SignExternal Method
Signs the document using an external signing facility.
Syntax
asicsigner.signExternal([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
Use this method to create an ASiC signature using an external signing facility for the cryptographic computations. SignExternal delegates the low-level signing operation to an external, remote, or custom signing engine. This method is useful if the signature has to be made by a device accessible through a custom or non-standard signing interface.
When all preparations are done and hash is computed, the class fires ExternalSign event which allows to pass the hash value for signing.