text: /*
   * hostapd / EAP-GPSK (RFC 5433) server
   * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
   *
   * This software may be distributed under the terms of the BSD license.
   * See README for more details.
   */
  
  #include "includes.h"
  
  #include "common.h"
  #include "crypto/random.h"
  #include "eap_server/eap_i.h"
  #include "eap_common/eap_gpsk_common.h"
  
  
  struct eap_gpsk_data {
  	enum { GPSK_1, GPSK_3, SUCCESS, FAILURE } state;
  	u8 rand_server[EAP_GPSK_RAND_LEN];
  	u8 rand_peer[EAP_GPSK_RAND_LEN];
  	u8 msk[EAP_MSK_LEN];
  	u8 emsk[EAP_EMSK_LEN];
  	u8 sk[EAP_GPSK_MAX_SK_LEN];
  	size_t sk_len;
  	u8 pk[EAP_GPSK_MAX_PK_LEN];
  	size_t pk_len;
  	u8 *id_peer;
  	size_t id_peer_len;
  #define MAX_NUM_CSUITES 2
  	struct eap_gpsk_csuite csuite_list[MAX_NUM_CSUITES];
  	size_t csuite_count;
  	int vendor; /* CSuite/Vendor */
  	int specifier; /* CSuite/Specifier */
  };
  
  
  static const char * eap_gpsk_state_txt(int state)
  {
  	switch (state) {
  	case GPSK_1:
  		return "GPSK-1";
  	case GPSK_3:
  		return "GPSK-3";
  	case SUCCESS:
  		return "SUCCESS";
  	case FAILURE:
  		return "FAILURE";
  	default:
  		return "?";
  	}
  }
  
  
  static void eap_gpsk_state(struct eap_gpsk_data *data, int state)
  {
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: %s -> %s",
  		   eap_gpsk_state_txt(data->state),
  		   eap_gpsk_state_txt(state));
  	data->state = state;
  }
  
  
  static void * eap_gpsk_init(struct eap_sm *sm)
  {
  	struct eap_gpsk_data *data;
  
  	data = os_zalloc(sizeof(*data));
  	if (data == NULL)
  		return NULL;
  	data->state = GPSK_1;
  
  	data->csuite_count = 0;
  	if (eap_gpsk_supported_ciphersuite(EAP_GPSK_VENDOR_IETF,
  					   EAP_GPSK_CIPHER_AES)) {
  		WPA_PUT_BE32(data->csuite_list[data->csuite_count].vendor,
  			     EAP_GPSK_VENDOR_IETF);
  		WPA_PUT_BE16(data->csuite_list[data->csuite_count].specifier,
  			     EAP_GPSK_CIPHER_AES);
  		data->csuite_count++;
  	}
  	if (eap_gpsk_supported_ciphersuite(EAP_GPSK_VENDOR_IETF,
  					   EAP_GPSK_CIPHER_SHA256)) {
  		WPA_PUT_BE32(data->csuite_list[data->csuite_count].vendor,
  			     EAP_GPSK_VENDOR_IETF);
  		WPA_PUT_BE16(data->csuite_list[data->csuite_count].specifier,
  			     EAP_GPSK_CIPHER_SHA256);
  		data->csuite_count++;
  	}
  
  	return data;
  }
  
  
  static void eap_gpsk_reset(struct eap_sm *sm, void *priv)
  {
  	struct eap_gpsk_data *data = priv;
  	os_free(data->id_peer);
  	os_free(data);
  }
  
  
  static struct wpabuf * eap_gpsk_build_gpsk_1(struct eap_sm *sm,
  					     struct eap_gpsk_data *data, u8 id)
  {
  	size_t len;
  	struct wpabuf *req;
  
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: Request/GPSK-1");
  
  	if (random_get_bytes(data->rand_server, EAP_GPSK_RAND_LEN)) {
  		wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to get random data");
  		eap_gpsk_state(data, FAILURE);
  		return NULL;
  	}
  	wpa_hexdump(MSG_MSGDUMP, "EAP-GPSK: RAND_Server",
  		    data->rand_server, EAP_GPSK_RAND_LEN);
  
  	len = 1 + 2 + sm->server_id_len + EAP_GPSK_RAND_LEN + 2 +
  		data->csuite_count * sizeof(struct eap_gpsk_csuite);
  	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, len,
  			    EAP_CODE_REQUEST, id);
  	if (req == NULL) {
  		wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to allocate memory "
  			   "for request/GPSK-1");
  		eap_gpsk_state(data, FAILURE);
  		return NULL;
  	}
  
