Password for X509 certificate

I need to sign and encrypt the message with X509 certificate. I saw the code you posted but what is the password parameter value ? Which password is that ? I have a private key and a public key from the SP. what should I put in for password?

If they dont have a password, you can pass a null value to that parameter. If a password is required, you may want to ask the provider. A password is usually required for a private key used to sign or encrypt SAML messages.