There’s a saying, “where there’s smoke, there’s fire.” This adage holds especially true in the context of WebPKI Certificate Authorities (CAs). Patterns of issues are one of the key tools that root programs use to understand what’s happening inside organizations. While audits are essential, they are often insufficient. Historical cases like Wirecard and Enron illustrate how audits can provide a partial and sometimes incorrect picture. Just as in most interactions in life, understanding who you are dealing with is crucial for successful navigation, especially when a power dynamic differential exists.

The Limitations of Audits

Currently, there are 86 organizations in the Microsoft root program. Most root programs have at most two people involved in monitoring and policing these 86 CAs. Technologies like Certificate Transparency make this possible, and open-source tools like Zlint and others use this data to find technically observable issues. However, these tools, combined with audits, only provide a small slice of the picture. Audits are backward-looking, not forward-looking. To understand where an organization is going, you need to understand how they operate and how focused they are on meeting their obligations.

This is where the nuanced side of root program management, the standards, and norms of the ecosystem, come into play. If we look at signals in isolation, they often appear trivial. However, when we examine them over a long enough period in the context of their neighboring signals, a more complete picture becomes apparent.

For example, consider a CA with minor compliance issues that seem trivial in isolation. A single misissued certificate might not seem alarming. But when you see a pattern of such incidents over time, combined with other issues like poor incident response or associations with controversial entities, the picture becomes clearer. These patterns reveal deeper issues within the organization, indicating potential systemic problems.

Root Program Challenges

Root programs face significant challenges in managing and monitoring numerous CAs. With limited personnel and resources, they rely heavily on technology and community vigilance. Certificate Transparency logs and tools like Zlint help identify and flag issues, but they are only part of the solution. Understanding the intentions and operational integrity of CAs requires a deeper dive into their practices and behaviors.

In the WebPKI ecosystem, context is everything. Root programs must consider the broader picture, evaluating CAs not just on isolated incidents but on their overall track record. This involves looking at how CAs handle their responsibilities, their commitment to security standards, and their transparency with the community. A CA that consistently falls short in these areas, even in seemingly minor ways, can pose a significant risk to the ecosystem.

Conclusion

Understanding the nuances of CA operations and focusing on their adherence to obligations is critical. By examining patterns over time and considering the broader context, root programs can better identify and address potential risks. The combination of audits, technological tools, and a keen understanding of organizational behavior forms a more comprehensive approach to maintaining trust in the WebPKI system.

It’s always important to remember that CAs need to be careful to keep this in mind. After all, it’s not just what you do, but what you think you do. Having your house in order is essential. By learning from past mistakes and focusing on continuous improvement, organizations can navigate public reporting obligations more effectively, ensuring they emerge stronger and more resilient.

Browser distrust events of WebPKI Certificate Authorities occur on average approximately every 1.23 years. These events highlight the critical role the WebPKI plays in maintaining secure communications on the internet and how failures within this system can have far-reaching implications. By examining these incidents, we can identify common patterns and underlying causes that lead to distrust, so as implementors and operators, we don’t end up repeating the same mistakes.

Identifying Common Patterns

As they say, those who don’t know history are destined to repeat it, so it is worthwhile to take a look at the history of CA distrust events to understand what, if any common patterns exist:

• Security Breaches: Involves unauthorized access to the CA’s infrastructure, leading to potential misuse of certificate issuance capabilities.
• Compromise of CA Infrastructure: Refers to breaches where the core infrastructure of the CA is compromised, resulting in unauthorized certificate issuance.
• Fraudulent Certificates: Occurs when certificates are issued without proper authorization, often leading to the impersonation of legitimate websites.
• Poor Incident Response Handling: Indicates that the CA failed to adequately respond to security incidents, exacerbating the impact of the initial problem.
• Misissuance of Certificates: Happens when CAs issue certificates incorrectly, either to the wrong entities or without proper validation, undermining trust.
• Facilitating Man-In-The-Middle Attacks: Refers to situations where misissued or improperly handled certificates enable attackers to intercept and alter communications.
• Improper Practices: Includes actions by CAs that deviate from accepted standards and best practices, leading to security risks.
• Deceptive Actions: Involves deliberate misleading actions by CAs, such as backdating certificates or other forms of dishonesty.
• Insecure Practices: Encompasses practices by CAs that fail to maintain adequate security controls, leading to vulnerabilities.
• Non-Compliance with Industry Standards: Indicates that the CA has repeatedly failed to adhere to industry standards and guidelines, leading to a loss of trust.
• Ties to Controversial Entities: Involves associations with entities that raise ethical or security concerns, leading to distrust.
• Limited Value to Ecosystem: Indicates that the CA does not provide significant value to the security ecosystem, often due to questionable practices or minimal compliance.
• Operational Vulnerabilities: Refers to weaknesses in the CA’s operational security, such as using default passwords or having exposed administrative tools, making them susceptible to attacks.

