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Do iPhones have some kind of tamper-proof clock? I want to lock-out certain features for a period of time unless the player has bought the full version of the game but I need to access a clock that the user can't change. If the iPhone had some kind of tamper-proof clock that just counts how longs it has been alive that would be great. Otherwise I guess I'll need to access a secure clock on-line.
Many thanks.
No way on the phone itself. The safest/most foolproof way would be to access a private server.
Can't you just use the built-in Timer object?
I assumed he was talking about checking the actual day and time, not a countdown timer in the app. Besides, the timer in the app would reset the moment you quit the app.
Thanks guys. Mobichan is right; I want the time elapsed since an event even if the app has been subsequently closed so the Timer object won't cut it. I really hoped the iPhone would have some sort of clock that could be read from but not written to. Oh well, I guess I'll have to do as mobichan says and use a private server.
Do other games that lock you out for a time require you to be online to play? I've never played it but doesn't Candy Crush limit how many plays you can have in a certain time period? How do they implement this?
You can store an internal timer value to an ini or array and save it locally to the device, in case the app is turned off. This is a way to deal with the app going to sleep. But you need to consider that iphones get their time from the cell towers. That is why they change when you enter different time zones. Even if you use a server, you would need to consider the timezone of the player. You can poll the phone's language country code and adjust based on that.
Thanks mobichan. I didn't know iPhones got their time from phone masts, I thought it was user set and incremented by the internal clock.
I don't see why the time zone matters if I get the time from a server. If, when a trigger event happens, the time is noted then all I care about is how long ago that trigger event happened. I don't care what time zone someone is in or even what the actual time or date is anywhere, I just care how much time has passed. Surely if the game is always using the same clock then that will be fine.
This is slightly unrelated but how easy is it for Joe Public to mess with a .ini file? All my data is unencrypted so, for someone with a jailbroken phone, changing the data will be no problem but your average guy on the street won't be accessing the .ini data will he?
Sorry, I assumed you wanted to see the content released at a specific time per region. But after looking, the iPhone does allow you to manually change the time (I just always left the default setting of automatic turned on). Ipods also would use manually set times. So even though I suggested you have a saved value in an ini/array, you would not be able to reliably check it against the internal clock. You would need to check that stored value against a server clock.
As for hacking an ini, it is pretty simple with programs like iExplorer. They allow you to browse the file structure like windows explorer. But nothing is hacker proof. And ultimately, the majority of people who would have paid you money won't be hacking anything.
That's what I thought. If even a regular iPhone user is likely to mess with the .ini file then I'd better do some simple encryption but as long as it's just a minority of people then I can't see the point; they'll just hack it anyway, at least this way it's easy/boring for them.Quote:
... the majority of people who would have paid you money won't be hacking anything.
Thanks for your help mobichan.
Again, the people who are going to hack aren't going to pay you in the first place for any content. Unless you had another reason for locking content behind a timer?
The idea of the timer is that you get so many (3?) plays and each time you use up a play you have to wait so long (30 minutes?) for it to become available again. If you buy the full version then you get unlimited plays.
Whether or not you have the full version would be stored in an .ini file and I absolutely agree that even if I encrypt the file hackers are going to get the full version without paying. However, if the game is successful then I want to make sure the majority of users won't fool the system which means:
1) If many iPhone users are likely to access the .ini file then I need to encrypt it.
2) The timed lock-out needs to be tamper-proof.
It sounds like I don't need to worry about the average user accessing the .ini file but even someone with no computer competency might try fiddling with the iPhone clock to fool the game. What do you think about each of these points mobichan? I'd be interested to hear what your view is as I have no experience with these sorts of things.
If your goal is to simply mimic what games like Candy Crush do and charge people to "skip the waiting" with real money purchases, then I would look into using a server. If this is a casual concern about some people hacking your game or writing scripts to do it for them, then you can use the local stored data we have been talking about. At least that is how I would handle this. ;)
yeah use a server, it can be done securely very easily, but you would have to use the get object to do the request over a working internet connection to verify the time.
I would do something like this in the php you make a get request to:
$seconds = time()-1430000000; //9 digits worth of seconds will work for 30 years or so.
$verify = md5('password'.$seconds);
echo $seconds.'delimiter'.$verify;
use string parser object in fusion to split by delimiter and do md5 conversion on "password"+seconds(element 0), and compare that string/text with verify(element 1), then you know it's the correct time from your server.