Definition – Certificate Signing Request (CSR)
CSR stands for Certificate Signing Request. It is a file generated by an entity (such as a website owner or server administrator) to request an SSL/TLS certificate from a Certificate Authority (CA). The CSR contains information about the entity requesting the certificate, including the domain name (common name), organization details, locality, and country. Additionally, the CSR includes a public key generated by the entity, which will be used to encrypt data and establish a secure connection with clients.
Here’s what a Certificate Signing Request (CSR) typically includes:
- Common Name (CN): The fully qualified domain name (FQDN) for which the SSL certificate will be issued (e.g., www.example.com).
- Organization (O): The legal name of the organization (company) requesting the SSL certificate.
- Organizational Unit (OU): (Optional) The department or division within the organization.
- Locality (L): The city or locality where the organization is located.
- State or Province (ST): The state or province where the organization is located.
- Country (C): The two-letter country code where the organization is located (e.g., US for United States, CA for Canada).
- Public Key: A cryptographic key pair consisting of a public key and a private key. The public key is included in the CSR and will be used by the CA to encrypt data sent to the server.
Summary – Certificate Signing Request (CSR)
The CSR is typically generated on the server where the SSL certificate will be installed. Once generated, the CSR is submitted to a CA, along with additional information required for certificate issuance (e.g., payment details, contact information). The CA uses the information in the CSR to verify the identity of the entity requesting the certificate and issue the SSL certificate.
It’s important to keep the private key associated with the CSR secure, as it is used to decrypt data encrypted with the public key. The private key should never be shared or exposed to unauthorized parties.
Useful Links
https://datatracker.ietf.org/doc/html/rfc5280
https://sanchitgurukul.com/basic-networking
https://sanchitgurukul.com/network-security
