wpa.c

WPA在Linux下实现的原代码 WPA在Linux下实现的原代码

/*
 * WPA Supplicant - WPA state machine and EAPOL-Key processing
 * Copyright (c) 2003-2007, Jouni Malinen <[e-mail]>
 *
 * 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 <stdlib.h>
#include <stdio.h>
#ifndef CONFIG_NATIVE_WINDOWS
#include <netinet/in.h>
#endif /* CONFIG_NATIVE_WINDOWS */
#include <string.h>

#include "common.h"
#include "md5.h"
#include "sha1.h"
#include "rc4.h"
#include "aes_wrap.h"
#include "wpa.h"
#include "eloop.h"
#include "wpa_supplicant.h"
#include "config.h"
#include "l2_packet.h"
#include "eapol_sm.h"
#include "preauth.h"
#include "wpa_i.h"


static const int WPA_SELECTOR_LEN = 4;
static const u8 WPA_OUI_TYPE[] = { 0x00, 0x50, 0xf2, 1 };
static const u16 WPA_VERSION = 1;
static const u8 WPA_AUTH_KEY_MGMT_NONE[] = { 0x00, 0x50, 0xf2, 0 };
static const u8 WPA_AUTH_KEY_MGMT_UNSPEC_802_1X[] = { 0x00, 0x50, 0xf2, 1 };
static const u8 WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X[] = { 0x00, 0x50, 0xf2, 2 };
static const u8 WPA_CIPHER_SUITE_NONE[] = { 0x00, 0x50, 0xf2, 0 };
static const u8 WPA_CIPHER_SUITE_WEP40[] = { 0x00, 0x50, 0xf2, 1 };
static const u8 WPA_CIPHER_SUITE_TKIP[] = { 0x00, 0x50, 0xf2, 2 };
static const u8 WPA_CIPHER_SUITE_WRAP[] = { 0x00, 0x50, 0xf2, 3 };
static const u8 WPA_CIPHER_SUITE_CCMP[] = { 0x00, 0x50, 0xf2, 4 };
static const u8 WPA_CIPHER_SUITE_WEP104[] = { 0x00, 0x50, 0xf2, 5 };

/* WPA IE version 1
 * 00-50-f2:1 (OUI:OUI type)
 * 0x01 0x00 (version; little endian)
 * (all following fields are optional:)
 * Group Suite Selector (4 octets) (default: TKIP)
 * Pairwise Suite Count (2 octets, little endian) (default: 1)
 * Pairwise Suite List (4 * n octets) (default: TKIP)
 * Authenticated Key Management Suite Count (2 octets, little endian)
 *    (default: 1)
 * Authenticated Key Management Suite List (4 * n octets)
 *    (default: unspec 802.1X)
 * WPA Capabilities (2 octets, little endian) (default: 0)
 */

struct wpa_ie_hdr {
	u8 elem_id;
	u8 len;
	u8 oui[3];
	u8 oui_type;
	u8 version[2];
} __attribute__ ((packed));


static const int RSN_SELECTOR_LEN = 4;
static const u16 RSN_VERSION = 1;
static const u8 RSN_AUTH_KEY_MGMT_UNSPEC_802_1X[] = { 0x00, 0x0f, 0xac, 1 };
static const u8 RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X[] = { 0x00, 0x0f, 0xac, 2 };
static const u8 RSN_CIPHER_SUITE_NONE[] = { 0x00, 0x0f, 0xac, 0 };
static const u8 RSN_CIPHER_SUITE_WEP40[] = { 0x00, 0x0f, 0xac, 1 };
static const u8 RSN_CIPHER_SUITE_TKIP[] = { 0x00, 0x0f, 0xac, 2 };
static const u8 RSN_CIPHER_SUITE_WRAP[] = { 0x00, 0x0f, 0xac, 3 };
static const u8 RSN_CIPHER_SUITE_CCMP[] = { 0x00, 0x0f, 0xac, 4 };
static const u8 RSN_CIPHER_SUITE_WEP104[] = { 0x00, 0x0f, 0xac, 5 };

