[thirdparty/hostap.git] / src / eap_server / eap_server_psk.c

/*
 * hostapd / EAP-PSK (RFC 4764) server
 * Copyright (c) 2005-2007, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 *
 * Note: EAP-PSK is an EAP authentication method and as such, completely
 * different from WPA-PSK. This file is not needed for WPA-PSK functionality.
 */

#include "includes.h"

#include "common.h"
#include "crypto/aes_wrap.h"
#include "crypto/random.h"
#include "eap_common/eap_psk_common.h"
#include "eap_server/eap_i.h"


struct eap_psk_data {
	enum { PSK_1, PSK_3, SUCCESS, FAILURE } state;
	u8 rand_s[EAP_PSK_RAND_LEN];
	u8 rand_p[EAP_PSK_RAND_LEN];
	u8 *id_p;
	size_t id_p_len;
	u8 ak[EAP_PSK_AK_LEN], kdk[EAP_PSK_KDK_LEN], tek[EAP_PSK_TEK_LEN];
	u8 msk[EAP_MSK_LEN];
	u8 emsk[EAP_EMSK_LEN];
};


static void * eap_psk_init(struct eap_sm *sm)
{
	struct eap_psk_data *data;

	data = os_zalloc(sizeof(*data));
	if (data == NULL)
		return NULL;
	data->state = PSK_1;

	return data;
}


static void eap_psk_reset(struct eap_sm *sm, void *priv)
{
	struct eap_psk_data *data = priv;
	os_free(data->id_p);
	bin_clear_free(data, sizeof(*data));
}


static struct wpabuf * eap_psk_build_1(struct eap_sm *sm,
				       struct eap_psk_data *data, u8 id)
{
	struct wpabuf *req;
	struct eap_psk_hdr_1 *psk;

	wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-1 (sending)");

	if (random_get_bytes(data->rand_s, EAP_PSK_RAND_LEN)) {
		wpa_printf(MSG_ERROR, "EAP-PSK: Failed to get random data");
		data->state = FAILURE;
		return NULL;
	}
	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_S (server rand)",
		    data->rand_s, EAP_PSK_RAND_LEN);

	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
			    sizeof(*psk) + sm->server_id_len,
			    EAP_CODE_REQUEST, id);
	if (req == NULL) {
		wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
			   "request");
		data->state = FAILURE;
		return NULL;
	}

	psk = wpabuf_put(req, sizeof(*psk));
	psk->flags = EAP_PSK_FLAGS_SET_T(0); /* T=0 */
	os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
	wpabuf_put_data(req, sm->server_id, sm->server_id_len);

	return req;
}


static struct wpabuf * eap_psk_build_3(struct eap_sm *sm,
				       struct eap_psk_data *data, u8 id)
{
	struct wpabuf *req;
	struct eap_psk_hdr_3 *psk;
	u8 *buf, *pchannel, nonce[16];
	size_t buflen;

	wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-3 (sending)");

	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
			    sizeof(*psk) + 4 + 16 + 1, EAP_CODE_REQUEST, id);
	if (req == NULL) {
		wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
			   "request");
		data->state = FAILURE;
		return NULL;
	}

	psk = wpabuf_put(req, sizeof(*psk));
	psk->flags = EAP_PSK_FLAGS_SET_T(2); /* T=2 */
	os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);

	/* MAC_S = OMAC1-AES-128(AK, ID_S||RAND_P) */
	buflen = sm->server_id_len + EAP_PSK_RAND_LEN;
	buf = os_malloc(buflen);
	if (buf == NULL)
		goto fail;

	os_memcpy(buf, sm->server_id, sm->server_id_len);
	os_memcpy(buf + sm->server_id_len, data->rand_p, EAP_PSK_RAND_LEN);
	if (omac1_aes_128(data->ak, buf, buflen, psk->mac_s)) {
		os_free(buf);
		goto fail;
	}
	os_free(buf);

	if (eap_psk_derive_keys(data->kdk, data->rand_p, data->tek, data->msk,
				data->emsk))
		goto fail;
	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: TEK", data->tek, EAP_PSK_TEK_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: MSK", data->msk, EAP_MSK_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: EMSK", data->emsk, EAP_EMSK_LEN);

	os_memset(nonce, 0, sizeof(nonce));
	pchannel = wpabuf_put(req, 4 + 16 + 1);
	os_memcpy(pchannel, nonce + 12, 4);
	os_memset(pchannel + 4, 0, 16); /* Tag */
	pchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_SUCCESS << 6;
	wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (plaintext)",
		    pchannel, 4 + 16 + 1);
	if (aes_128_eax_encrypt(data->tek, nonce, sizeof(nonce),
				wpabuf_head(req), 22,
				pchannel + 4 + 16, 1, pchannel + 4))
		goto fail;
	wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (encrypted)",
		    pchannel, 4 + 16 + 1);

