Code Signing Certificates: the ultimate guide

In today’s digital-first world, software integrity isn’t optional—it’s essential. A Code Signing Certificate is your digital signature, assuring users that your software hasn’t been tampered with and comes from a trusted source. 

This guide unpacks everything you need to know about Code Signing Certificates—from what they are and why they matter to how you can secure them for your business.

Dive in and discover how these certificates help safeguard your software and reputation in an ever-connected world.

What is a Code Signing Certificate?

A Code Signing Certificate is a digital certificate that plays a key role in verifying the authenticity and integrity of software code. It serves as a safeguard for both developers and users, ensuring that software remains trustworthy and secure.

When a developer uses a Code Signing Certificate to sign their code, it creates a unique digital signature. This signature tells users that the code originates from a verified source and has not been altered or tampered with since it was signed. This level of assurance is critical in preventing malicious interference and building confidence in the software.

Think of a Code Signing Certificate as a virtual seal of approval. It reassures users that the software they’re about to install is safe, reliable, and developed by a trusted source. Without this certificate, users may encounter warnings or question the software's authenticity.

By digitally signing their software, developers can remove trust barriers. They demonstrate their credibility, build stronger relationships with users, and protect their software from potential malicious activities. A Code Signing Certificate isn’t just a security measure; it’s a vital tool for fostering trust and ensuring smooth, worry-free installations.

Importance of code signing

The importance of code signing is hard to overstate in today’s digital world. It’s a critical process that assures users of software integrity while safeguarding against malicious imposters.

One of the key benefits of code signing is that it ensures the integrity of the software. By verifying that the code hasn’t been altered or corrupted since it was signed, code signing protects against tampering and gives users confidence in the software they’re installing. This assurance is essential for maintaining trust.

Code Signing Certificates also authenticate the source of the software. A credible digital signature tells users that the software is legitimate and comes from a trusted developer. This verification is vital for preventing the spread of malware and other security threats that could compromise systems and data.

In addition to enhancing trust, code signing is often a requirement for software distribution. Many operating systems and platforms mandate that software be signed before it can be installed, making code signing an essential step in reaching your audience.

Brief history of code signing

The practice of code signing dates back to the early days of the Internet, when software distribution began shifting online. At the time, there were few safeguards in place to ensure that software downloaded from the internet was safe or unaltered. This lack of security created a fertile ground for malware and other malicious software to spread.

In response to these challenges, code signing was introduced in the mid-1990s as a way to enhance software security. Microsoft was one of the first to adopt this technology, launching Authenticode—a tool designed to verify software publishers and confirm the integrity of their code. This innovation marked a turning point in how software authenticity and safety were managed.

Over time, the practice of code signing has evolved into an industry standard for software distribution. Today, Code Signing Certificates are issued by trusted Certificate Authorities (CAs) and serve as a cornerstone of software security. They ensure that users can trust the software they download and install.

How Code Signing Certificates work

The technical process of code signing involves several important steps to ensure software integrity and authenticity. Here's how it works:

Step 1: Purchase a Code Signing Certificate

The process begins with the developer purchasing a Code Signing Certificate from a trusted Certificate Authority (CA) such as Sectigo. This certificate contains two important components:

• A public key, which is shared with users.

• An associated private key, which the developer keeps secure.

Step 2: Generate a cryptographic hash

Before signing the code, the developer generates a cryptographic hash of the software. This hash is a unique, fixed-size string of bytes that represents the software’s content. Even the smallest change to the software will result in a completely different hash, making it a reliable indicator of the software’s integrity.

Step 3: Create a digital signature

The developer uses their private key to encrypt the cryptographic hash, creating a digital signature. This signature ensures that only the developer, as the certificate holder, could have signed the software.

Step 4: Distribute the signed code

The signed code, along with the digital signature and the developer’s public key, is distributed to users. These elements work together to verify the software’s authenticity.

When users download the software, their system uses the developer’s public key to decrypt the digital signature. It then compares the decrypted hash with the hash of the software they downloaded.

If the hashes match, it confirms that the software is authentic and has not been tampered with.

If they do not match, the system alerts the user, signaling potential security risks.

Key components and stakeholders of a Code Signing Certificate

Code Signing Certificates consist of three important components: the public key, the private key, and the digital signature:

• Public key:

  • Issued by a trusted certificate authority (CA).