Browser Distrust Events

1. DigiNotar (2011):
   • Event: DigiNotar was hacked, leading to the issuance of fraudulent certificates. This prompted Mozilla, Google, and Microsoft to revoke trust in DigiNotar certificates.
   • Labels: Security Breaches, Compromise of CA Infrastructure, Fraudulent Certificates, Poor Incident Response Handling
   • Details: Mozilla Security Blog, Threatpost
2. TurkTrust (2013):
   • Event: It was discovered that TurkTrust mistakenly issued two intermediate CA certificates, one of which was used to issue a fraudulent certificate for *.google.com. This led to the distrust of the TurkTrust CA by major browsers.
   • Labels: Misissuance of Certificates, Facilitating Man-In-The-Middle Attacks
   • Details: Krebs on Security
3. ANSSI (French CA) (2013):
   • Event: It was discovered that ANSSI had issued a certificate to a network appliance company, which used it to inspect encrypted traffic. This led Google to revoke trust in the intermediate certificate.
   • Labels: Misissuance of Certificates, Facilitating Man-In-The-Middle Attacks
   • Details: Google Security Blog, Mozilla Blog
4. CNNIC (China Internet Network Information Center) (2015):
   • Event: CNNIC was distrusted after it issued an intermediate certificate to MCS Holdings, which misused it to issue unauthorized certificates.
   • Labels: Misissuance of Certificates, Facilitating Man-In-The-Middle Attacks, Improper Practices
   • Details: Tom’s Hardware, Mozilla Security Blog, Mozilla Security Blog
5. WoSign and StartCom (2016):
   • Event: WoSign (and StartCom) were distrusted after discovering multiple security issues, including backdating certificates, lying, and improper issuance.
   • Labels: Misissuance of Certificates, Deceptive Actions, Insecure Practices
   • Details: Tom’s Hardware, Google Security Blog
6. Symantec (2017):
   • Event: Google announced a gradual distrust of Symantec certificates due to numerous instances of certificate misissuance, impacting millions of websites.
   • Labels: Misissuance of Certificates, Non-Compliance with Industry Standards, Poor Incident Response Handling
   • Details: Bleeping Computer, Google Security Blog
7. Certinomis (2019):
   • Event: Mozilla distrusted Certinomis due to numerous incidents of misissuance and poor handling of security concerns.
   • Labels: Misissuance of Certificates, Facilitating Man-In-The-Middle Attacks
   • Details: Venafi Blog
8. PROCERT (2020):
   • Event: Mozilla distrusted Procert due to numerous incidents of misissuance and poor handling of security concerns.
   • Labels: Non-Compliance with Industry Standards, Poor Incident Response Handling
   • Details: Venafi Blog
9. TrustCor (2022):
   • Event: TrustCor was distrusted due to concerns about its ties to companies linked to the US intelligence community and its failure to provide satisfactory responses to these concerns.
   • Labels: Ties to Controversial Entities, Limited Value to Ecosystem
   • Details: gHacks, SSLs.com, SSL Shopper
10. Camerfirma (2021):
    • Event: Mozilla and Google removed trust in Camerfirma due to a series of compliance issues and failure to maintain industry standards.
    • Labels: Non-Compliance with Industry Standards, Poor Incident Response Handling
    • Details: The Register
11. Visa (2022):
    • Event: Issues include incomplete security audits that are required according to the
    • Labels: Non-Compliance with Industry Standards, Poor Incident Response Handling
    • Details: Feisty Duck
12. e-Tugra (2023):
    • Event: e-Tugra was distrusted due to security concerns. A researcher found numerous vulnerabilities in e-Tugra’s systems, including default passwords and accessible administrative tools, leading to a loss of trust.
    • Labels: Operational Vulnerabilities, Insecure Practices, Poor Incident Response Handling
    • Details: Sectigo, GitHub, Ian Carroll’s Blog
13. Ecommerce CA (EU) (2024):
    • Event: The Ecommerce CA in the EU faced browser distrust due to various security and compliance issues, leading to its removal from trusted lists.
    • Labels: Non-Compliance with Industry Standards, Operational Vulnerabilities, Poor Incident Response Handling
    • Details: EuroCommerce, Ecommerce Europe
14. Entrust (2024):
    • Event: The Chrome Security Team announced the distrust of several Entrust roots due to a pattern of compliance failures and unmet improvement commitments.
    • Labels: Non-Compliance with Industry Standards, Poor Incident Response Handling
    • Details: Google Security Blog

Conclusion

The frequency and patterns of browser distrust events underscore the critical importance of preventive measures, transparency, and effective incident response.

