Const correctness in various interdependent files

21 files changed, 133 insertions, 133 deletions

diff --git a/testing/Messenger_test.c b/testing/Messenger_test.c
index a6efb433..7c1d64e7 100644
--- a/testing/Messenger_test.c
+++ b/testing/Messenger_test.c
@@ -66,7 +66,7 @@ void print_message(Messenger *m, int friendnumber, uint8_t *string, uint16_t len
  * networking_requesthandler and so cannot take a Messenger * */
 static Messenger *m;
 
-void print_request(Messenger *m, uint8_t *public_key, uint8_t *data, uint16_t length, void *userdata)
+void print_request(Messenger *m, const uint8_t *public_key, const uint8_t *data, uint16_t length, void *userdata)
 {
     printf("Friend request received from: \n");
     printf("ClientID: ");
diff --git a/toxcore/DHT.c b/toxcore/DHT.c
index fed12861..92d6e159 100644
--- a/toxcore/DHT.c
+++ b/toxcore/DHT.c
@@ -83,7 +83,7 @@ Client_data *DHT_get_close_list(DHT *dht)
  *  return 1 if client_id1 is closer.
  *  return 2 if client_id2 is closer.
  */
-int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2)
+int id_closest(const uint8_t *id, const uint8_t *id1, const uint8_t *id2)
 {
     size_t   i;
     uint8_t distance1, distance2;
@@ -106,7 +106,7 @@ int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2)
 /* Turns the result of id_closest into something quick_sort can use.
  * Assumes p1->c1 == p2->c1.
  */
-static int client_id_cmp(ClientPair p1, ClientPair p2)
+static int client_id_cmp(const ClientPair p1, const ClientPair p2)
 {
     int c = id_closest(p1.c1.client_id, p1.c2.client_id, p2.c2.client_id);
 
@@ -122,7 +122,7 @@ static int client_id_cmp(ClientPair p1, ClientPair p2)
  * If shared key is already in shared_keys, copy it to shared_key.
  * else generate it into shared_key and copy it to shared_keys
  */
-void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, uint8_t *secret_key, uint8_t *client_id)
+void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, const uint8_t *secret_key, const uint8_t *client_id)
 {
     uint32_t i, num = ~0, curr = 0;
 
@@ -168,7 +168,7 @@ void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, uint8_t *secr
 /* Copy shared_key to encrypt/decrypt DHT packet from client_id into shared_key
  * for packets that we receive.
  */
-void DHT_get_shared_key_recv(DHT *dht, uint8_t *shared_key, uint8_t *client_id)
+void DHT_get_shared_key_recv(DHT *dht, uint8_t *shared_key, const uint8_t *client_id)
 {
     return get_shared_key(&dht->shared_keys_recv, shared_key, dht->self_secret_key, client_id);
 }
@@ -176,7 +176,7 @@ void DHT_get_shared_key_recv(DHT *dht, uint8_t *shared_key, uint8_t *client_id)
 /* Copy shared_key to encrypt/decrypt DHT packet from client_id into shared_key
  * for packets that we send.
  */
-void DHT_get_shared_key_sent(DHT *dht, uint8_t *shared_key, uint8_t *client_id)
+void DHT_get_shared_key_sent(DHT *dht, uint8_t *shared_key, const uint8_t *client_id)
 {
     return get_shared_key(&dht->shared_keys_sent, shared_key, dht->self_secret_key, client_id);
 }
@@ -202,7 +202,7 @@ void to_host_family(IP *ip)
  * return length of packed nodes on success.
  * return -1 on failure.
  */
-int pack_nodes(uint8_t *data, uint16_t length, Node_format *nodes, uint16_t number)
+int pack_nodes(uint8_t *data, uint16_t length, const Node_format *nodes, uint16_t number)
 {
     uint32_t i, packed_length = 0;
 
@@ -263,7 +263,7 @@ int pack_nodes(uint8_t *data, uint16_t length, Node_format *nodes, uint16_t numb
  * return number of unpacked nodes on success.
  * return -1 on failure.
  */
-int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, uint8_t *data,
+int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, const uint8_t *data,
                  uint16_t length, uint8_t tcp_enabled)
 {
     uint32_t num = 0, len_processed = 0;
@@ -338,7 +338,7 @@ int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed
  *
  *  return True(1) or False(0)
  */
-static int client_or_ip_port_in_list(Client_data *list, uint32_t length, uint8_t *client_id, IP_Port ip_port)
+static int client_or_ip_port_in_list(Client_data *list, uint32_t length, const uint8_t *client_id, IP_Port ip_port)
 {
     uint32_t i;
     uint64_t temp_time = unix_time();
@@ -417,7 +417,7 @@ static int client_or_ip_port_in_list(Client_data *list, uint32_t length, uint8_t
  *  return 1 if true.
  *  return 0 if false.
  */
-static int client_in_nodelist(Node_format *list, uint32_t length, uint8_t *client_id)
+static int client_in_nodelist(const Node_format *list, uint32_t length, const uint8_t *client_id)
 {
     uint32_t i;
 
@@ -432,7 +432,7 @@ static int client_in_nodelist(Node_format *list, uint32_t length, uint8_t *clien
 /*  return friend number from the client_id.
  *  return -1 if a failure occurs.
  */
-static int friend_number(DHT *dht, uint8_t *client_id)
+static int friend_number(const DHT *dht, const uint8_t *client_id)
 {
     uint32_t i;
 
@@ -452,15 +452,15 @@ static int friend_number(DHT *dht, uint8_t *client_id)
  * return 4 if it can test other nodes correctly
  * return HARDENING_ALL_OK if all ok.
  */
-static uint8_t hardening_correct(Hardening *h)
+static uint8_t hardening_correct(const Hardening *h)
 {
     return h->routes_requests_ok + (h->send_nodes_ok << 1) + (h->testing_requests << 2);
 }
 /*
  * helper for get_close_nodes(). argument list is a monster :D
  */
-static void get_close_nodes_inner(uint8_t *client_id, Node_format *nodes_list,
-                                  sa_family_t sa_family, Client_data *client_list, uint32_t client_list_length,
+static void get_close_nodes_inner(const uint8_t *client_id, Node_format *nodes_list,
+                                  sa_family_t sa_family, const Client_data *client_list, uint32_t client_list_length,
                                   uint32_t *num_nodes_ptr, uint8_t is_LAN, uint8_t want_good)
 {
     if ((sa_family != AF_INET) && (sa_family != AF_INET6) && (sa_family != 0))
@@ -471,13 +471,13 @@ static void get_close_nodes_inner(uint8_t *client_id, Node_format *nodes_list,
     uint32_t i;
 
     for (i = 0; i < client_list_length; i++) {
-        Client_data *client = &client_list[i];
+        const Client_data *client = &client_list[i];
 
         /* node already in list? */
         if (client_in_nodelist(nodes_list, MAX_SENT_NODES, client->client_id))
             continue;
 
-        IPPTsPng *ipptp = NULL;
+        const IPPTsPng *ipptp = NULL;
 
         if (sa_family == AF_INET) {
             ipptp = &client->assoc4;
@@ -544,7 +544,7 @@ static void get_close_nodes_inner(uint8_t *client_id, Node_format *nodes_list,
  *
  * want_good : do we want only good nodes as checked with the hardening returned or not?
  */
-static int get_somewhat_close_nodes(DHT *dht, uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family,
+static int get_somewhat_close_nodes(const DHT *dht, const uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family,
                                     uint8_t is_LAN, uint8_t want_good)
 {
     uint32_t num_nodes = 0, i;
@@ -565,7 +565,7 @@ static int get_somewhat_close_nodes(DHT *dht, uint8_t *client_id, Node_format *n
     return num_nodes;
 }
 
