Author: Nishiket

Read Time: 10 minutes

As we live in the digital era, software security has become a critical concern in software development. With the increasing frequency and complexity of cybersecurity threats, developers must take proactive measures to safeguard their software and users. Digital signing using a code signing tool is an essential approach to ensure software security. By doing so, developers can add a layer of protection that verifies the authenticity and integrity of the software, preventing malicious attacks and ensuring user trust.

What is a Code Signing tool?

A code signing tool is a software application utilized in digitally signing software code or executable files. This process involves utilizing a cryptographic algorithm to generate a digital signature of the code. The digital signature can then be verified by operating systems or other software tools to ensure the integrity and authenticity of the code.

Code signing is a fundamental security measure that guarantees the authenticity of software code by affixing the developer’s digital signature. This security measure safeguards the code from tampering or modification and prevents malware or other security threats from infiltrating the software code and causing damage to systems or networks.

Software developers and publishers typically rely on code signing tools to sign their code before distributing it to end-users. Similarly, security professionals or IT administrators can use these tools to verify the digital signatures of code to ensure its safety during installation or execution.

Examples of widely used code signing tools include Microsoft Authenticode, Java Code Signing, and Apple Code Signing. These tools necessitate a digital certificate issued by a trusted third-party certificate authority to establish trust in the digital signature and ensure that the code remains untampered.

Code Signing Tools Use Cases

Code signing tools are a critical security measure for ensuring the authenticity and integrity of software code. The following are some typical use cases for code signing tools:

• Software Development

  During the development process, software developers commonly use code signing tools to sign their code before distributing it to end-users. This helps ensure that the code has not been tampered with or modified since signing and provides assurance that the software is safe to use.

• Code Authentication

  The code signature of a software piece verifies the identity of the creator, guarding against malware such as trojans that impersonate legitimate software to gain access to a computer.

• Prevention from Supply Chain Attacks

  Code signing tools safeguard software from supply chain attacks by verifying its authenticity and integrity. Here are some ways in which code-signing tools protect against supply chain attacks:

  • Authentication

    Code signing tools use digital certificates to authenticate the identity of the software developer.

  • Integrity and Verification

    Code signing tools use hash algorithms to create a unique signature for the software and verify whether the code has been corrupted.

  • Revocation

    If a code signing certificate is compromised, the certificate authority can revoke it, rendering any software signed with it invalid.

  • Operating System and Driver Updates

    Operating system and device driver manufacturers use code signing tools to sign their updates before releasing them to the public.

However, these benefits are contingent on the code signing process’s security. If an attacker can obtain signing keys or convince a company to sign their malicious code, it may appear legitimate to users. Thus, caution must be exercised during code signing to ensure the authenticity and integrity of the code.

Top Code Signing Tools in 2023

Code signatures are an essential security measure for verifying the authenticity and integrity of software code, and various tools are available for generating them. Here are some of the most commonly used tools for generating code signatures:

Encryption Consulting’s Code Sign Secure

Codesign Secure offers a secure and flexible code-signing solution for all operating systems, including Windows, Linux, Macintosh, Docker, and Android/iOS apps. With tamper-proof key storage and complete visibility and control over code-signing activities,

Codesign Secure helps customers stay ahead of the curve in today’s ever-evolving threat landscape.

Key Features consist of

• Restrict access only to authorized users.
• Avoid performance bottlenecks with Encryption Consulting’s state-of-the-art custom integrations.
• Well-defined management of private keys to avoid local storage on local build machines.
• Integration with leading hardware security module (HSM) vendors.

Advantages

• Private keys of the code-signing certificate can be stored in an HSM to eliminate the risks associated with stolen, corrupted, or misused keys.
• Client-side hashing ensures build performance and avoids unnecessary movement of files to provide greater security.
• Supports customized workflows of an “M of N” quorum with multi-tier support of approvers.

Microsoft SignTool

Microsoft SignTool, a command-line tool included in the Windows SDK, is used to create digital signatures for executable, dynamic link library, and driver files. These digital signatures contain a hash of the file and a digital certificate issued by a trusted authority, which Windows uses to verify the file’s integrity and authenticity.

