Securing data and ensuring the authenticity of websites are essential in today’s internet-driven world. SSL/TLS certificates play a critical role in this process. However, the concept of an SSL/TLS certificate chain is often misunderstood. In this article, we’ll break down what the SSL/TLS certificate chain is, why it’s important, and how it ensures a secure connection.
What Is the SSL/TLS Certificate Chain?
The SSL/TLS certificate chain, also known as the certificate chain of trust, is a hierarchical structure that links a website’s SSL/TLS certificate to a trusted root certificate authority (CA). The chain consists of three main components:
- Root Certificate: This is the top-level certificate issued by a trusted root CA. Root certificates are pre-installed in browsers and operating systems, making them inherently trusted by devices.
- Intermediate Certificate(s): These act as a bridge between the root certificate and the website’s SSL/TLS certificate. Intermediate certificates are used by CAs to issue SSL/TLS certificates securely without exposing the root certificate to unnecessary risk.
- Server Certificate: This is the SSL/TLS certificate installed on a website or application, which ensures that the connection between the server and the client is encrypted and authenticated
When a client (such as a browser) connects to a website, the server provides the certificate chain to verify its authenticity. The browser then checks each certificate in the chain to ensure it is valid and trusted, starting from the server certificate and working its way up to the root certificate.
How Does the SSL/TLS Certificate Chain Work?
Let’s walk through the process:
- Client Request: When a client initiates a connection to a secure website (HTTPS), the server responds by sending its SSL/TLS certificate along with any intermediate certificates.
- Chain Validation: The client validates the certificate chain by verifying each certificate against its issuer. The process continues until it reaches the root certificate.
- Trust Verification: If the root certificate is trusted (pre-installed in the client’s trust store) and all other certificates in the chain are valid, the connection is established securely.
How to check if certificate chain is correct ?
To check if the certificate chain is complete there’s a lot of different websites that have this tool. The one we recommend always its from SSLShopper, its simple and has more tools like check if certificate matches with private key.
https://www.sslshopper.com/ssl-checker.html
How to get full certificate chain?
To get all certificates and the correct order we recommend to use “What’s My Chain Cert?” its a simple website that we only need to write the name of the website or if its not avalable on interet we just need to upload the main certificate and the website will generate the full chain and downloads
