Windows CA issued certificate

This is a short step-by-step on how to import or generate a key on a YubiKey, create a certificate request, submit that request to a Windows CA and then load the certificate on the YubiKey. As an alternative, it also instructs you how to import a private key and certificate from a .pfx file for use on a YubiKey.

Prerequisites

  • a YubiKey with the PIV application loaded

  • the yubico-piv-tool software

  • credentials to request certs from a Windows CA

Request and load a certificate from Windows CA

  1. Import or generate the key in slot 9a:

    1. Import a key:

      yubico-piv-tool -s 9a -a import-key -i key.pem
      
    2. Generate a key:

      yubico-piv-tool -s 9a -a generate -o public.pem
      
  2. Request a certificate:

    yubico-piv-tool -a verify-pin -P 123456 -s 9a -a request-certificate \
    -S "/CN=example/O=test/" -i public.pem -o request.csr
    
  3. Submit the request to the Windows CA: (this step must be run on a windows machine that know about the CA)

    certreq -submit -attrib "CertificateTemplate:User" request.csr cert.crt
    
  4. Load the certificate on the YubiKe: (--key[=STRING] is needed if the management key value is not the default value)

    yubico-piv-tool -s 9a -a import-certificate -i cert.crt --key[=STRING]
    
  5. For it to be useful in windows a chuid must be set as well: (only if that wasn’t done earlier) (--key[=STRING] is needed if the management key value is no longer the default value)

    yubico-piv-tool -a set-chuid --key[=STRING]
    

Import a key and certificate from a .pfx file

  1. Both the key and certificate can be imported with a single command (for slot 9a): When prompted, enter the password for the .pfx file. (--key[=STRING] is needed if the management key value is no longer the default value)

    yubico-piv-tool -s 9a -i myfile.pfx -K PKCS12 -a import-key -a import-cert --key[=STRING]
    Enter Password:
    Successfully imported a new private key.
    Successfully imported a new certificate.