Certificate Signing Request
What is Certificate Signing Request?
A Certificate Signing Request, or CSR, is a file containing information about an entity and its public key that is sent to a certificate authority so a digital certificate can be issued.
Examples
- A web administrator generates a CSR for a company website and submits it to a certificate authority to obtain an HTTPS certificate.
- An organization creates a CSR for an internal server so it can receive a certificate trusted by the company's internal PKI.
Discover 🔎
Certificates do not appear out of nowhere. Before a certificate authority can issue a certificate, it needs a structured way to receive key information and identity details from the requester. That is the job of the Certificate Signing Request.
A CSR matters because it sits at a very important point in certificate-based trust. It is the formal request that says, in effect, “Here is the public key and identifying information that should be included in the certificate I am asking you to sign.” If that request is built correctly, the certificate process can move forward in a controlled way. If it is handled carelessly, the result may be delays, misissued certificates, or exposure of key material.
Summary 📝
A Certificate Signing Request is the structured request used to ask a certificate authority to issue a certificate. It contains the public key and identifying information for the subject, and it is signed with the matching private key to support the issuance process. The CSR is important because it connects secure key generation to trusted certificate creation without requiring the requester to expose the private key.
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