One key advantage of Microsoft SignTool is its compatibility as a command-line tool, making it easily usable for a wide range of users. Executables signed using Microsoft SignTool are also trusted by Windows, which eliminates security warnings for users during installation.

Key Features and Advantages of Microsoft SignTool include

• Command-line tool for ease of use and compatibility.
• Trusted by Windows, eliminating security warnings for users during installation.
• Ability to sign executable, dynamic link library, and driver files.
• Digital signatures include hash of the file and digital certificate issued by a trusted authority.

Limitations

• Limited functionality is a drawback of this tool.
• Managing certificate files can be challenging for some developers, as losing or misplacing the certificate file can result in the inability to update or distribute an app.

JarSigner

JarSigner, included in the Java Development Kit (JDK), is a command-line tool used to sign Java Archive (JAR) files digitally. The purpose of this tool is to verify the authenticity and integrity of JAR files used for distributing Java applications and libraries.

To use jarsigner, a public-private key pair is generated using a tool such as key tool included with the JDK. The JAR file is then signed using Jar Signer, which generates a digital signature that can be verified using the public key.

Key Features of jarsigner

• Generates digital signatures for JAR files using public key cryptography.
• Verifies digital signatures using the signer’s public key.
• Included in the Java Development Kit (JDK), making it a standard tool for Java developers.

Advantages of jarsigner

• Enhances the security of Java applications by digitally signing JAR files.
• Digital signatures generated by Jar Signer can be easily verified using the signer’s public key.
• Standard tool included in the JDK, making it easy for developers to use without requiring additional tools or software.

Limitations of jarsigner

• Can be complex for some developers to use.
• Compatibility issues may arise when dealing with different platforms or systems.

SignPath

SignPath is a codesigning procedure that offers a secure, automated, and repeatable solution for signing code in the cloud and on-premises.

It provides various key features such as:

• Integration with current continuous deployment (CD) pipelines using simple command line or API calls, eliminating the need to install cryptographic service providers (CSPs) or attach USB tokens.
• Ease of managing certificates, defining strict policies, monitoring private key usage, and delegating responsibility for signing releases with this codesigning tool.
• Unique solutions for open-source projects to establish a secure build chain for the end-user.

Despite its advantages, SignPath also has certain limitations, such as:

• The cost of using SignPath can be higher compared to other codesigning tools in the market.
• The reliance on SignPath’s cloud infrastructure for secure code signing can result in latency or downtime issues if the server goes down.

PrimeKey SignServer

PrimeKey SignServer is an open-source software solution that provides organizations with digital signature and public key infrastructure (PKI) services. It enables users to securely sign, verify, encrypt, and decrypt electronic documents and data and issue, manage, and revoke digital certificates.

Key Features of SignServer

• Sign Server supports various digital signature formats, including PDF, XML, and OpenPGP signatures, making it highly versatile.
• Sign Server is highly customizable and allows organizations to integrate it into their existing workflows and systems with ease.
• Sign Server supports multiple use cases, including code signing, document signing, and email signing.

Advantages of SignServer

• Sign Server provides organizations with a cost-effective solution for digital signature and PKI services.
• Sign Server enables organizations to maintain control of their PKI infrastructure and avoid vendor lock-in.
• Sign Server is highly scalable, allowing organizations to easily expand their infrastructure as needed.
• Sign Server is open source, which provides transparency and the ability for users to modify and customize the software to their specific needs.

Limitations of SignServer

• Implementation and configuration of Sign Server requires technical expertise and resources.
• Customization and integration with existing workflows can be time-consuming and require significant development effort.
• As an open-source solution, Sign Server may have less robust support and maintenance than commercial alternatives.

Apple Code Sign

Apple Code Signing is a security technology that provides digital signatures for software on Apple platforms, including macOS, iOS, watchOS, and tvOS. This technology offers a range of benefits, including enhanced security, improved user experience, and developer accountability. Additionally, Apple Code Signing facilitates the distribution of software packages.

Key Features

• Digitally signs software on Apple platforms, including macOS, iOS, watchOS, and tvOS.
• Provides enhanced security.
• Improves user experience.
• Facilitates distribution.

Advantages

• Helps ensure the authenticity and integrity of software.
• Gives users greater confidence in downloading and using software.
• Helps prevent malware and other security threats..
• Enables easier distribution of software.

