eap_aka.c

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	}
#endif /* EAP_AKA_PRIME */

	wpa_printf(MSG_DEBUG, "   AT_MAC");
	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}


static struct wpabuf * eap_aka_build_reauth(struct eap_sm *sm,
					    struct eap_aka_data *data, u8 id)
{
	struct eap_sim_msg *msg;

	wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Re-authentication");

	if (os_get_random(data->nonce_s, EAP_SIM_NONCE_S_LEN))
		return NULL;
	wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA: NONCE_S",
			data->nonce_s, EAP_SIM_NONCE_S_LEN);

	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
		eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
						 sm->identity,
						 sm->identity_len,
						 data->nonce_s,
						 data->msk, data->emsk);
	} else {
		eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
				    data->msk, data->emsk);
		eap_sim_derive_keys_reauth(data->counter, sm->identity,
					   sm->identity_len, data->nonce_s,
					   data->mk, data->msk, data->emsk);
	}

	msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
			       EAP_AKA_SUBTYPE_REAUTHENTICATION);

	if (eap_aka_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
		eap_sim_msg_free(msg);
		return NULL;
	}

	eap_aka_add_checkcode(data, msg);

	if (sm->eap_sim_aka_result_ind) {
		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
	}

	wpa_printf(MSG_DEBUG, "   AT_MAC");
	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}


static struct wpabuf * eap_aka_build_notification(struct eap_sm *sm,
						  struct eap_aka_data *data,
						  u8 id)
{
	struct eap_sim_msg *msg;

	wpa_printf(MSG_DEBUG, "EAP-AKA: Generating Notification");
	msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, data->eap_method,
			       EAP_AKA_SUBTYPE_NOTIFICATION);
	wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION (%d)", data->notification);
	eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
			NULL, 0);
	if (data->use_result_ind) {
		if (data->reauth) {
			wpa_printf(MSG_DEBUG, "   AT_IV");
			wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
			eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
						   EAP_SIM_AT_ENCR_DATA);
			wpa_printf(MSG_DEBUG, "   *AT_COUNTER (%u)",
				   data->counter);
			eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
					NULL, 0);

			if (eap_sim_msg_add_encr_end(msg, data->k_encr,
						     EAP_SIM_AT_PADDING)) {
				wpa_printf(MSG_WARNING, "EAP-AKA: Failed to "
					   "encrypt AT_ENCR_DATA");
				eap_sim_msg_free(msg);
				return NULL;
			}
		}

		wpa_printf(MSG_DEBUG, "   AT_MAC");
		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	}
	return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}


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

	data->auts_reported = 0;
	switch (data->state) {
	case IDENTITY:
		return eap_aka_build_identity(sm, data, id);
	case CHALLENGE:
		return eap_aka_build_challenge(sm, data, id);
	case REAUTH:
		return eap_aka_build_reauth(sm, data, id);
	case NOTIFICATION:
		return eap_aka_build_notification(sm, data, id);
	default:
		wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown state %d in "
			   "buildReq", data->state);
		break;
	}
	return NULL;
}


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

	pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, respData,
			       &len);
	if (pos == NULL || len < 3) {
		wpa_printf(MSG_INFO, "EAP-AKA: Invalid frame");
		return TRUE;
	}

	return FALSE;
}


static Boolean eap_aka_subtype_ok(struct eap_aka_data *data, u8 subtype)
{
	if (subtype == EAP_AKA_SUBTYPE_CLIENT_ERROR ||
	    subtype == EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT)
		return FALSE;

	switch (data->state) {
	case IDENTITY:
		if (subtype != EAP_AKA_SUBTYPE_IDENTITY) {
			wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
				   "subtype %d", subtype);
			return TRUE;
		}
		break;
	case CHALLENGE:
		if (subtype != EAP_AKA_SUBTYPE_CHALLENGE &&
		    subtype != EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE) {
			wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
				   "subtype %d", subtype);
			return TRUE;
		}
		break;
	case REAUTH:
		if (subtype != EAP_AKA_SUBTYPE_REAUTHENTICATION) {
			wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
				   "subtype %d", subtype);
			return TRUE;
		}
		break;
	case NOTIFICATION:
		if (subtype != EAP_AKA_SUBTYPE_NOTIFICATION) {
			wpa_printf(MSG_INFO, "EAP-AKA: Unexpected response "
				   "subtype %d", subtype);
			return TRUE;
		}
		break;
	default:
		wpa_printf(MSG_INFO, "EAP-AKA: Unexpected state (%d) for "
			   "processing a response", data->state);
		return TRUE;
	}

