toxcore/onion_announce.c
Rama master · réplica de lectura del repositorio original.
/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2016-2026 The TokTok team.
* Copyright © 2013 Tox project.
*/
/**
* Implementation of the announce part of docs/Prevent_Tracking.txt
*/
#include "onion_announce.h"
#include <assert.h>
#include <string.h>
#include "DHT.h"
#include "LAN_discovery.h"
#include "attributes.h"
#include "ccompat.h"
#include "crypto_core.h"
#include "logger.h"
#include "mem.h"
#include "mono_time.h"
#include "network.h"
#include "onion.h"
#include "shared_key_cache.h"
#include "sort.h"
#include "timed_auth.h"
#include "util.h"
#define PING_ID_TIMEOUT ONION_ANNOUNCE_TIMEOUT
#define ANNOUNCE_REQUEST_MIN_SIZE_RECV (ONION_ANNOUNCE_REQUEST_MIN_SIZE + ONION_RETURN_3)
#define ANNOUNCE_REQUEST_MAX_SIZE_RECV (ONION_ANNOUNCE_REQUEST_MAX_SIZE + ONION_RETURN_3)
/* TODO(Jfreegman): DEPRECATE */
#define ANNOUNCE_REQUEST_SIZE_RECV (ONION_ANNOUNCE_REQUEST_SIZE + ONION_RETURN_3)
#define DATA_REQUEST_MIN_SIZE ONION_DATA_REQUEST_MIN_SIZE
#define DATA_REQUEST_MIN_SIZE_RECV (DATA_REQUEST_MIN_SIZE + ONION_RETURN_3)
#define ONION_MINIMAL_SIZE (ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE * 2 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH)
/* Settings for the shared key cache */
#define MAX_KEYS_PER_SLOT 4
#define KEYS_TIMEOUT 600
static_assert(ONION_PING_ID_SIZE == CRYPTO_PUBLIC_KEY_SIZE,
"announce response packets assume that ONION_PING_ID_SIZE is equal to CRYPTO_PUBLIC_KEY_SIZE");
typedef struct Onion_Announce_Entry {
uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE];
IP_Port ret_ip_port;
uint8_t ret[ONION_RETURN_3];
uint8_t data_public_key[CRYPTO_PUBLIC_KEY_SIZE];
uint64_t announce_time;
} Onion_Announce_Entry;
struct Onion_Announce {
const Logger *_Nonnull log;
const Mono_Time *_Nonnull mono_time;
const Random *_Nonnull rng;
const Memory *_Nonnull mem;
DHT *_Nonnull dht;
Networking_Core *_Nonnull net;
Onion_Announce_Entry entries[ONION_ANNOUNCE_MAX_ENTRIES];
uint8_t hmac_key[CRYPTO_HMAC_KEY_SIZE];
Shared_Key_Cache *_Nonnull shared_keys_recv;
uint16_t extra_data_max_size;
pack_extra_data_cb *_Nullable extra_data_callback;
void *_Nullable extra_data_object;
};
void onion_announce_extra_data_callback(Onion_Announce *onion_a, uint16_t extra_data_max_size,
pack_extra_data_cb *extra_data_callback, void *extra_data_object)
{
onion_a->extra_data_max_size = extra_data_max_size;
onion_a->extra_data_callback = extra_data_callback;
onion_a->extra_data_object = extra_data_object;
}
uint8_t *onion_announce_entry_public_key(Onion_Announce *onion_a, uint32_t entry)
{
return onion_a->entries[entry].public_key;
}
void onion_announce_entry_set_time(Onion_Announce *onion_a, uint32_t entry, uint64_t announce_time)
{
onion_a->entries[entry].announce_time = announce_time;
}
/** @brief Create an onion announce request packet in packet of max_packet_length.
*
* Recommended value for max_packet_length is ONION_ANNOUNCE_REQUEST_MIN_SIZE.
*
* dest_client_id is the public key of the node the packet will be sent to.
* public_key and secret_key is the kepair which will be used to encrypt the request.
* ping_id is the ping id that will be sent in the request.
* client_id is the client id of the node we are searching for.
* data_public_key is the public key we want others to encrypt their data packets with.