	return req;

fail:
	wpabuf_free(req);
	data->state = FAILURE;
	return NULL;
}


static struct wpabuf * eap_psk_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
	struct eap_psk_data *data = priv;

	switch (data->state) {
	case PSK_1:
		return eap_psk_build_1(sm, data, id);
	case PSK_3:
		return eap_psk_build_3(sm, data, id);
	default:
		wpa_printf(MSG_DEBUG, "EAP-PSK: Unknown state %d in buildReq",
			   data->state);
		break;
	}
	return NULL;
}


static Boolean eap_psk_check(struct eap_sm *sm, void *priv,
			     struct wpabuf *respData)
{
	struct eap_psk_data *data = priv;
	size_t len;
	u8 t;
	const u8 *pos;

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
	if (pos == NULL || len < 1) {
		wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
		return TRUE;
	}
	t = EAP_PSK_FLAGS_GET_T(*pos);

	wpa_printf(MSG_DEBUG, "EAP-PSK: received frame: T=%d", t);

	if (data->state == PSK_1 && t != 1) {
		wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-2 - "
			   "ignore T=%d", t);
		return TRUE;
	}

	if (data->state == PSK_3 && t != 3) {
		wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-4 - "
			   "ignore T=%d", t);
		return TRUE;
	}

	if ((t == 1 && len < sizeof(struct eap_psk_hdr_2)) ||
	    (t == 3 && len < sizeof(struct eap_psk_hdr_4))) {
		wpa_printf(MSG_DEBUG, "EAP-PSK: Too short frame");
		return TRUE;
	}

	return FALSE;
}


static void eap_psk_process_2(struct eap_sm *sm,
			      struct eap_psk_data *data,
			      struct wpabuf *respData)
{
	const struct eap_psk_hdr_2 *resp;
	u8 *pos, mac[EAP_PSK_MAC_LEN], *buf;
	size_t left, buflen;
	int i;
	const u8 *cpos;

	if (data->state != PSK_1)
		return;

	wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-2");

	cpos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData,
				&left);
	if (cpos == NULL || left < sizeof(*resp)) {
		wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
		return;
	}
	resp = (const struct eap_psk_hdr_2 *) cpos;
	cpos = (const u8 *) (resp + 1);
	left -= sizeof(*resp);

	os_free(data->id_p);
	data->id_p = os_memdup(cpos, left);
	if (data->id_p == NULL) {
		wpa_printf(MSG_INFO, "EAP-PSK: Failed to allocate memory for "
			   "ID_P");
		return;
	}
	data->id_p_len = left;
	wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PSK: ID_P",
			  data->id_p, data->id_p_len);

	if (eap_user_get(sm, data->id_p, data->id_p_len, 0) < 0) {
		wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: unknown ID_P",
				  data->id_p, data->id_p_len);
		data->state = FAILURE;
		return;
	}

	for (i = 0;
	     i < EAP_MAX_METHODS &&
		     (sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
		      sm->user->methods[i].method != EAP_TYPE_NONE);
	     i++) {
		if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
		    sm->user->methods[i].method == EAP_TYPE_PSK)
			break;
	}

	if (i >= EAP_MAX_METHODS ||
	    sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
	    sm->user->methods[i].method != EAP_TYPE_PSK) {
		wpa_hexdump_ascii(MSG_DEBUG,
				  "EAP-PSK: EAP-PSK not enabled for ID_P",
				  data->id_p, data->id_p_len);
		data->state = FAILURE;
		return;
	}

	if (sm->user->password == NULL ||
	    sm->user->password_len != EAP_PSK_PSK_LEN) {
		wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: invalid password in "
				  "user database for ID_P",
				  data->id_p, data->id_p_len);
		data->state = FAILURE;
		return;
	}
	if (eap_psk_key_setup(sm->user->password, data->ak, data->kdk)) {
		data->state = FAILURE;
		return;
	}
	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: AK", data->ak, EAP_PSK_AK_LEN);
	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: KDK", data->kdk, EAP_PSK_KDK_LEN);

	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_P (client rand)",
		    resp->rand_p, EAP_PSK_RAND_LEN);
	os_memcpy(data->rand_p, resp->rand_p, EAP_PSK_RAND_LEN);

