TLS/SSL certificates ensure that data transmitted over the internet or within a network is unreadable during its journey. Through encryption algorithms, TLS certificates encrypt data as it travels, thwarting any attempts by cybercriminals to intercept and read the information as it moves across the network.
To achieve this, a TLS/SSL connection is initiated via a handshake, involving a sequence of communication exchanges between the client and the server. Although TLS 1.3 has simplified this process, the handshake protocol still involves several intricate steps. Here is an overview of the basic stages in the TLS handshake:
- The client initiates contact with the server to establish a secure connection. In response, the server sends a list of cipher suites it supports, each suite representing a set of algorithms used to create encrypted connections. The client then compares this list with its own supported cipher suites, chooses the most suitable one, and notifies the server of its selection.
- Next, the server provides its TLS certificate, which is an electronic document certified by a third-party authority that verifies the server’s identity. This step uses asymmetric encryption, as the SSL certificate includes the server’s public key. Upon receiving the certificate, the client proceeds to verify the authenticity of the certificate.
- With the server’s public key, the client and server collaboratively generate a session key that they will both use for symmetric encryption throughout their communication session. This session key is established through the Diffie-Hellman key exchange method, allowing both parties to securely encrypt their communications.
If the exchange of messages during the TLS handshake between the server and the client is unsuccessful, HTTPS will not be able to establish a secure connection, leading to a TLS/SSL handshake failure.
Resolving TLS/SSL Connections 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.
If you’re facing TLS/SSL connection errors, here are some quick troubleshooting methods to resolve TLS handshake issues:
- Verify and adjust TLS protocols: Ensure your browser’s configured TLS protocol aligns with the server’s supported protocol. Disabling older protocols may be necessary to establish communication with a mutually supported protocol.
- Confirm server SNI support: Server Name Indication (SNI) allows hosting multiple TLS certificates and protocols for one IP address securely. Misconfigured SNI settings can lead to TLS handshake errors as the server fails to recognize the certificate.
- Match cipher suites: TLS handshake errors can stem from mismatched cipher suites used for securing network connections. Review your cipher suite configuration and update any weak suites to match browser support.
- Align browser configuration with the latest TLS protocol: Browser extensions or security software might intercept TLS connections, causing handshake issues. Viruses or malware can also disrupt connections. To resolve this, consider disabling security software, browser extensions, or resetting the browser.
- Update system date and time: System time determines certificate validity, leading to certificate expiration errors if there’s a mismatch between device and server time. Set your system time to automatic to ensure accuracy and resolve this issue.
Learn more about machine identity security, and how it can benefit your organization!
