bstrPrivateKeyFile

Character string that contains the name of the file that stores the private key which will be used to encrypt the Message Authentication Code (MAC). The method accepts private keys from files in any of the following formats:

Privacy Enhanced Mail (PEM)

Distinguished Encoding Rules (DER)

Public Key Cryptography Standard (PKCS) #8 PEM

PKCS#8 DER

PKCS#12

Use the parameter bstrPassword to specify the password if the private key is stored encrypted.