I have tried searching, and all questions are related to specific things like "how to generate key", and the like. Can anybody explain how different types of software activation work?
In the most simplistic case, it is as maxwell5555 described. A registration code ("CD key") is sent to the user who enters it into the program or installer. The whole process can basically be done offline; the program itself locally determines that the code is valid or invalid.
This is nice and easy, but it extremely vulnerable to key sharing - since there's no "phoning home" then the application cannot know that thousands of different people are all using the same key that they got off the internet or a serial library or their friend. It's also reasonably easy to make "keygens" which generate valid-seeming keys that were never actually issued by the developers.
Then we get into online registration. You still have some kind of code, but the program will phone home back to the server to determine whether the code is valid and usually unique. This stops basic key sharing, because the company knows if too many people from all over the world are all using the same key. Perhaps there is some kind of indentification involved using MAC address, too, with infinte registrations allowed on the same hardware but maybe a limited number on what appears to be a different computer.
This is still pretty easy and stops simple key sharing. People will actually have to get into cracking the software or faking the server response to get past it.
Sometimes the program itself is partially/mostly encrypted and is only decrypted by the online registration step. Depending on how well this is obfuscated then it can be pretty difficult and time consuming to crack. Bioshock was a high-profile example of this - debuting with a brand new encryption/copy protection scheme that took around two weeks from release to be broken.
Finally, a particularly guarded applciation might stay in constant contact with the server, refusing to work at all if the connection is severed. In this case to get arouind the activation you need to fake the server itself. Steam emulators and private WoW servers are an example of this.
And in the end, nothing is uncrackable.
I suspect a lot of the implementers will not give this information out because it opens them to hacking. But if I were to do this, this is how I would go about it:
Decide if the software is licensed to a person or a computer.
Find a way of identifying the person/computer (login account or ID from the computer hardware).
On request/payment: in your private database, create a licence key and add an entry for the person/PC with this key.
Provide the client software with the key.
Your software either stores the key locally, or regularly checks for the key giving a service of yours the identifying information in return for which your service supplies the key if there is one. If none is found, your software offers them details to purchase a licence. The latter allows for floating keys, computer upgrades, and identifying duplicate installations.
Is that what you were asking for?
A common, simple way of implementing software activation/registration is to create a license algorithm. For example, lets say I have some shareware I want to protect and when someone gives me money, I send them a 4-byte registration code. I could build the algorithm into my shareware such that it validates the code the users enters. My algorithm would be as follows:
1) Byte0 * Byte1 = 6
2) Byte2 - Byte3 = 1
3) Byte0 + Byte2 = 8
Two possible valid codes are:
3254
1676
When the user enters a valid code, the software unlocks its regular functionality by setting a flag somewhere. Obviously, this is an extremely simplistic example. Registration validation algorithms can be as complex as you want.
You can also perform this registration over the internet to protect your validation algorithm from reverse engineering, and keep people from sharing keys. No validation scheme is perfect though.
Related
I searched a lot about what is the best way to secure your program and I found many results and there were two good ways.
The first one is to hash the mac address of the computer and link it with an activation code but it's still vulnerable.
And the second one is to use a usb device but I didn't find any detail so can anybody tell me in details what is the best way and how to implement it please.
First of all, you need to consider that it doesn't matter what you do, someone will be able to crack it, and because of this is that you need to consider a balance between the security of your application and how hard you will make it for legitimate users (since you don't want to punish a user who already paid for your product, just because you want to protect your applications from the guys who don't want to pay).
Having this in mind, you could go with digital signatures using asymmetric encryption, where you'll sign your license "activation" with your private key, and then your application will use its public key to verify that the received license was submitted by you. You should also take a look at this discussion (I recommend you to focus on the 2nd answer, not the selected one) and this one.
But again, your objective should be to just make things hard for bad guys, but without punishing your legitimate users, because for an attacker, it could be as easy as de-compiling your program and removing your logic to validate the license (unless you're creating an "always online" application, but usually users don't like that, and I'm saying this as a user).