* sendback_data is the data of ONION_ANNOUNCE_SENDBACK_DATA_LENGTH length that we expect to
* receive back in the response.
*
* return -1 on failure.
* return packet length on success.
*/
int create_announce_request(const Memory *mem, const Random *rng, uint8_t *packet, uint16_t max_packet_length, const uint8_t *dest_client_id,
const uint8_t *public_key, const uint8_t *secret_key, const uint8_t *ping_id, const uint8_t *client_id,
const uint8_t *data_public_key, uint64_t sendback_data)
{
if (max_packet_length < ONION_ANNOUNCE_REQUEST_MIN_SIZE) {
return -1;
}
uint8_t plain[ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE +
ONION_ANNOUNCE_SENDBACK_DATA_LENGTH];
memcpy(plain, ping_id, ONION_PING_ID_SIZE);
memcpy(plain + ONION_PING_ID_SIZE, client_id, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE, data_public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE, &sendback_data,
sizeof(sendback_data));
packet[0] = NET_PACKET_ANNOUNCE_REQUEST_OLD;
random_nonce(rng, packet + 1);
const int len = encrypt_data(mem, dest_client_id, secret_key, packet + 1, plain, sizeof(plain),
packet + 1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE);
if ((uint32_t)len + 1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE != ONION_ANNOUNCE_REQUEST_MIN_SIZE) {
return -1;
}
memcpy(packet + 1 + CRYPTO_NONCE_SIZE, public_key, CRYPTO_PUBLIC_KEY_SIZE);
return ONION_ANNOUNCE_REQUEST_MIN_SIZE;
}
/** @brief Create an onion data request packet in packet of max_packet_length.
*
* Recommended value for max_packet_length is ONION_ANNOUNCE_REQUEST_SIZE.
*
* public_key is the real public key of the node which we want to send the data of length length to.
* encrypt_public_key is the public key used to encrypt the data packet.
*
* nonce is the nonce to encrypt this packet with
*
* return -1 on failure.
* return 0 on success.
*/
int create_data_request(const Memory *mem, const Random *rng, uint8_t *packet, uint16_t max_packet_length, const uint8_t *public_key,
const uint8_t *encrypt_public_key, const uint8_t *nonce, const uint8_t *data, uint16_t length)
{
if (DATA_REQUEST_MIN_SIZE + length > max_packet_length) {
return -1;
}
if (DATA_REQUEST_MIN_SIZE + length > ONION_MAX_DATA_SIZE) {
return -1;
}
packet[0] = NET_PACKET_ONION_DATA_REQUEST;
memcpy(packet + 1, public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, nonce, CRYPTO_NONCE_SIZE);
uint8_t random_public_key[CRYPTO_PUBLIC_KEY_SIZE];
uint8_t random_secret_key[CRYPTO_SECRET_KEY_SIZE];
crypto_new_keypair(rng, random_public_key, random_secret_key);
memcpy(packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE, random_public_key, CRYPTO_PUBLIC_KEY_SIZE);
const int len = encrypt_data(mem, encrypt_public_key, random_secret_key, packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, data, length,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE);
if (1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE + len != DATA_REQUEST_MIN_SIZE +
length) {
return -1;
}
return DATA_REQUEST_MIN_SIZE + length;
}
/** @brief Create and send an onion announce request packet.
*
* path is the path the request will take before it is sent to dest.
*
* public_key and secret_key is the kepair which will be used to encrypt the request.
* ping_id is the ping id that will be sent in the request.
* client_id is the client id of the node we are searching for.
* data_public_key is the public key we want others to encrypt their data packets with.
* sendback_data is the data of ONION_ANNOUNCE_SENDBACK_DATA_LENGTH length that we expect to
* receive back in the response.
*
* return -1 on failure.
* return 0 on success.
