A CSR (Certificate Signing Request) is required to validate the information the certification authority (CA) needs to issue a certificate. It contains the public key and information about your organization.
If you need a CSR to issue a certificate to secure your IIS server, you can follow these instructions.
1 - mmc.exe
Open the Microsoft Management Console by typing the following in Windows Search:
mmc.exe
2 - Add snap-in
Click "File" -> "Add/Remove Snap-in...".
Then, add the "Certificates" snap-in to the list of "Selected snap-ins" and click "OK".
3 - Custom request
Now right-click on the "Personal" folder and select "All Tasks" -> "Advanced Operations" -> "Create Custom Request...".
A new window will open. Click "Next".
Click "Next" again.
Select PKCS #10 and click "Next" again.
Expand "Details" and click "Properties".
Specify the certificate friendly name.
Enter all information relevant to the certificate under the "Subject" tab.
ATTENTION: For "C" or "Country" the 2-digit ISO code must be used (e.g. AT, DE)
In the "Private Key" tab, under "Key options," select the key size "4096" and under "Select Hash Algorithm," select the value "sha256."
Optional: Check "Make private key exportable" so you can export the private key later if needed.
3 - Conclusion
Close the window with "OK" and save the CSR file to any location using the ".req" format.
The CSR has now been successfully created and can be used to issue an SSL certificate.