It’s called activation for a license key (activation code) or serial key, and it’s very simple. It also works in any older version like Avast 2017, 2016, 2015, 2014, 8, 7, 6, 5 or v4.8. In the past, Avast was also using license files which were generated for a specific e-mail address.
Active12 months ago
How can I create a product key for my C# Application?
I need to create a product (or license) key that I update annually. Additionally I need to create one for trial versions.
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J3r3myKJ3r3myK
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14 Answers
You can do something like create a record which contains the data you want to authenticate to the application. This could include anything you want - e.g. program features to enable, expiry date, name of the user (if you want to bind it to a user). Then encrypt that using some crypto algorithm with a fixed key or hash it. Then you just verify it within your program. One way to distribute the license file (on windows) is to provide it as a file which updates the registry (saves the user having to type it).
Beware of false sense of security though - sooner or later someone will simply patch your program to skip that check, and distribute the patched version. Or, they will work out a key that passes all checks and distribute that, or backdate the clock, etc. It doesn't matter how convoluted you make your scheme, anything you do for this will ultimately be security through obscurity and they will always be able to this. Even if they can't someone will, and will distribute the hacked version. Same applies even if you supply a dongle - if someone wants to, they can patch out the check for that too. Digitally signing your code won't help, they can remove that signature, or resign it.
You can complicate matters a bit by using techniques to prevent the program running in a debugger etc, but even this is not bullet proof. So you should just make it difficult enough that an honest user will not forget to pay. Also be very careful that your scheme does not become obtrusive to paying users - it's better to have some ripped off copies than for your paying customers not to be able to use what they have paid for.
Another option is to have an online check - just provide the user with a unique ID, and check online as to what capabilities that ID should have, and cache it for some period. All the same caveats apply though - people can get round anything like this. Super bike race game download.
Consider also the support costs of having to deal with users who have forgotten their key, etc.
edit: I just want to add, don't invest too much time in this or think that somehow your convoluted scheme will be different and uncrackable. It won't, and cannot be as long as people control the hardware and OS your program runs on. Developers have been trying to come up with ever more complex schemes for this, thinking that if they develop their own system for it then it will be known only to them and therefore 'more secure'. But it really is the programming equivalent of trying to build a perpetual motion machine. :-)
frankodwyerfrankodwyer
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Who do you trust?
I've always considered this area too critical to trust a third party to manage the runtime security of your application. Once that component is cracked for one application, it's cracked for all applications. It happened to Discreet in five minutes once they went with a third-party license solution for 3ds Max years ago.. Good times!
Seriously, consider rolling your own for having complete control over your algorithm. If you do, consider using components in your key along the lines of:
Then checksum the hell out of them and add whatever (reversable) encryption you want to it to make it harder to crack.
To make a trial license key, simply have set values for the above values that translate as 'trial mode'.
And since this is now probably the most important code in your application/company, on top of/instead of obfuscation consider putting the decrypt routines in a native DLL file and simply P/Invoke to it.
Several companies I've worked for have adopted generalised approaches for this with great success. Or maybe the products weren't worth cracking ;)
Peter Mortensen
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Software Keys And Serials
SpiffeahSpiffeah
If you are asking about the keys that you can type in, like Windows product keys, then they are based on some checks. If you are talking about the keys that you have to copy paste, then they are based on a digitial signature (private key encryption).
A simple product key logic could be to start with saying that the product key consists of four 5-digit groups, like
abcde-fghij-kljmo-pqrst , and then go on to specify internal relationships like f+k+p should equal a, meaning the first digits of the 2, 3 and 4 group should total to a. This means that 8xxxx-2xxxx-4xxxx-2xxxx is valid, so is 8xxxx-1xxxx-0xxxx-7xxxx. Of course, there would be other relationships as well, including complex relations like, if the second digit of the first group is odd, then the last digit of the last group should be odd too. This way there would be generators for product keys and verification of product keys would simply check if it matches all the rules.
Encryption are normally the string of information about the license encrypted using a private key ( digitally signed) and converted to Base64. The public key is distributed with the application. When the Base64 string arrives, it is verified (decrypted) by the public key and if found valid, the product is activated.
Peter Mortensen
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Kinjal DixitKinjal Dixit
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Whether it's trivial or hard to crack, I'm not sure that it really makes much of a difference.
The likelihood of your app being cracked is far more proportional to its usefulness rather than the strength of the product key handling.