*/
int send_announce_request(
const Logger *log, const Memory *mem, const Networking_Core *net, const Random *rng,
const Onion_Path *path, const Node_format *dest,
const uint8_t *public_key, const uint8_t *secret_key,
const uint8_t *ping_id, const uint8_t *client_id,
const uint8_t *data_public_key, uint64_t sendback_data)
{
uint8_t request[ONION_ANNOUNCE_REQUEST_MIN_SIZE];
int len = create_announce_request(mem, rng, request, sizeof(request), dest->public_key, public_key, secret_key, ping_id,
client_id, data_public_key, sendback_data);
if (len != sizeof(request)) {
return -1;
}
uint8_t packet[ONION_MAX_PACKET_SIZE];
len = create_onion_packet(mem, rng, packet, sizeof(packet), path, &dest->ip_port, request, sizeof(request));
if (len == -1) {
return -1;
}
if (sendpacket(net, &path->ip_port1, packet, len) != len) {
return -1;
}
return 0;
}
/** @brief Create and send an onion data request packet.
*
* path is the path the request will take before it is sent to dest.
* (if dest knows the person with the public_key they should
* send the packet to that person in the form of a response)
*
* public_key is the real public key of the node which we want to send the data of length length to.
* encrypt_public_key is the public key used to encrypt the data packet.
*
* nonce is the nonce to encrypt this packet with
*
* The maximum length of data is MAX_DATA_REQUEST_SIZE.
*
* return -1 on failure.
* return 0 on success.
*/
int send_data_request(
const Logger *log, const Memory *mem, const Networking_Core *net, const Random *rng, const Onion_Path *path, const IP_Port *dest,
const uint8_t *public_key, const uint8_t *encrypt_public_key, const uint8_t *nonce,
const uint8_t *data, uint16_t length)
{
uint8_t request[ONION_MAX_DATA_SIZE];
int len = create_data_request(mem, rng, request, sizeof(request), public_key, encrypt_public_key, nonce, data, length);
if (len == -1) {
return -1;
}
uint8_t packet[ONION_MAX_PACKET_SIZE];
len = create_onion_packet(mem, rng, packet, sizeof(packet), path, dest, request, len);
if (len == -1) {
return -1;
}
if (sendpacket(net, &path->ip_port1, packet, len) != len) {
return -1;
}
return 0;
}
/** @brief check if public key is in entries list
*
* return -1 if no
* return position in list if yes
*/
static int in_entries(const Onion_Announce *_Nonnull onion_a, const uint8_t *_Nonnull public_key)
{
for (unsigned int i = 0; i < ONION_ANNOUNCE_MAX_ENTRIES; ++i) {
if (!mono_time_is_timeout(onion_a->mono_time, onion_a->entries[i].announce_time, ONION_ANNOUNCE_TIMEOUT)
&& pk_equal(onion_a->entries[i].public_key, public_key)) {
return i;
}
}
return -1;
}
typedef struct Onion_Announce_Entry_Cmp {
const Memory *_Nonnull mem;
const Mono_Time *_Nonnull mono_time;
const uint8_t *_Nonnull comp_public_key;
} Onion_Announce_Entry_Cmp;
static int onion_announce_entry_cmp(const Onion_Announce_Entry_Cmp *_Nonnull cmp, const Onion_Announce_Entry *_Nonnull entry1, const Onion_Announce_Entry *_Nonnull entry2)
{
const bool t1 = mono_time_is_timeout(cmp->mono_time, entry1->announce_time, ONION_ANNOUNCE_TIMEOUT);
const bool t2 = mono_time_is_timeout(cmp->mono_time, entry2->announce_time, ONION_ANNOUNCE_TIMEOUT);
if (t1 && t2) {
return 0;
}
if (t1) {
return -1;
}
if (t2) {
return 1;
}
const int closest = id_closest(cmp->comp_public_key, entry1->public_key, entry2->public_key);
if (closest == 1) {
return 1;
}
if (closest == 2) {
return -1;
}
return 0;
}
static bool onion_announce_entry_less_handler(const void *_Nonnull object, const void *_Nonnull a, const void *_Nonnull b)
{
const Onion_Announce_Entry_Cmp *cmp = (const Onion_Announce_Entry_Cmp *)object;
const Onion_Announce_Entry *entry1 = (const Onion_Announce_Entry *)a;
const Onion_Announce_Entry *entry2 = (const Onion_Announce_Entry *)b;
return onion_announce_entry_cmp(cmp, entry1, entry2) < 0;
}
static const void *_Nonnull onion_announce_entry_get_handler(const void *_Nonnull arr, uint32_t index)
{
