Gets a key's information and public key.
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:
'err' is the error that occurred. If there was no error, then 'err' is 'null'.
'err' has 2 properties which hold detailed information:
This method gets the information, including the public key, for the key specified by KeyName. The VersionId configuration setting can be used to target a specific key version. Alternatively, the GetDeleted configuration setting can be enabled to get a soft-deleted key's information (but only for the last version).
When the information is returned, the class clears the Key* properties and repopulates them with a single item that contains the key's information, and repopulates the Tag* properties with the key's tags. The KeyList event is also fired.