/* EAPOL-Key Key Data Encapsulation
 * GroupKey and STAKey require encryption, otherwise, encryption is optional.
 */
static const u8 RSN_KEY_DATA_GROUPKEY[] = { 0x00, 0x0f, 0xac, 1 };
static const u8 RSN_KEY_DATA_STAKEY[] = { 0x00, 0x0f, 0xac, 2 };
static const u8 RSN_KEY_DATA_MAC_ADDR[] = { 0x00, 0x0f, 0xac, 3 };
static const u8 RSN_KEY_DATA_PMKID[] = { 0x00, 0x0f, 0xac, 4 };

/* 1/4: PMKID
 * 2/4: RSN IE
 * 3/4: one or two RSN IEs + GTK IE (encrypted)
 * 4/4: empty
 * 1/2: GTK IE (encrypted)
 * 2/2: empty
 */

/* RSN IE version 1
 * 0x01 0x00 (version; little endian)
 * (all following fields are optional:)
 * Group Suite Selector (4 octets) (default: CCMP)
 * Pairwise Suite Count (2 octets, little endian) (default: 1)
 * Pairwise Suite List (4 * n octets) (default: CCMP)
 * Authenticated Key Management Suite Count (2 octets, little endian)
 *    (default: 1)
 * Authenticated Key Management Suite List (4 * n octets)
 *    (default: unspec 802.1X)
 * RSN Capabilities (2 octets, little endian) (default: 0)
 * PMKID Count (2 octets) (default: 0)
 * PMKID List (16 * n octets)
 */

struct rsn_ie_hdr {
	u8 elem_id; /* WLAN_EID_RSN */
	u8 len;
	u8 version[2];
} __attribute__ ((packed));


struct wpa_eapol_key {
	u8 type;
	/* Note: key_info, key_length, and key_data_length are unaligned */
	u8 key_info[2];
	u8 key_length[2];
	u8 replay_counter[WPA_REPLAY_COUNTER_LEN];
	u8 key_nonce[WPA_NONCE_LEN];
	u8 key_iv[16];
	u8 key_rsc[8];
	u8 key_id[8]; /* Reserved in IEEE 802.11i/RSN */
	u8 key_mic[16];
	u8 key_data_length[2];
	/* followed by key_data_length bytes of key_data */
} __attribute__ ((packed));

#define WPA_KEY_INFO_TYPE_MASK (BIT(0) | BIT(1) | BIT(2))
#define WPA_KEY_INFO_TYPE_HMAC_MD5_RC4 BIT(0)
#define WPA_KEY_INFO_TYPE_HMAC_SHA1_AES BIT(1)
#define WPA_KEY_INFO_KEY_TYPE BIT(3) /* 1 = Pairwise, 0 = Group key */
/* bit4..5 is used in WPA, but is reserved in IEEE 802.11i/RSN */
#define WPA_KEY_INFO_KEY_INDEX_MASK (BIT(4) | BIT(5))
#define WPA_KEY_INFO_KEY_INDEX_SHIFT 4
#define WPA_KEY_INFO_INSTALL BIT(6) /* pairwise */
#define WPA_KEY_INFO_TXRX BIT(6) /* group */
#define WPA_KEY_INFO_ACK BIT(7)
#define WPA_KEY_INFO_MIC BIT(8)
#define WPA_KEY_INFO_SECURE BIT(9)
#define WPA_KEY_INFO_ERROR BIT(10)
#define WPA_KEY_INFO_REQUEST BIT(11)
#define WPA_KEY_INFO_ENCR_KEY_DATA BIT(12) /* IEEE 802.11i/RSN only */