After the Sony PSN debacle, I am trying to find examples of secure hardware tethering to a network. There are two use cases in particular:
1- computer downloads a piece of software that then uniquely and securely labels it to a cloud service
2- a hardware manufacturer uniquely labels a hardware device that then negotiates membership on the network.
Given the fact that the hardware device might have to change (revoke or service enhancements) it feels like #2 becomes #1.
The broad outline is this:
- connect to the service via HTTPS to protect against man in the middle
- device generates a GUID and presents it via HTTPS to service
- service records GUID against account
- on success, service 'enables' device
But how do you protect the GUID so that it cannot be stolen?
I just wanted to comment here:
Sony's PSN issues started with horrible practices with regards to their QA environment.
First, they defaulted to trusting anything that was sent to those servers using their developers toolkit. The reason they did this was that the dev kit used to cost upwards of $10k US and therefore they thought anyone who paid that amount would be on the up and up. However, when they radically lowered the price things changed externally and they didn't account for it.
The second issue with PSN was that the security between QA and live was, well, weak at best and easily circumvented. My understanding is that you could send commands to live using QA credentials. Because QA credentials were used, all chargeable actions were approved without money changing hands and the actions were applied to live accounts. When several people told Sony about this they did nothing.
A third issue was a reliance on hardware based encryption keys. Even hardware encryption keys installed on the devices can be figured out.
Point is, Sony dug their own grave on it so I wouldn't use anything they did as a template for how to do things. Heck, a lot of their websites were open to SQL injection which in today's day and age should get you fired.
Another example here is the iPhone. Each iPhone has a unique identifier that installed apps can grab and send back across the network; similar to a serial number. Some apps use this ID to try and tie a particular device to a person. However, it's trivial to create ID's and broadcast them, so this hasn't worked out so well for the partners. Also Apple does not expose a way to ensure a given ID (UUID) is valid to app producers.
A third example is mobile phone carriers. They use a particular ID baked into your SIM card to identify your account in order to know who to bill when a call is made. This ID is verified whenever the phone checks in with the network. However, we're dealing with radio signals and any device that can broadcast a correct ID can gain access. Point is, honest people think that only AT&T approved devices can get on an AT&T network. Reality is, anything can but they are going to bill the owner of the particular ID...
That said, any software you have running on a remote device that is not under your direct control is likely to be hacked. The popularity of the device will increase the likelihood of it happening sooner rather than later.
Where do we go from here?
On a basic level you associate an ID with an account in your service. PSN, Apple and others have done this. When an ID is broadcast, you need to verify that it exists AND that it's tied to an active account. If both pass then you have two options: either perform the action requested OR request additional verification.
For any actions that require money to be spent, do the additional verification (usually some form of username/password), capture the funds, then perform the action. Go one step further and every time a bad login is entered, send an email to the user on file. Further, automatically send a receipt. These are typically done so that your honest users can tell when something is going on.
Anything else just let through.
Bearing in mind, of course, that QA credentials should NOT work in your Live environment. Those systems should not be tied to each other under any condition and, quite frankly, should even live on separate hardware. In other words, QA and Live should NOT share a login database.
The thing here is that you shouldn't care about the device itself; just the account. You can't control the device as it's out of your hands; heck you can't even be sure it hasn't been physically tampered with. (XBox has been fighting this one with people adding resistors or burning out certain components to get past physical security features).
So, IMHO, do a bit to keep honest people honest but overall don't worry about it. Now, you should transfer everything via SSL or someother encrypted connection between the device and your cloud so that you don't leak ID's to anyone that wants to grab them. This will help protect those honest people.
Further, you shouldn't have a direct way to query whether an ID is valid or not from the outside. This will make it a bit more difficult for a hacker to find existing valid IDs and take over accounts. If you want to get fancy you could honey pot those and track the hackers down in order to sue them into oblivion, but that takes time and resources companies don't normally have. Also you could log all of the requests that contained bad IDs and use that to track hackers down.
Note that even after the device has been "enabled" I still suggest you have two levels of authentication. The first is for simple actions like downloading free content; the second kicks in anytime there is a fee associated. Again, we're trying to protect your honest subscribers.
