Creating a Certificate Signing Request (CSR) using the Keychain Access application on macOS is a straightforward process. Below, we'll guide you through each step to generate your CSR and save it securely.

Introduction

A Certificate Signing Request (CSR) is essential for obtaining an SSL/TLS certificate from a Certificate Authority (CA). This request is typically used when applying for a server or domain-level certificate. Using Keychain Access, you can create a CSR and manage your cryptographic keys.

Steps to Create a CSR

1. Open Keychain Access

• Launch the Keychain Access application on your macOS device.
• If you don't have it installed, you can download it from the Apple App Store or Mac App Store.

2. Select the Category

• In the main window of Keychain Access, select the category that matches your needs:
  • Identity: For user or client authentication.
  • Server: For SSL/TLS server certificates.
  • Email: For email certificates.
  • Other My Cards: For custom purposes.

3. Create a New Item

• Click on the + button in the bottom-left corner to add a new item.
• In the window that appears:
  • Name: Enter a name for your CSR (e.g., "My Domain").
  • Kind: Select "Certificate Signing Request."
  • User ID: Provide your user ID or leave it blank if you don't have one.

4. Set Preferences

• Click on the Preferences button in the top-right corner to access advanced options.
• Under Key Pair, choose a key size and algorithm:
  • Key Size: 2048 bits is recommended for most cases.
  • Algorithm: RSA is typically used for SSL/TLS certificates.

5. Generate the CSR

• Click Continue to proceed.
• If you want to specify additional information, fill in the fields provided.
• After setting your preferences, click Generate to create the CSR.

6. Save Your CSR

• The system will prompt you to save the file.
• Name your file with a .certSigningRequest extension (e.g., "My Domain.certSigningRequest").
• Choose a location to save it and click Save.

7. Verify Your Private Key

• After generating the CSR, your private key is created simultaneously.
• To locate your private key:
  • Open Keychain Access and select All Items from the Category menu.
  • Use the search bar to find your domain name.
  • Your private key will appear in the list.

8. Use the CSR

• Open the saved .certSigningRequest file with a text editor (e.g., TextEdit).
• Copy the content of this file to use it when applying for your SSL/TLS certificate.

Notes

• File Naming: Ensure your CSR file ends with .certSigningRequest.
• Wildcard Domains: If you're applying for a wildcard SSL, prepend your domain with an asterisk (e.g., *.example.com).
• Key Pair: The same key pair is used for both the CSR and the private key.

Conclusion

By following these steps, you've successfully created a Certificate Signing Request using Keychain Access. This request allows you to apply for SSL/TLS certificates from trusted Certificate Authorities, enabling secure communication for your domain or server.