Implementing robust security practices, conducting regular audits, and maintaining compliance with industry standards can significantly reduce the risk of such incidents. Transparency in operations and public disclosure of security issues foster an environment of accountability and trust.

An ounce of prevention is indeed worth more than a pound of cure. By focusing on proactive measures and cultivating a culture of continuous improvement, Certificate Authorities can better navigate the complexities of WebPKI. Effective crisis communication and incident response plans are essential for managing the fallout from security breaches and maintaining the trust of users and the broader web community.

By learning from past incidents and addressing their root causes, we can work towards a more secure and resilient internet, where trust in the WebPKI system is consistently upheld. The collective effort of CAs, browser vendors, and security researchers will play a pivotal role in achieving this goal, ensuring the integrity and reliability of our online ecosystem.

When it comes to workload and service credential management, a common misconception is that you can simply reuse your existing Certificate Authority (CA) and Certificate Lifecycle Management (CLM) infrastructure to achieve your desired end-state more quickly. Given that nearly every organization has client and server TLS certificates for devices and web servers and many have made significant investments in managing and issuing these certificates, this notion seems logical. However, the design constraints of these use cases differ significantly. The transition from static to dynamic environments, along with the associated credential governance problems, makes it clear that a purpose-built approach is necessary for managing workload and service credentials.

The Static Nature of Traditional CA and CLM Infrastructure

Traditional CA and CLM infrastructure primarily deals with TLS server certificates, where the identities involved are usually domain names or IP addresses. These identifiers are largely static, pre-defined, and managed out-of-band. As a result, the lifecycle of these certificates, which includes issuance, renewal, and revocation, follows a relatively predictable pattern. These certificates are usually issued for validity periods ranging from 90 days to a year, and the processes and infrastructure are designed to handle these constraints. However, use cases surrounding workload and service credentials have a totally different set of constraints, given the highly dynamic environment and various regulatory frameworks they must adhere to.

The Dynamic Nature of Workloads and Services

Workloads and services operate in a significantly different environment. These identities often come and go as services scale up or down or undergo updates. The sheer scale at which workload and service credentials are issued and managed can be hundreds of times greater than that of traditional client and server TLS certificate use cases.

Unlike the static domain names or IP addresses used in these traditional TLS certificates, the identifiers for workloads and services are dynamically assigned as workloads spin up and down or are updated. Workload and service credentials often have a much shorter lifespan compared to server certificates. They might need to be reissued every few minutes or hours, depending on the nature of the workload and the policies of the environment. This changes the expectations of the availability and scalability of the issuing infrastructure, leading to a need for credentials to be issued as close to the workload as possible to ensure issuance doesn’t become a source of downtime.

These workloads and services are also often deployed in clusters across various geographic locations to ensure fault tolerance and scalability. Unlike server certificates that can rely on a centralized CA, workload and service credentials often need a more distributed approach to minimize latency and meet performance requirements.

Another critical difference lies in the scope of trust. For TLS client and server certificates, the security domain is essentially defined by a root certificate or the corresponding root store. However, in the context of workloads and services, the goal is to achieve least privilege. This often necessitates a much more complicated PKI to deliver on this least-privileged design.

Additionally, federation is often needed in these use cases, and it is usually not possible to standardize on just X.509. For example, you might need to interoperate with a service that works based on OAuth. Even in such cases, you want to manage all of this within one common framework to have unified control and visibility regardless of the technology used for the deployment.

Purpose-Built Solutions for Workload and Service Credential Management

Given the unique challenges of managing workload and service credentials in dynamic, cloud-native environments, existing CA and CLM investments often fall short. Purpose-built solutions, such as those based on SPIFFE (Secure Production Identity Framework for Everyone), tend to offer a more effective approach by providing dynamic, attested identities tailored for these environments.