For the dishonest ones you will have to apply some statistical analysis on the transactions coming across. Things like the transaction rate can help identify bots that are running and allow you to kill their IDs. There are others but they'll be unique to your application.
This was long winded. But my point is:
You can't secure the ID or anything else you pass out.
You can't ensure the requests are coming from your devices or your own approved devices.
You better take actions to keep QA and production separate for those building software for these devices using your services.
You better take actions to protect your normal honest users.
Trust NOTHING.
Due to the above you should evaluate your business model so that you don't care what device was used and instead focus on the individual accounts themselves; which you do have control over.
I am not sure I entirely understand the question, but I think you want some sort of device to hold on to a GUID assigned to it by a web service, and you don't want someone finding out what that GUID is, correct?
If so, there isn't a lot you can do. You have already mentioned one option... using HTTPS during the assigning of the ID. That is a good start, but remember that anyone who has physical access to the device can do a lot of things to look up this ID.
In short, it is impossible to completely hide. Someone can always reverse engineer it. There are folks out there reading data right out of memory with hardware.
i got a little program that i want to send it to some other peoples.
But i want to prevent that they can easily share it with others.
Is there some easy protection i can use? It doesnt need to be unhackable, just a little protection that you cant just send the app around.
It can't be uncrackable anyway :) There are lots of different protections that you can use, but it always come down to the skill of the reverse engineer.
A pretty standard technique is to pack your software with a packer like asprotect, armadillo, aspack, upx, there are tons of options. This would make it difficult for them to hexedit your software, debug and disassemble it.
If you want to use a serial protection, there are lots of things you could do. One of my favourites is using the key to dynamically decrypt preencrypted blocks of code and execute them. This is called polymorphism and along with self modifying code, it can be a pretty frustrating protection.
If you want to keep things really simple, you could just create a xor protection where correct_serial XOR constant == another_constant. Using constant XOR another_constant, you could simply create a key.
Really tons of things to do here, it's always a matter of taste and knowledge.
There are lots of free solutions, most are crackable. In spite of popular opinion, modern dongles can be 1) trouble-free and 2) uncrackable. But they can cost $25-$100 each, so not a good choice for low-value software.
the use of keys is frequently tied to symmetric key encryption of the .exe so it can't be easily copied. The key is unique to the installation, and can be created by tying it to the machine characteristics like CPU serial number, MAC address, HD serial number, etc. You can also build a small table of those fingerprints and register that user/SN with that table; then have the app "phone home" from time to time to compare to a server DB. Both these methods are crackable, but you said you weren't looking for something unhackable. Downside of HW fingerprinting is that it can fail when the user upgrades the net card or HD. then you have an unhappy customer because they paid for the license and it won't run.
There are MANY approaches to this, this is one:
Create an authentication web service.
Get your app to generate a unique key from something that identifies the machine.
This gets sent you you and you generate a companion key that your app can verify against its unique key.
As you can imagine this is not something you quickly add in. It requires infrastructure and management, which is tricky.
this is my first question so please be gentle...
I am working on a software which I would like to protect using some kind of licensing scheme.
A basic scheme would be to generate some "unique" key for a user. The user sends this key and a registration code when he wants to register the software and receives an activation code.
When the application runs it validates the activation code by comparing the "unique" key and a datablob received by decrypting the activation code.
This is fair and quite simple to implement, one can choose different crypto algorithms etc. however this scheme lacks two properties:
If the user manages to spoof hardware signature etc. to produce the same "unique" key on another computer he could use the same license data.
If the user decides to uninstall the application and wants to move it to another computer, there is nothing that prevents him from using the old license data again at the old computer and still obtaining new license data for the new installation.
Do you have any suggestions on how to resolve these issues?
One idea I had was to add some random data to the "unique" key, this random data would be stored in an obscure way, if the user deinstalls the application this random data would be removed, and some kind of hash with the previous random data and the license data would be generated which could be sent to me to verify that he really have uninstalled the application and made me sure that he wont be able to use the previous license data again since the random data had changed.
