
		privkey_len = os_strlen(key) / 2;
		privkey = os_malloc(privkey_len);
		if (!privkey ||
		    hexstr2bin(key, privkey, privkey_len) < 0)
			goto fail;
	}

	pk = dpp_keygen(bi, curve, privkey, privkey_len);
	if (!pk)
		goto fail;

	len = 4; /* "DPP:" */
	if (chan) {
		if (dpp_parse_uri_chan_list(bi, chan) < 0)
			goto fail;
		len += 3 + os_strlen(chan); /* C:...; */
	}
	if (mac) {
		if (dpp_parse_uri_mac(bi, mac) < 0)
			goto fail;
		len += 3 + os_strlen(mac); /* M:...; */
	}
	if (info) {
		if (dpp_parse_uri_info(bi, info) < 0)
			goto fail;
		len += 3 + os_strlen(info); /* I:...; */
	}
	len += 4 + os_strlen(pk);
	bi->uri = os_malloc(len + 1);
	if (!bi->uri)
		goto fail;
	os_snprintf(bi->uri, len + 1, "DPP:%s%s%s%s%s%s%s%s%sK:%s;;",
		    chan ? "C:" : "", chan ? chan : "", chan ? ";" : "",
		    mac ? "M:" : "", mac ? mac : "", mac ? ";" : "",
		    info ? "I:" : "", info ? info : "", info ? ";" : "",
		    pk);
	bi->id = wpas_dpp_next_id(wpa_s);
	dl_list_add(&wpa_s->dpp_bootstrap, &bi->list);
	ret = bi->id;
	bi = NULL;
fail:
	os_free(curve);
	os_free(pk);
	os_free(chan);
	os_free(mac);
	os_free(info);
	str_clear_free(key);
	bin_clear_free(privkey, privkey_len);
	dpp_bootstrap_info_free(bi);
	return ret;
}


static struct dpp_bootstrap_info *
dpp_bootstrap_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
{
	struct dpp_bootstrap_info *bi;

	dl_list_for_each(bi, &wpa_s->dpp_bootstrap, struct dpp_bootstrap_info,
			 list) {
		if (bi->id == id)
			return bi;
	}
	return NULL;
}


static int dpp_bootstrap_del(struct wpa_supplicant *wpa_s, unsigned int id)
{
	struct dpp_bootstrap_info *bi, *tmp;
	int found = 0;

	dl_list_for_each_safe(bi, tmp, &wpa_s->dpp_bootstrap,
			      struct dpp_bootstrap_info, list) {
		if (id && bi->id != id)
			continue;
		found = 1;
		dl_list_del(&bi->list);
		dpp_bootstrap_info_free(bi);
	}

	if (id == 0)
		return 0; /* flush succeeds regardless of entries found */
	return found ? 0 : -1;
}


int wpas_dpp_bootstrap_remove(struct wpa_supplicant *wpa_s, const char *id)
{
	unsigned int id_val;

	if (os_strcmp(id, "*") == 0) {
		id_val = 0;
	} else {
		id_val = atoi(id);
		if (id_val == 0)
			return -1;
	}

	return dpp_bootstrap_del(wpa_s, id_val);
}


const char * wpas_dpp_bootstrap_get_uri(struct wpa_supplicant *wpa_s,
					unsigned int id)
{
	struct dpp_bootstrap_info *bi;

	bi = dpp_bootstrap_get_id(wpa_s, id);
	if (!bi)
		return NULL;
	return bi->uri;
}


int wpas_dpp_init(struct wpa_supplicant *wpa_s)
{
	dl_list_init(&wpa_s->dpp_bootstrap);
	wpa_s->dpp_init_done = 1;
	return 0;
}


void wpas_dpp_deinit(struct wpa_supplicant *wpa_s)
{
	if (!wpa_s->dpp_init_done)
		return;
	dpp_bootstrap_del(wpa_s, 0);
}