	return FALSE;
}


static void eap_aka_determine_identity(struct eap_sm *sm,
				       struct eap_aka_data *data,
				       int before_identity, int after_reauth)
{
	const u8 *identity;
	size_t identity_len;
	int res;

	identity = NULL;
	identity_len = 0;

	if (after_reauth && data->reauth) {
		identity = data->reauth->identity;
		identity_len = data->reauth->identity_len;
	} else if (sm->identity && sm->identity_len > 0 &&
		   sm->identity[0] == EAP_AKA_PERMANENT_PREFIX) {
		identity = sm->identity;
		identity_len = sm->identity_len;
	} else {
		identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv,
						    sm->identity,
						    sm->identity_len,
						    &identity_len);
		if (identity == NULL) {
			data->reauth = eap_sim_db_get_reauth_entry(
				sm->eap_sim_db_priv, sm->identity,
				sm->identity_len);
			if (data->reauth &&
			    data->reauth->aka_prime !=
			    (data->eap_method == EAP_TYPE_AKA_PRIME)) {
				wpa_printf(MSG_DEBUG, "EAP-AKA: Reauth data "
					   "was for different AKA version");
				data->reauth = NULL;
			}
			if (data->reauth) {
				wpa_printf(MSG_DEBUG, "EAP-AKA: Using fast "
					   "re-authentication");
				identity = data->reauth->identity;
				identity_len = data->reauth->identity_len;
				data->counter = data->reauth->counter;
				if (data->eap_method == EAP_TYPE_AKA_PRIME) {
					os_memcpy(data->k_encr,
						  data->reauth->k_encr,
						  EAP_SIM_K_ENCR_LEN);
					os_memcpy(data->k_aut,
						  data->reauth->k_aut,
						  EAP_AKA_PRIME_K_AUT_LEN);
					os_memcpy(data->k_re,
						  data->reauth->k_re,
						  EAP_AKA_PRIME_K_RE_LEN);
				} else {
					os_memcpy(data->mk, data->reauth->mk,
						  EAP_SIM_MK_LEN);
				}
			}
		}
	}

	if (identity == NULL ||
	    eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity,
				      sm->identity_len) < 0) {
		if (before_identity) {
			wpa_printf(MSG_DEBUG, "EAP-AKA: Permanent user name "
				   "not known - send AKA-Identity request");
			eap_aka_state(data, IDENTITY);
			return;
		} else {
			wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown whether the "
				   "permanent user name is known; try to use "
				   "it");
			/* eap_sim_db_get_aka_auth() will report failure, if
			 * this identity is not known. */
		}
	}

	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Identity",
			  identity, identity_len);

	if (!after_reauth && data->reauth) {
		eap_aka_state(data, REAUTH);
		return;
	}

	res = eap_sim_db_get_aka_auth(sm->eap_sim_db_priv, identity,
				      identity_len, data->rand, data->autn,
				      data->ik, data->ck, data->res,
				      &data->res_len, sm);
	if (res == EAP_SIM_DB_PENDING) {
		wpa_printf(MSG_DEBUG, "EAP-AKA: AKA authentication data "
			   "not yet available - pending request");
		sm->method_pending = METHOD_PENDING_WAIT;
		return;
	}