-int get_close_nodes(DHT *dht, uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family, uint8_t is_LAN,
+int get_close_nodes(const DHT *dht, const uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family, uint8_t is_LAN,
                     uint8_t want_good)
 {
     memset(nodes_list, 0, MAX_SENT_NODES * sizeof(Node_format));
@@ -632,7 +632,7 @@ int get_close_nodes(DHT *dht, uint8_t *client_id, Node_format *nodes_list, sa_fa
  */
 static int replace_bad(    Client_data    *list,
                            uint32_t        length,
-                           uint8_t        *client_id,
+                           const uint8_t  *client_id,
                            IP_Port         ip_port )
 {
     if ((ip_port.ip.family != AF_INET) && (ip_port.ip.family != AF_INET6))
@@ -680,7 +680,7 @@ static int replace_bad(    Client_data    *list,
 /* Sort the list. It will be sorted from furthest to closest.
  *  Turns list into data that quick sort can use and reverts it back.
  */
-static void sort_list(Client_data *list, uint32_t length, uint8_t *comp_client_id)
+static void sort_list(Client_data *list, uint32_t length, const uint8_t *comp_client_id)
 {
     Client_data cd;
     ClientPair pairs[length];
@@ -706,9 +706,9 @@ static void sort_list(Client_data *list, uint32_t length, uint8_t *comp_client_i
  */
 static int replace_possible_bad(    Client_data    *list,
                                     uint32_t        length,
-                                    uint8_t        *client_id,
+                                    const uint8_t  *client_id,
                                     IP_Port         ip_port,
-                                    uint8_t        *comp_client_id )
+                                    const uint8_t  *comp_client_id )
 {
     if ((ip_port.ip.family != AF_INET) && (ip_port.ip.family != AF_INET6))
         return 1;
@@ -762,9 +762,9 @@ static int replace_possible_bad(    Client_data    *list,
  *  returns 0 when the item was stored, 1 otherwise */
 static int replace_good(   Client_data    *list,
                            uint32_t        length,
-                           uint8_t        *client_id,
+                           const uint8_t  *client_id,
                            IP_Port         ip_port,
-                           uint8_t        *comp_client_id )
+                           const uint8_t  *comp_client_id )
 {
     if ((ip_port.ip.family != AF_INET) && (ip_port.ip.family != AF_INET6))
         return 1;
@@ -825,7 +825,7 @@ static int replace_good(   Client_data    *list,
  *
  *  returns 1+ if the item is used in any list, 0 else
  */
-int addto_lists(DHT *dht, IP_Port ip_port, uint8_t *client_id)
+int addto_lists(DHT *dht, IP_Port ip_port, const uint8_t *client_id)
 {
     uint32_t i, used = 0;
 
@@ -892,7 +892,7 @@ int addto_lists(DHT *dht, IP_Port ip_port, uint8_t *client_id)
 /* If client_id is a friend or us, update ret_ip_port
  * nodeclient_id is the id of the node that sent us this info.
  */
-static int returnedip_ports(DHT *dht, IP_Port ip_port, uint8_t *client_id, uint8_t *nodeclient_id)
+static int returnedip_ports(DHT *dht, IP_Port ip_port, const uint8_t *client_id, const uint8_t *nodeclient_id)
 {
     uint32_t i, j;
     uint64_t temp_time = unix_time();
@@ -961,7 +961,7 @@ end:
 
 /* Send a getnodes request.
    sendback_node is the node that it will send back the response to (set to NULL to disable this) */
-static int getnodes(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *client_id, Node_format *sendback_node)
+static int getnodes(DHT *dht, IP_Port ip_port, const uint8_t *public_key, const uint8_t *client_id, const Node_format *sendback_node)
 {
     /* Check if packet is going to be sent to ourself. */
     if (id_equal(public_key, dht->self_public_key))
@@ -1017,8 +1017,8 @@ static int getnodes(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *cli
 }
 
 /* Send a send nodes response: message for IPv6 nodes */
-static int sendnodes_ipv6(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *client_id, uint8_t *sendback_data,
-                          uint16_t length, uint8_t *shared_encryption_key)
+static int sendnodes_ipv6(const DHT *dht, IP_Port ip_port, const uint8_t *public_key, const uint8_t *client_id, const uint8_t *sendback_data,
+                          uint16_t length, const uint8_t *shared_encryption_key)
 {
     /* Check if packet is going to be sent to ourself. */
     if (id_equal(public_key, dht->self_public_key))
@@ -1105,7 +1105,7 @@ static int handle_getnodes(void *object, IP_Port source, uint8_t *packet, uint32
 }
 /* return 0 if no
    return 1 if yes */
-static uint8_t sent_getnode_to_node(DHT *dht, uint8_t *client_id, IP_Port node_ip_port, uint64_t ping_id,
+static uint8_t sent_getnode_to_node(DHT *dht, const uint8_t *client_id, IP_Port node_ip_port, uint64_t ping_id,
                                     Node_format *sendback_node)
 {
     uint8_t data[sizeof(Node_format) * 2];
@@ -1128,10 +1128,10 @@ static uint8_t sent_getnode_to_node(DHT *dht, uint8_t *client_id, IP_Port node_i
 }
 
 /* Function is needed in following functions. */
-static int send_hardening_getnode_res(DHT *dht, Node_format *sendto, uint8_t *queried_client_id, uint8_t *nodes_data,
+static int send_hardening_getnode_res(const DHT *dht, const Node_format *sendto, const uint8_t *queried_client_id, const uint8_t *nodes_data,
                                       uint16_t nodes_data_length);
 
-static int handle_sendnodes_core(void *object, IP_Port source, uint8_t *packet, uint32_t length,
+static int handle_sendnodes_core(void *object, IP_Port source, const uint8_t *packet, uint32_t length,
                                  Node_format *plain_nodes, uint16_t size_plain_nodes, uint32_t *num_nodes_out)
 {
     DHT *dht = object;
@@ -1244,7 +1244,7 @@ static void get_bunchnodes(DHT *dht, Client_data *list, uint16_t length, uint16_
     }
 }
 */
-int DHT_addfriend(DHT *dht, uint8_t *client_id)
+int DHT_addfriend(DHT *dht, const uint8_t *client_id)
 {
     if (friend_number(dht, client_id) != -1) /* Is friend already in DHT? */
         return 1;
@@ -1298,7 +1298,7 @@ int DHT_addfriend(DHT *dht, uint8_t *client_id)
     return 0;
 }
 
-int DHT_delfriend(DHT *dht, uint8_t *client_id)
+int DHT_delfriend(DHT *dht, const uint8_t *client_id)
 {
     uint32_t i;
     DHT_Friend *temp;
@@ -1334,7 +1334,7 @@ int DHT_delfriend(DHT *dht, uint8_t *client_id)
 }
 
 /* TODO: Optimize this. */
-int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port)
+int DHT_getfriendip(const DHT *dht, const uint8_t *client_id, IP_Port *ip_port)
 {
     uint32_t i, j;
 
@@ -1367,7 +1367,7 @@ int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port)
 }
 
 /* returns number of nodes not in kill-timeout */
-static uint8_t do_ping_and_sendnode_requests(DHT *dht, uint64_t *lastgetnode, uint8_t *client_id,
+static uint8_t do_ping_and_sendnode_requests(DHT *dht, uint64_t *lastgetnode, const uint8_t *client_id,
         Client_data *list, uint32_t list_count, uint32_t *bootstrap_times)
 {
     uint32_t i;
@@ -1454,12 +1454,12 @@ static void do_Close(DHT *dht)
     }
 }
 
