Strings now no longer need to be NULL terminated.

4 files changed, 46 insertions, 28 deletions

diff --git a/toxcore/Messenger.c b/toxcore/Messenger.c
index e3dcf2a1..da326b88 100644
--- a/toxcore/Messenger.c
+++ b/toxcore/Messenger.c
@@ -690,7 +690,7 @@ static int set_friend_statusmessage(Messenger *m, int32_t friendnumber, uint8_t
     if (friend_not_valid(m, friendnumber))
         return -1;
 
-    uint8_t *newstatus = calloc(length, 1);
+    uint8_t *newstatus = calloc(length + 1, 1);
     memcpy(newstatus, status, length);
     free(m->friendlist[friendnumber].statusmessage);
     m->friendlist[friendnumber].statusmessage = newstatus;
@@ -957,10 +957,12 @@ static void group_message_function(Group_Chat *chat, int peer_number, uint8_t *m
     if (i == -1)
         return;
 
-    message[length - 1] = 0; /* Force NULL terminator */
+    uint8_t message_terminated[length + 1];
+    memcpy(message_terminated, message, length);
+    message_terminated[length] = 0; /* Force NULL terminator */
 
     if (m->group_message)
-        (*m->group_message)(m, i, peer_number, message, length, m->group_message_userdata);
+        (*m->group_message)(m, i, peer_number, message_terminated, length, m->group_message_userdata);
 }
 
 static void group_action_function(Group_Chat *chat, int peer_number, uint8_t *action, uint16_t length, void *userdata)
@@ -971,10 +973,12 @@ static void group_action_function(Group_Chat *chat, int peer_number, uint8_t *ac
     if (i == -1)
         return;
 
-    action[length - 1] = 0; /* Force NULL terminator */
+    uint8_t action_terminated[length + 1];
+    memcpy(action_terminated, action, length);
+    action_terminated[length] = 0; /* Force NULL terminator */
 
     if (m->group_action)
-        (*m->group_action)(m, i, peer_number, action, length, m->group_action_userdata);
+        (*m->group_action)(m, i, peer_number, action_terminated, length, m->group_action_userdata);
 }
 
 static void group_namelistchange_function(Group_Chat *chat, int peer, uint8_t change, void *userdata)
@@ -1912,13 +1916,15 @@ void do_friends(Messenger *m)
                             break;
 
                         /* Make sure the NULL terminator is present. */
-                        data[data_length - 1] = 0;
+                        uint8_t data_terminated[data_length + 1];
+                        memcpy(data_terminated, data, data_length);
+                        data_terminated[data_length] = 0;
 
                         /* inform of namechange before we overwrite the old name */
                         if (m->friend_namechange)
-                            m->friend_namechange(m, i, data, data_length, m->friend_namechange_userdata);
+                            m->friend_namechange(m, i, data_terminated, data_length, m->friend_namechange_userdata);
 
-                        memcpy(m->friendlist[i].name, data, data_length);
+                        memcpy(m->friendlist[i].name, data_terminated, data_length + 1);
                         m->friendlist[i].name_length = data_length;
 
                         break;
@@ -1928,13 +1934,16 @@ void do_friends(Messenger *m)
                         if (data_length == 0 || data_length > MAX_STATUSMESSAGE_LENGTH)
                             break;
 
-                        data[data_length - 1] = 0; /* Make sure the NULL terminator is present. */
+                        /* Make sure the NULL terminator is present. */
+                        uint8_t data_terminated[data_length + 1];
+                        memcpy(data_terminated, data, data_length);
+                        data_terminated[data_length] = 0;
 
                         if (m->friend_statusmessagechange)
-                            m->friend_statusmessagechange(m, i, data, data_length,
+                            m->friend_statusmessagechange(m, i, data_terminated, data_length,
                                                           m->friend_statuschange_userdata);
 
-                        set_friend_statusmessage(m, i, data, data_length);
+                        set_friend_statusmessage(m, i, data_terminated, data_length);
                         break;
                     }
 
@@ -1974,14 +1983,17 @@ void do_friends(Messenger *m)
                         uint8_t *message = data + message_id_length;
                         uint16_t message_length = data_length - message_id_length;
 
-                        message[message_length - 1] = 0;/* Make sure the NULL terminator is present. */
+                        /* Make sure the NULL terminator is present. */
+                        uint8_t message_terminated[message_length + 1];
+                        memcpy(message_terminated, message, message_length);
+                        message_terminated[message_length] = 0;
 
                         if (m->friendlist[i].receives_read_receipts) {
                             write_cryptpacket_id(m, i, PACKET_ID_RECEIPT, message_id, message_id_length);
                         }
 
                         if (m->friend_message)
-                            (*m->friend_message)(m, i, message, message_length, m->friend_message_userdata);
+                            (*m->friend_message)(m, i, message_terminated, message_length, m->friend_message_userdata);
 