Personally, I think there are two classes of user. Those who pay. Those who don't. The ones that do will likely do so with even the most trivial protection. Those who don't will wait for a crack or look elsewhere. Either way, it won't get you any more money.
spenderspender
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I have to admit I'd do something rather insane.
When they find and remove the LicenseCheck, what fun will followwhen the DLL starts segmentation faulting.
Peter Mortensen
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JoshuaJoshua
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There is the option Microsoft Software Licensing and Protection (SLP) Services as well. After reading about it I really wish I could use it.
I really like the idea of blocking parts of code based on the license. Hot stuff, and the most secure for .NET. Interesting read even if you don't use it!
Microsoft® Software Licensing and Protection (SLP) Services is a software activation service that enables independent software vendors (ISVs) to adopt flexible licensing terms for their customers. Microsoft SLP Services employs a unique protection method that helps safeguard your application and licensing information allowing you to get to market faster while increasing customer compliance.
Note: This is the only way I would release a product with sensitive code (such as a valuable algorithm). Jio live tv.
Peter Mortensen
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ccookccook
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If you want a simple solution just to create and verify serial numbers, try Ellipter. It uses elliptic curves cryptography and has an 'Expiration Date' feature so you can create trial verisons or time-limited registration keys.
Peter Mortensen
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RolandRoland
Another good inexpensive tool for product keys and activations is a product called InstallKey. Take a look at www.lomacons.com
CheChe
One simple method is using a Globally Unique Identifier (GUID). GUIDs are usually stored as 128-bit values and are commonly displayed as 32 hexadecimal digits with groups separated by hyphens, such as
{21EC2020-3AEA-4069-A2DD-08002B30309D} .
Use the following code in C# by
System.Guid.NewGuid() .
I hope it helps.
Peter Mortensen
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Aishwar C NigamAishwar C Nigam
The trick is to have an algorithm that only you know (such that it could be decoded at the other end).
There are simple things like, 'Pick a prime number and add a magic number to it'
More convoluted options such as using asymmetric encryption of a set of binary data (that could include a unique identifier, version numbers, etc) and distribute the encrypted data as the key.
Might also be worth reading the responses to this question as well
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Rowland ShawRowland Shaw
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There are some tools and API's available for it. However, I do not think you'll find one for free ;)
There is for instance the OLicense suite:http://www.olicense.de/index.php?lang=en
Frederik GheyselsFrederik Gheysels
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You can check LicenseSpot. It provides:
JoseJose
I'm going to piggyback a bit on @frankodwyer's great answer and dig a little deeper into online-based licensing. I'm the founder of Keygen, a licensing REST API built for developers.
Since you mentioned wanting 2 'types' of licenses for your application, i.e. a 'full version' and a 'trial version', we can simplify that and use a feature license model where you license specific features of your application (in this case, there's a 'full' feature-set and a 'trial' feature-set).
To start off, we could create 2 license types (called policies in Keygen) and whenever a user registers an account you can generate a 'trial' license for them to start out (the 'trial' license implements our 'trial' feature policy), which you can use to do various checks within the app e.g. can user use Trial-Feature-A and Trial-Feature-B.
And building on that, whenever a user purchases your app (whether you're using PayPal, Stripe, etc.), you can generate a license implementing the 'full' feature policy and associate it with the user's account. Now within your app you can check if the user has a 'full' license that can do Pro-Feature-X and Pro-Feature-Y (by doing something like
user.HasLicenseFor(FEATURE_POLICY_ID) ).
I mentioned allowing your users to create user accounts—what do I mean by that? I've gone into this in detail in a couple other answers, but a quick rundown as to why I think this is a superior way to authenticate and identify your users:
Of course, if you don't want to handle user accounts and you want your users to input license keys, that's completely fine (and Keygen supports doing that as well). I'm just offering another way to go about handling that aspect of licensing and hopefully provide a nice UX for your customers.
Finally since you also mentioned that you want to update these licenses annually, you can set a duration on your policies so that 'full' licenses will expire after a year and 'trial' licenses last say 2 weeks, requiring that your users purchase a new license after expiration.
I could dig in more, getting into associating machines with users and things like that, but I thought I'd try to keep this answer short and focus on simply licensing features to your users.