#ifdef EAP_AKA_PRIME
	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
		/* Note: AUTN = (SQN ^ AK) || AMF || MAC which gives us the
		 * needed 6-octet SQN ^AK for CK',IK' derivation */
		eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
						 data->autn,
						 data->network_name,
						 data->network_name_len);
	}
#endif /* EAP_AKA_PRIME */

	data->reauth = NULL;
	data->counter = 0; /* reset re-auth counter since this is full auth */

	if (res != 0) {
		wpa_printf(MSG_INFO, "EAP-AKA: Failed to get AKA "
			   "authentication data for the peer");
		data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
		eap_aka_state(data, NOTIFICATION);
		return;
	}
	if (sm->method_pending == METHOD_PENDING_WAIT) {
		wpa_printf(MSG_DEBUG, "EAP-AKA: AKA authentication data "
			   "available - abort pending wait");
		sm->method_pending = METHOD_PENDING_NONE;
	}

	identity_len = sm->identity_len;
	while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
		wpa_printf(MSG_DEBUG, "EAP-AKA: Workaround - drop last null "
			   "character from identity");
		identity_len--;
	}
	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Identity for MK derivation",
			  sm->identity, identity_len);

	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
		eap_aka_prime_derive_keys(identity, identity_len, data->ik,
					  data->ck, data->k_encr, data->k_aut,
					  data->k_re, data->msk, data->emsk);
	} else {
		eap_aka_derive_mk(sm->identity, identity_len, data->ik,
				  data->ck, data->mk);
		eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
				    data->msk, data->emsk);
	}

	eap_aka_state(data, CHALLENGE);
}


static void eap_aka_process_identity(struct eap_sm *sm,
				     struct eap_aka_data *data,
				     struct wpabuf *respData,
				     struct eap_sim_attrs *attr)
{
	wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Identity");

	if (attr->mac || attr->iv || attr->encr_data) {
		wpa_printf(MSG_WARNING, "EAP-AKA: Unexpected attribute "
			   "received in EAP-Response/AKA-Identity");
		data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
		eap_aka_state(data, NOTIFICATION);
		return;
	}

	if (attr->identity) {
		os_free(sm->identity);
		sm->identity = os_malloc(attr->identity_len);
		if (sm->identity) {
			os_memcpy(sm->identity, attr->identity,
				  attr->identity_len);
			sm->identity_len = attr->identity_len;
		}
	}

	eap_aka_determine_identity(sm, data, 0, 0);
	if (eap_get_id(respData) == data->pending_id) {
		data->pending_id = -1;
		eap_aka_add_id_msg(data, respData);
	}
}


static int eap_aka_verify_mac(struct eap_aka_data *data,
			      const struct wpabuf *req,
			      const u8 *mac, const u8 *extra,
			      size_t extra_len)
{
	if (data->eap_method == EAP_TYPE_AKA_PRIME)
		return eap_sim_verify_mac_sha256(data->k_aut, req, mac, extra,
						 extra_len);
	return eap_sim_verify_mac(data->k_aut, req, mac, extra, extra_len);
}


static void eap_aka_process_challenge(struct eap_sm *sm,
				      struct eap_aka_data *data,
				      struct wpabuf *respData,
				      struct eap_sim_attrs *attr)
{
	const u8 *identity;
	size_t identity_len;

	wpa_printf(MSG_DEBUG, "EAP-AKA: Processing Challenge");

#ifdef EAP_AKA_PRIME
#if 0
	/* KDF negotiation; to be enabled only after more than one KDF is
	 * supported */
	if (data->eap_method == EAP_TYPE_AKA_PRIME &&
	    attr->kdf_count == 1 && attr->mac == NULL) {
		if (attr->kdf[0] != EAP_AKA_PRIME_KDF) {
			wpa_printf(MSG_WARNING, "EAP-AKA': Peer selected "
				   "unknown KDF");
			data->notification =
				EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
			eap_aka_state(data, NOTIFICATION);
			return;
		}

		data->kdf = attr->kdf[0];

		/* Allow negotiation to continue with the selected KDF by
		 * sending another Challenge message */
		wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
		return;
	}
#endif
#endif /* EAP_AKA_PRIME */

	if (attr->checkcode &&
	    eap_aka_verify_checkcode(data, attr->checkcode,
				     attr->checkcode_len)) {
		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
			   "message");
		data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
		eap_aka_state(data, NOTIFICATION);
		return;
	}
	if (attr->mac == NULL ||
	    eap_aka_verify_mac(data, respData, attr->mac, NULL, 0)) {
		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
			   "did not include valid AT_MAC");
		data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
		eap_aka_state(data, NOTIFICATION);
		return;
	}

	/*
	 * AT_RES is padded, so verify that there is enough room for RES and