	/* MAC_P = OMAC1-AES-128(AK, ID_P||ID_S||RAND_S||RAND_P) */
	buflen = data->id_p_len + sm->server_id_len + 2 * EAP_PSK_RAND_LEN;
	buf = os_malloc(buflen);
	if (buf == NULL) {
		data->state = FAILURE;
		return;
	}
	os_memcpy(buf, data->id_p, data->id_p_len);
	pos = buf + data->id_p_len;
	os_memcpy(pos, sm->server_id, sm->server_id_len);
	pos += sm->server_id_len;
	os_memcpy(pos, data->rand_s, EAP_PSK_RAND_LEN);
	pos += EAP_PSK_RAND_LEN;
	os_memcpy(pos, data->rand_p, EAP_PSK_RAND_LEN);
	if (omac1_aes_128(data->ak, buf, buflen, mac)) {
		os_free(buf);
		data->state = FAILURE;
		return;
	}
	os_free(buf);
	wpa_hexdump(MSG_DEBUG, "EAP-PSK: MAC_P", resp->mac_p, EAP_PSK_MAC_LEN);
	if (os_memcmp_const(mac, resp->mac_p, EAP_PSK_MAC_LEN) != 0) {
		wpa_printf(MSG_INFO, "EAP-PSK: Invalid MAC_P");
		wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Expected MAC_P",
			    mac, EAP_PSK_MAC_LEN);
		data->state = FAILURE;
		return;
	}

	data->state = PSK_3;
}


static void eap_psk_process_4(struct eap_sm *sm,
			      struct eap_psk_data *data,
			      struct wpabuf *respData)
{
	const struct eap_psk_hdr_4 *resp;
	u8 *decrypted, nonce[16];
	size_t left;
	const u8 *pos, *tag;

	if (data->state != PSK_3)
		return;

	wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-4");

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &left);
	if (pos == NULL || left < sizeof(*resp)) {
		wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
		return;
	}
	resp = (const struct eap_psk_hdr_4 *) pos;
	pos = (const u8 *) (resp + 1);
	left -= sizeof(*resp);

	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Encrypted PCHANNEL", pos, left);

	if (left < 4 + 16 + 1) {
		wpa_printf(MSG_INFO, "EAP-PSK: Too short PCHANNEL data in "
			   "PSK-4 (len=%lu, expected 21)",
			   (unsigned long) left);
		return;
	}

	if (pos[0] == 0 && pos[1] == 0 && pos[2] == 0 && pos[3] == 0) {
		wpa_printf(MSG_DEBUG, "EAP-PSK: Nonce did not increase");
		return;
	}

	os_memset(nonce, 0, 12);
	os_memcpy(nonce + 12, pos, 4);
	pos += 4;
	left -= 4;
	tag = pos;
	pos += 16;
	left -= 16;

	decrypted = os_memdup(pos, left);
	if (decrypted == NULL)
		return;

	if (aes_128_eax_decrypt(data->tek, nonce, sizeof(nonce),
				wpabuf_head(respData), 22, decrypted, left,
				tag)) {
		wpa_printf(MSG_WARNING, "EAP-PSK: PCHANNEL decryption failed");
		os_free(decrypted);
		data->state = FAILURE;
		return;
	}
	wpa_hexdump(MSG_DEBUG, "EAP-PSK: Decrypted PCHANNEL message",
		    decrypted, left);

	/* Verify R flag */
	switch (decrypted[0] >> 6) {
	case EAP_PSK_R_FLAG_CONT:
		wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - CONT - unsupported");
		data->state = FAILURE;
		break;
	case EAP_PSK_R_FLAG_DONE_SUCCESS:
		wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_SUCCESS");
		data->state = SUCCESS;
		break;
	case EAP_PSK_R_FLAG_DONE_FAILURE:
		wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_FAILURE");
		data->state = FAILURE;
		break;
	}
	os_free(decrypted);
}


static void eap_psk_process(struct eap_sm *sm, void *priv,
			    struct wpabuf *respData)
{
	struct eap_psk_data *data = priv;
	const u8 *pos;
	size_t len;

	if (sm->user == NULL || sm->user->password == NULL) {
		wpa_printf(MSG_INFO, "EAP-PSK: Plaintext password not "
			   "configured");
		data->state = FAILURE;
		return;
	}

