Sign Method
Signs the current message.
Syntax
sfilemailer.sign([callback])
Callback
The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).
The callback for this method is defined as:
function(err){ }
'err' is the error that occurred. If there was no error, then 'err' is 'null'.
'err' has 2 properties which hold detailed information:
err.code err.message
Remarks
This method digitally signs the input data with the certificate provided. Certificates are provided by specifying the Certificate property. The IncludeCertificate property allows you to specify whether to include the certificate when signing the message.