What is Code Signing?
Code signing is a process to confirm the authenticity and originality of digital information especially a software code and assuring that this digital information is valid and additionally establishes the legitimacy of the author. It also provides assurance that this piece of digital information has not changed or revoked after it has been signed by the validity of signature.
Whenever we download a program or software, and we see a pop saying “Are you sure you want to run this?” or when we install a software and try to run then you get asked “Do you want to allow the following program to make changes to this computer” then that means code signing in action. And if the program downloaded or installed has not been code signed then we can see a small warning sign stating the same that it has not been code signed.
Why Code Sign?
Code Signing plays an important role as it can enable identification of a legitimate software v/s a malware or a rogue code. In technical terms, code signing creates a hash of the code and encrypts it with a private key adding its signature. During executing this signature is validated and if the hash match it gives assurance that the code has not been modified. It also establishes assurance that the code is issued from a legitimate author that it is claiming to be once it has been digitally signed.
Risks associated with Code Signing:
Few challenges come along with code signing like any other development process. Code signing is only effective if the associated software is secured.
Below are the few risks associated,
- Stolen, corrupted or misused keys.
- When access is granted to an unauthorized user in the system using malicious signature certificates, then that is going to hamper the code signing process.
- Unsecured CA private keys would also lead to comprising the code signing system.
- Establishing trust in the unauthorized certificates issued by would lead to the malfunction of the system.
- The signing of unauthorized code.
- Code signing can get hampered in an insecure cryptography system.
Best Practices for Code Signing:
- Establishing a high state of security on Private Keys – using HSMs or in a purpose-built environment.
- Keeping track of Private Keys and Code Signing events – Maintaining and providing visibility access about who signed what and when.
- Managing the assignment and revocation of publishers – Ensuring the access of Private Keys to only the authorized users.
- Auditing Capability – Gives accountability and forensic insights on code signing activities.
- It is of great importance if policies and procedures are reviewed before the signing of code as it would lead the development process to be more trustworthy and healthy.
- Developing a strongly secured cryptography system will have no risk impact on the code signing process.