-void DHT_getnodes(DHT *dht, IP_Port *from_ipp, uint8_t *from_id, uint8_t *which_id)
+void DHT_getnodes(DHT *dht, const IP_Port *from_ipp, const uint8_t *from_id, const uint8_t *which_id)
 {
     getnodes(dht, *from_ipp, from_id, which_id, NULL);
 }
 
-void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key)
+void DHT_bootstrap(DHT *dht, IP_Port ip_port, const uint8_t *public_key)
 {
     /*#ifdef ENABLE_ASSOC_DHT
        if (dht->assoc) {
@@ -1474,7 +1474,7 @@ void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key)
     getnodes(dht, ip_port, public_key, dht->self_public_key, NULL);
 }
 int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enabled,
-                               uint16_t port, uint8_t *public_key)
+                               uint16_t port, const uint8_t *public_key)
 {
     IP_Port ip_port_v64;
     IP *ip_extra = NULL;
@@ -1506,13 +1506,13 @@ int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enable
  *
  *  return -1 if failure.
  */
-int route_packet(DHT *dht, uint8_t *client_id, uint8_t *packet, uint32_t length)
+int route_packet(const DHT *dht, const uint8_t *client_id, const uint8_t *packet, uint32_t length)
 {
     uint32_t i;
 
     for (i = 0; i < LCLIENT_LIST; ++i) {
         if (id_equal(client_id, dht->close_clientlist[i].client_id)) {
-            Client_data *client = &dht->close_clientlist[i];
+            const Client_data *client = &dht->close_clientlist[i];
 
             if (ip_isset(&client->assoc6.ip_port.ip))
                 return sendpacket(dht->net, client->assoc6.ip_port, packet, length);
@@ -1533,7 +1533,7 @@ int route_packet(DHT *dht, uint8_t *client_id, uint8_t *packet, uint32_t length)
  *  return 0 if we are connected to friend or if no ips were found.
  *  return -1 if no such friend.
  */
-static int friend_iplist(DHT *dht, IP_Port *ip_portlist, uint16_t friend_num)
+static int friend_iplist(const DHT *dht, IP_Port *ip_portlist, uint16_t friend_num)
 {
     if (friend_num >= dht->num_friends)
         return -1;
@@ -1601,7 +1601,7 @@ static int friend_iplist(DHT *dht, IP_Port *ip_portlist, uint16_t friend_num)
  *  return ip for friend.
  *  return number of nodes the packet was sent to. (Only works if more than (MAX_FRIEND_CLIENTS / 4).
  */
-int route_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length)
+int route_tofriend(const DHT *dht, const uint8_t *friend_id, const uint8_t *packet, uint32_t length)
 {
     int num = friend_number(dht, friend_id);
 
@@ -1656,7 +1656,7 @@ int route_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t lengt
  *
  *  return number of nodes the packet was sent to.
  */
-static int routeone_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length)
+static int routeone_tofriend(DHT *dht, const uint8_t *friend_id, const uint8_t *packet, uint32_t length)
 {
     int num = friend_number(dht, friend_id);
 
@@ -1709,7 +1709,7 @@ static int routeone_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint
  *  return 0 if we are connected to friend or if no ips were found.
  *  return -1 if no such friend.
  */
-int friend_ips(DHT *dht, IP_Port *ip_portlist, uint8_t *friend_id)
+int friend_ips(const DHT *dht, IP_Port *ip_portlist, const uint8_t *friend_id)
 {
     uint32_t i;
 
@@ -1725,7 +1725,7 @@ int friend_ips(DHT *dht, IP_Port *ip_portlist, uint8_t *friend_id)
 /*----------------------------------------------------------------------------------*/
 /*---------------------BEGINNING OF NAT PUNCHING FUNCTIONS--------------------------*/
 
-static int send_NATping(DHT *dht, uint8_t *public_key, uint64_t ping_id, uint8_t type)
+static int send_NATping(DHT *dht, const uint8_t *public_key, uint64_t ping_id, uint8_t type)
 {
     uint8_t data[sizeof(uint64_t) + 1];
     uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
@@ -1753,7 +1753,7 @@ static int send_NATping(DHT *dht, uint8_t *public_key, uint64_t ping_id, uint8_t
 }
 
 /* Handle a received ping request for. */
-static int handle_NATping(void *object, IP_Port source, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
+static int handle_NATping(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet, uint32_t length)
 {
     if (length != sizeof(uint64_t) + 1)
         return 1;
@@ -1962,7 +1962,7 @@ static int send_hardening_getnode_req(DHT *dht, Node_format *dest, Node_format *
 }
 
 /* Send a get node hardening response */
-static int send_hardening_getnode_res(DHT *dht, Node_format *sendto, uint8_t *queried_client_id, uint8_t *nodes_data,
+static int send_hardening_getnode_res(const DHT *dht, const Node_format *sendto, const uint8_t *queried_client_id, const uint8_t *nodes_data,
                                       uint16_t nodes_data_length)
 {
     if (!ip_isset(&sendto->ip_port.ip))
@@ -1983,7 +1983,7 @@ static int send_hardening_getnode_res(DHT *dht, Node_format *sendto, uint8_t *qu
 }
 
 /* TODO: improve */
-static IPPTsPng *get_closelist_IPPTsPng(DHT *dht, uint8_t *client_id, sa_family_t sa_family)
+static IPPTsPng *get_closelist_IPPTsPng(DHT *dht, const uint8_t *client_id, sa_family_t sa_family)
 {
     uint32_t i;
 
@@ -2032,7 +2032,7 @@ static uint32_t have_nodes_closelist(DHT *dht, Node_format *nodes, uint16_t num)
 #define HARDEN_TIMEOUT 1200
 
 /* Handle a received hardening packet */
-static int handle_hardening(void *object, IP_Port source, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
+static int handle_hardening(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet, uint32_t length)
 {
     DHT *dht = object;
 
@@ -2422,7 +2422,7 @@ void kill_DHT(DHT *dht)
 #define DHT_STATE_TYPE_CLIENTS_ASSOC46  4
 
 /* Get the size of the DHT (for saving). */
-uint32_t DHT_size(DHT *dht)
+uint32_t DHT_size(const DHT *dht)
 {
     uint32_t num = 0, i;
 
@@ -2481,7 +2481,7 @@ void DHT_save(DHT *dht, uint8_t *data)
     }
 }
 
-static int dht_load_state_callback(void *outer, uint8_t *data, uint32_t length, uint16_t type)
+static int dht_load_state_callback(void *outer, const uint8_t *data, uint32_t length, uint16_t type)
 {
     DHT *dht = outer;
     uint32_t num, i, j;
@@ -2547,7 +2547,7 @@ static int dht_load_state_callback(void *outer, uint8_t *data, uint32_t length,
  *  return -1 if failure.
  *  return 0 if success.
  */
-int DHT_load(DHT *dht, uint8_t *data, uint32_t length)
+int DHT_load(DHT *dht, const uint8_t *data, uint32_t length)
 {
     uint32_t cookie_len = sizeof(uint32_t);
 