const Onion_Announce_Entry *entries = (const Onion_Announce_Entry *)arr;
return &entries[index];
}
static void onion_announce_entry_set_handler(void *_Nonnull arr, uint32_t index, const void *_Nonnull val)
{
Onion_Announce_Entry *entries = (Onion_Announce_Entry *)arr;
const Onion_Announce_Entry *entry = (const Onion_Announce_Entry *)val;
entries[index] = *entry;
}
static void *_Nonnull onion_announce_entry_subarr_handler(void *_Nonnull arr, uint32_t index, uint32_t size)
{
Onion_Announce_Entry *entries = (Onion_Announce_Entry *)arr;
return &entries[index];
}
static void *_Nullable onion_announce_entry_alloc_handler(const void *_Nonnull object, uint32_t size)
{
const Onion_Announce_Entry_Cmp *cmp = (const Onion_Announce_Entry_Cmp *)object;
Onion_Announce_Entry *tmp = (Onion_Announce_Entry *)mem_valloc(cmp->mem, size, sizeof(Onion_Announce_Entry));
if (tmp == nullptr) {
return nullptr;
}
return tmp;
}
static void onion_announce_entry_delete_handler(const void *_Nonnull object, void *_Nonnull arr, uint32_t size)
{
const Onion_Announce_Entry_Cmp *cmp = (const Onion_Announce_Entry_Cmp *)object;
mem_delete(cmp->mem, arr);
}
static const Sort_Funcs onion_announce_entry_cmp_funcs = {
onion_announce_entry_less_handler,
onion_announce_entry_get_handler,
onion_announce_entry_set_handler,
onion_announce_entry_subarr_handler,
onion_announce_entry_alloc_handler,
onion_announce_entry_delete_handler,
};
static void sort_onion_announce_list(const Memory *_Nonnull mem, const Mono_Time *_Nonnull mono_time, Onion_Announce_Entry *_Nonnull list, unsigned int length,
const uint8_t *_Nonnull comp_public_key)
{
// Pass comp_public_key to sort with each Onion_Announce_Entry entry, so the
// comparison function can use it as the base of comparison.
const Onion_Announce_Entry_Cmp cmp = {
mem,
mono_time,
comp_public_key,
};
merge_sort(list, length, &cmp, &onion_announce_entry_cmp_funcs);
}
/** @brief add entry to entries list
*
* return -1 if failure
* return position if added
*/
static int add_to_entries(Onion_Announce *_Nonnull onion_a, const IP_Port *_Nonnull ret_ip_port, const uint8_t *_Nonnull public_key, const uint8_t *_Nonnull data_public_key,
const uint8_t *_Nonnull ret)
{
int pos = in_entries(onion_a, public_key);
if (pos == -1) {
for (unsigned i = 0; i < ONION_ANNOUNCE_MAX_ENTRIES; ++i) {
if (mono_time_is_timeout(onion_a->mono_time, onion_a->entries[i].announce_time, ONION_ANNOUNCE_TIMEOUT)) {
pos = i;
}
}
}
if (pos == -1) {
if (id_closest(dht_get_self_public_key(onion_a->dht), public_key, onion_a->entries[0].public_key) == 1) {
pos = 0;
}
}
if (pos == -1) {
return -1;
}
memcpy(onion_a->entries[pos].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
onion_a->entries[pos].ret_ip_port = *ret_ip_port;
memcpy(onion_a->entries[pos].ret, ret, ONION_RETURN_3);
memcpy(onion_a->entries[pos].data_public_key, data_public_key, CRYPTO_PUBLIC_KEY_SIZE);
onion_a->entries[pos].announce_time = mono_time_get(onion_a->mono_time);
sort_onion_announce_list(onion_a->mem, onion_a->mono_time,
onion_a->entries, ONION_ANNOUNCE_MAX_ENTRIES,
dht_get_self_public_key(onion_a->dht));
return in_entries(onion_a, public_key);
}
static void make_announce_payload_helper(const Onion_Announce *_Nonnull onion_a, const uint8_t *_Nonnull ping_id, uint8_t *_Nonnull response, int index,
const uint8_t *_Nonnull packet_public_key, const uint8_t *_Nonnull data_public_key)
{
if (index < 0) {
response[0] = 0;
memcpy(response + 1, ping_id, ONION_PING_ID_SIZE);
return;
}
if (pk_equal(onion_a->entries[index].public_key, packet_public_key)) {
if (!pk_equal(onion_a->entries[index].data_public_key, data_public_key)) {
response[0] = 0;
memcpy(response + 1, ping_id, ONION_PING_ID_SIZE);
} else {
response[0] = 2;
memcpy(response + 1, ping_id, ONION_PING_ID_SIZE);
}
} else {
response[0] = 1;
memcpy(response + 1, onion_a->entries[index].data_public_key, CRYPTO_PUBLIC_KEY_SIZE);
}
}
/** @brief Handle an onion announce request, possibly with extra data for group chats.
