What is a code-signing certificate?
A code-signing certificate is a digital certificate that verifies a software developer's identity and confirms the code hasn't been tampered with. A public-private key pair is used to achieve this.
How does a code-signing certificate work?
A code-signing certificate utilizes public key cryptography.
The developer first applies to a certificate authority (CA) to validate their identity. The CA then verifies their identity through background checks and documentation. Once that's done, the CA issues a code-signing certificate that contains the developer's information and a public-private key pair. The public key is visible to everyone, while the private key is kept secret.
The developer then uses the private key to create a unique signature for their code. This process generates a cryptographic hash (a unique fingerprint) for the software, which is then encrypted with the private key and attached to the code along with the certificate.
When the software is installed, the operating system of the machine automatically checks the signature. It uses the public key from the certificate to decrypt the signature and verify two things: that the code came from the claimed developer (authentication) and that it hasn't been altered since signing (integrity). The system also checks that the certificate was issued by a trusted CA and hasn't expired or been revoked. If everything checks out, the software is marked as verified and trusted.
What are the different types of code-signing certificates?
There are two main types of code-signing certificates:
- 01.
Organization validation or standard validation certificates
Organization validation (OV) and standard validation (SV) certificates are certificates that involve basic verification of the developer or entity to confirm their identity. The CA confirms business registration and contact details before issuing the certificate. These certificates are stored as software files on the developer's computer.
- 02.
Extended validation certificates
Extended validation (EV) certificates go through a thorough verification process, including extensive background checks and legal entity verification. This process can take one to two weeks and requires substantial documentation, including articles of incorporation, business licenses, and verified contact information. Unlike OV certificates, EV certificates are issued on dedicated hardware security modules (HSMs), typically USB tokens or FIPS-compliant devices. The private key is generated and stored directly on this hardware and cannot be exported or copied. Naturally, EV certificates are more expensive than SV certificates.
Other types of code-signing certificates include:
- 03.
Platform-specific certificates
Different platforms require specialized certificates; for example, Windows code-signing certificates are needed for signing Windows applications, drivers, and executable files (.exe, .dll, .cab files); Apple certificates for iOS or macOS apps; and Java-signing certificates for signing Java applets, applications, and other Java-based software. Each type is designed to work with a specific operating system or development environment only.
- 04.
User-based certificates
Code-signing certificates can be issued to individual developers or to organizations, called individual certificates and organizational certificates respectively. In the case of individual certificates, the identity of the solo developer is verified before issuance, while organizational certificates are issued to registered companies with verified business credentials
Why are code-signing certificates important?
Code-signing certificates protect both developers and end users from security threats. When software is signed with a certificate, it creates a cryptographic fingerprint that cannot be replicated or forged. If even a single byte of the code is altered after signing, the signature becomes invalid, immediately alerting users of potential tampering. This mechanism prevents malicious actors from injecting malware into legitimate software or distributing counterfeit applications under a developer's name. It provides verifiable proof that the software comes from who it says it does and hasn't been compromised during distribution.
Further, beyond security, operating systems and platforms have made code signing a practical requirement for software distribution. Without a valid code signature, applications trigger security warnings that may affect downloads and installations, significantly impacting software adoption rates. App stores and distribution platforms mandate code signing as a prerequisite for publication, and it's also crucial from an audit and compliance perspective (for NIST, SOC 2, and more).
Managing code-signing certificates with Key Manager Plus
Organizations managing hundreds of code-signing certificates across development teams manually face significant operational challenges as well as security issues that arise out of expired certificates. Private keys stored on individual machines create blind spots as they can be lost, accidentally deleted, stolen, or misused without proper oversight. Development workflows often stall when certificates expire unexpectedly or when team members can't locate the necessary credentials for signing releases. All of this makes manual tracking and management of code-signing certificate life cycles across different platforms and projects increasingly difficult as teams and organizations scale.
Key Manager Plus helps organizations address this challenge by unifying the complete certificate life cycle management of all SSL/TLS certificates, including code-signing certificates, in a single, central console. Key Manager Plus provides a centralized inventory of all your code-signing certificates, and it also enables you to raise certificate signing requests and create new code-signing certificates with both public CA as well as private CA certificates for internal use.
Key Manager Plus also provides a centralized vault to store all private keys with role-based access controls. Development teams can retrieve certificates for signing operations without direct access to the private keys themselves, maintaining security while enabling productivity. Further, Key Manager Plus' automated alerts notify teams before certificates expire, preventing last-minute scrambles that could delay software releases. For organizations using EV certificates with hardware tokens, Key Manager Plus integrates with HSMs, enabling secure certificate sharing across distributed teams without compromising the hardware-level security that EV certificates require.
Irrespective of the type of code-signing certificate you want to manage, Key Manager Plus can help you store, track, and manage renewal of these digital certificates, giving you complete visibility over all of them so you don't miss a single expiry.