@@ -2564,13 +2564,13 @@ int DHT_load(DHT *dht, uint8_t *data, uint32_t length)
 /*  return 0 if we are not connected to the DHT.
  *  return 1 if we are.
  */
-int DHT_isconnected(DHT *dht)
+int DHT_isconnected(const DHT *dht)
 {
     uint32_t i;
     unix_time_update();
 
     for (i = 0; i < LCLIENT_LIST; ++i) {
-        Client_data *client = &dht->close_clientlist[i];
+        const Client_data *client = &dht->close_clientlist[i];
 
         if (!is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT) ||
                 !is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT))
diff --git a/toxcore/DHT.h b/toxcore/DHT.h
index 57813132..97a7109f 100644
--- a/toxcore/DHT.h
+++ b/toxcore/DHT.h
@@ -147,7 +147,7 @@ Node_format;
  * return length of packed nodes on success.
  * return -1 on failure.
  */
-int pack_nodes(uint8_t *data, uint16_t length, Node_format *nodes, uint16_t number);
+int pack_nodes(uint8_t *data, uint16_t length, const Node_format *nodes, uint16_t number);
 
 /* Unpack data of length into nodes of size max_num_nodes.
  * Put the length of the data processed in processed_data_len.
@@ -156,7 +156,7 @@ int pack_nodes(uint8_t *data, uint16_t length, Node_format *nodes, uint16_t numb
  * return number of unpacked nodes on success.
  * return -1 on failure.
  */
-int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, uint8_t *data,
+int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, const uint8_t *data,
                  uint16_t length, uint8_t tcp_enabled);
 
 
@@ -176,7 +176,7 @@ typedef struct {
 
 /*----------------------------------------------------------------------------------*/
 
-typedef int (*cryptopacket_handler_callback)(void *object, IP_Port ip_port, uint8_t *source_pubkey, uint8_t *data,
+typedef int (*cryptopacket_handler_callback)(void *object, IP_Port ip_port, const uint8_t *source_pubkey, const uint8_t *data,
         uint32_t len);
 
 typedef struct {
@@ -221,19 +221,19 @@ typedef struct {
  * If shared key is already in shared_keys, copy it to shared_key.
  * else generate it into shared_key and copy it to shared_keys
  */
-void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, uint8_t *secret_key, uint8_t *client_id);
+void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, const uint8_t *secret_key, const uint8_t *client_id);
 
 /* Copy shared_key to encrypt/decrypt DHT packet from client_id into shared_key
  * for packets that we receive.
  */
-void DHT_get_shared_key_recv(DHT *dht, uint8_t *shared_key, uint8_t *client_id);
+void DHT_get_shared_key_recv(DHT *dht, uint8_t *shared_key, const uint8_t *client_id);
 
 /* Copy shared_key to encrypt/decrypt DHT packet from client_id into shared_key
  * for packets that we send.
  */
-void DHT_get_shared_key_sent(DHT *dht, uint8_t *shared_key, uint8_t *client_id);
+void DHT_get_shared_key_sent(DHT *dht, uint8_t *shared_key, const uint8_t *client_id);
 
-void DHT_getnodes(DHT *dht, IP_Port *from_ipp, uint8_t *from_id, uint8_t *which_id);
+void DHT_getnodes(DHT *dht, const IP_Port *from_ipp, const uint8_t *from_id, const uint8_t *which_id);
 
 /* Add a new friend to the friends list.
  * client_id must be CLIENT_ID_SIZE bytes long.
@@ -241,7 +241,7 @@ void DHT_getnodes(DHT *dht, IP_Port *from_ipp, uint8_t *from_id, uint8_t *which_
  *  return 0 if success.
  *  return 1 if failure (friends list is full).
  */
-int DHT_addfriend(DHT *dht, uint8_t *client_id);
+int DHT_addfriend(DHT *dht, const uint8_t *client_id);
 
 /* Delete a friend from the friends list.
  * client_id must be CLIENT_ID_SIZE bytes long.
@@ -249,7 +249,7 @@ int DHT_addfriend(DHT *dht, uint8_t *client_id);
  *  return 0 if success.
  *  return 1 if failure (client_id not in friends list).
  */
-int DHT_delfriend(DHT *dht, uint8_t *client_id);
+int DHT_delfriend(DHT *dht, const uint8_t *client_id);
 
 /* Get ip of friend.
  *  client_id must be CLIENT_ID_SIZE bytes long.
@@ -270,7 +270,7 @@ int DHT_delfriend(DHT *dht, uint8_t *client_id);
  *  return  0, -- if client_id refers to a friend and we failed to find the friend (yet)
  *  return  1, ip if client_id refers to a friend and we found him
  */
-int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port);
+int DHT_getfriendip(const DHT *dht, const uint8_t *client_id, IP_Port *ip_port);
 
 /* Compares client_id1 and client_id2 with client_id.
  *
@@ -278,7 +278,7 @@ int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port);
  *  return 1 if client_id1 is closer.
  *  return 2 if client_id2 is closer.
  */
-int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2);
+int id_closest(const uint8_t *id, const uint8_t *id1, const uint8_t *id2);
 
 /* Get the (maximum MAX_SENT_NODES) closest nodes to client_id we know
  * and put them in nodes_list (must be MAX_SENT_NODES big).
@@ -290,7 +290,7 @@ int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2);
  * return the number of nodes returned.
  *
  */
-int get_close_nodes(DHT *dht, uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family, uint8_t is_LAN,
+int get_close_nodes(const DHT *dht, const uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family, uint8_t is_LAN,
                     uint8_t want_good);
 
 
@@ -317,7 +317,7 @@ void do_DHT(DHT *dht);
 /* Sends a "get nodes" request to the given node with ip, port and public_key
  *   to setup connections
  */
-void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key);
+void DHT_bootstrap(DHT *dht, IP_Port ip_port, const uint8_t *public_key);
 /* Resolves address into an IP address. If successful, sends a "get nodes"
  *   request to the given node with ip, port and public_key to setup connections
  *
@@ -330,7 +330,7 @@ void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key);
  *  returns 0 otherwise
  */
 int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enabled,
-                               uint16_t port, uint8_t *public_key);
+                               uint16_t port, const uint8_t *public_key);
 
 
 /* ROUTING FUNCTIONS */
@@ -339,13 +339,13 @@ int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enable
  *
  *  return -1 if failure.
  */
-int route_packet(DHT *dht, uint8_t *client_id, uint8_t *packet, uint32_t length);
+int route_packet(const DHT *dht, const uint8_t *client_id, const uint8_t *packet, uint32_t length);
 
 /* Send the following packet to everyone who tells us they are connected to friend_id.
  *
  *  return number of nodes it sent the packet to.
  */
-int route_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length);
+int route_tofriend(const DHT *dht, const uint8_t *friend_id, const uint8_t *packet, uint32_t length);
 
 /* Function to handle crypto packets.
  */
@@ -359,12 +359,12 @@ void cryptopacket_registerhandler(DHT *dht, uint8_t byte, cryptopacket_handler_c
  *  returns number of ips returned.
  *  returns -1 if no such friend.
  */
-int friend_ips(DHT *dht, IP_Port *ip_portlist, uint8_t *friend_id);
+int friend_ips(const DHT *dht, IP_Port *ip_portlist, const uint8_t *friend_id);
 
 /* SAVE/LOAD functions */
 
 /* Get the size of the DHT (for saving). */
-uint32_t DHT_size(DHT *dht);
+uint32_t DHT_size(const DHT *dht);
 
 /* Save the DHT in data where data is an array of size DHT_size(). */
 void DHT_save(DHT *dht, uint8_t *data);
@@ -374,7 +374,7 @@ void DHT_save(DHT *dht, uint8_t *data);
  *  return -1 if failure.
  *  return 0 if success.
  */
-int DHT_load(DHT *dht, uint8_t *data, uint32_t length);
+int DHT_load(DHT *dht, const uint8_t *data, uint32_t length);
 