*
* @param onion_a The announce object.
* @param source Requester IP/Port.
* @param packet Encrypted incoming packet.
* @param length Length of incoming packet.
* @param response_packet_id Packet ID to use for the onion announce response.
* @param plain_size Expected size of the decrypted packet. This function returns an error if the
* actual decrypted size is not exactly equal to this number.
* @param want_node_count If true, the packed nodes in the response are preceded by the number of
* nodes sent in the packet. This is necessary if you want to send extra data after the nodes.
* @param max_extra_size Amount of memory to allocate in the outgoing packet to be filled by the
* extra data callback.
* @param pack_extra_data_callback Callback that may write extra data into the packet.
*
* @retval 1 on failure.
* @retval 0 on success.
*/
static int handle_announce_request_common(
Onion_Announce *_Nonnull onion_a, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length,
uint8_t response_packet_id, uint16_t plain_size, bool want_node_count, uint16_t max_extra_size,
pack_extra_data_cb *_Nullable pack_extra_data_callback)
{
if (max_extra_size > ONION_RESPONSE_MAX_DATA_SIZE) {
return 1;
}
const uint8_t *packet_public_key = packet + 1 + CRYPTO_NONCE_SIZE;
const uint8_t *shared_key = shared_key_cache_lookup(onion_a->shared_keys_recv, packet_public_key);
if (shared_key == nullptr) {
/* Error looking up/deriving the shared key */
return 1;
}
uint8_t *plain = (uint8_t *)mem_balloc(onion_a->mem, plain_size);
if (plain == nullptr) {
return 1;
}
const int decrypted_len = decrypt_data_symmetric(onion_a->mem, shared_key, packet + 1,
packet + 1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE, plain_size + CRYPTO_MAC_SIZE, plain);
if ((uint32_t)decrypted_len != plain_size) {
mem_delete(onion_a->mem, plain);
return 1;
}
const uint16_t ping_id_data_len = CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT;
uint8_t ping_id_data[CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT];
memcpy(ping_id_data, packet_public_key, CRYPTO_PUBLIC_KEY_SIZE);
const int packed_len = pack_ip_port(onion_a->log, &ping_id_data[CRYPTO_PUBLIC_KEY_SIZE], SIZE_IPPORT, source);
if (packed_len < 0) {
LOGGER_ERROR(onion_a->log, "failed to pack IP/Port");
mem_delete(onion_a->mem, plain);
return 1;
}
assert(packed_len <= SIZE_IPPORT);
memzero(&ping_id_data[CRYPTO_PUBLIC_KEY_SIZE + packed_len], SIZE_IPPORT - packed_len);
const uint8_t *data_public_key = plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE;
int index;
if (check_timed_auth(onion_a->mono_time, PING_ID_TIMEOUT, onion_a->hmac_key,
ping_id_data, ping_id_data_len, plain)) {
index = add_to_entries(onion_a, source, packet_public_key, data_public_key,
packet + (length - ONION_RETURN_3));
} else {
index = in_entries(onion_a, plain + ONION_PING_ID_SIZE);
}
/* Respond with a announce response packet */
Node_format nodes_list[MAX_SENT_NODES];
const unsigned int num_nodes =
get_close_nodes(onion_a->dht, plain + ONION_PING_ID_SIZE, nodes_list, net_family_unspec(), ip_is_lan(&source->ip), false);
assert(num_nodes <= UINT8_MAX);
uint8_t nonce[CRYPTO_NONCE_SIZE];
random_nonce(onion_a->rng, nonce);
const uint16_t nodes_offset = 1 + ONION_PING_ID_SIZE + (want_node_count ? 1 : 0);
const uint16_t response_size = nodes_offset
+ MAX_SENT_NODES * PACKED_NODE_SIZE_IP6
+ max_extra_size;
uint8_t *response = (uint8_t *)mem_balloc(onion_a->mem, response_size);