Over and out, for now...
EDIT:
I currently have a scheme that works, I should mention that the most common product is installed in an embedded enviroment where hardware-changes are very rare and if there is a hardware failure then most certain the machine is broken. But I could modify the hardware-key scheme to take into account and allow for some changes.
Also because of this the software will most likely not be run inside a VM, good point though and I haven't thought about that.
The application does not call out regularly, if a network connection is available the user gets the option to make a more automatic registration, otherwise he/she gets a registration key, enters it in the software and gets an installation ID which is provided to me, registration code + installation ID generates an activation key that the user gets from me which then unlocks the software.
What I am looking for is good/feasible solutions to the 2 points. Hardware spoofing, Revoking license keys i.e. to be sure the user can not use the same regcode+activationcode.
Thank you for all your feedback
It is not necessary to
First, you should make it clear what you're trying to protect. Apparently, you want to ensure that for each purchase of your application, there will only ever be one computer on which the application is installed and runnable.
You propose to use a hardware signature as part of each user's unique key. What happens if my hardware fails (e.g. my hard disk breaks)? I'm certainly not going to purchase your application if I can't go on using it after a hardware problem, so at a minimum you must be prepared to handle key change requests. You'd better respond fast, because if your application is important I want to minimize downtime. And I'm not inviting you to check that my hardware has failed, so you'll have to take my word for it. That means any user can get a free licenses from time to time by pretexting a hardware failure.
What about virtual machines? It's probably feasible to detect all currently existing virtual machine configuration, at the risk of a few false positives now and then. If you forbid virtual machines, how do you justify this to users? If you allow virtual machines, how do you prevent the user from making multiple copies of the whole VM? (This can happen even with physical machines, with hibernation).
Is the application going to call back to you every time it starts? I guess so, from your deinstallation scheme. That's a bandwidth and availabilty cost, and will also put off some users — not everyone is online, especially in sensitive environments. But then you don't need such a complex scheme: your server can keep track of how many copies of the application are running, though you do have to handle the case when the application doesn't terminate cleanly for any reason (application crash, OS crash, power failure, loss of connectivity...).
You don't discuss this in your question, but you have to protect the application executable, so that someone can't bypass the license check with a debugger.
Place your software into appliance hardware and put a padlock on the hardware. Ship the appliance to the customer.
If you believe the customer will hacksaw the appliance open to get your code, consider encrypting the storage medium.... Then they have to hacksaw the box AND find the keys. A TPM chip or secure USB token may aid with the latter.
Being a shareware author and longtime member of ASP myself i think you are going into the wrong direction with your solution. The only way to make this workable is with a hardware device as already suggested. This or constant online activations is the only way if you want to be sure and your product is so good and without competitors that your customers will still use it.
But what we (organized small ISV's) learned from practice is that you should not do what you are trying to do. Do not bind it to hardware. Sell one license per person not one license per computer. In the end you will make more sales because of the relaxed license.
Just do enough to make the honest people stay honest. So limit the trail version (i decided to terminate the application after one hour for me) and leave the final version free from all stuff. Give a separate download for payed customers and thats it. Be a nice company and not a greedy profit maximizing by legal restrictions company.
I used some of the better windows protection programs first but they all had serious problems with my code. And they call get cracked sooner or later. So i gave up all of them.
P.S.: I use a hardware fingerprint schema on windows where i don't restrict the program but just to keep people away from getting new trial keys every 30 days. Together with a nag screen it seems to work. The fingerprint is an xor of user name, windows installation time, modify time stamp of a system files and harddisk serial id.
Let the registration code also be the activation code.
You generate the unique registration code at point of sale, or packaged with the product. Customer registers/activates/deactivates with you (or your server) in one step using that single code. The customer's hardware doesn't have to generate any keys.
Reregistering/reactivating still requires contact with you, so you're aware of reinstall attempts.
I think that the only solution to your problem is a cryptographic hardware dongle. Usually it would be a USB-based tamper-resistant challenge-response dongle, that can be easily transferred between computers.