 /* Initialize DHT. */
 DHT *new_DHT(Networking_Core *net);
@@ -384,9 +384,9 @@ void kill_DHT(DHT *dht);
 /*  return 0 if we are not connected to the DHT.
  *  return 1 if we are.
  */
-int DHT_isconnected(DHT *dht);
+int DHT_isconnected(const DHT *dht);
 
-int addto_lists(DHT *dht, IP_Port ip_port, uint8_t *client_id);
+int addto_lists(DHT *dht, IP_Port ip_port, const uint8_t *client_id);
 
 #endif
 
diff --git a/toxcore/Messenger.c b/toxcore/Messenger.c
index 037b0e66..931468ec 100644
--- a/toxcore/Messenger.c
+++ b/toxcore/Messenger.c
@@ -86,7 +86,7 @@ int realloc_friendlist(Messenger *m, uint32_t num)
 /*  return the friend id associated to that public key.
  *  return -1 if no such friend.
  */
-int32_t getfriend_id(Messenger *m, uint8_t *client_id)
+int32_t getfriend_id(const Messenger *m, const uint8_t *client_id)
 {
     uint32_t i;
 
@@ -256,7 +256,7 @@ int32_t m_addfriend(Messenger *m, uint8_t *address, uint8_t *data, uint16_t leng
     return FAERR_UNKNOWN;
 }
 
-int32_t m_addfriend_norequest(Messenger *m, uint8_t *client_id)
+int32_t m_addfriend_norequest(Messenger *m, const uint8_t *client_id)
 {
     if (getfriend_id(m, client_id) != -1)
         return -1;
@@ -356,7 +356,7 @@ int m_friend_exists(Messenger *m, int32_t friendnumber)
  *  return the message id if packet was successfully put into the send queue.
  *  return 0 if it was not.
  */
-uint32_t m_sendmessage(Messenger *m, int32_t friendnumber, uint8_t *message, uint32_t length)
+uint32_t m_sendmessage(Messenger *m, int32_t friendnumber, const uint8_t *message, uint32_t length)
 {
     if (friend_not_valid(m, friendnumber))
         return 0;
@@ -373,7 +373,7 @@ uint32_t m_sendmessage(Messenger *m, int32_t friendnumber, uint8_t *message, uin
     return 0;
 }
 
-uint32_t m_sendmessage_withid(Messenger *m, int32_t friendnumber, uint32_t theid, uint8_t *message, uint32_t length)
+uint32_t m_sendmessage_withid(Messenger *m, int32_t friendnumber, uint32_t theid, const uint8_t *message, uint32_t length)
 {
     if (length >= (MAX_CRYPTO_DATA_SIZE - sizeof(theid)))
         return 0;
@@ -456,7 +456,7 @@ int setfriendname(Messenger *m, int32_t friendnumber, uint8_t *name, uint16_t le
  *  return 0 if success.
  *  return -1 if failure.
  */
-int setname(Messenger *m, uint8_t *name, uint16_t length)
+int setname(Messenger *m, const uint8_t *name, uint16_t length)
 {
     if (length > MAX_NAME_LENGTH || length == 0)
         return -1;
@@ -519,7 +519,7 @@ int m_get_self_name_size(Messenger *m)
     return m->name_length;
 }
 
-int m_set_statusmessage(Messenger *m, uint8_t *status, uint16_t length)
+int m_set_statusmessage(Messenger *m, const uint8_t *status, uint16_t length)
 {
     if (length > MAX_STATUSMESSAGE_LENGTH)
         return -1;
@@ -722,10 +722,10 @@ void m_set_sends_receipts(Messenger *m, int32_t friendnumber, int yesno)
 
 /* static void (*friend_request)(uint8_t *, uint8_t *, uint16_t); */
 /* Set the function that will be executed when a friend request is received. */
-void m_callback_friendrequest(Messenger *m, void (*function)(Messenger *m, uint8_t *, uint8_t *, uint16_t, void *),
+void m_callback_friendrequest(Messenger *m, void (*function)(Messenger *m, const uint8_t *, const uint8_t *, uint16_t, void *),
                               void *userdata)
 {
-    void (*handle_friendrequest)(void *, uint8_t *, uint8_t *, uint16_t, void *) = (void *)function;
+    void (*handle_friendrequest)(void *, const uint8_t *, const uint8_t *, uint16_t, void *) = (void *)function;
     callback_friendrequest(&(m->fr), handle_friendrequest, m, userdata);
 }
 
@@ -1701,7 +1701,7 @@ int send_custom_lossy_packet(Messenger *m, int32_t friendnumber, uint8_t *data,
 
 
 /* Function to filter out some friend requests*/
-static int friend_already_added(uint8_t *client_id, void *data)
+static int friend_already_added(const uint8_t *client_id, void *data)
 {
     Messenger *m = data;
 
@@ -2503,7 +2503,7 @@ static uint32_t friends_list_save(Messenger *m, uint8_t *data)
     return num * sizeof(struct SAVED_FRIEND);
 }
 
-static int friends_list_load(Messenger *m, uint8_t *data, uint32_t length)
+static int friends_list_load(Messenger *m, const uint8_t *data, uint32_t length)
 {
     if (length % sizeof(struct SAVED_FRIEND) != 0) {
         return -1;
@@ -2626,7 +2626,7 @@ void messenger_save(Messenger *m, uint8_t *data)
     data += len;
 }
 
-static int messenger_load_state_callback(void *outer, uint8_t *data, uint32_t length, uint16_t type)
+static int messenger_load_state_callback(void *outer, const uint8_t *data, uint32_t length, uint16_t type)
 {
     Messenger *m = outer;
 
diff --git a/toxcore/Messenger.h b/toxcore/Messenger.h
index 51d5c73b..ad51a754 100644
--- a/toxcore/Messenger.h
+++ b/toxcore/Messenger.h
@@ -274,12 +274,12 @@ int32_t m_addfriend(Messenger *m, uint8_t *address, uint8_t *data, uint16_t leng
  *  return the friend number if success.
  *  return -1 if failure.
  */
-int32_t m_addfriend_norequest(Messenger *m, uint8_t *client_id);
+int32_t m_addfriend_norequest(Messenger *m, const uint8_t *client_id);
 
 /*  return the friend number associated to that client id.
  *  return -1 if no such friend.
  */
-int32_t getfriend_id(Messenger *m, uint8_t *client_id);
+int32_t getfriend_id(const Messenger *m, const uint8_t *client_id);
 
 /* Copies the public key associated to that friend id into client_id buffer.
  * Make sure that client_id is of size CLIENT_ID_SIZE.
@@ -321,8 +321,8 @@ int m_friend_exists(Messenger *m, int32_t friendnumber);
  *  m_sendmessage_withid will send a message with the id of your choosing,
  *  however we can generate an id for you by calling plain m_sendmessage.
  */
-uint32_t m_sendmessage(Messenger *m, int32_t friendnumber, uint8_t *message, uint32_t length);
-uint32_t m_sendmessage_withid(Messenger *m, int32_t friendnumber, uint32_t theid, uint8_t *message, uint32_t length);
+uint32_t m_sendmessage(Messenger *m, int32_t friendnumber, const uint8_t *message, uint32_t length);
+uint32_t m_sendmessage_withid(Messenger *m, int32_t friendnumber, uint32_t theid, const uint8_t *message, uint32_t length);
 