if (response == nullptr) {
mem_delete(onion_a->mem, plain);
return 1;
}
uint8_t ping_id[TIMED_AUTH_SIZE];
generate_timed_auth(onion_a->mono_time, PING_ID_TIMEOUT, onion_a->hmac_key,
ping_id_data, ping_id_data_len, ping_id);
make_announce_payload_helper(onion_a, ping_id, response, index, packet_public_key, data_public_key);
int nodes_length = 0;
if (num_nodes != 0) {
nodes_length = pack_nodes(onion_a->log, &response[nodes_offset], num_nodes * PACKED_NODE_SIZE_IP6, nodes_list,
(uint16_t)num_nodes);
if (nodes_length <= 0 || (size_t)nodes_length > num_nodes * PACKED_NODE_SIZE_IP6) {
LOGGER_WARNING(onion_a->log, "Failed to pack nodes");
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 1;
}
}
uint16_t offset = nodes_offset + nodes_length;
if (want_node_count) {
response[1 + ONION_PING_ID_SIZE] = (uint8_t)num_nodes;
}
const int extra_size = pack_extra_data_callback == nullptr ? 0
: pack_extra_data_callback(onion_a->extra_data_object,
onion_a->log, onion_a->mem, onion_a->mono_time, num_nodes,
plain + ONION_MINIMAL_SIZE, length - ANNOUNCE_REQUEST_MIN_SIZE_RECV,
response, response_size, offset);
if (extra_size < 0 || extra_size > max_extra_size) {
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 1;
}
offset += extra_size;
/* Allocate the output buffer to exactly fit the ciphertext we are about
* to produce. Using a fixed constant here would be wrong: when the GCA
* extra-data callback is active, offset can exceed
* ONION_ANNOUNCE_RESPONSE_MAX_SIZE - 33, overflowing any static buffer
* sized from that constant. */
const uint16_t data_size = (uint16_t)(
1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE
+ offset + CRYPTO_MAC_SIZE);
uint8_t *data = (uint8_t *)mem_balloc(onion_a->mem, data_size);
if (data == nullptr) {
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 1;
}
const int len = encrypt_data_symmetric(onion_a->mem, shared_key, nonce, response, offset,
data + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE);
if (len != offset + CRYPTO_MAC_SIZE) {
LOGGER_ERROR(onion_a->log, "Failed to encrypt announce response");
mem_delete(onion_a->mem, data);
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 1;
}
data[0] = response_packet_id;
memcpy(data + 1, plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE,
ONION_ANNOUNCE_SENDBACK_DATA_LENGTH);
memcpy(data + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH, nonce, CRYPTO_NONCE_SIZE);
if (send_onion_response(onion_a->log, onion_a->net, source, data,
1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE + len,
packet + (length - ONION_RETURN_3)) == -1) {
mem_delete(onion_a->mem, data);
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 1;
}
mem_delete(onion_a->mem, data);
mem_delete(onion_a->mem, response);
mem_delete(onion_a->mem, plain);
return 0;
}
static int handle_gca_announce_request(Onion_Announce *_Nonnull onion_a, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length)
{
if (length > ANNOUNCE_REQUEST_MAX_SIZE_RECV || length <= ANNOUNCE_REQUEST_MIN_SIZE_RECV) {
return 1;
}
if (onion_a->extra_data_callback == nullptr) {
return 1;
}
return handle_announce_request_common(onion_a, source, packet, length, NET_PACKET_ANNOUNCE_RESPONSE,
ONION_MINIMAL_SIZE + length - ANNOUNCE_REQUEST_MIN_SIZE_RECV,
true, onion_a->extra_data_max_size, onion_a->extra_data_callback);
}
static int handle_announce_request(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length,
void *_Nullable userdata)
{
