eap_sim_common.c

一个Linux下无线网卡的设置工具

/*
 * WPA Supplicant / EAP-SIM/AKA shared routines
 * Copyright (c) 2004-2005, 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>
#include <string.h>

#include "common.h"
#include "eap_i.h"
#include "sha1.h"
#include "crypto.h"
#include "aes_wrap.h"
#include "eap_sim_common.h"


static void eap_sim_prf(const u8 *key, u8 *x, size_t xlen)
{
	u8 xkey[64];
	u32 t[5], _t[5];
	int i, j, m, k;
	u8 *xpos = x;
	u32 carry;

	/* FIPS 186-2 + change notice 1 */

	memcpy(xkey, key, EAP_SIM_MK_LEN);
	memset(xkey + EAP_SIM_MK_LEN, 0, 64 - EAP_SIM_MK_LEN);
	t[0] = 0x67452301;
	t[1] = 0xEFCDAB89;
	t[2] = 0x98BADCFE;
	t[3] = 0x10325476;
	t[4] = 0xC3D2E1F0;

	m = xlen / 40;
	for (j = 0; j < m; j++) {
		/* XSEED_j = 0 */
		for (i = 0; i < 2; i++) {
			/* XVAL = (XKEY + XSEED_j) mod 2^b */

			/* w_i = G(t, XVAL) */
			memcpy(_t, t, 20);
			sha1_transform((u8 *) _t, xkey);
			_t[0] = host_to_be32(_t[0]);
			_t[1] = host_to_be32(_t[1]);
			_t[2] = host_to_be32(_t[2]);
			_t[3] = host_to_be32(_t[3]);
			_t[4] = host_to_be32(_t[4]);
			memcpy(xpos, _t, 20);

			/* XKEY = (1 + XKEY + w_i) mod 2^b */
			carry = 1;
			for (k = 19; k >= 0; k--) {
				carry += xkey[k] + xpos[k];
				xkey[k] = carry & 0xff;
				carry >>= 8;
			}

			xpos += SHA1_MAC_LEN;
		}
		/* x_j = w_0|w_1 */
	}
}


void eap_sim_derive_keys(const u8 *mk, u8 *k_encr, u8 *k_aut, u8 *msk)
{
	u8 buf[120], *pos;
	eap_sim_prf(mk, buf, 120);
	pos = buf;
	memcpy(k_encr, pos, EAP_SIM_K_ENCR_LEN);
	pos += EAP_SIM_K_ENCR_LEN;
	memcpy(k_aut, pos, EAP_SIM_K_AUT_LEN);
	pos += EAP_SIM_K_AUT_LEN;
	memcpy(msk, pos, EAP_SIM_KEYING_DATA_LEN);

	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_encr",
			k_encr, EAP_SIM_K_ENCR_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_aut",
			k_aut, EAP_SIM_K_ENCR_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: keying material",
			msk, EAP_SIM_KEYING_DATA_LEN);
}


void eap_sim_derive_keys_reauth(u16 _counter,
				const u8 *identity, size_t identity_len,
				const u8 *nonce_s, const u8 *mk, u8 *msk)
{
	u8 xkey[SHA1_MAC_LEN];
	u8 counter[2];
	const u8 *addr[4];
	size_t len[4];

	addr[0] = identity;
	len[0] = identity_len;
	addr[1] = counter;
	len[1] = 2;
	addr[2] = nonce_s;
	len[2] = EAP_SIM_NONCE_S_LEN;
	addr[3] = mk;
	len[3] = EAP_SIM_MK_LEN;

	WPA_PUT_BE16(counter, _counter);

	wpa_printf(MSG_DEBUG, "EAP-SIM: Deriving keying data from reauth");
	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
			  identity, identity_len);
	wpa_hexdump(MSG_DEBUG, "EAP-SIM: counter", counter, 2);
	wpa_hexdump(MSG_DEBUG, "EAP-SIM: NONCE_S", nonce_s,
		    EAP_SIM_NONCE_S_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", mk, EAP_SIM_MK_LEN);