 /* Send an action to an online friend.
  *
@@ -355,7 +355,7 @@ int setfriendname(Messenger *m, int32_t friendnumber, uint8_t *name, uint16_t le
  *  return 0 if success.
  *  return -1 if failure.
  */
-int setname(Messenger *m, uint8_t *name, uint16_t length);
+int setname(Messenger *m, const uint8_t *name, uint16_t length);
 
 /*
  * Get your nickname.
@@ -387,7 +387,7 @@ int m_get_self_name_size(Messenger *m);
  *  returns 0 on success.
  *  returns -1 on failure.
  */
-int m_set_statusmessage(Messenger *m, uint8_t *status, uint16_t length);
+int m_set_statusmessage(Messenger *m, const uint8_t *status, uint16_t length);
 int m_set_userstatus(Messenger *m, uint8_t status);
 
 /*  return the length of friendnumber's status message, including null on success.
@@ -442,7 +442,7 @@ void m_set_sends_receipts(Messenger *m, int32_t friendnumber, int yesno);
 /* Set the function that will be executed when a friend request is received.
  *  Function format is function(uint8_t * public_key, uint8_t * data, uint16_t length)
  */
-void m_callback_friendrequest(Messenger *m, void (*function)(Messenger *m, uint8_t *, uint8_t *, uint16_t, void *),
+void m_callback_friendrequest(Messenger *m, void (*function)(Messenger *m, const uint8_t *, const uint8_t *, uint16_t, void *),
                               void *userdata);
 
 /* Set the function that will be executed when a message from a friend is received.
diff --git a/toxcore/friend_requests.c b/toxcore/friend_requests.c
index eb2a791c..4bf95a44 100644
--- a/toxcore/friend_requests.c
+++ b/toxcore/friend_requests.c
@@ -72,7 +72,7 @@ uint32_t get_nospam(Friend_Requests *fr)
 
 
 /* Set the function that will be executed when a friend request is received. */
-void callback_friendrequest(Friend_Requests *fr, void (*function)(void *, uint8_t *, uint8_t *, uint16_t, void *),
+void callback_friendrequest(Friend_Requests *fr, void (*function)(void *, const uint8_t *, const uint8_t *, uint16_t, void *),
                             void *object, void *userdata)
 {
     fr->handle_friendrequest = function;
@@ -81,14 +81,14 @@ void callback_friendrequest(Friend_Requests *fr, void (*function)(void *, uint8_
     fr->handle_friendrequest_userdata = userdata;
 }
 /* Set the function used to check if a friend request should be displayed to the user or not. */
-void set_filter_function(Friend_Requests *fr, int (*function)(uint8_t *, void *), void *userdata)
+void set_filter_function(Friend_Requests *fr, int (*function)(const uint8_t *, void *), void *userdata)
 {
     fr->filter_function = function;
     fr->filter_function_userdata = userdata;
 }
 
 /* Add to list of received friend requests. */
-static void addto_receivedlist(Friend_Requests *fr, uint8_t *client_id)
+static void addto_receivedlist(Friend_Requests *fr, const uint8_t *client_id)
 {
     if (fr->received_requests_index >= MAX_RECEIVED_STORED)
         fr->received_requests_index = 0;
@@ -102,7 +102,7 @@ static void addto_receivedlist(Friend_Requests *fr, uint8_t *client_id)
  *  return 0 if it did not.
  *  return 1 if it did.
  */
-static int request_received(Friend_Requests *fr, uint8_t *client_id)
+static int request_received(Friend_Requests *fr, const uint8_t *client_id)
 {
     uint32_t i;
 
@@ -133,7 +133,7 @@ int remove_request_received(Friend_Requests *fr, uint8_t *client_id)
 }
 
 
-static int friendreq_handlepacket(void *object, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
+static int friendreq_handlepacket(void *object, const uint8_t *source_pubkey, const uint8_t *packet, uint32_t length)
 {
     Friend_Requests *fr = object;
 
diff --git a/toxcore/friend_requests.h b/toxcore/friend_requests.h
index 429ffbad..58ff91ce 100644
--- a/toxcore/friend_requests.h
+++ b/toxcore/friend_requests.h
@@ -30,12 +30,12 @@
 
 typedef struct {
     uint32_t nospam;
-    void (*handle_friendrequest)(void *, uint8_t *, uint8_t *, uint16_t, void *);
+    void (*handle_friendrequest)(void *, const uint8_t *, const uint8_t *, uint16_t, void *);
     uint8_t handle_friendrequest_isset;
     void *handle_friendrequest_object;
     void *handle_friendrequest_userdata;
 
-    int (*filter_function)(uint8_t *, void *);
+    int (*filter_function)(const uint8_t *, void *);
     void *filter_function_userdata;
     /* NOTE: The following is just a temporary fix for the multiple friend requests received at the same time problem.
      *  TODO: Make this better (This will most likely tie in with the way we will handle spam.)
@@ -66,14 +66,14 @@ int remove_request_received(Friend_Requests *fr, uint8_t *client_id);
 /* Set the function that will be executed when a friend request for us is received.
  *  Function format is function(uint8_t * public_key, uint8_t * data, uint16_t length, void * userdata)
  */
-void callback_friendrequest(Friend_Requests *fr, void (*function)(void *, uint8_t *, uint8_t *, uint16_t, void *),
+void callback_friendrequest(Friend_Requests *fr, void (*function)(void *, const uint8_t *, const uint8_t *, uint16_t, void *),
                             void *object, void *userdata);
 
 /* Set the function used to check if a friend request should be displayed to the user or not.
  * Function format is int function(uint8_t * public_key, void * userdata)
  * It must return 0 if the request is ok (anything else if it is bad.)
  */
-void set_filter_function(Friend_Requests *fr, int (*function)(uint8_t *, void *), void *userdata);
+void set_filter_function(Friend_Requests *fr, int (*function)(const uint8_t *, void *), void *userdata);
 
 /* Sets up friendreq packet handlers. */
 void friendreq_init(Friend_Requests *fr, Onion_Client *onion_c);
diff --git a/toxcore/group_chats.c b/toxcore/group_chats.c
index fbe76d16..85928436 100644
--- a/toxcore/group_chats.c
+++ b/toxcore/group_chats.c
@@ -675,7 +675,7 @@ static uint32_t group_send_nick(Group_Chat *chat, uint8_t *nick, uint16_t nick_l
     return send_data(chat, nick, nick_len, GROUP_CHAT_PEER_NICK);
 }
 
-int set_nick(Group_Chat *chat, uint8_t *nick, uint16_t nick_len)
+int set_nick(Group_Chat *chat, const uint8_t *nick, uint16_t nick_len)
 {
     if (nick_len > MAX_NICK_BYTES || nick_len == 0)
         return -1;
diff --git a/toxcore/group_chats.h b/toxcore/group_chats.h
index d9da54a5..49b83c81 100644
--- a/toxcore/group_chats.h
+++ b/toxcore/group_chats.h
@@ -144,7 +144,7 @@ uint32_t group_sendaction(Group_Chat *chat, uint8_t *action, uint32_t length);
  *
  * returns -1 on failure, 0 on success.
  */
-int set_nick(Group_Chat *chat, uint8_t *nick, uint16_t nick_len);
+int set_nick(Group_Chat *chat, const uint8_t *nick, uint16_t nick_len);
 
