Generating a CSR for an S/MIME Personal certificate using OpenSSL

Openprovider’s SSL panel currently does not support generating a CSR for S/MIME Personal Certificates, which requires an email address in the ‘Common Name’ field. OpenSSL is a versatile command-line tool widely used across UNIX, Linux, BSD, and Windows systems for managing cryptographic operations. This guide outlines the steps to create a private key and CSR, essential for obtaining an email signing certificate (also known as an S/MIME or client certificate).

Prerequisites

• Ensure OpenSSL is installed on your system.
• Create a secure directory to store your private key and CSR files.
• Protect this directory to prevent unauthorized access.

Step-by-Step Instructions

1. Open the Terminal
   Launch the terminal application on your computer.
   
   
2. Generate the Private Key and CSR
   Execute the following command:

   openssl req -nodes -newkey rsa:2048 -keyout certificate.key -out certificate.csr
   

   
   This command creates a 2048-bit RSA private key (certificate.key) and a CSR (certificate.csr).
   
   
3. Provide Certificate Details
   You'll be prompted to enter the following information:
4. • • Country Name (2-letter code): e.g., NL
     • State or Province Name: e.g., Gelderland
     • Locality Name: e.g., Nijmegen
     • Organization Name: e.g., Your Company Name
     • Organizational Unit Name: e.g., IT Department
     • Common Name: Your Email address for which the S/MIME Personal certificate to be generated
     • Email Address: Contact point of the certificate owner e.g., john.doe@example.com
     • Challenge Password (Optional): (Leave blank)
     • Optional Company Name: (Leave blank)

• Review and Save the CSR
  The certificate.csr file is now created in your current directory. Open this file with a text editor and copy its entire contents, including the -----BEGIN CERTIFICATE REQUEST----- and -----END CERTIFICATE REQUEST----- lines.
  
  
• Submit the CSR
  Paste the copied CSR into the appropriate field during the certificate ordering process on your Openprovider SSL panel.
  
  After purchasing the certificate please refer https://openprovider.help/books/ssl-certificates/page/how-to-generate-public-key-pfx to generate a PFX certificate using OpenSSL to use with email client like outlook.
  
  
  Note: Always keep your private key (certificate.key) secure and never share it.