Draft:DNS-Based Software Licensing

DNS-based licensing is a system designed to validate software licenses through the use of the Domain Name System (DNS). In this process, when the software is launched or accessed, it sends specific queries to a designated DNS server that is responsible for storing and managing the relevant license information.

The DNS server, after receiving the query, searches its database to determine the status of the requested license. It then responds with detailed information indicating whether the license is valid, meaning it is active and authorized for use; or unauthorized, suggesting that the license is either invalid or not allowed for that particular software instance.

In the process of performing a DNS query, specific information such as the license key, device details, and user credentials is utilized. This information is essential for the DNS server to accurately locate and authenticate the requested license.

To enhance security and protect sensitive information, it is crucial that the license key undergoes encoding or hashing prior to being included in the DNS query. This transformation not only allows the license key to be recognized in DNS logs but also mitigates the risk of exposing the actual key, ensuring better confidentiality and integrity of the data transmitted. By adopting this practice, organizations can effectively safeguard their licensing information while still facilitating seamless DNS operations.

To validate a license key such as 11111-22222-33333-44444, follow these steps:

• Hash Generation: Begin by generating a hash of the license key. This can be accomplished using a secure hashing algorithm like SHA-256, which will convert the license key into a fixed-length string that is representative of the original data.

• DNS Query Setup: Construct a DNS query that incorporates the generated hash. For instance, you might format the query as “abcdefg.license.example.com,” where “abcdefg” is a placeholder representing the hashed value of your license key.

• DNS Resolution: Send the DNS query to any recursive DNS server. This server will check its records to see if the queried domain is valid and whether it corresponds to an active license.

• Result Evaluation: Once you receive a response from the DNS server, evaluate the result. If the response indicates that the domain exists and is correctly associated with a valid license key, you should proceed to allow the user to run the software. Conversely, if the domain does not resolve or does not correspond to a valid license, you will need to disallow the execution of the software.

By following these steps, you can effectively manage license validation for your software application.

To prevent the tampering of DNS records, it is essential to implement DNS Security Extensions (DNSSEC). DNSSEC enhances the security of the Domain Name System by using public key cryptography to validate the authenticity of the responses generated from DNS queries. This process involves the use of digital signatures that are created for each DNS record. When a user makes a DNS query, the response is accompanied by these signatures, which can be verified using the corresponding public keys stored in the DNS hierarchy. By ensuring that the DNS responses are validated, DNSSEC helps protect against various threats such as cache poisoning and man-in-the-middle attacks, ultimately ensuring the integrity and trustworthiness of the domain resolution process.

To develop a license validation system that utilizes DNS with DNSSEC enabled, it is essential to implement specialized or customized DNS server software. This software must be capable of performing a series of tasks to ensure that the validation process is secure and efficient.

First, the server should be designed to retrieve and check the hashed license key against a secure database that stores valid license keys. This involves creating a robust query mechanism that efficiently accesses the database while maintaining data integrity and security.

Next, the server must be configured to generate DNS responses that not only include the validation result but also incorporate the necessary DNSSEC signatures. This adds a layer of security to the responses by ensuring that they can be verified for authenticity and integrity, thus protecting against spoofing and other types of attacks.

Additionally, considerations should be made for implementing logging and monitoring features to track validation requests and responses, which can help with troubleshooting and ensuring compliance with security policies. Overall, the system should be robust, scalable, and designed with security in mind to effectively handle license validation through DNS.

External links

• DNS-Based Software Licensing Software