  	wpabuf_put_u8(req, EAP_GPSK_OPCODE_GPSK_1);
  	wpabuf_put_be16(req, sm->server_id_len);
  	wpabuf_put_data(req, sm->server_id, sm->server_id_len);
  	wpabuf_put_data(req, data->rand_server, EAP_GPSK_RAND_LEN);
  	wpabuf_put_be16(req,
  			data->csuite_count * sizeof(struct eap_gpsk_csuite));
  	wpabuf_put_data(req, data->csuite_list,
  			data->csuite_count * sizeof(struct eap_gpsk_csuite));
  
  	return req;
  }
  
  
  static struct wpabuf * eap_gpsk_build_gpsk_3(struct eap_sm *sm,
  					     struct eap_gpsk_data *data, u8 id)
  {
  	u8 *pos, *start;
  	size_t len, miclen;
  	struct eap_gpsk_csuite *csuite;
  	struct wpabuf *req;
  
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: Request/GPSK-3");
  
  	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
  	len = 1 + 2 * EAP_GPSK_RAND_LEN + 2 + sm->server_id_len +
  		sizeof(struct eap_gpsk_csuite) + 2 + miclen;
  	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, len,
  			    EAP_CODE_REQUEST, id);
  	if (req == NULL) {
  		wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to allocate memory "
  			   "for request/GPSK-3");
  		eap_gpsk_state(data, FAILURE);
  		return NULL;
  	}
  
  	wpabuf_put_u8(req, EAP_GPSK_OPCODE_GPSK_3);
  	start = wpabuf_put(req, 0);
  
  	wpabuf_put_data(req, data->rand_peer, EAP_GPSK_RAND_LEN);
  	wpabuf_put_data(req, data->rand_server, EAP_GPSK_RAND_LEN);
  	wpabuf_put_be16(req, sm->server_id_len);
  	wpabuf_put_data(req, sm->server_id, sm->server_id_len);
  	csuite = wpabuf_put(req, sizeof(*csuite));
  	WPA_PUT_BE32(csuite->vendor, data->vendor);
  	WPA_PUT_BE16(csuite->specifier, data->specifier);
  
  	/* no PD_Payload_2 */
  	wpabuf_put_be16(req, 0);
  
  	pos = wpabuf_put(req, miclen);
  	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
  				 data->specifier, start, pos - start, pos) < 0)
  	{
  		os_free(req);
  		eap_gpsk_state(data, FAILURE);
  		return NULL;
  	}
  
  	return req;
  }
  
  
  static struct wpabuf * eap_gpsk_buildReq(struct eap_sm *sm, void *priv, u8 id)
  {
  	struct eap_gpsk_data *data = priv;
  
  	switch (data->state) {
  	case GPSK_1:
  		return eap_gpsk_build_gpsk_1(sm, data, id);
  	case GPSK_3:
  		return eap_gpsk_build_gpsk_3(sm, data, id);
  	default:
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Unknown state %d in buildReq",
  			   data->state);
  		break;
  	}
  	return NULL;
  }
  
  
  static Boolean eap_gpsk_check(struct eap_sm *sm, void *priv,
  			      struct wpabuf *respData)
  {
  	struct eap_gpsk_data *data = priv;
  	const u8 *pos;
  	size_t len;
  
  	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respData, &len);
  	if (pos == NULL || len < 1) {
  		wpa_printf(MSG_INFO, "EAP-GPSK: Invalid frame");
  		return TRUE;
  	}
  
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received frame: opcode=%d", *pos);
  
  	if (data->state == GPSK_1 && *pos == EAP_GPSK_OPCODE_GPSK_2)
  		return FALSE;
  
  	if (data->state == GPSK_3 && *pos == EAP_GPSK_OPCODE_GPSK_4)
  		return FALSE;
  
  	wpa_printf(MSG_INFO, "EAP-GPSK: Unexpected opcode=%d in state=%d",
  		   *pos, data->state);
  
  	return TRUE;
  }
  
  
  static void eap_gpsk_process_gpsk_2(struct eap_sm *sm,
  				    struct eap_gpsk_data *data,
  				    const u8 *payload, size_t payloadlen)
  {
  	const u8 *pos, *end;
  	u16 alen;
  	const struct eap_gpsk_csuite *csuite;
  	size_t i, miclen;
  	u8 mic[EAP_GPSK_MAX_MIC_LEN];
  
  	if (data->state != GPSK_1)
  		return;
  