  • Openly available and used to verify the digital signature.

• Private key:

  • Kept secret by the developer.

  • Used to create the digital signature by encrypting the cryptographic hash of the software.

• Digital signature:

  • Created by encrypting a cryptographic hash of the software with the developer’s private key.

  • Attached to the software to verify its integrity and authenticity.

Meanwhile, these are the three key stakeholders involved in the code signing process:

• Developers: For developers, Code Signing Certificates confirm the authorship of their software, ensuring that their work is recognized and trusted. They also protect against tampering, safeguarding the integrity of the code. Additionally, Code Signing Certificates eliminate "unknown publisher" warnings, enhancing the developer's credibility and improving visibility to users.

• Users: For users, Code Signing Certificates provide assurance that the software they download is legitimate and secure. By verifying the source of the software through the certificate’s information about the developer or organization, users can trust that the software is authentic and has not been altered.

• Certificate Authorities (CAs): As the entities that manage Code Signing Certificates, CA play a critical role in the code signing process. They are responsible for validating the identity of the certificate holder before issuing a Code Signing certificate. Acting as trusted intermediaries, CAs ensure that the developer or organization requesting the certificate is legitimate. This validation process reinforces the chain of trust between developers and users, providing an additional layer of security and reliability.

Types of Code Signing Certificates

Individual vs. organization

Code Signing Certificates can be issued to both individuals and organizations, each serving a specific purpose with distinct levels of validation and trust.

Individual Code Signing Certificates are designed for single developers and are used to sign software created by that individual. While these certificates provide assurance that the software comes from a specific person, they tend to carry less weight in terms of trust compared to organizational certificates.

Organizational Code Signing Certificates, on the other hand, are issued to companies or organizations. Obtaining one involves a more thorough validation process, including verification of the organization’s legal existence and identity. Because of this added scrutiny, software signed with an organizational certificate is often seen as more credible and trustworthy, which is particularly important for businesses distributing software to a wide audience.

EV Code Signing Certificates

Extended Validation (EV) Code Signing Certificates provide a higher level of security and trust compared to standard Code Signing Certificates. Obtaining an EV certificate requires a stringent vetting process, including thorough verification of the organization’s identity and legal status. This rigorous validation ensures that only reputable entities can be issued an EV certificate.

One of the standout benefits of an EV Code Signing Certificate is its instant reputation with Microsoft SmartScreen. This feature helps protect users from downloading malicious software and significantly reduces the chances of triggering security warnings during installation. As a result, software signed with an EV certificate offers a smoother and more trustworthy user experience.

EV certificates also include hardware-based storage for private keys, adding another layer of security. By keeping the private key in secure hardware, organizations can prevent unauthorized access and enhance overall protection.

Self-signed certificates

Self-signed certificates offer an alternative to certificates issued by trusted certificate authorities (CAs). In this case, the developer generates their own certificate and uses it to sign their code. While this approach is both cost-effective and quick, it has significant drawbacks that limit its practicality for public software distribution.

The main issue with self-signed certificates is the absence of third-party validation. Without an external entity confirming the certificate holder’s identity, there’s no assurance of trustworthiness. As a result, operating systems and browsers typically do not trust these certificates by default, leading to security warnings during installation. These warnings can discourage users from downloading or installing the software, ultimately affecting its distribution and adoption.

While self-signed certificates may be suitable for internal testing or development environments, they are not ideal for software intended for public use. For developers looking to distribute software widely, obtaining a certificate from a trusted CA is highly recommended. Certificates from trusted CAs provide the necessary validation to build trust, enhance credibility, and ensure security.

How to get a Code Signing Certificate

Step 1. Choosing a provider

Choosing a provider for your Code Signing Certificate is a crucial step in ensuring the security and trustworthiness of your software. Several factors should guide your decision when selecting a certificate authority (CA).

First, reputation and trustworthiness are key. Established CAs like Sectigo have built strong credibility in the industry, making them reliable choices for securing your software.

Next, consider the level of customer support provided. The certification process can sometimes be complex, and having access to knowledgeable and responsive support can make a significant difference. Some providers offer more robust support and resources, which can save time and reduce frustration.

Pricing is another important consideration. While budget-friendly options might seem appealing, they may lack the thorough validation and support offered by more reputable providers. Balancing cost with quality is essential to avoid potential issues down the line.