/**
 * wpa_cipher_txt - Convert cipher suite to a text string
 * @cipher: Cipher suite (WPA_CIPHER_* enum)
 * Returns: Pointer to a text string of the cipher suite name
 */
static const char * wpa_cipher_txt(int cipher)
{
	switch (cipher) {
	case WPA_CIPHER_NONE:
		return "NONE";
	case WPA_CIPHER_WEP40:
		return "WEP-40";
	case WPA_CIPHER_WEP104:
		return "WEP-104";
	case WPA_CIPHER_TKIP:
		return "TKIP";
	case WPA_CIPHER_CCMP:
		return "CCMP";
	default:
		return "UNKNOWN";
	}
}


/**
 * wpa_key_mgmt_txt - Convert key management suite to a text string
 * @key_mgmt: Key management suite (WPA_KEY_MGMT_* enum)
 * @proto: WPA/WPA2 version (WPA_PROTO_*)
 * Returns: Pointer to a text string of the key management suite name
 */
static const char * wpa_key_mgmt_txt(int key_mgmt, int proto)
{
	switch (key_mgmt) {
	case WPA_KEY_MGMT_IEEE8021X:
		return proto == WPA_PROTO_RSN ?
			"WPA2/IEEE 802.1X/EAP" : "WPA/IEEE 802.1X/EAP";
	case WPA_KEY_MGMT_PSK:
		return proto == WPA_PROTO_RSN ?
			"WPA2-PSK" : "WPA-PSK";
	case WPA_KEY_MGMT_NONE:
		return "NONE";
	case WPA_KEY_MGMT_IEEE8021X_NO_WPA:
		return "IEEE 802.1X (no WPA)";
	default:
		return "UNKNOWN";
	}
}


static int wpa_selector_to_bitfield(const u8 *s)
{
	if (memcmp(s, WPA_CIPHER_SUITE_NONE, WPA_SELECTOR_LEN) == 0)
		return WPA_CIPHER_NONE;
	if (memcmp(s, WPA_CIPHER_SUITE_WEP40, WPA_SELECTOR_LEN) == 0)
		return WPA_CIPHER_WEP40;
	if (memcmp(s, WPA_CIPHER_SUITE_TKIP, WPA_SELECTOR_LEN) == 0)
		return WPA_CIPHER_TKIP;
	if (memcmp(s, WPA_CIPHER_SUITE_CCMP, WPA_SELECTOR_LEN) == 0)
		return WPA_CIPHER_CCMP;
	if (memcmp(s, WPA_CIPHER_SUITE_WEP104, WPA_SELECTOR_LEN) == 0)
		return WPA_CIPHER_WEP104;
	return 0;
}


static int wpa_key_mgmt_to_bitfield(const u8 *s)
{
	if (memcmp(s, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X, WPA_SELECTOR_LEN) == 0)
		return WPA_KEY_MGMT_IEEE8021X;
	if (memcmp(s, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X, WPA_SELECTOR_LEN) ==
	    0)
		return WPA_KEY_MGMT_PSK;
	if (memcmp(s, WPA_AUTH_KEY_MGMT_NONE, WPA_SELECTOR_LEN) == 0)
		return WPA_KEY_MGMT_WPA_NONE;
	return 0;
}


static int rsn_selector_to_bitfield(const u8 *s)
{
	if (memcmp(s, RSN_CIPHER_SUITE_NONE, RSN_SELECTOR_LEN) == 0)
		return WPA_CIPHER_NONE;
	if (memcmp(s, RSN_CIPHER_SUITE_WEP40, RSN_SELECTOR_LEN) == 0)
		return WPA_CIPHER_WEP40;
	if (memcmp(s, RSN_CIPHER_SUITE_TKIP, RSN_SELECTOR_LEN) == 0)
		return WPA_CIPHER_TKIP;
	if (memcmp(s, RSN_CIPHER_SUITE_CCMP, RSN_SELECTOR_LEN) == 0)
		return WPA_CIPHER_CCMP;
	if (memcmp(s, RSN_CIPHER_SUITE_WEP104, RSN_SELECTOR_LEN) == 0)
		return WPA_CIPHER_WEP104;
	return 0;
}