Dynamic Identifier Assignment

Unlike static identifiers managed by traditional CLM solutions, SPIFFE dynamically assigns identifiers as workloads spin up and down, aligning with the nature of modern cloud environments.

Decentralized Issuance

By issuing credentials as close to the workload as possible, SPIFFE-based solutions reduce latency and align issuance with the availability goals of these deployments, ensuring that credentials are issued and managed efficiently without becoming a source of downtime.

Granular Policy Enforcement

SPIFFE-based solutions enable enforcing fine-grained policy through its namespacing and security domain concepts. This enables organizations to define and enforce policies at a more granular level, ensuring that workloads only access the necessary resources.

Identity Governance and Federation

SPIFFE-based solutions tend to support extending existing identity governance programs to workload and service credentials while also facilitating seamless and secure access to external services across different trust domains.

Multifactor Authentication

These SPIFFE-based solutions also provide support for attestation, which can be thought of as multi-factor authentication for workloads. This attestation verifies the workload and services’ running state and environment, tying the credentials to those environments and helping minimize the risks of credential theft.

Integration with Other Systems and Protocols

These environments can seldom rely exclusively on just X.509, which is why SPIFFE supports both X.509 and JWT formats of credentials. This flexibility allows seamless integration with various systems and protocols within cloud deployments.

Conclusion

While it might be tempting to reuse existing CA and CLM infrastructure for workload and service credential management, this approach fails to address the unique challenges posed by dynamic, cloud-native environments. The ephemeral nature of workload identities, the high frequency of credential issuance, and the need for granular trust domains necessitate purpose-built solutions like those based on SPIFFE.

These purpose-built systems are designed to handle the dynamic nature of modern environments, providing strong, attested identities and ensuring that credential management aligns with the evolving needs of cloud-native workloads. Understanding these distinctions is crucial for developing an effective identity management strategy for modern workloads and services without having to go through a reset event down the line.

To learn more about effective machine identity management, check out SPIRL and see how they are leading the way.

If we examine the contents of most secret management solutions, like HashiCorp Vault, we will find that we primarily store the logical equivalent of user IDs and passwords for services, workloads, and machines. Much like the old-school practice of writing passwords on post-it notes and sharing them, these secrets are then distributed to whatever entity needs access to the protected resource. As a result, it is no surprise that we encounter the same problems as password management: weak secrets, shared secrets, and stolen secrets. This is why we see machine credentials and keys being stolen in events like STORM 0558.

Secret Management: A Machine-Scale Password Management

Secret management can be seen as password management at a machine scale. These systems centralize secrets  (e.g., API keys, tokens, and passwords) to manage their sprawl and then make it easy to pass these shared secrets around various services and applications. However, just as simple passwords alone are seen as insufficient for user authentication—necessitating the adoption of multi-factor authentication (MFA) and migration to non-password authenticators like Passkeys—the same shortcomings apply to this legacy approach to managing these credentials.

The reality is that these secret managers were designed to address the symptoms rather than the root cause of secret sprawl. By storing and distributing these static secrets without treating them as credentials to be managed, you centralize the chaos but do not solve the fundamental problem: the need for robust, scalable machine identity management. Machines, services, and workloads, much like users credentials, require purpose-built approaches. Just as we have applied multi-factor authentication, identity governance and administration (IGA) and solutions like OKTA to user management, we need analogous systems for machines.

Credential Management for Machines

At machine and workload scale, credential management solutions need to be architected differently to handle the dynamic nature of modern cloud environments. This is where purpose-built solutions come into play. These solutions must address the unique challenges of credential management in dynamic, cloud-native environments. Unlike secret management, which often relies on static secrets, credential management provides dynamic, attested identities for workloads. For example, SPIFFE (Secure Production Identity Framework for Everyone) offers a strategy for managing dynamic identities, providing the foundation for standards-based, scalable, and robust workload identity management.

Higher-Level Concepts in Workload Credential Management:

1. Provisioning and Deprovisioning:
   • Efficiently creating, updating, and removing machine identities as services start, stop, and scale.
2. Role-Based Access Control (RBAC):
   • Assigning access rights based on predefined roles, ensuring that machines and services have appropriate permissions.
3. Periodic Reviews:
   • Conducting regular reviews of machine access rights to ensure compliance and appropriateness.
4. Policy Enforcement:
   • Defining and enforcing access control policies, ensuring that machines and services adhere to security guidelines.
5. Audit and Reporting:
   • Generating comprehensive reports to demonstrate compliance with regulatory requirements and internal policies.
6. Risk Analysis:
   • Identifying and mitigating risks associated with machine identities and their entitlements.
7. Behavioral Analysis:
   • Monitoring machine behavior to detect anomalies and potential security threats.