Onion_Announce *onion_a = (Onion_Announce *)object;
if (length != ANNOUNCE_REQUEST_MIN_SIZE_RECV) {
return handle_gca_announce_request(onion_a, source, packet, length);
}
return handle_announce_request_common(onion_a, source, packet, length, NET_PACKET_ANNOUNCE_RESPONSE,
ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE * 2 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
true, 0, nullptr);
}
/* TODO(Jfreegman): DEPRECATE */
static int handle_announce_request_old(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length,
void *_Nullable userdata)
{
Onion_Announce *onion_a = (Onion_Announce *)object;
if (length != ANNOUNCE_REQUEST_SIZE_RECV) {
return 1;
}
return handle_announce_request_common(onion_a, source, packet, length, NET_PACKET_ANNOUNCE_RESPONSE_OLD,
ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE * 2 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
false, 0, nullptr);
}
static int handle_data_request(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, void *_Nonnull userdata)
{
const Onion_Announce *onion_a = (const Onion_Announce *)object;
if (length <= DATA_REQUEST_MIN_SIZE_RECV) {
return 1;
}
if (length > ONION_MAX_PACKET_SIZE) {
return 1;
}
const int index = in_entries(onion_a, packet + 1);
if (index == -1) {
return 1;
}
const uint16_t data_size = length - (CRYPTO_PUBLIC_KEY_SIZE + ONION_RETURN_3);
VLA(uint8_t, data, data_size);
data[0] = NET_PACKET_ONION_DATA_RESPONSE;
memcpy(data + 1, packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, length - (1 + CRYPTO_PUBLIC_KEY_SIZE + ONION_RETURN_3));
if (send_onion_response(onion_a->log, onion_a->net, &onion_a->entries[index].ret_ip_port, data, data_size,
onion_a->entries[index].ret) == -1) {
return 1;
}
return 0;
}
Onion_Announce *new_onion_announce(const Logger *log, const Memory *mem, const Random *rng, const Mono_Time *mono_time, DHT *dht,
Networking_Core *net)
{
if (dht == nullptr) {
return nullptr;
}
Onion_Announce *onion_a = (Onion_Announce *)mem_alloc(mem, sizeof(Onion_Announce));
if (onion_a == nullptr) {
return nullptr;
}
Shared_Key_Cache *const shared_keys_recv = shared_key_cache_new(log, mono_time, mem, dht_get_self_secret_key(dht), KEYS_TIMEOUT, MAX_KEYS_PER_SLOT);
if (shared_keys_recv == nullptr) {
mem_delete(mem, onion_a);
return nullptr;
}
onion_a->shared_keys_recv = shared_keys_recv;
onion_a->log = log;
onion_a->rng = rng;
onion_a->mem = mem;
onion_a->mono_time = mono_time;
onion_a->dht = dht;
onion_a->net = net;
onion_a->extra_data_max_size = 0;
onion_a->extra_data_callback = nullptr;
onion_a->extra_data_object = nullptr;
new_hmac_key(rng, onion_a->hmac_key);
networking_registerhandler(onion_a->net, NET_PACKET_ANNOUNCE_REQUEST, &handle_announce_request, onion_a);
networking_registerhandler(onion_a->net, NET_PACKET_ANNOUNCE_REQUEST_OLD, &handle_announce_request_old, onion_a);
networking_registerhandler(onion_a->net, NET_PACKET_ONION_DATA_REQUEST, &handle_data_request, onion_a);
return onion_a;
}
void kill_onion_announce(Onion_Announce *onion_a)
{
if (onion_a == nullptr) {
return;
}
networking_registerhandler(onion_a->net, NET_PACKET_ANNOUNCE_REQUEST, nullptr, nullptr);
networking_registerhandler(onion_a->net, NET_PACKET_ANNOUNCE_REQUEST_OLD, nullptr, nullptr);
networking_registerhandler(onion_a->net, NET_PACKET_ONION_DATA_REQUEST, nullptr, nullptr);
crypto_memzero(onion_a->hmac_key, CRYPTO_HMAC_KEY_SIZE);
shared_key_cache_free(onion_a->shared_keys_recv);
mem_delete(onion_a->mem, onion_a);
}