static int rsn_key_mgmt_to_bitfield(const u8 *s)
{
	if (memcmp(s, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X, RSN_SELECTOR_LEN) == 0)
		return WPA_KEY_MGMT_IEEE8021X;
	if (memcmp(s, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X, RSN_SELECTOR_LEN) ==
	    0)
		return WPA_KEY_MGMT_PSK;
	return 0;
}


static int wpa_parse_wpa_ie_wpa(const u8 *wpa_ie, size_t wpa_ie_len,
				struct wpa_ie_data *data)
{
	const struct wpa_ie_hdr *hdr;
	const u8 *pos;
	int left;
	int i, count;

	data->proto = WPA_PROTO_WPA;
	data->pairwise_cipher = WPA_CIPHER_TKIP;
	data->group_cipher = WPA_CIPHER_TKIP;
	data->key_mgmt = WPA_KEY_MGMT_IEEE8021X;
	data->capabilities = 0;
	data->pmkid = NULL;
	data->num_pmkid = 0;

	if (wpa_ie_len == 0) {
		/* No WPA IE - fail silently */
		return -1;
	}

	if (wpa_ie_len < sizeof(struct wpa_ie_hdr)) {
		wpa_printf(MSG_DEBUG, "%s: ie len too short %lu",
			   __func__, (unsigned long) wpa_ie_len);
		return -1;
	}

	hdr = (const struct wpa_ie_hdr *) wpa_ie;

	if (hdr->elem_id != GENERIC_INFO_ELEM ||
	    hdr->len != wpa_ie_len - 2 ||
	    memcmp(&hdr->oui, WPA_OUI_TYPE, WPA_SELECTOR_LEN) != 0 ||
	    WPA_GET_LE16(hdr->version) != WPA_VERSION) {
		wpa_printf(MSG_DEBUG, "%s: malformed ie or unknown version",
			   __func__);
		return -1;
	}

	pos = (const u8 *) (hdr + 1);
	left = wpa_ie_len - sizeof(*hdr);

	if (left >= WPA_SELECTOR_LEN) {
		data->group_cipher = wpa_selector_to_bitfield(pos);
		pos += WPA_SELECTOR_LEN;
		left -= WPA_SELECTOR_LEN;
	} else if (left > 0) {
		wpa_printf(MSG_DEBUG, "%s: ie length mismatch, %u too much",
			   __func__, left);
		return -1;
	}

	if (left >= 2) {
		data->pairwise_cipher = 0;
		count = WPA_GET_LE16(pos);
		pos += 2;
		left -= 2;
		if (count == 0 || left < count * WPA_SELECTOR_LEN) {
			wpa_printf(MSG_DEBUG, "%s: ie count botch (pairwise), "
				   "count %u left %u", __func__, count, left);
			return -1;
		}
		for (i = 0; i < count; i++) {
			data->pairwise_cipher |= wpa_selector_to_bitfield(pos);
			pos += WPA_SELECTOR_LEN;
			left -= WPA_SELECTOR_LEN;
		}
	} else if (left == 1) {
		wpa_printf(MSG_DEBUG, "%s: ie too short (for key mgmt)",
			   __func__);
		return -1;
	}

	if (left >= 2) {
		data->key_mgmt = 0;
		count = WPA_GET_LE16(pos);
		pos += 2;
		left -= 2;
		if (count == 0 || left < count * WPA_SELECTOR_LEN) {
			wpa_printf(MSG_DEBUG, "%s: ie count botch (key mgmt), "
				   "count %u left %u", __func__, count, left);
			return -1;
		}
		for (i = 0; i < count; i++) {
			data->key_mgmt |= wpa_key_mgmt_to_bitfield(pos);
			pos += WPA_SELECTOR_LEN;
			left -= WPA_SELECTOR_LEN;
		}
	} else if (left == 1) {
		wpa_printf(MSG_DEBUG, "%s: ie too short (for capabilities)",
			   __func__);
		return -1;
	}