	/* XKEY' = SHA1(Identity|counter|NONCE_S|MK) */
	sha1_vector(4, addr, len, xkey);
	wpa_hexdump(MSG_DEBUG, "EAP-SIM: XKEY'", xkey, SHA1_MAC_LEN);

	eap_sim_prf(xkey, msk, EAP_SIM_KEYING_DATA_LEN);
	wpa_hexdump(MSG_DEBUG, "EAP-SIM: keying material",
		    msk, EAP_SIM_KEYING_DATA_LEN);
}


int eap_sim_verify_mac(const u8 *k_aut, const u8 *req, size_t req_len,
		       const u8 *mac, const u8 *extra, size_t extra_len)
{
	unsigned char hmac[SHA1_MAC_LEN];
	const u8 *addr[2];
	size_t len[2];
	u8 *tmp;

	if (mac == NULL || req_len < EAP_SIM_MAC_LEN || mac < req ||
	    mac > req + req_len - EAP_SIM_MAC_LEN)
		return -1;

	tmp = malloc(req_len);
	if (tmp == NULL)
		return -1;

	addr[0] = tmp;
	len[0] = req_len;
	addr[1] = extra;
	len[1] = extra_len;

	/* HMAC-SHA1-128 */
	memcpy(tmp, req, req_len);
	memset(tmp + (mac - req), 0, EAP_SIM_MAC_LEN);
	hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
	free(tmp);

	return (memcmp(hmac, mac, EAP_SIM_MAC_LEN) == 0) ? 0 : 1;
}


void eap_sim_add_mac(const u8 *k_aut, u8 *msg, size_t msg_len, u8 *mac,
		     const u8 *extra, size_t extra_len)
{
	unsigned char hmac[SHA1_MAC_LEN];
	const u8 *addr[2];
	size_t len[2];

	addr[0] = msg;
	len[0] = msg_len;
	addr[1] = extra;
	len[1] = extra_len;

	/* HMAC-SHA1-128 */
	memset(mac, 0, EAP_SIM_MAC_LEN);
	hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
	memcpy(mac, hmac, EAP_SIM_MAC_LEN);
}


int eap_sim_parse_attr(const u8 *start, const u8 *end,
		       struct eap_sim_attrs *attr, int aka, int encr)
{
	const u8 *pos = start, *apos;
	size_t alen, plen;
	int list_len, i;

	memset(attr, 0, sizeof(*attr));
	attr->id_req = NO_ID_REQ;
	attr->notification = -1;
	attr->counter = -1;
	attr->selected_version = -1;
	attr->client_error_code = -1;

	while (pos < end) {
		if (pos + 2 > end) {
			wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow(1)");
			return -1;
		}
		wpa_printf(MSG_MSGDUMP, "EAP-SIM: Attribute: Type=%d Len=%d",
			   pos[0], pos[1] * 4);
		if (pos + pos[1] * 4 > end) {
			wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow "
				   "(pos=%p len=%d end=%p)",
				   pos, pos[1] * 4, end);
			return -1;
		}
		apos = pos + 2;
		alen = pos[1] * 4 - 2;
		wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Attribute data",
			    apos, alen);

