License Key Generation Algorithm C%23

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When a web application develops, we need to protect user passwords from security attacks. When your application operates on a license key, we need to validate the license.
In todays world providing security to your system is bit crucial. We have to face malicious scripts, security threats and unwanted attacks in out there. Let’s see how we can prevent those kind of attacks.

In hashing, we are going to convert password string into a byte array. Hashing is a one way funtion, we can’t reverse it. We can see many hashing algorithms available.
Let’s say we hashed the users password and stored in our database. When user second time logs in, we have to verify entered password is correct. What we can do is, we can hash the entered text into password field and compare it with the hashed value from the database. Since Hashing is a one way function, we can’t decrypt and retrieve original text.

When user enters wrong password, System should not let the user know it’s Invalid password , instead of it should tell Invalid username or password . Then if hacker tries to login into your system, he doesn’t know whether username or password got wrong.

A public/private key pair is generated whenever a new instance of an asymmetric algorithm class is created. After a new instance of the class is created, the key information can be extracted using the ExportParameters method, which returns an RSAParameters structure that holds the key information. Example Product Key generator - posted in Professional Code: I decided to stray away from using a RSA generated public key as a license key, because it is not easily human readable. Instead, I designed a very simple key generator that outputs keys in the well known 25 character format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX The key generator does not simply generate a unique random product key, but also. The generator has a private key, which it uses to compute the signatures; the checker only knows the corresponding public key. The trouble with this setup is not really about verification time, even in Javascript; rather, it is the size of the signature which is a problem. This function manipulates the key sequence according to a mathematical algorithm and attempts to match the. Here's a 'proof of concept' demo program implementing my ideas far an algorithm to generate program license keys when a. 4.For each license key to be. Algorithm Generator Online; Key Algorithm Definition. Generating Activation Key from the Serial Number. The second step is to create the key generator which will generate the activation key from a given serial number. This generator will be placed in a class called KeyGenerator. This class will contain a function which will apply a simple mathematical function on the serial number to get the.

SHA1, MD5 are popular hashing algorithms. SHA1 got inspired from MD algorithms and created SHA algorithms. From these two algorithms, better to use SHA1, Because it’s high secure than MD5. MD5 is going to convert a string into 128 bits. But SHA1 convert a string into 160 bits. In MD5 less no of operations required to crack the message, when compared to SHA1. But MD is faster than SHA1. However it’s better to use SHA1 algorithm instead of MD5, since MD5 can be broken easily.

Hackers can guess passwords and simply hash them with a hashing algorithm and try it in your system. It takes few seconds to generate a hash. Within a limited amount of time, your passwords can be cracked easily. These type of guessing password and hashing is called as Dictionary attacks and Brute force attacks.
In dictionary attacks, it uses a file with some words. These words can be extracted from a database or else from set of paragraphs. Most hackers guess passwords from common terms like, hello, hellow, he11o3 etc. They take a string and try to replace letters in it, like hello, he33o, heiio, etc. Then these words are hashed and use against the password hash.
Brute Force attacks going to try out every possible of character combinations to a certain string length. It’s a very expensive computational process, But eventually it’s going to find out your password! That’s why we need lenghtier passwords, So it will take long time to crack your passwords.
By hashing your passwords, We can’t prevent Dictionary attacks or Brute force attacks, But we can minimize them.
While Dictionary attacks and Brute force attacks are time consuming, Hackers has another kid in their block, It’s Lookup Table. In Lookup table, It’s going to precompute the hashes of passwords and used to store them in a dictionary file.
So hundrends of guesses can be done in a second. It’s a very effective method to crack your passwords.
Rainbow Tables, Beware guys, it can crack any 8 characters lengthy MD5 password. Rainbow table is same as Lookup table. In here hash cracking speed is slower, compared to lookup table. But lookup table size is smaller, so more hashes can be stored in the same space. So Rainbow tables are more effective than Lookup tables.

If we use a salt with password hashing, It’s impossible to crack your passwords through Rainbow tables and lookup tables. In lookup tables, hackers are going to hash same list of passwords and try out in your system. Let’s say two users are having same password in your system. When we hash these passwords, It’s same password hash. In Salting, we are adding a random number along with hashed password. So two users never get same salted password hash. And mind you don’t use same salt with different user passwords, don’t repeat the salting. If new user registers into your system or else change password, generate a new salt. Use a new salt for every user password. If hacker is smart enough, He may be able to crack a one or two user passwords, But not more than that. Eventhough many users have same password, Hacker will not be able to crack their passwords using a lookup table. Don’t use shorter salt, Then hacker can create a lookup table to generate every possible salt.

In this example, we are passing usernam and company code to generate a license key. Using GenerateSalt method, we can generate a random number. I used to create a 32 bytes lenth salt number using RNGCryptoServiceProvider class. Using Rfc289DeriveVytes class we can generate a salted hashing value. Along with the generated license key, we used to store salted number as well.

I used 64 byte array as a license key and 32 byte array as a salted value. We can use SequenceEqual method to compare entered license key with stored license key as above.

You can find a sample application from here, https://github.com/hansamaligamage/LicenseKey

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Version 1.3

Here's an example of how to generate Secure Boot keys (PK and others) by using a hardware security module (HSM).

You'll need to know the Secure Boot Public Key Infrastructure (PKI). For more info, see Windows 8.1 Secure Boot Key Creation and Management Guidance.

