What are the Best Code Signing Practices?

Best Code Signing Practices

Software is responsible for connecting everything by running millions of lines of code- whether it is your workplace, home, or virtually anywhere.

If you are a software developer or publisher, you already know how important it is to get a Code Signing certificate for all the software you develop. It helps the users authenticate the software’s publisher or source and get an assurance that the signed software has not been subjected to alteration since its signing.

But you already know that signing code is crucial. Also, you know that buying Code Signing certificate must be from a trusted certificate authority (CA). However, what you do not know is that Code Signing your software is not sufficient. It is important to protect cryptographic keys and certificates.

If the keys are not secure, you might run into more problems than not Code Signing your software. It is primarily because the former becomes an easy target for threat actors.

Digital Certificates and their private keys that are secured suitably often run into the risk of getting compromised. When that happens, the certificate loses its credibility, thereby sabotaging the software that is already Code Signed.

You can consider the following Code Signing best practices to:

  • Limit access to Private Keys
  • Time Stamping Your Code While Signing
  • Authenticating Code Before You Sign It
  • Use Cryptographic Hardware
  • Scan Your Code for Viruses Before Signing
  • Avoid Overusing One Private Key for Signing

1. Limit access to Private Keys

One of the most humongous security threats is the compromise, loss, or exfiltration of a code signing certificate’s private key. Thanks to the liberty the hackers get for signing any code anywhere, the private key is their hot target, to such an extent that you can see the sale of the compromised private key on the dark web.

Their price is sometimes higher than guns, passports, or other important assets, indicating the high demand for Code Signing Certificates for illegal activities.

Thus, losing a private key to your certificate is something you cannot afford. To avoid it, you can:

  • Allow limited access of computers to private keys
  • Limit the access of private keys by only giving rights to authorized individuals
  • Maximize physical security controls to reduce access to private keys

2. Time Stamping Your Code While Signing

A small piece of information or data that is incorporated with your signature whenever you sign your software, apps or other files with a Code Signing Certificate is called a timestamp. In this process, the timestamp is a server given by the Code Signing Certificate provider.

So, when the end-user sees your signature with the timestamp, it assures that the certificate was valid during the Code Signing. Simply put, it is one of the best Code Signing practices to timestamp as it verifies your Code even after the expiry of revoke of the certificate.

3. Authenticating Code Before You Sign It

As a part of the actual development cycle, code authentication must be included, and it should be authenticated before its release. Before signing, you must fully authenticate your software, executable files, codes, and applications. The process helps you know that your software or file is all ready to be signed.

This process will help you know that your files or software is ready to be signed.

Some of the best practices to follow for code authentication are:

  • Before signing and releasing your software, executables, or other files with the key, make sure they are fully authenticated.
  • Set up a different process for Code Signing submission and approval. This will avoid the signing of malicious or unapproved Codes.
  • Log all the Code Signing activities for incident response and auditing purposes.

4. Use Cryptographic Hardware

The application of cryptographic hardware is one of the ideal ways of securing your certificate’s private keys. This is because the cryptographic hardware employs the latest encryption algorithms, thereby protecting private keys and ensuring that no third party can gain unauthorized access to private keys.

For keeping your private keys secure, you can use a FIPS 140 Level 2-certified product to keep all your private keys secure. The device will prevent the export of private keys and demand multi-factor authentication.

5. Scan Your Code for Viruses Before Signing

It is no brainer; still, we will mention it separately. Code signing is not used to confirm the quality or safety of your software, executables, or other files you sign. It validates the publisher’s name and whether or not the Code has been tampered with since its signing.

Recommended: How to Check If a File Has a Virus or not Before Downloading It?

Also, if your Code Signing certificate is used for signing any malicious code and it ends up on the user’s system, it will end up in a bad fallout.

Your reputation gets affected, and this will result in the revocation of your Code Signing certificate. Just not that, you will have a tough time getting another one due to the validation process.

So it is recommended to adhere to certain Code Signing practices before you sign your software. You can:

  • Perform full code review to ensure all lines of Code have been checked and confirmed.
  • Ensure comprehensive QA testing to avoid Code that can result in unforeseen bugs or problems.
  • Doing proper virus scanning helps you double-check the safety of your released Code.
  • Take proper care of your code or software integration with other sources.

6. Avoid Overusing One Private Key for Signing

There is always a small chance that things might go south when you sign any file or software. Although modern cryptography is quite tough to break, there is some risk involved.

For example, losing a private key can result in the revocation of a certificate, ultimately leading to your signature revocation.

Therefore, it is best to take a diversified approach by not signing all of your Code with one single key and certificate and keep changing it once in a while. It will help you avoid any conflict.

Concluding Lines of Best Code Signing Practices

Oftentimes, people take security measures for granted until they encounter any dangerous threat. This holds true when we talk about the security of Code Signing. Having said that, you can follow some of the above-mentioned practices. It will prove beneficial for your business and your end-users as well.

People think buying a Cheap Code Signing Certificate might cause trouble, but it is not the case. You have to follow safe practices to ensure the safety of your software.

Janki Mehta

Janki Mehta is a Cyber-Security Enthusiast who constantly updates herself with new advancements in the Web/Cyber Security niche. Along with theoretical knowledge, she also implements her practical expertise in day-to-day tasks and helps others to protect themselves from threats.

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