Community♦
ezekgezekg
Please check this answer: https://stackoverflow.com/a/38598174/1275924
The idea is to use Cryptolens as the license server. Here's a step-by-step example (in C# and VB.NET). I've also attached a code snippet for key verification below (in C#):
ArtemArtem
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Active2 years, 1 month ago
Are there any files probably contained in the Windows directory that have the product key?
I need to re install the OS of my laptop but have misplaced the CD key.
WillWill
migrated from stackoverflow.comSep 18 '11 at 19:58
This question came from our site for professional and enthusiast programmers.
4 Answers
You could use ProduKey to retrieve your key.
ProduKey is a small utility that displays the ProductID and the CD-Key of Microsoft Office (Microsoft Office 2003, Microsoft Office 2007), Windows (Including Windows 7 and Windows Vista), Exchange Server, and SQL Server installed on your computer.
This utility can be useful if you lost the product key of your Windows/Office, and you want to reinstall it on your computer.
slhck
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Saket
I found this:
21 Best Tools to Recover Windows 7/Vista/XP Product Keys
A CD key (aka product key, activation key, key code, installation key, and serial number) is used to identify that the copy of the program or game is original. In simple terms, Product key is a long series of numbers and letters that many software programs prompts you to enter during the setup process. Windows does not provide a way to view the product key of the application currently installed. If you have lost your key or the printed registration card then you are out of luck. Re-installing Windows requires you to have the original product key. Following are the list of 21 Free Product Keys recovery tools that scan through the Windows Registry to retrieve the Windows product keys and all the serial numbers for the applications installed. The serial keys finder tools listed below can be useful to recover your License Key, CD Product key for Windows or Office programs while reinstalling / repairing your Windows or Office setup.
1) Magical Jelly Bean Keyfinder
Windows 7/Vista/XP and Office 2007 Product Key (CD Key) can be recovered easily with the Magical Jelly Bean Keyfinder. It is a powerful and freeware open source utility that retrieves your Product Key used to install Windows from your registry. It can even retrieve product keys from unbootable Windows installations. The tool lets you print or save your License keys for safe backup. Keyfinder also works with Windows 95, 98, ME, 2000, Server 2003, Server 2008, Office XP, Office 2003 and its community-updated configuration file helps in retrieving product keys for many other applications too.
2) ProduKey
The tool helps in retrieving the ProductID and the CD-Key of Microsoft Office (Microsoft Office 2003, Microsoft Office 2007), Windows (Including Windows 7 and Windows Vista), Exchange Server, and SQL Server installed on your computer. Using command-line options ProductID can be grabbed for current operating system or for another operating system/computer. For more information on ProduKey visit nirsoft.
3) WinGuggle
It is a powerful tool that allows you to recover Windows 7/Vista/XP and Office Product Key (CD Key) quickly. In addition, you can Set, Change, remove and Backup your Original Equipment Manufacturer’s (OEM) Logo Information Settings.
4) WinKeyFinder
WinkeyFinder 1.73RC2 allows you to recover lost product keys, CD Keys or License keys your Windows XP, Windows Vista, MS Office 2007, Windows me, 98, 2003 and .NET Product keys from the registry and display it for you. The Product Key recovery tool helps you to take back up of WinXP Activation Key, re-store WinXP activation key, Change / copy Volume Serial number and save the product key By Encrypting It. With WinkeyFinder 1.73RC2 unique passwords can be generated by entering a combination of KeyCode.
5) Simple KeyFinder
Quickly recover your lost Windows Vista (32bit), Windows xp, Windows 2000, Windows 2003 Product Key From Windows Command Prompt. The tools helps you to retrieve CD Keys from existing installations of Windows.
6) Windows Vista Cd Key Finder
Recovers your windows Vista Cd Key or product key safely and securely. Windows Vista Cd Key Finder allows you to encrypt or decrypt the product key. Save CD Key, Copy to Clipboard and print. The product key finder tool supports All versions of Windows Vista.
7) Product Key Finder
Product Key Finder retrieves license key information (CD Keys) from the Windows registry and also helps in recovering product keys of 200+ windows applications such Microsoft Windows, Microsoft Office and Adobe Acrobat.
8) Keyfinder-Thing
The tool retrieves Serial numbers or CD Keys of Microsoft software installed on your system. This free product key recovery tool scans the system registry for 90 supported software titles and displays product names and icons in the result window. Keyfinder-Thing allows you to copy or export all keys to a text or HTML file.