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
	if (pos == NULL || len < 1)
		return;

	switch (EAP_PSK_FLAGS_GET_T(*pos)) {
	case 1:
		eap_psk_process_2(sm, data, respData);
		break;
	case 3:
		eap_psk_process_4(sm, data, respData);
		break;
	}
}


static Boolean eap_psk_isDone(struct eap_sm *sm, void *priv)
{
	struct eap_psk_data *data = priv;
	return data->state == SUCCESS || data->state == FAILURE;
}


static u8 * eap_psk_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_psk_data *data = priv;
	u8 *key;

	if (data->state != SUCCESS)
		return NULL;

	key = os_memdup(data->msk, EAP_MSK_LEN);
	if (key == NULL)
		return NULL;
	*len = EAP_MSK_LEN;

	return key;
}


static u8 * eap_psk_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_psk_data *data = priv;
	u8 *key;

	if (data->state != SUCCESS)
		return NULL;

	key = os_memdup(data->emsk, EAP_EMSK_LEN);
	if (key == NULL)
		return NULL;
	*len = EAP_EMSK_LEN;

	return key;
}


static Boolean eap_psk_isSuccess(struct eap_sm *sm, void *priv)
{
	struct eap_psk_data *data = priv;
	return data->state == SUCCESS;
}


static u8 * eap_psk_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_psk_data *data = priv;
	u8 *id;

	if (data->state != SUCCESS)
		return NULL;

	*len = 1 + 2 * EAP_PSK_RAND_LEN;
	id = os_malloc(*len);
	if (id == NULL)
		return NULL;

	id[0] = EAP_TYPE_PSK;
	os_memcpy(id + 1, data->rand_p, EAP_PSK_RAND_LEN);
	os_memcpy(id + 1 + EAP_PSK_RAND_LEN, data->rand_s, EAP_PSK_RAND_LEN);
	wpa_hexdump(MSG_DEBUG, "EAP-PSK: Derived Session-Id", id, *len);

	return id;
}


int eap_server_psk_register(void)
{
	struct eap_method *eap;

	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
				      EAP_VENDOR_IETF, EAP_TYPE_PSK, "PSK");
	if (eap == NULL)
		return -1;

	eap->init = eap_psk_init;
	eap->reset = eap_psk_reset;
	eap->buildReq = eap_psk_buildReq;
	eap->check = eap_psk_check;
	eap->process = eap_psk_process;
	eap->isDone = eap_psk_isDone;
	eap->getKey = eap_psk_getKey;
	eap->isSuccess = eap_psk_isSuccess;
	eap->get_emsk = eap_psk_get_emsk;
	eap->getSessionId = eap_psk_get_session_id;

