What is a CSR (Certificate Signing Request) and Why Do You Need It?
If you’re setting up an SSL/TLS certificate for a website or server, you’ll come across the term CSR (Certificate Signing Request). But what exactly is it, and why is it important?
In this guide, we’ll explain what it is, how it works, and why you need it to secure your website or server.
What is a CSR?
A Certificate Signing Request (CSR) is a special file that contains your website or server’s information and is used to request an SSL/TLS certificate from a Certificate Authority (CA) (such as Let’s Encrypt).
Think of a CSR as a digital application form for an SSL certificate. It contains important details about your domain and organization, including:
- Domain name (e.g., example.com)
- Company or organization name
- City and country
- Public key (used for encryption)
It does NOT contain the private key, which is kept secret and stored securely on your server.
Why Do You Need a CSR?
A Certificate Signing Request is required because it helps a Certificate Authority (CA) verify that you are the rightful owner of the domain or server before issuing an SSL certificate.
Without a CSR, a CA cannot generate a valid SSL certificate, which means:
- Your website won’t be encrypted with HTTPS.
- Your users’ data won’t be securely transmitted.
- Browsers will show a “Not Secure” warning for your site.
So, if you want to protect your website with HTTPS encryption, a Certificate Signing Request is the first step in getting an SSL certificate.
How Do You Generate It?
Generating a CSR depends on your server type, but the basic steps are:
- Use OpenSSL or a web hosting control panel (like cPanel) to generate a CSR.
- Provide the required details (domain name, organization, country, etc.).
- A private key and CSR file are created (store the private key safely!).
- Submit the CSR to a Certificate Authority (CA) when purchasing an SSL certificate.
Once the CA verifies your information, they will issue the SSL certificate, which you can install on your server.
Conclusion
A CSR (Certificate Signing Request) is a critical step in securing your website with SSL/TLS encryption. It’s used to request a valid SSL certificate from a trusted Certificate Authority, ensuring that your website is encrypted and protected with HTTPS. Without it, you can’t get an SSL certificate, meaning your website may be flagged as insecure by web browsers.