User's Manual

5.6 Remote control

The remote control feature and in the case in point the possibility to read from and write on the WebIdentity token

memory is carried out with simple calls to the server ActiveX methods for creating the desired command and with the

call of a client ActiveX method for the actual execution of the requested command. The command and all the necessary

information for execution are encapsulated inside an encrypted string by the server ActiveX and decrypted and executed

by the client ActiveX. The response containing the command status and all that concerns the result is encapsulated into

a string encrypted by the client ActiveX and decrypted and controlled by the server ActiveX subsequently.

The commands that it is possible to execute on the token are the synchronization between the server and the token, the

reading of the remote token memory and the writing into the remote token memory.

5.6.1 Synchronize Command

A counter has been introduced for preventing write commands from being reused on the key, as they might be

contained in scripts that are locally stored on the computer. This counter is incremented at each reading on the token

and it is necessary to state the value subsequent to the current one at each writing attempt. The Synchronize command

enables synchronizing such a value, that is, knowing which number will be associated during the next writing into the

memory. During the authentication phase, in addition to the authentication itself the writing counter is also

synchronized, therefore it should not be necessary to use the Synchronize command explicitly unless in case of special

needs.

The response of the synchronize command is an object containing the value of the progressive content on the remote

token.

5.6.2 Read Command

The Read command enables reading from the remote token the full memory area or a specific memory area. The

available memory on the token is about 8 KB. In the read command the start position of the reading and the length of

readable data is indicated.

The response of the read command is an object containing the operation result, the initial position of said data, the

length of the read data and the read data themselves.

5.6.3 Write Command

The Write command enables writing on the remote token the full memory area or a specific memory area. For security

reasons a progressive counter is used for writing management; it prevents the repeated execution of the same command.

In the write command the value subsequent to the current progressive value is specified, as well as the start position for

writing, the writable data length and the data themselves.

The write command response is an object containing the result of the operation with the counter value for any

subsequent writing operation.

All commands and information exchanged between the client and the server are encrypted with Blowfish following the

same procedure that is described under section Errore. L'origine riferimento non è stata trovata..