Limitations

• Limited use of the Apple Code Signing tool, designed specifically for signing macOS and iOS app packages.
• Cannot be used to sign other types of files, such as Android APKs or Docker images.

Docker Trust Sign

Docker Trust Sign is a process that adds a digital signature to a Docker image by a trusted entity to ensure its authenticity and integrity. This establishes trust between the image publisher and consumer, with a unique cryptographic signature that guarantees the image has not been tampered with. The benefits of Docker Trust Sign include enhanced authenticity and security, compliance, and simplified deployment. However, this process has limitations, including its complexity, cost, and limited access. Additionally, managing keys and certificates for Docker Trust Sign can be a challenge.

Key Features

• Signing Docker images ensures their authenticity and integrity, establishing trust between image publishers and consumers
• Docker images are given a unique cryptographic signature that can be verified by anyone who downloads the image

Advantages

• Improved authenticity and security of Docker images
• Enables compliance with security policies and regulations
• Simplifies deployment processes

Limitations

• Can be complex to set up and manage
• May involve additional costs, such as for obtaining and managing digital certificates
• Access to Docker Trust Sign may be limited to certain users or organizations
• Key management can present a challenge, particularly for large-scale deployments

APK Signer

APK signer is a software tool designed to sign Android APK (Android Package) files using digital signatures. This process ensures that the file is authentic and has not been tampered with. Users can choose to self-sign APK files or obtain certificates from a certificate authority (CA) for added security.

While there are various tools available for signing APK files, including command-line tools and integrated development environments, APK signer is a popular choice due to its simple graphical interface and cross-platform compatibility.

Key Features

• APK signer is a tool to sign Android APK files with digital signatures.
• Different signing tools are available, such as the Android Studio IDE or command-line tools like the JDK’s jarsigner tool.
• APK signer provides a simple graphical interface and can be used on any platform that supports Java.

Advantages

• Authenticity: APK signer adds a digital signature to the APK file, which verifies its authenticity.
• Integrity: The digital signature added by APK signer ensures that the APK file has not been tampered with or altered.
• Security: Signing an APK file with APK signer enhances the security of the app.
• Compatibility: APK signer can be used on any platform that supports Java, making it a widely accessible tool.

Limitations

• Complexity: APK signing can be a complex process, and APK signer may require some technical knowledge to use.
• KeyStore Management: Users must manage their KeyStore carefully to prevent misuse or unauthorized access.
• Risk of being misused: Like any tool, APK signer could be misused if used by malicious individuals to sign and distribute malware or harmful apps.

These are just a few examples of tools for generating code signatures. The choice of tool will depend on the specific requirements of the code being signed and the target platform or ecosystem.

To learn more about Encryption Consulting’s Code Signing Tool, visit our CodeSigning Solution

Conclusion

To sum up, code signing plays a vital role in software security to safeguard it against tampering and malicious attacks. The code signing tools discussed in this article are some of the most trusted and widely-used solutions available today. They come with a range of key features and advantages, such as seamless integration with existing development processes, robust authentication and encryption, and flexible pricing plans. Selecting the most suitable code signing tool for your organization will depend on your specific needs and preferences.

Read time: 6 minutes

Over the past two years, you’ve probably heard more than you ever wanted or expected to hear about supply chain attacks. According to a study, these attacks have seen approx. 650% year-over-year growth. The survey discovered that software development environments still have low levels of security. Additionally, every business analyzed had flaws and configuration errors that made them vulnerable to supply chain attacks.

What is Software Supply Chain Attacks?

When nefarious hackers penetrate third-party software dependencies utilized in numerous “downstream” applications, it results in a software supply chain attack. The common element is open-source software, frequently an automatically trusted source of code utilized by internal system developers. Attackers may potentially steal sensitive information from, disrupt services for, or breach networks at hundreds or even thousands of businesses by infiltrating a single open-source program or library.