These devices cost less than $1 for large quantities, and not more than $10 for very small quantities. The good ones are very hard to forge, very easy to embed in your application, and usually supplied with a free EXE encryptor which also contains anti-debugging and anti-reverse-engineering functionality.
I was asked implement a licensing schema for our product. They are very expensive products with few customers sparsely distributed around the world and basically every one of them has a design environment (a windows application installed on single windows machines, from 1 to 150 client machines per customer) and a web server that hosts production environment (1 to 8 machines per customer). Our product is licensed for server usage so customers can use any number of clients; we've decided not to license the server part (because it's subject to SLA agreements) but only the client, because, after some time without capability to use the client the system becomes basically useless.
Our basic assumption is that the customer is "honest enough" and only thing we would like to cover is stopping the client design environment if not properly licensed with a time expiration license.
I've evaluated different licensing product and they are or too expensive or too difficult to manage, so I've come up with this simple solution:
The license will be a simple signed XML file, signed using the standard XML Signature feature of w3c, using a private key that will be given to the admin department on a USB key; if they lose of copy it then the licensing schema will fail but it will be their fault
The client will open the license file on startup and check its validity using a public key embedded in the binaries
If license XML is valid and the data in it (expiration date and product name) are correct than the designer work; if not, an appropriate message will be shown
Any ideas about possible problems or how to improve the scenario?
I have yet to see a licensing scheme that wasn't broken in a few weeks provided there was sufficient interest. Your scheme looks very good (though be certain that if someone really wants to, they'll break it).
Whatever you do, you should follow Eric Sink's advice:
The goal should simply be to "keep
honest people honest". If we go
further than this, only two things
happen:
We fight a battle we cannot win. Those who want to cheat will succeed.
We hurt the honest users of our product by making it more difficult to
use.
Since you're implementing a license scheme for a program designed for corporate use, you can go even simpler and just keep some kind of id and expiration date along with a simple signature on the client and refuse to start if the license expired or signature failed. It's not that hard to break it, but no licensing scheme is and if you consider your customers honest, this will be more than enough.
It's not completely clear from your question how your scheme works. Does every instance of the client software have a different key? How long does the license last? Do you have a different key per customer? How is the license paid for? How is a license renewed?
If you are trying to control numbers of usages of the client code then only the first one above will do it.
At the end of the day, in the world you appear to inhabit, I suspect that you are going to have to live in trust that there are no blatant infringements of your license. Most decent sized organisations (which it sounds like your customers would be) have a responsibility not to infringe which can lead them to serious consequences if they break the license agreements. They will be audited on it periodically too and you probably have some statutory rights to go and check their usage (if not you should write it into your license agreement).
Where it becomes very dangerous for you is if the contents of the USB keys find their way onto the web. In that regard any scheme which uses a published key is vulnerable to a wilful disclosure of the secrets.
I'm certain there is a lot of literature on this subject, so it is probably worth you continuing your research.
BTW I'm not sure about your reference to SLAs in the middle part about your server licensing. Licensing and SLAs are very different. A license is the clients obligation an SLA is yours.
if you give them the private key, what is to prevent them from creating more signed XML files instead of buying additional licenses from you? or is it a site-license? if the latter, what is to prevent them from creating licenses for other people/sites?
in general, development licensing schemes tie the license to a particular machine using the MAC address and/or hard drive serial number, or sometimes just with an activation key (which is usually just a hash of the hardware info)
and typically the encoding is done with a private key that you keep secret, and the license is verified with a public key; the client never has the private key, otherwise they can - if so inclined - generate their own licenses
I agree with Steven A. Lowe (I don't have 15 reputation, so I couldn't vote him up).
This also seems too complicated. Do you want it to be unbreakable? you can't. Any sufficiently motivated guru would find a way around it.
Sometimes a simple licensing scheme works best:
I suggest a simple encrypted file that the admin puts somewhere the client can access - it would contain the client name and expiry date. You use the client name from the file in all printed reports (that's what most PHBs care About, that way they would not use the license that prints somebody else's name).