What is a TLS/SSL certificate?
SSL (Secure Sockets Layer) was the original technology for keeping internet connections secure and safeguarding the data that is exchanged between two machines. It has now been replaced by TLS (Transport Layer Security), which is an updated, more secure, version of SSL.
Both protocols rely on digital certificates to make sure communication between a user and a machine (or a machine and a machine) is encrypted and secure. TLS/SSL certificates verify the authenticity of machine identities to prevent cybercriminals from accessing or modifying information, such as sensitive personal data, that is sent across the internet.
How do TLS/SSL certificates create secure connections?
TLS/SSL certificates make sure that any data transferred over the internet (or within a network) remains impossible to read during transit. TLS certificates use encryption algorithms to scramble data in transit, preventing cybercriminals from reading it as it is sent over the connection.
To do this, a TLS/SSL connection is established though a handshake, which is a series of communications exchanges between the client and the server. Even though it has been simplified in TLS 1.3, the handshake process remains somewhat complex. Here are the basic steps that the TLS handshake follows.
- The client contacts the server and requests a secure connection. The server replies with the list of cipher suites that it knows how to use. A cipher suite is an algorithmic toolkit of creating encrypted connections. The client compares this list against its own list of supported cipher suites, selects one, and informs the server accordingly.
- The server then provides its TLS digital certificate, an electronic document issued by a third-party authority confirming the server's identity (more on this shortly after). This is where asymmetric encryption is employed since the SSL certificate contains the server's public key. Once the client receives the certificate, it confirms the certificate's authenticity.
- Using the server's public key, the client and server establish a session key that both will use for the rest of the session to encrypt communication using symmetric encryption. To establish the session key, the two parties use Diffie-Hellman key exchange.
However, if the back-and-forth communication of the TLS handshake fails between the server and the client, HTTPS won’t generate a secure connection, which will result in a TLS/SSL handshake failure.
Resolving TLS/SSL Connection Errors
Despite the prevalence of TLS handshake errors, the most common cause of a TLS/SSL connection error is an expired certificate, which will trigger a system or application outage. And chances are that if a certificate has expired, you weren’t tracking it properly. So, it may take considerable time and effort to identify an expired certificate as the problem, locate it, and replace it. These types of outages not only cause productivity downtime, but they can also consume valuable staffing resources that should be better deployed elsewhere.
To prevent TLS/SSL connection errors, such as outages, it’s important that your TLS certificates are properly configured. To make sure of that, you’ll need to know everything you can about these machine identities: how many certificates you’re using, when they expire, where they are installed, and which attributes they are configured for. Of course, there are many ways to check SSL certificates. But most of those efforts do not scale. For larger organizations using thousands of certificates, the use of a machine identity management platform becomes even more of a critical necessity.
As mentioned earlier, a TLS/SSL connection issue may be caused by a faulty TLS handshake. Here are some more common TLS handshake errors.
- Incorrect system time. The date and time of the client device are not correct.
- Browser error. Configuration of a browser is causing the error.
- Man-in-the-middle attack. The connection is manipulated or intercepted by a third-party.
- Protocol mismatches. The server doesn’t support the protocol used by the client.
- Cipher suite mismatch. The server doesn’t support the cipher suite used by the client.
- SNI-enabled server. SNI-enabled servers can’t communicate with the client or the name on the certificate doesn’t match with the hostname in the URL.
- Incorrect certificate. Incomplete or invalid certificate chain; or the SSL/TLS Certificate is expired or revoked.
In a pinch, you can you can try to quickly resolve TLS/SSL connection errors by using some of the following methods to troubleshoot TLS handshake issues.
- Check and change TLS protocols. You may also experience a TLS handshake error if the browser is configured for a specific TLS protocol, but the server only supports a different, probably later, protocol. You may need to disable older protocols to enable communication between the device and browser using a mutually supported protocol.
- Verify your server supports SNI. Server name indication (SNI) enables a server to securely host multiple TLS certificates and protocols for one IP address. SNI misconfiguration is one of the key causes of TLS issues. So, if the server isn’t SNI-enabled, it may cause a TLS handshake error because the server can’t recognize the certificate.
- Ensure that cipher suites match. TLS handshake errors can also be caused by mismatched cipher suites, which are used to secure TLS/SSL network connections. You’ll want to check your cipher suite configuration and if you find that they are weak, you’ll need to correct them by comparing them with your browser support.
- Make sure your browser’s configuration matches the latest TLS protocol. Sometimes a browser extension or security software on your device will intercept the TLS connections and cause a problematic TLS handshake. It could also be a virus or malware on the system causing the connection issues. To fix this problem, you may need to disable the security software or browser extensions or reset your browser.
- Update your system’s date and time. Because the system time helps to determine whether a certificate is valid or expired, a valid certificate will appear to be expired if there is a mismatch between your device’s time or date and that of the server. One way to fix the time and date is to set it to be automatic.
Managing the Growth of TLS/SSL Connections
Given the rapid growth of TLS/SSL connections, the occurrence of errors will continue to plague organizations like yours. Case in point, the average large enterprise will have three times the number of machine identities in 2024 as it does now. This translates to greater risk of outages, as well as security breaches and connection errors.
Given the exponential growth of machines and their increasingly transient nature, IT and security teams are discovering that the tools and strategies they are currently using are no match for managing millions of machine identities, particularly in hybrid and multi-cloud environments.
A comprehensive machine identity management program leverages automation to orchestrate the many actions necessary for securing machine identities throughout their lifecycles. Particularly in cloud native architectures, machine identity management that provides visibility and intelligence into all machine identities—no matter how ephemeral—and the automation to ensure that machine identities adhere to corporate security policies that govern TLS/SSL connections.
Here are some best practices for effective TLS machine identity management.
- Locate all your machine identities. Getting a list of all your machine identities and knowing where they’re all installed, who owns them, and how they’re used is the first step in effectively managing them.
- Set up and enforce security policies. To keep your machine identities safe, you need to set up corporate policies and best practices to govern these critical security assets.
- Continuously gather machine identity intelligence. Because the number and type of machines on your network are constantly changing, you need an ongoing program to update intelligence on your machine identities.
- Automate the machine identity lifecycle. Automating the entire machine identity life cycle helps you to avoid error-prone, resource-intensive manual actions, while improving operations and security.
- Validate correct installation and configuration. Validation ensures that machine identities are installed properly and working correctly.
- Monitor for anomalous use. Monitoring and flagging anomalous behavior, which can indicate a machine identity compromise.
- Set up notifications and alerts. The ability to find and evaluate potential machine identity issues before they become business interruptions or exposures is critical.
- Remediate machine identities that don’t conform to policy. Automated, intelligence-driven action allows you to quickly address all compliance issues.
- Use a certificate service to deliver machine identities. Providing end-users with an easy way to access machine identities allows you to quickly deliver secure, policy-enforced machine identities to all business units.
Secure communication between machines is essential to the success of every enterprise. But how do you keep TLS/SSL connections secure when their machine identities are added and changed every day? Venafi can help you build your own Transport Layer Security (TLS) machine identity management program to protect all the machine identities you’re using today and position you to keep up with the growing number of machines your enterprise will need moving forward.