Just as legacy approaches to secret management fail for workloads, machines, and services, these legacy IGA approaches will not work either. We need built-for-purpose solutions to adapt and not repeat the mistakes of the past. Those solutions will look like credential management systems that enable these functions as a byproduct of how they work, rather than bolting them onto an existing secret management or IGA process. 

This is why I have been an advisor to SPIRL since its founding. The founders, Evan and Eli, are why I knew I had to be involved. As the authors of the standard and having had real production-at-scale experience with SPIFFE, I knew they had what it took, which is why I have been working with them in a more formal capacity as of this last month. They are building the infrastructure that makes, as I like to say, the right thing the easy thing, ensuring their customers don’t repeat the mistakes of the past when it comes to workload and service identity.

Conclusion

Secret management tools were a necessary step in addressing the sprawl of machine secrets, and they will continue to be needed. However, as the complexity and scale of cloud environments grow, so does the need for more sophisticated solutions for workload and service credentials. Credential management systems provide the dynamic, robust framework required for modern machine identity management.

By adopting credential management as the primary approach and using secret management as the exception, organizations can achieve greater security, scalability, and operational efficiency in their cloud-native architectures. To learn more about effective machine identity management, check out SPIRL and see how they are leading the way.

Every service should strive to provide perfect availability, the reality is that it’s not possible to be perfect. Mistakes happen, it’s how you deal with them that is important.

Successfully dealing with availability issues requires planning, and when dealing with a client-server solution, it requires both parties to make improvements.

In the context of ACME today the large majority of clients have no failover or logic. This means if the enrollment fails due to connectivity issues to the specified CA, the CA has an outage, or the CA suspends operations for one reason or another the enrollment will fail.

This is a problem for any service protected with TLS, which is basically every service, that wants to have a highly available service. One of the ways services deal with this is to proactively acquire two certificates for every endpoint, this is viable, but I would argue this is not the right solution.

The right solution is to not rely on a single CA and instead failover between many CAs that are capable of servicing your needs. This way if any single CA fails you are fine, you can just keep chugging along.

That is not sufficient to address this risk though. Not all certificates have the same level of device trust. Sometimes clients make bad assumptions and trust specific CA hierarchies assuming these configurations are static, even when they are not.

To help mitigate this behavior clients should implement a round-robin or random CA selection logic so that subsequent renewals will hit different CAs. This will force clients to make sure they work with any of your chosen CAs. This way you won’t find yourself breaking apps that make those bad assumptions when your CA fails.

Caddy Server already implements both of these strategies as I understand it but every ACME client should be doing the same thing.

My father always says it’s not a problem to make a mistake, what is important is how you deal with it. 

The same thing is true when it comes to WebPKI CAs, broadly the incident response process used in this ecosystem could be categorized as Blameless Post Mortem. The focus is on what happened, what contributed to it, and what was done to address the issue and not on fault.

A few years ago a number of large CAs had to do millions of revocations, in all of the cases I am thinking the required deadline for those revocations was 5 days. Revoking a large number of certificates that are not directly obvious but if you’re a CA who has done any moderate level of planning it’s something you should be up for.

The thing is that doing so can cause harm, for example, the issue that necessitates the revocation might be incredibly subtle and not security-impacting. Nonetheless, the requirement is what the requirement is — the certificate needs to be revoked.

The question then becomes how can you meet that timeline objective without creating an unnecessary outage for customers? If you defy the rules you risk being distrusted, if you act blindly you could take down your customer’s services.

The question then becomes how do you contact millions of customers and give them enough time to replace their certificates without an outage with these constraints?

Like most scale problems the answer is automation, in the context of certificate lifecycle management that means an extension to the ACME protocol. To that end, there is now a draft for something called “ACME Renewal Information” which when implemented by CAs and ACME clients will enable a CA to signal that there may be a need to replace their certificate earlier than expected.

The basic idea with this proposal is that the CA will make available hints on when it would like certificates to be updated and the client will periodically check this information and use it to guide its renewal behavior.

To be clear, this is just a hint, a CA might be providing this hint just to smooth out the load, but there is no mandate to rely on the hint. With that said I do hope that all major ACME clients implement this standard and respect it by default because it will make the WebPKI a lot less fragile.