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Response/GPSK-2");
  
  	pos = payload;
  	end = payload + payloadlen;
  
  	if (end - pos < 2) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "ID_Peer length");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	alen = WPA_GET_BE16(pos);
  	pos += 2;
  	if (end - pos < alen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "ID_Peer");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	os_free(data->id_peer);
  	data->id_peer = os_malloc(alen);
  	if (data->id_peer == NULL) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Not enough memory to store "
  			   "%d-octet ID_Peer", alen);
  		return;
  	}
  	os_memcpy(data->id_peer, pos, alen);
  	data->id_peer_len = alen;
  	wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Peer",
  			  data->id_peer, data->id_peer_len);
  	pos += alen;
  
  	if (end - pos < 2) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "ID_Server length");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	alen = WPA_GET_BE16(pos);
  	pos += 2;
  	if (end - pos < alen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "ID_Server");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (alen != sm->server_id_len ||
  	    os_memcmp(pos, sm->server_id, alen) != 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-1 and "
  			   "GPSK-2 did not match");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	pos += alen;
  
  	if (end - pos < EAP_GPSK_RAND_LEN) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "RAND_Peer");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	os_memcpy(data->rand_peer, pos, EAP_GPSK_RAND_LEN);
  	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer",
  		    data->rand_peer, EAP_GPSK_RAND_LEN);
  	pos += EAP_GPSK_RAND_LEN;
  
  	if (end - pos < EAP_GPSK_RAND_LEN) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "RAND_Server");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (os_memcmp(data->rand_server, pos, EAP_GPSK_RAND_LEN) != 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1 and "
  			   "GPSK-2 did not match");
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1",
  			    data->rand_server, EAP_GPSK_RAND_LEN);
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-2",
  			    pos, EAP_GPSK_RAND_LEN);
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	pos += EAP_GPSK_RAND_LEN;
  
  	if (end - pos < 2) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "CSuite_List length");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	alen = WPA_GET_BE16(pos);
  	pos += 2;
  	if (end - pos < alen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "CSuite_List");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (alen != data->csuite_count * sizeof(struct eap_gpsk_csuite) ||
  	    os_memcmp(pos, data->csuite_list, alen) != 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_List in GPSK-1 and "
  			   "GPSK-2 did not match");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	pos += alen;
  
  	if (end - pos < (int) sizeof(*csuite)) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "CSuite_Sel");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	csuite = (const struct eap_gpsk_csuite *) pos;
  	for (i = 0; i < data->csuite_count; i++) {
  		if (os_memcmp(csuite, &data->csuite_list[i], sizeof(*csuite))
  		    == 0)
  			break;
  	}
  	if (i == data->csuite_count) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Peer selected unsupported "
  			   "ciphersuite %d:%d",
  			   WPA_GET_BE32(csuite->vendor),
  			   WPA_GET_BE16(csuite->specifier));
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	data->vendor = WPA_GET_BE32(csuite->vendor);
  	data->specifier = WPA_GET_BE16(csuite->specifier);
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_Sel %d:%d",
  		   data->vendor, data->specifier);
  	pos += sizeof(*csuite);	
  
  	if (end - pos < 2) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "PD_Payload_1 length");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	alen = WPA_GET_BE16(pos);
  	pos += 2;
  	if (end - pos < alen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "PD_Payload_1");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_1", pos, alen);
  	pos += alen;
  
  	if (sm->user == NULL || sm->user->password == NULL) {
  		wpa_printf(MSG_INFO, "EAP-GPSK: No PSK/password configured "
  			   "for the user");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  
  	if (eap_gpsk_derive_keys(sm->user->password, sm->user->password_len,
  				 data->vendor, data->specifier,
  				 data->rand_peer, data->rand_server,
  				 data->id_peer, data->id_peer_len,
  				 sm->server_id, sm->server_id_len,
  				 data->msk, data->emsk,
  				 data->sk, &data->sk_len,
  				 data->pk, &data->pk_len) < 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive keys");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  
  	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
  	if (end - pos < (int) miclen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC "
  			   "(left=%lu miclen=%lu)",
  			   (unsigned long) (end - pos),
  			   (unsigned long) miclen);
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
  				 data->specifier, payload, pos - payload, mic)
  	    < 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to compute MIC");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (os_memcmp(mic, pos, miclen) != 0) {
  		wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-2");
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	pos += miclen;
  
  	if (pos != end) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra "
  			   "data in the end of GPSK-2",
  			   (unsigned long) (end - pos));
  	}
  
  	eap_gpsk_state(data, GPSK_3);
  }
  
  
  static void eap_gpsk_process_gpsk_4(struct eap_sm *sm,
  				    struct eap_gpsk_data *data,
  				    const u8 *payload, size_t payloadlen)
  {
  	const u8 *pos, *end;
  	u16 alen;
  	size_t miclen;
  	u8 mic[EAP_GPSK_MAX_MIC_LEN];
  
  	if (data->state != GPSK_3)
  		return;
  