Lastly, evaluate the specific features and benefits offered by the CA. Features like hardware security modules (HSMs) for securely storing private keys or compatibility with various platforms can add significant value. These enhancements can make your certificate more secure and versatile.

Step 2. Getting your Code Signing Certificate

The application process for obtaining a Code Signing Certificate involves a series of important steps to ensure your software is secure and trusted by users.

1. First, choose a trusted certificate authority (CA) and determine the type of certificate you need. Options include individual, organizational, or extended validation (EV) certificates, depending on your specific requirements.

2. Next, submit an application through your chosen provider, such as Openprovider. This will involve providing detailed information about your identity or organization. For organizational certificates, this typically includes business registration documents. For individual certificates, you may need to verify your identity with a government-issued ID.

3. Once you submit your application through the provider, the CA will begin the validation process. This can take several days for standard certificates, while EV certificates may take longer due to the more rigorous checks required to confirm the organization’s identity and legal status.

4. After the CA completes the validation process, they will issue your Code Signing Certificate. You can then download it and begin using it to sign your software, ensuring that it is secure and trusted by users during installation.

This thorough process provides the necessary verification to build trust and protect the integrity of your software.

Step 3. Installation and configuration

Once you have obtained your Code Signing Certificate, the next step is to install and configure it for use.

Start by downloading the certificate from the certificate authority (CA) and saving it to a secure location on your computer. Along with the certificate, you will also receive a private key. This key must be stored securely, often in a hardware security module (HSM) for enhanced protection against unauthorized access.

Next, import the certificate into your development environment. Most integrated development environments (IDEs) and build systems, such as Visual Studio or Jenkins, offer tools for importing and managing certificates. Be sure to follow the specific instructions for your platform to ensure the certificate is installed correctly.

After importing the certificate, configure your signing tools to use it for signing your code. This step typically involves specifying the path to the certificate and private key in your build scripts or project settings.

Proper installation and configuration of your Code Signing Certificate ensure that your software is securely signed and ready for distribution, providing users with confidence in its authenticity and integrity.

Best practices for code signing

Maintaining security

Maintaining security is paramount when using Code Signing Certificates. 

• Protect your private key:

  • Store the private key in a hardware security module (HSM) or secure hardware token to prevent unauthorized access.

  • Use strong passwords and enable multi-factor authentication to secure access to the key.

• Keep tools up to date:

  • Regularly update your development environment and code signing tools to patch vulnerabilities and ensure you’re using the latest security features.

• Monitor and audit usage:

  • Track the use of your Code Signing Certificates to detect any suspicious or unauthorized activity.

  • Revoke the certificate immediately and obtain a new one if you suspect the private key has been compromised.

• Use timestamping:

  • Always apply timestamping when signing your code to ensure the signature remains valid even after the certificate expires.

Regularly updating certificates

Regularly updating your Code Signing Certificates is vital for maintaining security and trust in your software.

Code Signing Certificates have a limited validity, typically lasting one to three years. Once expired, they can no longer be used, which may result in users encountering security warnings or being unable to install your software. To avoid disruptions, it’s important to renew your certificate before it expires. Starting the renewal process well in advance ensures a seamless transition and uninterrupted software distribution.

In addition to timely renewals, periodically review the cryptographic standards of your certificate. Advances in computing power can render older encryption algorithms vulnerable over time. Upgrading to stronger encryption methods ensures your certificate remains secure and meets the latest security requirements.

Troubleshooting common issues

These are a few common issues that may occur to Code Signing Certificates:

• Security warnings despite a valid certificate:

  • This can happen if the certificate chain is incomplete or the root certificate is not trusted.

  • Ensure all intermediate certificates are installed correctly.

  • Verify that the root certificate is recognized by the operating system.

• Certificate not recognized by the development environment:

  • Check that the certificate is correctly imported into your environment.

  • Ensure the private key is accessible and properly stored.

  • Look for any updates or patches for your development tools that could resolve compatibility issues.

• Signed code becoming invalid after certificate expiration:

  • This occurs if the code is not timestamped.

  • Always use timestamping to ensure the digital signature remains valid even after the certificate expires.

By addressing these common issues proactively, you can maintain the integrity and reliability of your code signing process.

Buy your Code Signing certificate through Openprovider today.