	return eap_server_method_register(eap);
}
Commit	Line	Data
6fc6879b JM	1	/*
	2	* hostapd / EAP-PSK (RFC 4764) server
	3	* Copyright (c) 2005-2007, Jouni Malinen <j@w1.fi>
	4	*
0f3d578e JM	5	* This software may be distributed under the terms of the BSD license.
0f3d578e JM	6	* See README for more details.
6fc6879b JM	7	*
	8	* Note: EAP-PSK is an EAP authentication method and as such, completely
	9	* different from WPA-PSK. This file is not needed for WPA-PSK functionality.
	10	*/
	11
	12	#include "includes.h"
	13
	14	#include "common.h"
03da66bd	15	#include "crypto/aes_wrap.h"
3642c431	16	#include "crypto/random.h"
6fc6879b	17	#include "eap_common/eap_psk_common.h"
03da66bd	18	#include "eap_server/eap_i.h"
6fc6879b JM	19
	20
	21	struct eap_psk_data {
	22	enum { PSK_1, PSK_3, SUCCESS, FAILURE } state;
	23	u8 rand_s[EAP_PSK_RAND_LEN];
	24	u8 rand_p[EAP_PSK_RAND_LEN];
a607b42e JM	25	u8 *id_p;
a607b42e JM	26	size_t id_p_len;
6fc6879b JM	27	u8 ak[EAP_PSK_AK_LEN], kdk[EAP_PSK_KDK_LEN], tek[EAP_PSK_TEK_LEN];
	28	u8 msk[EAP_MSK_LEN];
	29	u8 emsk[EAP_EMSK_LEN];
	30	};
	31
	32
	33	static void * eap_psk_init(struct eap_sm *sm)
	34	{
	35	struct eap_psk_data *data;
	36
	37	data = os_zalloc(sizeof(*data));
	38	if (data == NULL)
	39	return NULL;
	40	data->state = PSK_1;
6fc6879b JM	41
	42	return data;
	43	}
	44
	45
	46	static void eap_psk_reset(struct eap_sm sm, void priv)
	47	{
	48	struct eap_psk_data *data = priv;
	49	os_free(data->id_p);
0a13e06b	50	bin_clear_free(data, sizeof(*data));
6fc6879b JM	51	}
	52
	53
	54	static struct wpabuf * eap_psk_build_1(struct eap_sm *sm,
	55	struct eap_psk_data *data, u8 id)
	56	{
	57	struct wpabuf *req;
	58	struct eap_psk_hdr_1 *psk;
	59
	60	wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-1 (sending)");
	61
3642c431	62	if (random_get_bytes(data->rand_s, EAP_PSK_RAND_LEN)) {
6fc6879b JM	63	wpa_printf(MSG_ERROR, "EAP-PSK: Failed to get random data");
	64	data->state = FAILURE;
	65	return NULL;
	66	}
	67	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_S (server rand)",
	68	data->rand_s, EAP_PSK_RAND_LEN);
	69
	70	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
a607b42e	71	sizeof(*psk) + sm->server_id_len,
6fc6879b JM	72	EAP_CODE_REQUEST, id);
	73	if (req == NULL) {
	74	wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
	75	"request");
	76	data->state = FAILURE;
	77	return NULL;
	78	}
	79
	80	psk = wpabuf_put(req, sizeof(*psk));
	81	psk->flags = EAP_PSK_FLAGS_SET_T(0); /* T=0 */
	82	os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
a607b42e	83	wpabuf_put_data(req, sm->server_id, sm->server_id_len);
6fc6879b JM	84
	85	return req;
	86	}
	87
	88
	89	static struct wpabuf * eap_psk_build_3(struct eap_sm *sm,
	90	struct eap_psk_data *data, u8 id)
	91	{
	92	struct wpabuf *req;
	93	struct eap_psk_hdr_3 *psk;
	94	u8 buf, pchannel, nonce[16];
	95	size_t buflen;
	96
	97	wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-3 (sending)");
	98
	99	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
	100	sizeof(*psk) + 4 + 16 + 1, EAP_CODE_REQUEST, id);
	101	if (req == NULL) {
	102	wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
	103	"request");
	104	data->state = FAILURE;
	105	return NULL;
	106	}
	107
	108	psk = wpabuf_put(req, sizeof(*psk));
	109	psk->flags = EAP_PSK_FLAGS_SET_T(2); /* T=2 */
	110	os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
	111
	112	/* MAC_S = OMAC1-AES-128(AK, ID_S\|\|RAND_P) */
a607b42e	113	buflen = sm->server_id_len + EAP_PSK_RAND_LEN;
6fc6879b JM	114	buf = os_malloc(buflen);
	115	if (buf == NULL)
	116	goto fail;
	117
a607b42e JM	118	os_memcpy(buf, sm->server_id, sm->server_id_len);
a607b42e JM	119	os_memcpy(buf + sm->server_id_len, data->rand_p, EAP_PSK_RAND_LEN);
864a8e3b JM	120	if (omac1_aes_128(data->ak, buf, buflen, psk->mac_s)) {
864a8e3b JM	121	os_free(buf);
6fc6879b	122	goto fail;
864a8e3b	123	}
6fc6879b JM	124	os_free(buf);
	125
	126	if (eap_psk_derive_keys(data->kdk, data->rand_p, data->tek, data->msk,