		switch (pos[0]) {
		case EAP_SIM_AT_RAND:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RAND");
			apos += 2;
			alen -= 2;
			if ((!aka && (alen % GSM_RAND_LEN)) ||
			    (aka && alen != AKA_RAND_LEN)) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_RAND"
					   " (len %lu)",
					   (unsigned long) alen);
				return -1;
			}
			attr->rand = apos;
			attr->num_chal = alen / GSM_RAND_LEN;
			break;
		case EAP_SIM_AT_AUTN:
			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_AUTN");
			if (!aka) {
				wpa_printf(MSG_DEBUG, "EAP-SIM: "
					   "Unexpected AT_AUTN");
				return -1;
			}
			apos += 2;
			alen -= 2;
			if (alen != AKA_AUTN_LEN) {
				wpa_printf(MSG_INFO, "EAP-AKA: Invalid AT_AUTN"
					   " (len %lu)",
					   (unsigned long) alen);
				return -1;
			}
			attr->autn = apos;
			break;
		case EAP_SIM_AT_PADDING:
			if (!encr) {
				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
					   "AT_PADDING");
				return -1;
			}
			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_PADDING");
			for (i = 2; i < alen; i++) {
				if (apos[i] != 0) {
					wpa_printf(MSG_INFO, "EAP-SIM: (encr) "
						   "AT_PADDING used a non-zero"
						   " padding byte");
					wpa_hexdump(MSG_DEBUG, "EAP-SIM: "
						    "(encr) padding bytes",
						    apos + 2, alen - 2);
					return -1;
				}
			}
			break;
		case EAP_SIM_AT_NONCE_MT:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NONCE_MT");
			if (alen != 2 + EAP_SIM_NONCE_MT_LEN) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
					   "AT_NONCE_MT length");
				return -1;
			}
			attr->nonce_mt = apos + 2;
			break;
		case EAP_SIM_AT_PERMANENT_ID_REQ:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_PERMANENT_ID_REQ");
			attr->id_req = PERMANENT_ID;
			break;
		case EAP_SIM_AT_MAC:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_MAC");
			if (alen != 2 + EAP_SIM_MAC_LEN) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_MAC "
					   "length");
				return -1;
			}
			attr->mac = apos + 2;
			break;
		case EAP_SIM_AT_NOTIFICATION:
			if (alen != 2) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
					   "AT_NOTIFICATION length %lu",
					   (unsigned long) alen);
				return -1;
			}
			attr->notification = apos[0] * 256 + apos[1];
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NOTIFICATION %d",
				   attr->notification);
			break;
		case EAP_SIM_AT_ANY_ID_REQ:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ANY_ID_REQ");
			attr->id_req = ANY_ID;
			break;
		case EAP_SIM_AT_IDENTITY:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IDENTITY");
			attr->identity = apos + 2;
			attr->identity_len = alen - 2;
			break;
		case EAP_SIM_AT_VERSION_LIST:
			if (aka) {
				wpa_printf(MSG_DEBUG, "EAP-AKA: "
					   "Unexpected AT_VERSION_LIST");
				return -1;
			}
			list_len = apos[0] * 256 + apos[1];
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_VERSION_LIST");
			if (list_len < 2 || list_len > alen - 2) {
				wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
					   "AT_VERSION_LIST (list_len=%d "
					   "attr_len=%lu)", list_len,
					   (unsigned long) alen);
				return -1;
			}
			attr->version_list = apos + 2;
			attr->version_list_len = list_len;
			break;
		case EAP_SIM_AT_SELECTED_VERSION:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION");
			if (alen != 2) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
					   "AT_SELECTED_VERSION length %lu",
					   (unsigned long) alen);
				return -1;
			}
			attr->selected_version = apos[0] * 256 + apos[1];
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION "
				   "%d", attr->selected_version);
			break;
		case EAP_SIM_AT_FULLAUTH_ID_REQ:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_FULLAUTH_ID_REQ");
			attr->id_req = FULLAUTH_ID;
			break;
		case EAP_SIM_AT_COUNTER:
			if (!encr) {
				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
					   "AT_COUNTER");
				return -1;
			}
			if (alen != 2) {
				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
					   "AT_COUNTER (alen=%lu)",
					   (unsigned long) alen);
				return -1;
			}
			attr->counter = apos[0] * 256 + apos[1];
			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_COUNTER %d",
				   attr->counter);
			break;
		case EAP_SIM_AT_NONCE_S:
			if (!encr) {
				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
					   "AT_NONCE_S");
				return -1;
			}
			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
				   "AT_NONCE_S");
			if (alen != 2 + EAP_SIM_NONCE_S_LEN) {
				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
					   "AT_NONCE_S (alen=%lu)",
					   (unsigned long) alen);
				return -1;
			}
			attr->nonce_s = apos + 2;
			break;
		case EAP_SIM_AT_CLIENT_ERROR_CODE:
			if (alen != 2) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
					   "AT_CLIENT_ERROR_CODE length %lu",
					   (unsigned long) alen);
				return -1;
			}
			attr->client_error_code = apos[0] * 256 + apos[1];
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_CLIENT_ERROR_CODE "
				   "%d", attr->client_error_code);
			break;
		case EAP_SIM_AT_IV:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IV");
			if (alen != 2 + EAP_SIM_MAC_LEN) {
				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_IV "
					   "length %lu", (unsigned long) alen);
				return -1;
			}
			attr->iv = apos + 2;
			break;
		case EAP_SIM_AT_ENCR_DATA:
			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ENCR_DATA");
			attr->encr_data = apos + 2;
			attr->encr_data_len = alen - 2;