fix: Avoid memcpy-ing structs into onion ping id data.

Although it is only ever read back on the machine it originated from,
it's bad practice and we should not make our protocol have
system-specific undefined padding bytes in it.

toxcore/onion_announce.c

@@ -24,6 +24,7 @@
 #include "onion.h"
 #include "shared_key_cache.h"
 #include "timed_auth.h"
+#include "util.h"
 
 #define PING_ID_TIMEOUT ONION_ANNOUNCE_TIMEOUT
 
@@ -463,10 +464,11 @@ static int handle_announce_request_common(
         return 1;
     }
 
-    const uint16_t ping_id_data_len = CRYPTO_PUBLIC_KEY_SIZE + sizeof(*source);
-    uint8_t ping_id_data[CRYPTO_PUBLIC_KEY_SIZE + sizeof(*source)];
+    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);
-    memcpy(ping_id_data + CRYPTO_PUBLIC_KEY_SIZE, source, sizeof(*source));
+    const int packed_len = pack_ip_port(onion_a->log, &ping_id_data[CRYPTO_PUBLIC_KEY_SIZE], SIZE_IPPORT, source);
+    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;
 
@@ -510,7 +512,7 @@ static int handle_announce_request_common(
     int nodes_length = 0;
 
     if (num_nodes != 0) {
-        nodes_length = pack_nodes(onion_a->log, response + nodes_offset, sizeof(nodes_list), nodes_list,
+        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) {

toxcore/onion_client.c

@@ -576,11 +576,12 @@ non_null()
 static int new_sendback(Onion_Client *onion_c, uint32_t num, const uint8_t *public_key, const IP_Port *ip_port,
                         uint32_t path_num, uint64_t *sendback)
 {
-    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port) + sizeof(uint32_t)];
+    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT + sizeof(uint32_t)];
     memcpy(data, &num, sizeof(uint32_t));
-    memcpy(data + sizeof(uint32_t), public_key, CRYPTO_PUBLIC_KEY_SIZE);
-    memcpy(data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE, ip_port, sizeof(IP_Port));
-    memcpy(data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port), &path_num, sizeof(uint32_t));
+    memcpy(&data[sizeof(uint32_t)], public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    const int packed_len = pack_ip_port(onion_c->logger, &data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE], SIZE_IPPORT, ip_port);
+    memzero(&data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + packed_len], SIZE_IPPORT - packed_len);
+    memcpy(&data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT], &path_num, sizeof(uint32_t));
     *sendback = ping_array_add(onion_c->announce_ping_array, onion_c->mono_time, onion_c->rng, data, sizeof(data));
 
     if (*sendback == 0) {
@@ -607,15 +608,15 @@ static uint32_t check_sendback(Onion_Client *onion_c, const uint8_t *sendback, u
 {
     uint64_t sback;
     memcpy(&sback, sendback, sizeof(uint64_t));
-    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port) + sizeof(uint32_t)];
+    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT + sizeof(uint32_t)];
 
     if (ping_array_check(onion_c->announce_ping_array, onion_c->mono_time, data, sizeof(data), sback) != sizeof(data)) {
         return -1;
     }
 
     memcpy(ret_pubkey, data + sizeof(uint32_t), CRYPTO_PUBLIC_KEY_SIZE);
-    memcpy(ret_ip_port, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE, sizeof(IP_Port));
-    memcpy(path_num, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port), sizeof(uint32_t));
+    unpack_ip_port(ret_ip_port, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE, SIZE_IPPORT, false);
+    memcpy(path_num, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + SIZE_IPPORT, sizeof(uint32_t));
 
     uint32_t num;
     memcpy(&num, data, sizeof(uint32_t));