	127	data->emsk))
	128	goto fail;
	129	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: TEK", data->tek, EAP_PSK_TEK_LEN);
	130	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: MSK", data->msk, EAP_MSK_LEN);
	131	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: EMSK", data->emsk, EAP_EMSK_LEN);
	132
	133	os_memset(nonce, 0, sizeof(nonce));
	134	pchannel = wpabuf_put(req, 4 + 16 + 1);
	135	os_memcpy(pchannel, nonce + 12, 4);
	136	os_memset(pchannel + 4, 0, 16); /* Tag */
	137	pchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_SUCCESS << 6;
	138	wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (plaintext)",
	139	pchannel, 4 + 16 + 1);
	140	if (aes_128_eax_encrypt(data->tek, nonce, sizeof(nonce),
	141	wpabuf_head(req), 22,
	142	pchannel + 4 + 16, 1, pchannel + 4))
	143	goto fail;
	144	wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (encrypted)",
	145	pchannel, 4 + 16 + 1);
	146
	147	return req;
	148
	149	fail:
	150	wpabuf_free(req);
	151	data->state = FAILURE;
	152	return NULL;
	153	}
	154
	155
	156	static struct wpabuf * eap_psk_buildReq(struct eap_sm sm, void priv, u8 id)
	157	{
	158	struct eap_psk_data *data = priv;
	159
	160	switch (data->state) {
	161	case PSK_1:
	162	return eap_psk_build_1(sm, data, id);
	163	case PSK_3:
	164	return eap_psk_build_3(sm, data, id);
	165	default:
	166	wpa_printf(MSG_DEBUG, "EAP-PSK: Unknown state %d in buildReq",
	167	data->state);
	168	break;
	169	}
	170	return NULL;
	171	}
	172
	173
	174	static Boolean eap_psk_check(struct eap_sm sm, void priv,
	175	struct wpabuf *respData)
	176	{
	177	struct eap_psk_data *data = priv;
	178	size_t len;
	179	u8 t;
	180	const u8 *pos;
	181
	182	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
	183	if (pos == NULL \|\| len < 1) {
	184	wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
	185	return TRUE;
	186	}
	187	t = EAP_PSK_FLAGS_GET_T(*pos);
188
189	wpa_printf(MSG_DEBUG, "EAP-PSK: received frame: T=%d", t);
190
191	if (data->state == PSK_1 && t != 1) {
192	wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-2 - "
193	"ignore T=%d", t);
194	return TRUE;
195	}
196
197	if (data->state == PSK_3 && t != 3) {
198	wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-4 - "
199	"ignore T=%d", t);
200	return TRUE;
201	}
202
203	if ((t == 1 && len < sizeof(struct eap_psk_hdr_2)) \|\|
204	(t == 3 && len < sizeof(struct eap_psk_hdr_4))) {
205	wpa_printf(MSG_DEBUG, "EAP-PSK: Too short frame");
206	return TRUE;
207	}
208
209	return FALSE;
210	}
211
212
213	static void eap_psk_process_2(struct eap_sm *sm,
214	struct eap_psk_data *data,
215	struct wpabuf *respData)
216	{
217	const struct eap_psk_hdr_2 *resp;
218	u8 pos, mac[EAP_PSK_MAC_LEN], buf;
219	size_t left, buflen;
220	int i;
221	const u8 *cpos;
222
223	if (data->state != PSK_1)
224	return;
225
226	wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-2");
227
228	cpos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData,
229	&left);
230	if (cpos == NULL \|\| left < sizeof(*resp)) {
231	wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
232	return;
233	}
234	resp = (const struct eap_psk_hdr_2 *) cpos;
235	cpos = (const u8 *) (resp + 1);
236	left -= sizeof(*resp);
237
238	os_free(data->id_p);
a1f11e34	239	data->id_p = os_memdup(cpos, left);
6fc6879b JM	240	if (data->id_p == NULL) {
	241	wpa_printf(MSG_INFO, "EAP-PSK: Failed to allocate memory for "
	242	"ID_P");
	243	return;
	244	}
6fc6879b JM	245	data->id_p_len = left;
	246	wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PSK: ID_P",
	247	data->id_p, data->id_p_len);
	248
	249	if (eap_user_get(sm, data->id_p, data->id_p_len, 0) < 0) {
	250	wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: unknown ID_P",
	251	data->id_p, data->id_p_len);
	252	data->state = FAILURE;
	253	return;
	254	}
	255
	256	for (i = 0;
	257	i < EAP_MAX_METHODS &&
	258	(sm->user->methods[i].vendor != EAP_VENDOR_IETF \|\|