 /*
  * Tell everyone about a new peer (a person we are inviting for example.)
diff --git a/toxcore/net_crypto.c b/toxcore/net_crypto.c
index 47b23d54..bb38af26 100644
--- a/toxcore/net_crypto.c
+++ b/toxcore/net_crypto.c
@@ -2466,7 +2466,7 @@ void save_keys(Net_Crypto *c, uint8_t *keys)
 /* Load the public and private keys from the keys array.
  * Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES.
  */
-void load_keys(Net_Crypto *c, uint8_t *keys)
+void load_keys(Net_Crypto *c, const uint8_t *keys)
 {
     memcpy(c->self_public_key, keys, crypto_box_PUBLICKEYBYTES);
     memcpy(c->self_secret_key, keys + crypto_box_PUBLICKEYBYTES, crypto_box_SECRETKEYBYTES);
diff --git a/toxcore/net_crypto.h b/toxcore/net_crypto.h
index a3c7e7db..b1108ae1 100644
--- a/toxcore/net_crypto.h
+++ b/toxcore/net_crypto.h
@@ -347,7 +347,7 @@ void save_keys(Net_Crypto *c, uint8_t *keys);
 /* Load the public and private keys from the keys array.
  *  Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES.
  */
-void load_keys(Net_Crypto *c, uint8_t *keys);
+void load_keys(Net_Crypto *c, const uint8_t *keys);
 
 /* Create new instance of Net_Crypto.
  *  Sets all the global connection variables to their default values.
diff --git a/toxcore/onion_client.c b/toxcore/onion_client.c
index dfdb1638..8e28eae5 100644
--- a/toxcore/onion_client.c
+++ b/toxcore/onion_client.c
@@ -467,7 +467,7 @@ static int handle_data_response(void *object, IP_Port source, uint8_t *packet, u
 #define FAKEID_DATA_ID 156
 #define FAKEID_DATA_MIN_LENGTH (1 + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES)
 #define FAKEID_DATA_MAX_LENGTH (FAKEID_DATA_MIN_LENGTH + sizeof(Node_format)*MAX_SENT_NODES)
-static int handle_fakeid_announce(void *object, uint8_t *source_pubkey, uint8_t *data, uint32_t length)
+static int handle_fakeid_announce(void *object, const uint8_t *source_pubkey, const uint8_t *data, uint32_t length)
 {
     Onion_Client *onion_c = object;
 
@@ -483,8 +483,8 @@ static int handle_fakeid_announce(void *object, uint8_t *source_pubkey, uint8_t
         return 1;
 
     uint64_t no_replay;
-    net_to_host(data + 1, sizeof(no_replay));
     memcpy(&no_replay, data + 1, sizeof(uint64_t));
+    net_to_host((uint8_t *) &no_replay, sizeof(no_replay));
 
     if (no_replay <= onion_c->friends_list[friend_num].last_noreplay)
         return 1;
@@ -623,7 +623,7 @@ static int send_dht_fakeid(Onion_Client *onion_c, int friend_num, uint8_t *data,
     return route_tofriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id, packet, len);
 }
 
-static int handle_dht_fakeid(void *object, IP_Port source, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
+static int handle_dht_fakeid(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet, uint32_t length)
 {
     Onion_Client *onion_c = object;
 
@@ -702,7 +702,7 @@ static int send_fakeid_announce(Onion_Client *onion_c, uint16_t friend_num, uint
  * return -1 on failure.
  * return friend number on success.
  */
-int onion_friend_num(Onion_Client *onion_c, uint8_t *client_id)
+int onion_friend_num(const Onion_Client *onion_c, const uint8_t *client_id)
 {
     uint32_t i;
 
@@ -744,7 +744,7 @@ static int realloc_onion_friends(Onion_Client *onion_c, uint32_t num)
  * return -1 on failure.
  * return the friend number on success or if the friend was already added.
  */
-int onion_addfriend(Onion_Client *onion_c, uint8_t *client_id)
+int onion_addfriend(Onion_Client *onion_c, const uint8_t *client_id)
 {
     int num = onion_friend_num(onion_c, client_id);
 
@@ -831,7 +831,7 @@ int recv_tcp_relay_handler(Onion_Client *onion_c, int friend_num, int (*tcp_rela
  * return -1 on failure.
  * return 0 on success.
  */
-int onion_set_friend_DHT_pubkey(Onion_Client *onion_c, int friend_num, uint8_t *dht_key, uint64_t timestamp)
+int onion_set_friend_DHT_pubkey(Onion_Client *onion_c, int friend_num, const uint8_t *dht_key, uint64_t timestamp)
 {
     if ((uint32_t)friend_num >= onion_c->num_friends)
         return -1;
diff --git a/toxcore/onion_client.h b/toxcore/onion_client.h
index 9cf6cf3e..7995fa3a 100644
--- a/toxcore/onion_client.h
+++ b/toxcore/onion_client.h
@@ -102,7 +102,7 @@ typedef struct {
     uint32_t tcp_relay_node_callback_number;
 } Onion_Friend;
 
-typedef int (*oniondata_handler_callback)(void *object, uint8_t *source_pubkey, uint8_t *data, uint32_t len);
+typedef int (*oniondata_handler_callback)(void *object, const uint8_t *source_pubkey, const uint8_t *data, uint32_t len);
 
 typedef struct {
     DHT     *dht;
@@ -136,14 +136,14 @@ typedef struct {
  * return -1 on failure.
  * return the friend number on success or if the friend was already added.
  */
-int onion_friend_num(Onion_Client *onion_c, uint8_t *client_id);
+int onion_friend_num(const Onion_Client *onion_c, const uint8_t *client_id);
 
 /* Add a friend who we want to connect to.
  *
  * return -1 on failure.
  * return the friend number on success.
  */
-int onion_addfriend(Onion_Client *onion_c, uint8_t *client_id);
+int onion_addfriend(Onion_Client *onion_c, const uint8_t *client_id);
 
 /* Delete a friend.
  *
@@ -190,7 +190,7 @@ int recv_tcp_relay_handler(Onion_Client *onion_c, int friend_num, int (*tcp_rela
  * return -1 on failure.
  * return 0 on success.
  */
-int onion_set_friend_DHT_pubkey(Onion_Client *onion_c, int friend_num, uint8_t *dht_key, uint64_t timestamp);
+int onion_set_friend_DHT_pubkey(Onion_Client *onion_c, int friend_num, const uint8_t *dht_key, uint64_t timestamp);
 
 /* Copy friends DHT public key into dht_key.
  *
diff --git a/toxcore/ping.c b/toxcore/ping.c
index c01170ab..ea8fd04d 100644
--- a/toxcore/ping.c
+++ b/toxcore/ping.c
@@ -58,7 +58,7 @@ struct PING {
 #define DHT_PING_SIZE (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + PING_PLAIN_SIZE + crypto_box_MACBYTES)
 #define PING_DATA_SIZE (CLIENT_ID_SIZE + sizeof(IP_Port))
 
-int send_ping_request(PING *ping, IP_Port ipp, uint8_t *client_id)
+int send_ping_request(PING *ping, IP_Port ipp, const uint8_t *client_id)
 {
     uint8_t   pk[DHT_PING_SIZE];
     int       rc;
@@ -100,7 +100,7 @@ int send_ping_request(PING *ping, IP_Port ipp, uint8_t *client_id)
     return sendpacket(ping->dht->net, ipp, pk, sizeof(pk));
 }
 