9) Product Key Finder PRO
A software utility allows you to recover your License Key, CD Product key for Windows or Office programs while reinstalling / repairing your Windows or Office setup. Recover your lost key for (Windows) 2000, XP, 2003, Vista. (Office) XP, 2003, 2007. The utility provides you with an option to save your product keys to a file and Print your product keys for secure backup.
10) RockXP
It is a small but powerful tool that lets you recover all Microsoft Software Serials instantly. With RockXP you can change your XP key, save you XP activation key, retrieve your internet connection parameters (like passwords), retrieve MSN login and password, recover XP login and HASH password, display system password (LSA) and generate random password. RockXP 4.0
11) Windows Product Key Finder Professional
It is one of the best and powerful Windows, Office, and Product Key Code Finder Retriever. Product Key Finder PRO utility allows you to recover your CD Product key for Windows. Recover your lost key or serial for (Windows) 2000, XP, 2003, Vista. (Office) XP, 2003, 2007. Retrieve Product Keys for: Windows 2000 Windows XP Windows 2003 Windows Vista Office XP Office 2003 Office 2007
12) Product Key Finder
With the Product Key Finder you can easily recover lost product key (CD Key) for Windows 7, Vista, 2008, XP, 2003, 2000, Microsoft Office, SQL Server, Exchange Server and many other products.
13) License Crawler
This free windows license key and product key scanning utility scans your Windows Registry to retrieve the Windows product keys and all the serial numbers for the applications installed. This scanning tool finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, Windows Server 2003, Windows 2000, and Windows XP, Microsoft Office 2007, Office 2003, most Adobe products, and many more.
You can run License Crawler from a USB stick or via local network to scan the computers. Once the search is completed users can get the license keys or serial numbers from the screen directly in a detailed list format.
https://5e-Crafting-Magic-Items-Dmg-128.peatix.com/. 14) Product Key Finder (OTT Solution)
Make Installation File With Serial Key Activation Code
Product Key Finder is a free tool that will display the installed Windows Product Key for Windows operating systems (2000, 2003, XP, Vista, 2008, 7), 32-bit and 64-bit. The tool also lets you save all product keys to a text or an xml file. You can also change your Windows product key instantly without having to re-install; this is helpful if you are using a leaked product key and are unable to install updates.
15) geProduct Key Finder
This serial Key recovery tool enables you to recover your product CD-keys and serial numbers for Microsoft products as well as several 3rd party products. It is important to note that geProductKeys does not work with Windows 7 or Windows Vista and you may have to disable Data Execution Prevention to use this program in Windows XP SP2 and later.
Activation Key Download
16) MSKeyViewer Plus
Simple utility to view program installation keys, service pack levels, and product IDs along with detecting many other non-licensed program versions. Supports Microsoft Windows, Office, Exchange, SQL Server, Norton AntiVirus 2004-2007, and more.
17) Product Key Informer
It retrieves product key or License Key information pertaining to the operating system. The tool is very useful for Network Administrators for organizing the product key info of their network terminals.
18) ViewKeyXP
This is a simple tool that recovers your Windows XP key quickly.
Download chevrolet camaro wallpaper for free on start screen. 19) Game Key Revealer
If you are looking for a free tool to retrieve the CD-Key and Serial for installed games on computer then Game Key Revealer is the best pickup. If you lost legal CD-Keys or Serials of your purchased games, you can easily recover them using Game Key Revealer. You can easily recover serial keys of around 1000 games with Game Key Revealer. The tool also provides you with an option to Save to Text or Word or Print Product Keys for secure backup
20) SyberCorp’ Windows Product Key Viewer
It is yet another and simple serial key (CD Keys) recovery software. With Windows Product Key Viewer you can view and change your Windows Product Key anytime.
21) Skeleton Key Rosetta stone setup download.
https://yellowtattoo389.weebly.com/blog/download-my-image-garden-mac. Skeleton Key is an open source and simplest software to find a product key.
slhck
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kokbirakokbira
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Nope, the CD key is not stored directly in any file. For some Microsoft products (e.g., Office, and apparently Windows 7 too), the registry contains a licensing blob where the CD key can be extracted. See the link for a program that can extract this information.
Chris Jester-YoungChris Jester-Young
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I've successfully activated (an inactivated version of) Windows XP Pro with a key found by Produkey, so I assume in Windows XP there is a key in the install files. I do not know the legality of this endeavor, though.
Steve JobsSteve Jobs
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