  	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Response/GPSK-4");
  
  	pos = payload;
  	end = payload + payloadlen;
  
  	if (end - pos < 2) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "PD_Payload_1 length");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	alen = WPA_GET_BE16(pos);
  	pos += 2;
  	if (end - pos < alen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
  			   "PD_Payload_1");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_1", pos, alen);
  	pos += alen;
  
  	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
  	if (end - pos < (int) miclen) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC "
  			   "(left=%lu miclen=%lu)",
  			   (unsigned long) (end - pos),
  			   (unsigned long) miclen);
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
  				 data->specifier, payload, pos - payload, mic)
  	    < 0) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to compute MIC");
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	if (os_memcmp(mic, pos, miclen) != 0) {
  		wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-4");
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
  		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
  		eap_gpsk_state(data, FAILURE);
  		return;
  	}
  	pos += miclen;
  
  	if (pos != end) {
  		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra "
  			   "data in the end of GPSK-4",
  			   (unsigned long) (end - pos));
  	}
  
  	eap_gpsk_state(data, SUCCESS);
  }
  
  
  static void eap_gpsk_process(struct eap_sm *sm, void *priv,
  			     struct wpabuf *respData)
  {
  	struct eap_gpsk_data *data = priv;
  	const u8 *pos;
  	size_t len;
  
  	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respData, &len);
  	if (pos == NULL || len < 1)
  		return;
  
  	switch (*pos) {
  	case EAP_GPSK_OPCODE_GPSK_2:
  		eap_gpsk_process_gpsk_2(sm, data, pos + 1, len - 1);
  		break;
  	case EAP_GPSK_OPCODE_GPSK_4:
  		eap_gpsk_process_gpsk_4(sm, data, pos + 1, len - 1);
  		break;
  	}
  }
  
  
  static Boolean eap_gpsk_isDone(struct eap_sm *sm, void *priv)
  {
  	struct eap_gpsk_data *data = priv;
  	return data->state == SUCCESS || data->state == FAILURE;
  }
  
  
  static u8 * eap_gpsk_getKey(struct eap_sm *sm, void *priv, size_t *len)
  {
  	struct eap_gpsk_data *data = priv;
  	u8 *key;
  
  	if (data->state != SUCCESS)
  		return NULL;
  
  	key = os_malloc(EAP_MSK_LEN);
  	if (key == NULL)
  		return NULL;
  	os_memcpy(key, data->msk, EAP_MSK_LEN);
  	*len = EAP_MSK_LEN;
  
  	return key;
  }
  
  
  static u8 * eap_gpsk_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
  {
  	struct eap_gpsk_data *data = priv;
  	u8 *key;
  
  	if (data->state != SUCCESS)
  		return NULL;
  
  	key = os_malloc(EAP_EMSK_LEN);
  	if (key == NULL)
  		return NULL;
  	os_memcpy(key, data->emsk, EAP_EMSK_LEN);
  	*len = EAP_EMSK_LEN;
  
  	return key;
  }
  
  
  static Boolean eap_gpsk_isSuccess(struct eap_sm *sm, void *priv)
  {
  	struct eap_gpsk_data *data = priv;
  	return data->state == SUCCESS;
  }
  
  
  int eap_server_gpsk_register(void)
  {
  	struct eap_method *eap;
  	int ret;
  
  	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
  				      EAP_VENDOR_IETF, EAP_TYPE_GPSK, "GPSK");
  	if (eap == NULL)
  		return -1;
  
  	eap->init = eap_gpsk_init;
  	eap->reset = eap_gpsk_reset;
  	eap->buildReq = eap_gpsk_buildReq;
  	eap->check = eap_gpsk_check;
  	eap->process = eap_gpsk_process;
  	eap->isDone = eap_gpsk_isDone;
  	eap->getKey = eap_gpsk_getKey;
  	eap->isSuccess = eap_gpsk_isSuccess;
  	eap->get_emsk = eap_gpsk_get_emsk;
  
  	ret = eap_server_method_register(eap);
  	if (ret)
  		eap_server_method_free(eap);
  	return ret;
  }
  