Fix for meso exploit with shops

I usually don't share fixes with the public anymore, only with Lai, though he has fixed most of the exploits I find already. :D: Anyways, decided to release the fix for this one because the guys who did it on my server yesterday are fags and they don't deserve to be able to exploit, not even on Soul's servers. I assume this works on most servers because I haven't seen this fixed in any public sources.

MapleShop.java

Code:

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if (c.getPlayer().getMeso() >= item.getPrice() * quantity) {

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Change that to either

Code:

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if (c.getPlayer().getMeso() >= (long) item.getPrice() * quantity) {

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or (I suggest to use this method, otherwise you will also have to check for the quantity not being negative.)

Code:

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int price = item.getPrice() * quantity;
if (price >= 0 && c.getPlayer().getMeso() >= price) {

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to prevent overflow.

Nice released flav, :S

nice release, btw, isn't it supposed to be

Code:

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int price = item.getPrice() * quantity;
if (price >= 0 && c.getPlayer().getMeso() >= price) {

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If meso > price and not >=, players will not be able to buy any items although their meso is same price as items

Of course, just a typo. :) Fixed.

well done flav. Even though thats fixed by most unstupid coders :D.

^ So you're saying flav was stupid for not fixing it earlier?

I bet he fixed it earlier. He just now released it boy :)

The reason for the rollback...
Anyways thanks for sharing it with us.

Quote:

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Originally Posted by Xerixe

^ So you're saying flav was stupid for not fixing it earlier?

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This made me giggle. Careful what you say, The almighty eye is watching.

OT: Thanks Flav, Nice Release.

---------- Post added at 06:15 PM ---------- Previous post was at 06:14 PM ----------

Quote:

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Originally Posted by nugyyman

The reason for the rollback...
Anyways thanks for sharing it with us.

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lolwut?

Quote:

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Originally Posted by maxcloud

This made me giggle. Careful what you say, The almighty eye is watching.

OT: Thanks Flav, Nice Release.

---------- Post added at 06:15 PM ---------- Previous post was at 06:14 PM ----------



lolwut?

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almighty eye...., you mean your whispering-eye :X

OT : nice XD

Quote:

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Originally Posted by xReflex

well done flav. Even though thats fixed by most unstupid coders :D.

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You can't fix something you don't know "exist".

Let's not turn this into some pathetic argument over who is better at what... Stick to the topic.

Code:

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if (item != null && item.getPrice() > 0) {
            if (c.getPlayer().getMeso() >= item.getPrice() * quantity) {

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Wouldn't this also work? Found it in my source.

Quote:

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Originally Posted by SeanDev

Code:

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if (item != null && item.getPrice() > 0) {
            if (c.getPlayer().getMeso() >= item.getPrice() * quantity) {

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Wouldn't this also work? Found it in my source.

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The problem is that if you buy so many of the item that the the price goes higher than Integer.MAX_VALUE (2,147,483,647) it goes negative again, then the player surely has more mesos than the price is. Then he gets the items and doesn't lose but gains the money he should pay.

Quote:

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Originally Posted by flav

The problem is that if you buy so many of the item that the the price goes higher than Integer.MAX_VALUE (2,147,483,647) it goes negative again, then the player surely has more mesos than the price is. Then he gets the items and doesn't lose but gains the money he should pay.

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Correct me if I'm wrong, but doesn't the price > 0 thing fix that?

Wait I feel stupid.

Indeed, price > 0 should fix it. But yeah, flav also posted that in the very first post.

Code:

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int price = item.getPrice() * quantity;
if (price >= 0 && c.getPlayer().getMeso() >= price) {

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Is it possible for a player to buy so many of an expensive item the price overflows to positive again?

I never tried but Lai says it's not. I prefer the converting to long method, though it wastes 4 bytes.

Quote:

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Originally Posted by SeanDev

Correct me if I'm wrong, but doesn't the price > 0 thing fix that?

Wait I feel stupid.

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But you have to multiply the price with the quantity before you check for the price being >= 0.

just wondering why are you using long and not just stick to an int?

Quote:

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Originally Posted by mertjuh

just wondering why are you using long and not just stick to an int?

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Look up what a Long is, then an Integer.

Quote:

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Originally Posted by mertjuh

just wondering why are you using long and not just stick to an int?

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There's 2 solutions, both work. One uses Long and the other one uses Integer.

Just to add on ,this fix is also available for hiredmerchants/playershops.

Most meso exploits have something to do with overflow.

Quote:

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Originally Posted by xReflex

well done flav. Even though thats fixed by most unstupid coders :D.

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Not really, seeing as it was in nearly every public server.

Quote:

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Originally Posted by xReflex

I bet he fixed it earlier. He just now released it boy :)

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Nope he found out about it not long ago.

Quote:

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Originally Posted by maxcloud

This made me giggle. Careful what you say, The almighty eye is watching.

OT: Thanks Flav, Nice Release.

---------- Post added at 06:15 PM ---------- Previous post was at 06:14 PM ----------



lolwut?

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The almighty eye? really now? :ehh:

Quote:

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Originally Posted by mertjuh

just wondering why are you using long and not just stick to an int?

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If you stick to the int the players get a negative amount of mesos after you multiple the price of an item and the amount of items. Therefore you need to make sure that total amount of mesos after multiplying isn't negative.

Quote:

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Originally Posted by flav

Most meso exploits have something to do with overflow.

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cntrl + f meso

what about Integer.MAX_VALUE since you guys wanna get all preppy now.