-static int send_ping_response(PING *ping, IP_Port ipp, uint8_t *client_id, uint64_t ping_id,
+static int send_ping_response(PING *ping, IP_Port ipp, const uint8_t *client_id, uint64_t ping_id,
                               uint8_t *shared_encryption_key)
 {
     uint8_t   pk[DHT_PING_SIZE];
@@ -225,13 +225,13 @@ static int handle_ping_response(void *_dht, IP_Port source, uint8_t *packet, uin
  * return 1 if it is.
  * return 0 if it isn't.
  */
-static int in_list(Client_data *list, uint32_t length, uint8_t *client_id, IP_Port ip_port)
+static int in_list(const Client_data *list, uint32_t length, const uint8_t *client_id, IP_Port ip_port)
 {
     uint32_t i;
 
     for (i = 0; i < length; ++i) {
         if (id_equal(list[i].client_id, client_id)) {
-            IPPTsPng *ipptp;
+            const IPPTsPng *ipptp;
 
             if (ip_port.ip.family == AF_INET) {
                 ipptp = &list[i].assoc4;
@@ -257,7 +257,7 @@ static int in_list(Client_data *list, uint32_t length, uint8_t *client_id, IP_Po
  *  return 0 if node was added.
  *  return -1 if node was not added.
  */
-int add_to_ping(PING *ping, uint8_t *client_id, IP_Port ip_port)
+int add_to_ping(PING *ping, const uint8_t *client_id, IP_Port ip_port)
 {
     if (!ip_isset(&ip_port.ip))
         return -1;
diff --git a/toxcore/ping.h b/toxcore/ping.h
index 168870d7..c19c912a 100644
--- a/toxcore/ping.h
+++ b/toxcore/ping.h
@@ -36,12 +36,12 @@ typedef struct PING PING;
  *  return 0 if node was added.
  *  return -1 if node was not added.
  */
-int add_to_ping(PING *ping, uint8_t *client_id, IP_Port ip_port);
+int add_to_ping(PING *ping, const uint8_t *client_id, IP_Port ip_port);
 void do_to_ping(PING *ping);
 
 PING *new_ping(DHT *dht);
 void kill_ping(PING *ping);
 
-int send_ping_request(PING *ping, IP_Port ipp, uint8_t *client_id);
+int send_ping_request(PING *ping, IP_Port ipp, const uint8_t *client_id);
 
 #endif /* __PING_H__ */
diff --git a/toxcore/ping_array.c b/toxcore/ping_array.c
index e6f684ef..5c92527e 100644
--- a/toxcore/ping_array.c
+++ b/toxcore/ping_array.c
@@ -59,7 +59,7 @@ static void ping_array_clear_timedout(Ping_Array *array)
  * return ping_id on success.
  * return 0 on failure.
  */
-uint64_t ping_array_add(Ping_Array *array, uint8_t *data, uint32_t length)
+uint64_t ping_array_add(Ping_Array *array, const uint8_t *data, uint32_t length)
 {
     ping_array_clear_timedout(array);
     uint32_t index = array->last_added % array->total_size;
diff --git a/toxcore/ping_array.h b/toxcore/ping_array.h
index c5811b16..364ad833 100644
--- a/toxcore/ping_array.h
+++ b/toxcore/ping_array.h
@@ -48,7 +48,7 @@ typedef struct {
  * return ping_id on success.
  * return 0 on failure.
  */
-uint64_t ping_array_add(Ping_Array *array, uint8_t *data, uint32_t length);
+uint64_t ping_array_add(Ping_Array *array, const uint8_t *data, uint32_t length);
 
 /* Check if ping_id is valid and not timed out.
  *
diff --git a/toxcore/tox.c b/toxcore/tox.c
index 12bee911..7cb7d692 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -138,7 +138,7 @@ int tox_friend_exists(Tox *tox, int32_t friendnumber)
  *  m_sendmessage_withid will send a message with the id of your choosing,
  *  however we can generate an id for you by calling plain m_sendmessage.
  */
-uint32_t tox_send_message(Tox *tox, int32_t friendnumber, uint8_t *message, uint32_t length)
+uint32_t tox_send_message(Tox *tox, int32_t friendnumber, const uint8_t *message, uint32_t length)
 {
     Messenger *m = tox;
     return m_sendmessage(m, friendnumber, message, length);
@@ -362,7 +362,7 @@ uint32_t tox_get_friendlist(Tox *tox, int32_t *out_list, uint32_t list_size)
 /* Set the function that will be executed when a friend request is received.
  *  Function format is function(uint8_t * public_key, uint8_t * data, uint16_t length)
  */
-void tox_callback_friend_request(Tox *tox, void (*function)(Tox *tox, uint8_t *, uint8_t *, uint16_t, void *),
+void tox_callback_friend_request(Tox *tox, void (*function)(Tox *tox, const uint8_t *, const uint8_t *, uint16_t, void *),
                                  void *userdata)
 {
     Messenger *m = tox;
diff --git a/toxcore/tox.h b/toxcore/tox.h
index 5a63063f..c217e1a1 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -156,7 +156,7 @@ int tox_friend_exists(Tox *tox, int32_t friendnumber);
  * m_sendmessage_withid will send a message with the id of your choosing,
  * however we can generate an id for you by calling plain m_sendmessage.
  */
-uint32_t tox_send_message(Tox *tox, int32_t friendnumber, uint8_t *message, uint32_t length);
+uint32_t tox_send_message(Tox *tox, int32_t friendnumber, const uint8_t *message, uint32_t length);
 uint32_t tox_send_message_withid(Tox *tox, int32_t friendnumber, uint32_t theid, uint8_t *message, uint32_t length);
 
 /* Send an action to an online friend.
@@ -289,7 +289,7 @@ uint32_t tox_get_friendlist(Tox *tox, int32_t *out_list, uint32_t list_size);
 /* Set the function that will be executed when a friend request is received.
  *  Function format is function(Tox *tox, uint8_t * public_key, uint8_t * data, uint16_t length, void *userdata)
  */
-void tox_callback_friend_request(Tox *tox, void (*function)(Tox *tox, uint8_t *, uint8_t *, uint16_t, void *),
+void tox_callback_friend_request(Tox *tox, void (*function)(Tox *tox, const uint8_t *, const uint8_t *, uint16_t, void *),
                                  void *userdata);
 
 /* Set the function that will be executed when a message from a friend is received.
diff --git a/toxcore/util.c b/toxcore/util.c
index e3bfac4c..969ee704 100644
--- a/toxcore/util.c
+++ b/toxcore/util.c
@@ -86,7 +86,7 @@ void host_to_net(uint8_t *num, uint16_t numbytes)
 
 /* state load/save */
 int load_state(load_state_callback_func load_state_callback, void *outer,
-               uint8_t *data, uint32_t length, uint16_t cookie_inner)
+               const uint8_t *data, uint32_t length, uint16_t cookie_inner)
 {
     if (!load_state_callback || !data) {
 #ifdef DEBUG
diff --git a/toxcore/util.h b/toxcore/util.h
index 74348c11..955ce8c4 100644
--- a/toxcore/util.h
+++ b/toxcore/util.h
@@ -43,9 +43,9 @@ void host_to_net(uint8_t *num, uint16_t numbytes);
 #define net_to_host(x, y) host_to_net(x, y)
 
 /* state load/save */
-typedef int (*load_state_callback_func)(void *outer, uint8_t *data, uint32_t len, uint16_t type);
+typedef int (*load_state_callback_func)(void *outer, const uint8_t *data, uint32_t len, uint16_t type);
 int load_state(load_state_callback_func load_state_callback, void *outer,
-               uint8_t *data, uint32_t length, uint16_t cookie_inner);
+               const uint8_t *data, uint32_t length, uint16_t cookie_inner);
 
 /* Converts 4 bytes to uint32_t */
 void bytes_to_U32(uint32_t *dest, const uint8_t *bytes);