	259	sm->user->methods[i].method != EAP_TYPE_NONE);
	260	i++) {
	261	if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
	262	sm->user->methods[i].method == EAP_TYPE_PSK)
	263	break;
	264	}
	265
	266	if (i >= EAP_MAX_METHODS \|\|
	267	sm->user->methods[i].vendor != EAP_VENDOR_IETF \|\|
	268	sm->user->methods[i].method != EAP_TYPE_PSK) {
	269	wpa_hexdump_ascii(MSG_DEBUG,
	270	"EAP-PSK: EAP-PSK not enabled for ID_P",
	271	data->id_p, data->id_p_len);
	272	data->state = FAILURE;
	273	return;
	274	}
	275
	276	if (sm->user->password == NULL \|\|
	277	sm->user->password_len != EAP_PSK_PSK_LEN) {
	278	wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: invalid password in "
	279	"user database for ID_P",
	280	data->id_p, data->id_p_len);
	281	data->state = FAILURE;
	282	return;
	283	}
	284	if (eap_psk_key_setup(sm->user->password, data->ak, data->kdk)) {
	285	data->state = FAILURE;
	286	return;
	287	}
	288	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: AK", data->ak, EAP_PSK_AK_LEN);
	289	wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: KDK", data->kdk, EAP_PSK_KDK_LEN);
	290
	291	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_P (client rand)",
	292	resp->rand_p, EAP_PSK_RAND_LEN);
	293	os_memcpy(data->rand_p, resp->rand_p, EAP_PSK_RAND_LEN);
	294
	295	/* MAC_P = OMAC1-AES-128(AK, ID_P\|\|ID_S\|\|RAND_S\|\|RAND_P) */
a607b42e	296	buflen = data->id_p_len + sm->server_id_len + 2 * EAP_PSK_RAND_LEN;
6fc6879b JM	297	buf = os_malloc(buflen);
	298	if (buf == NULL) {
	299	data->state = FAILURE;
	300	return;
	301	}
	302	os_memcpy(buf, data->id_p, data->id_p_len);
	303	pos = buf + data->id_p_len;
a607b42e JM	304	os_memcpy(pos, sm->server_id, sm->server_id_len);
a607b42e JM	305	pos += sm->server_id_len;
6fc6879b JM	306	os_memcpy(pos, data->rand_s, EAP_PSK_RAND_LEN);
	307	pos += EAP_PSK_RAND_LEN;
	308	os_memcpy(pos, data->rand_p, EAP_PSK_RAND_LEN);
	309	if (omac1_aes_128(data->ak, buf, buflen, mac)) {
	310	os_free(buf);
	311	data->state = FAILURE;
	312	return;
	313	}
	314	os_free(buf);
	315	wpa_hexdump(MSG_DEBUG, "EAP-PSK: MAC_P", resp->mac_p, EAP_PSK_MAC_LEN);
46854825	316	if (os_memcmp_const(mac, resp->mac_p, EAP_PSK_MAC_LEN) != 0) {
6fc6879b JM	317	wpa_printf(MSG_INFO, "EAP-PSK: Invalid MAC_P");
	318	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Expected MAC_P",
	319	mac, EAP_PSK_MAC_LEN);
	320	data->state = FAILURE;
	321	return;
	322	}
	323
	324	data->state = PSK_3;
	325	}
	326
	327
	328	static void eap_psk_process_4(struct eap_sm *sm,
	329	struct eap_psk_data *data,
	330	struct wpabuf *respData)
	331	{
	332	const struct eap_psk_hdr_4 *resp;
	333	u8 *decrypted, nonce[16];
	334	size_t left;
	335	const u8 pos, tag;
	336
	337	if (data->state != PSK_3)
	338	return;
	339
	340	wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-4");
	341
	342	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &left);
	343	if (pos == NULL \|\| left < sizeof(*resp)) {
	344	wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
	345	return;
	346	}
	347	resp = (const struct eap_psk_hdr_4 *) pos;
	348	pos = (const u8 *) (resp + 1);
	349	left -= sizeof(*resp);
	350
	351	wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Encrypted PCHANNEL", pos, left);
	352
	353	if (left < 4 + 16 + 1) {
	354	wpa_printf(MSG_INFO, "EAP-PSK: Too short PCHANNEL data in "
	355	"PSK-4 (len=%lu, expected 21)",
	356	(unsigned long) left);
	357	return;
	358	}
	359
	360	if (pos[0] == 0 && pos[1] == 0 && pos[2] == 0 && pos[3] == 0) {
	361	wpa_printf(MSG_DEBUG, "EAP-PSK: Nonce did not increase");
	362	return;
	363	}
	364
	365	os_memset(nonce, 0, 12);
	366	os_memcpy(nonce + 12, pos, 4);
	367	pos += 4;
	368	left -= 4;
	369	tag = pos;
	370	pos += 16;
	371	left -= 16;
	372
a1f11e34	373	decrypted = os_memdup(pos, left);
6fc6879b JM	374	if (decrypted == NULL)
6fc6879b JM	375	return;
6fc6879b JM	376
	377	if (aes_128_eax_decrypt(data->tek, nonce, sizeof(nonce),
	378	wpabuf_head(respData), 22, decrypted, left,