                         break;
                     }
@@ -1996,14 +2008,17 @@ void do_friends(Messenger *m)
                         uint8_t *action = data + message_id_length;
                         uint16_t action_length = data_length - message_id_length;
 
-                        action[action_length - 1] = 0;/* Make sure the NULL terminator is present. */
+                        /* Make sure the NULL terminator is present. */
+                        uint8_t action_terminated[action_length + 1];
+                        memcpy(action_terminated, action, action_length);
+                        action_terminated[action_length] = 0;
 
                         if (m->friendlist[i].receives_read_receipts) {
                             write_cryptpacket_id(m, i, PACKET_ID_RECEIPT, message_id, message_id_length);
                         }
 
                         if (m->friend_action)
-                            (*m->friend_action)(m, i, action, action_length, m->friend_action_userdata);
+                            (*m->friend_action)(m, i, action_terminated, action_length, m->friend_action_userdata);
 
                         break;
                     }
@@ -2062,10 +2077,13 @@ void do_friends(Messenger *m)
                         m->friendlist[i].file_receiving[filenumber].size = filesize;
                         m->friendlist[i].file_receiving[filenumber].transferred = 0;
 
-                        data[data_length - 1] = 0; /* Force NULL terminate file name. */
+                        /* Force NULL terminate file name. */
+                        uint8_t filename_terminated[data_length - 1 - sizeof(uint64_t) + 1];
+                        memcpy(filename_terminated, data + 1 + sizeof(uint64_t), data_length - 1 - sizeof(uint64_t));
+                        filename_terminated[data_length - 1 - sizeof(uint64_t)] = 0;
 
                         if (m->file_sendrequest)
-                            (*m->file_sendrequest)(m, i, filenumber, filesize, data + 1 + sizeof(uint64_t), data_length - 1 - sizeof(uint64_t),
+                            (*m->file_sendrequest)(m, i, filenumber, filesize, filename_terminated, data_length - 1 - sizeof(uint64_t),
                                                    m->file_sendrequest_userdata);
 
                         break;
diff --git a/toxcore/friend_requests.c b/toxcore/friend_requests.c
index 9ac72097..987b1a4a 100644
--- a/toxcore/friend_requests.c
+++ b/toxcore/friend_requests.c
@@ -141,9 +141,11 @@ static int friendreq_handlepacket(void *object, uint8_t *source_pubkey, uint8_t
 
     addto_receivedlist(fr, source_pubkey);
 
-    packet[length - 1] = 0; /* Force NULL terminator. */
+    uint8_t message[length - 4 + 1];
+    memcpy(message, packet + 4, length - 4);
+    message[sizeof(message) - 1] = 0; /* Be sure the message is null terminated. */
 
-    (*fr->handle_friendrequest)(source_pubkey, packet + 4, length - 4, fr->handle_friendrequest_userdata);
+    (*fr->handle_friendrequest)(source_pubkey, message, length - 4, fr->handle_friendrequest_userdata);
     return 0;
 }
 
diff --git a/toxcore/group_chats.c b/toxcore/group_chats.c
index 1ec8ede5..22cac286 100644
--- a/toxcore/group_chats.c
+++ b/toxcore/group_chats.c
@@ -335,7 +335,7 @@ int group_peername(Group_Chat *chat, int peernum, uint8_t *name)
 
 static void setnick(Group_Chat *chat, int peernum, uint8_t *contents, uint16_t contents_len)
 {
-    if (contents_len > MAX_NICK_BYTES || contents_len == 0)
+    if (contents_len >= MAX_NICK_BYTES || contents_len == 0)
         return;
 
     /* same name as already stored? */
@@ -345,7 +345,7 @@ static void setnick(Group_Chat *chat, int peernum, uint8_t *contents, uint16_t c
 
     memcpy(chat->group[peernum].nick, contents, contents_len);
     /* Force null termination */
-    chat->group[peernum].nick[contents_len - 1] = 0;
+    chat->group[peernum].nick[contents_len] = 0;
     chat->group[peernum].nick_len = contents_len;
 
     if (chat->peer_namelistchange != NULL)
diff --git a/toxcore/tox.h b/toxcore/tox.h
index 17bd4e1a..8fb03af3 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -97,13 +97,11 @@ TOX_USERSTATUS;
 typedef struct Tox Tox;
 #endif
 
-/* NOTE: Strings in Tox are all UTF-8, also the last byte in all strings must be NULL (0).
- *
- * The length when passing those strings to the core includes that NULL character.
- *
- * The length of all strings returned by the core include the NULL character.
- *
- * If you send non NULL terminated strings Tox will force NULL terminates them when it receives them.
+/* NOTE: Strings in Tox are all UTF-8, (This means that there is no terminating NULL character.)
+ * 
+ * The exact buffer you send will be received at the other end without modification.
+ * 
+ * Do not treat Tox strings as C strings.
  */
 
 /*  return TOX_FRIEND_ADDRESS_SIZE byte address to give to others.