In today’s software-driven world, trust is the most crucial component. But how do we know which programmes to trust and which to stay away from? We are indebted to the code signing process for that.
Code signing is the procedure by which developers prove that their programme is authentic, comes from a trusted source, and has not been tampered with in any manner. Code signing relies heavily on cryptography and, more specifically, something called a code signing certificate.
So, what exactly is a CSC?
A CSC is a type of digital certificate used to verify the legitimacy of a company. Clarifying how certificates function in general is necessary before understanding what a code signing certificate is.
Public key infrastructure relies heavily on certificates (PKI). They can be used for authentication, as they are founded on asymmetric cryptography. For this particular certificate, the private key half of a public-private key pair was used.
A certificate issued with a signature acts as a type of authentication and safeguards against forgery. With the associated public key, anyone can
- Make that the signature was signed by the right person, and
- Verify that the contents of the package have not changed (including any code, documents, or other data) since the signature was issued.
This reminds us of the code signing certificate, a subset of digital certificates used to verify the authenticity of code. Any user can confirm the software’s legitimacy by looking at the information provided in the code signing certificate, which includes the name of the company issuing the software.
- Identifying the Software’s Developer and
- Verifying that the software has not been modified in any way since it was shipped.
Why do we need a code signing certificate, and how does it work?
Certificate Authorities (CAs) are responsible for issuing certificates to the public, and developers can use these certificates to “sign” their code. Developers can sign their code before sending it to production if they have a valid code signing certificate. This signature comprises the full details of the certificate (including the company’s name, location, and more; think of it as a digital driver’s licence) and the date and time the code was signed using the certificate.
Notably, if a user tries to download or install software that does not have a signature from a code signing certificate issued by a trustworthy CA, the browser or device will display a security warning.
Common scenarios where a code signing certificate would be useful include:
- Introducing new mobile applications to a software distributor (i.e., Microsoft, Google, and Apple all require apps to be signed before they can be listed on their app stores)
- Providing Software for Widespread Use
- Creating company-wide information technology programmes (that way employees know they can trust the application)
When it comes to managing code signing and SSL certificates, many businesses rely on enterprise PKI software. This management is essential not just because it streamlines the code signing process for developers but also because businesses must protect their code signing certificates like they would any other private security element.
Malicious actors can distribute fake but seemingly valid software if they have access to a code signing certificate. If a code signing certificate is ever compromised, the information about it must be included in a certificate revocation list (CRL), rendering all code signed with that certificate useless. Because of this, it is crucial for businesses to implement a PKI system for managing and safeguarding code signing certificates.