	379	tag)) {
	380	wpa_printf(MSG_WARNING, "EAP-PSK: PCHANNEL decryption failed");
	381	os_free(decrypted);
	382	data->state = FAILURE;
	383	return;
	384	}
	385	wpa_hexdump(MSG_DEBUG, "EAP-PSK: Decrypted PCHANNEL message",
	386	decrypted, left);
	387
	388	/* Verify R flag */
	389	switch (decrypted[0] >> 6) {
	390	case EAP_PSK_R_FLAG_CONT:
	391	wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - CONT - unsupported");
	392	data->state = FAILURE;
	393	break;
	394	case EAP_PSK_R_FLAG_DONE_SUCCESS:
	395	wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_SUCCESS");
	396	data->state = SUCCESS;
	397	break;
	398	case EAP_PSK_R_FLAG_DONE_FAILURE:
	399	wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_FAILURE");
	400	data->state = FAILURE;
	401	break;
	402	}
	403	os_free(decrypted);
	404	}
	405
	406
	407	static void eap_psk_process(struct eap_sm sm, void priv,
	408	struct wpabuf *respData)
	409	{
	410	struct eap_psk_data *data = priv;
	411	const u8 *pos;
	412	size_t len;
	413
	414	if (sm->user == NULL \|\| sm->user->password == NULL) {
	415	wpa_printf(MSG_INFO, "EAP-PSK: Plaintext password not "
	416	"configured");
	417	data->state = FAILURE;
	418	return;
	419	}
	420
	421	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
	422	if (pos == NULL \|\| len < 1)
	423	return;
	424
	425	switch (EAP_PSK_FLAGS_GET_T(*pos)) {
	426	case 1:
	427	eap_psk_process_2(sm, data, respData);
	428	break;
	429	case 3:
	430	eap_psk_process_4(sm, data, respData);
	431	break;
	432	}
	433	}
	434
	435
	436	static Boolean eap_psk_isDone(struct eap_sm sm, void priv)
	437	{
	438	struct eap_psk_data *data = priv;
	439	return data->state == SUCCESS \|\| data->state == FAILURE;
440	}
441
442
443	static u8 * eap_psk_getKey(struct eap_sm sm, void priv, size_t *len)
444	{
445	struct eap_psk_data *data = priv;
446	u8 *key;
447
448	if (data->state != SUCCESS)
449	return NULL;
450
a1f11e34	451	key = os_memdup(data->msk, EAP_MSK_LEN);
6fc6879b JM	452	if (key == NULL)
6fc6879b JM	453	return NULL;
6fc6879b JM	454	*len = EAP_MSK_LEN;
	455
	456	return key;
	457	}
	458
	459
	460	static u8 * eap_psk_get_emsk(struct eap_sm sm, void priv, size_t *len)
	461	{
	462	struct eap_psk_data *data = priv;
	463	u8 *key;
	464
	465	if (data->state != SUCCESS)
	466	return NULL;
	467
a1f11e34	468	key = os_memdup(data->emsk, EAP_EMSK_LEN);
6fc6879b JM	469	if (key == NULL)
6fc6879b JM	470	return NULL;
6fc6879b JM	471	*len = EAP_EMSK_LEN;
	472
	473	return key;
	474	}
	475
	476
	477	static Boolean eap_psk_isSuccess(struct eap_sm sm, void priv)
	478	{
	479	struct eap_psk_data *data = priv;
	480	return data->state == SUCCESS;
	481	}
	482
	483
d1f89dd7 JM	484	static u8 * eap_psk_get_session_id(struct eap_sm sm, void priv, size_t *len)
	485	{
	486	struct eap_psk_data *data = priv;
	487	u8 *id;
	488
	489	if (data->state != SUCCESS)
	490	return NULL;
	491
	492	len = 1 + 2 EAP_PSK_RAND_LEN;
	493	id = os_malloc(*len);
	494	if (id == NULL)
	495	return NULL;
	496
	497	id[0] = EAP_TYPE_PSK;
	498	os_memcpy(id + 1, data->rand_p, EAP_PSK_RAND_LEN);
	499	os_memcpy(id + 1 + EAP_PSK_RAND_LEN, data->rand_s, EAP_PSK_RAND_LEN);
	500	wpa_hexdump(MSG_DEBUG, "EAP-PSK: Derived Session-Id", id, *len);
	501
	502	return id;
	503	}
	504
	505
6fc6879b JM	506	int eap_server_psk_register(void)
	507	{
	508	struct eap_method *eap;
6fc6879b JM	509
	510	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
	511	EAP_VENDOR_IETF, EAP_TYPE_PSK, "PSK");
	512	if (eap == NULL)
	513	return -1;
	514
	515	eap->init = eap_psk_init;
	516	eap->reset = eap_psk_reset;
	517	eap->buildReq = eap_psk_buildReq;
	518	eap->check = eap_psk_check;
	519	eap->process = eap_psk_process;
	520	eap->isDone = eap_psk_isDone;
	521	eap->getKey = eap_psk_getKey;
	522	eap->isSuccess = eap_psk_isSuccess;
	523	eap->get_emsk = eap_psk_get_emsk;
d1f89dd7	524	eap->getSessionId = eap_psk_get_session_id;
6fc6879b	525
814f43cf	526	return eap_server_method_register(eap);
6fc6879b	527	}