	if (left >= 2) {
		data->capabilities = WPA_GET_LE16(pos);
		pos += 2;
		left -= 2;
	}

	if (left > 0) {
		wpa_printf(MSG_DEBUG, "%s: ie has %u trailing bytes - ignored",
			   __func__, left);
	}

	return 0;
}


static int wpa_parse_wpa_ie_rsn(const u8 *rsn_ie, size_t rsn_ie_len,
				struct wpa_ie_data *data)
{
	const struct rsn_ie_hdr *hdr;
	const u8 *pos;
	int left;
	int i, count;

	data->proto = WPA_PROTO_RSN;
	data->pairwise_cipher = WPA_CIPHER_CCMP;
	data->group_cipher = WPA_CIPHER_CCMP;
	data->key_mgmt = WPA_KEY_MGMT_IEEE8021X;
	data->capabilities = 0;
	data->pmkid = NULL;
	data->num_pmkid = 0;

	if (rsn_ie_len == 0) {
		/* No RSN IE - fail silently */
		return -1;
	}

	if (rsn_ie_len < sizeof(struct rsn_ie_hdr)) {
		wpa_printf(MSG_DEBUG, "%s: ie len too short %lu",
			   __func__, (unsigned long) rsn_ie_len);
		return -1;
	}

	hdr = (const struct rsn_ie_hdr *) rsn_ie;

	if (hdr->elem_id != RSN_INFO_ELEM ||
	    hdr->len != rsn_ie_len - 2 ||
	    WPA_GET_LE16(hdr->version) != RSN_VERSION) {
		wpa_printf(MSG_DEBUG, "%s: malformed ie or unknown version",
			   __func__);
		return -1;
	}

	pos = (const u8 *) (hdr + 1);
	left = rsn_ie_len - sizeof(*hdr);

	if (left >= RSN_SELECTOR_LEN) {
		data->group_cipher = rsn_selector_to_bitfield(pos);
		pos += RSN_SELECTOR_LEN;
		left -= RSN_SELECTOR_LEN;
	} else if (left > 0) {
		wpa_printf(MSG_DEBUG, "%s: ie length mismatch, %u too much",
			   __func__, left);
		return -1;
	}

	if (left >= 2) {
		data->pairwise_cipher = 0;
		count = WPA_GET_LE16(pos);
		pos += 2;
		left -= 2;
		if (count == 0 || left < count * RSN_SELECTOR_LEN) {
			wpa_printf(MSG_DEBUG, "%s: ie count botch (pairwise), "
				   "count %u left %u", __func__, count, left);
			return -1;
		}
		for (i = 0; i < count; i++) {
			data->pairwise_cipher |= rsn_selector_to_bitfield(pos);
			pos += RSN_SELECTOR_LEN;
			left -= RSN_SELECTOR_LEN;
		}
	} else if (left == 1) {
		wpa_printf(MSG_DEBUG, "%s: ie too short (for key mgmt)",
			   __func__);
		return -1;
	}

	if (left >= 2) {
		data->key_mgmt = 0;
		count = WPA_GET_LE16(pos);
		pos += 2;
		left -= 2;
		if (count == 0 || left < count * RSN_SELECTOR_LEN) {
			wpa_printf(MSG_DEBUG, "%s: ie count botch (key mgmt), "
				   "count %u left %u", __func__, count, left);
			return -1;
		}
		for (i = 0; i < count; i++) {
			data->key_mgmt |= rsn_key_mgmt_to_bitfield(pos);
			pos += RSN_SELECTOR_LEN;
			left -= RSN_SELECTOR_LEN;
		}
	} else if (left == 1) {
		wpa_printf(MSG_DEBUG, "%s: ie too short (for capabilities)",
			   __func__);
		return -1;
	}