Requirements

Tools Needed

  • certreq.exe – Available Inbox

  • certutil.exe – Available Inbox

  • Signtool.exe – Available in the latest Windows SDK

Hardware Security Module (HSM)

The whitepaper demonstrates the key generation using examples from the nCipher (now Thales) PCI HSM model nC1003P/nC3023P/nC3033P and the SafeNet Luna HSMs. Most of the concepts apply to other HSM vendors as well.

For other HSMs, contact your manufacturer for additional instructions on how to tailor your approach with the HSM Cryptographic Service Provider (CSP).

Approach

We use the Microsoft certificate creation tool: certreq.exe to generate the Secure Boot Platform Key (PK) and other keys needed for Secure Boot.

The certreq tool can be adapted to use an HSM by providing the Cryptographic Service Provider (CSP) to be the HSM.

Find the Cryptographic Service Provider (CSP)

You can use either the certutil.exe tool or a tool used by the HSM to list the CSPs.

  • This example uses the certutil tool to show the CSPs on the Thales/nCipher HSM:

    For the SHA-256 digesting algorithm, use the CNG provider: 'nCipher Security World Key Storage Provider'. Legacy providers do not support SHA-256 and are not suitable for use with Secure Boot.

  • This example uses the built-in Thales/nCipher tool to list the CSP:

    For the SHA-256 digesting algorithm, use the CNG provider: 'nCipher Security World Key Storage Provider'. Legacy providers do not support SHA-256 and are not suitable for use with Secure Boot.

  • This example uses the SafeNet Luna HSMs tool to list the CSP:

    For SHA-256 digest algorithm you will need to use a CNG provider – “SafeNet Key Storage Provider”. Legacy providers do not support SHA-256 and are not suitable for use with Secure Boot.

To generate the key:

Sample request.inf file:

Update the following values:

  • Subject: Replace the TODO’s with real data 'CN=Corporation TODO Platform Key,O=TODO Corporation,L=TODO_City,S=TODO_State,C=TODO_Country'.

  • ValidityPeriod, ValidityPeriodUnits: Use the validity period of 6 years. While a PK may only be valid for 2 years, the 6-year period allows for potential future servicing.

  • KeyContainer: Enter the container id that you used to create the Key with the HSM. You may be asked to provide the tokens that you have used to create the Security World for the Thales HSM. Bmw coding tool 2.5.0 download.

Validating certificate (self-signed)

Verify that the certificate has been generated correctly:

For example: certutil -store -v my '7569d364a2e77b814274c81ae6360ffe'

Sample output:

Backing up the certificate

Back up your certificates. This way, if either the certificate store or the server goes down, you can add the certificate back to the store. For more info on certreq.exe, see Advanced Certificate Enrollment and Management: Appendix 3: Certreq.exe Syntax

Note, the PK is a self-signed certificate, and is also used to sign the KEK.

There are 2 parts to PK signing / initial provisioning. Please talk to your Microsoft contact to get these scripts:

  • subcreate_set_PK_example_initial_provisioning_example.ps1. Used by the signtool to sign the PK comes later in the servicing case.

  • subcreate_set_PK_service_example.ps1. Since we are dealing with the HSM case, the following line applies in the script applies.

Signing with PK certificate (servicing scenario)

This section applies to signing with your PK certificate and may not be applicable for initial provisioning of system. However, you can use the method here to test your service scenario.

Determine the certificate hash (sha1)

Determine the SHA1 hash of the certificate. You can get the SHA1 hash by using either of the following methods:

  • In Windows, open the Certificate file, select the Details tab, and check the value for Thumbprint.

  • Or use the following command:

    Sample output:

Sign with signtool with the certificate store specified as a reference

Use the SHA1 hash to sign the KEK certificate:

Where KEK.bin is the filename of the binary certificate you want to sign.

License Key Generation Algorithm C 23 Answers

Sample output:

NOTE For compatibility with the UEFI Specification and maximum compatibility across UEFI implementations, the /p7co and /p7ce parameters must be present, the value passed to /p7co must be 1.2.840.113549.1.7.1, and the value passed to /p7ce must be DetachedSignedData. Also, for improved compatibility with production signing environments, a signtool.exe commandline that fully specifies the hardware key container is as follows:

For more info, see Sign Tool (SignTool.exe) and Windows 8.1 Secure Boot Key Creation and Management Guidance.

Appendix A – Using Thales KeySafe for viewing keys

Thales KeySafe is based on a GUI.

To use KeySafe, you must have installed JRE/JDK 1.4.2, 1.5, or 1.6. Install Java before you install the nCipher software.

Configure the hardserver config file under the %NFAST_KMDATA%config folder:

Edit settings in the server_startup section:

nonpriv_port. This field specifies the port on which the hardserver listens for local non-privileged TCP connections.

  • Default to connecting to port 9000.

  • If the NFAST_SERVER_PORT environment variable is set, it overrides any value set for nonpriv_port

priv_port. This field specifies the port on which the hardserver listens for local privileged TCP connections.

  • Default to connecting to port 9001.

  • If the NFAST_SERVER_PRIVPORT environment variable is set, it overrides any value set for priv_port

The following are screenshots from the Thales KeySafe GUI:

The following image is generated by launching the KeySafe utility and then navigating to the KeyList menu.

For more info, see the nCipher/Thales Users Guide.

Appendix B: Using SafeNet CMU Utility to view keys

License Key Generation Algorithm C 23 Code

For more details, please consult the SafeNet Luna HSM documentation.

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