Convert IIS SSL certificate to Apache

Source:  http://www.petefreitag.com/item/16.cfm

First Export your IIS certificate into a pfx file (this is something you should do anyways for backup)

• Run mmc.exe
• Click the 'Console' menu and then click 'Add/Remove? Snap-in'.
• Click the 'Add' button and then choose the 'certificates' snap-in and click on 'Add'.
• Select 'Computer Account' then click 'Next'.
• Select 'Local Computer' and then click 'OK'.
• Click 'Close' and then click 'OK'.
• Expand the menu for 'Certificates' and click on the 'Personal' folder.
• Right click on the certificate that you want to export and select 'All tasks' -> 'Export'.
• A wizard will appear. Make sure you check the box to include the private key and continue through with this wizard until you have a .PFX file.

Next run openssl to extract the private key, and the cert file

# Export the private key file from the pfx file
openssl pkcs12 -in filename.pfx -nocerts -out key.pem
# Export the certificate file from the pfx file
openssl pkcs12 -in filename.pfx -clcerts -nokeys -out cert.pem
# This removes the passphrase from the private key so Apache won't
# prompt you for your passphase when it starts
openssl rsa -in key.pem -out server.key