Damage dealt

More recent research sheds light on the tendency that three out of five companies were subject to software supply chain attacks. In 2021, Only 38% of businesses claimed that they were unaffected by this attack. Not every attack is the same; some are big, while others are swiftly in the rearview mirror. Some of the High-profile Software attacks which took the internet off the storms were:

• Solarwinds (Dec 2020)

  Threat actors used the Orion software as a weapon to access several government networks and thousands of private systems worldwide, making the SolarWinds supply chain attack a worldwide hack. The US departments of health, treasury, and state were noteworthy victims of this attack.

• Codecov (April 2021)

  Attackers were able to insert a backdoor into Codecov to gain access to sensitive client data, which led to a recent large breach. Very skilled attackers used a flaw in how Codecov created Docker images to carry out this intrusion. They utilized this to alter a script that let them launch several attacks from a remote server using the environment variables from the CI of Codecov users.

• Microsoft’s Winget (May 2021)

  WinGet’s software registry was inundated with pull requests for applications that were either duplicates or misbehaved the weekend after launch. It was inundated with faulty or duplicate packets, which overwrote the already present ones.

• Kaseya (July 2021)

  Numerous managed security providers’ remote monitoring and management software platforms contained a zero-day vulnerability that a ransomware organization found and exploited. This incident encrypted the files of over 1,500 businesses.

• Log4j Vulnerability (Dec 2021)

  The flaw enables attackers to obtain remote access to Log4j-using apps. The vulnerability is in the communication mechanism, allowing an attacker to insert malicious code into the logs and have it run on the system.

And many more on the list.

Top Attack vectors

Many distinct attack vectors are utilized to compromise a software provider and successfully attack through the development pipeline. Attackers mainly concentrated their attacks on these points:

• Exploiting Open-Source applications flaws

  Most commercial software has open-source code. Two areas are the focus of vulnerable application supply chain assaults:

  • One is exploiting flaws in previously extensively installed and disseminated programs. E.g., Log4j vulnerability.
  • Including malicious code in well-known private and open-source packages to get automated pipeline tools to include them in the application build process. E.g., us-parser-js package poisoning.

• Compromised Pipeline tools and altered the build process

  The second attack method is the compromise of pipeline tools, which enables attackers to alter or introduce malicious code. The source code of an application, which serves as its blueprint as well as the development infrastructure and procedures, can be made public by a compromised CI/CD pipeline.

  At the same time, the program is being built (as was the case of SolarWinds). Additionally, the pipeline is coupled with dozens of external dependencies that can be utilized to access and launch attacks, like the Codecov attack.

• Manipulating the Code of Integrity

  Sensitive data in code, poor code quality, and security vulnerabilities were frequently observed in the environments of many of the customers. The submission of flawed code to source code repositories has been recognized as the third risk factor. This influences the security posture and artifact quality.

How can Codesigning help?

Code signing is a process to confirm the authenticity and originality of digital information, such as a piece of software code. It assures users that this digital information is valid and establishes the author’s legitimacy.

Code signing also ensures that this digital information has not changed or been revoked after it was validly signed. Code signing can assure double authentication, thwart attacks, and even avoid namespace conflicts as you share source code throughout the SDLC.

Best Practices

Here are a few code-signing best practices to guarantee the security of your application code.

• Securing all the private keys

  The loss, theft, or compromise of a code-signing private key poses a serious security risk. There are some simple rules we can follow to avoid the risk:

  • Restricting unauthorized access to the keys.
  • Implementing physical security control over the keys to limit the process.
  • Securing keys with cryptographic hardware items.

• Automating the signing process by Pipelines

  An end-to-end centralized approach to code signing procedures while enforcing security regulations is part of the automated code signing process. Without slowing down the SDLC, this automation approach connects with CI/CD pipelines and uses granular access control.

• Describe the roles, responsibilities, and procedures for approval.
• Integrating with existing environments and tools can make code signing quick and simple for the internal teams.
• Using time stamps to record all codesigning activities.

Conclusion

Your software supply chain is intricate, extensive, and interrelated, making it vulnerable to attacks. There have been a few devastating and small attacks in the past, and the future could be much better. Attackers have been using different attack vectors to target a specific side. The application of code signing is a crucial security-hardening technique.

Code signing ensures no tampering from unapproved parties and that the final published software is from the original publisher. By following certain code signing best practices, we can ensure that the Supply Chain attacks no longer threaten us.

For more information, you can contact us info@encryptionconsulting.com