Sun Microsystems V2.0 manual Changing the owner of a Sun Spot, Sharing Sun SPOTs

Models: V2.0

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Even if you aren’t concerned about security, you need to be aware of this if you want to be able to use Sun SPOTs interchangeably amongst two or more SDK installations. See the section Sharing Sun SPOTs.

Changing the owner of a Sun SPOT

Once set, only the owner can change the public key remotely, although anyone who has physical access to the Sun SPOT can also change the public key. If user B wishes to use a Sun SPOT device previously owned by user A, they can become the new owner in one of two ways:

If user B does not have physical access to the device, user A can use the command

ant deletepublickey

to remove their public key from the Sun SPOT. User A can also use this procedure remotely, for example

ant deletepublickey -DremoteId=0014.4F01.0000.0006

User B can then deploy an application to the remote spot using a command like

ant deploy -DremoteId=0014.4F01.0000.0006

and will become the new owner automatically. During the time that the device has no owner (after user A has executed deletepublickey and before user B has executed deploy) the Sun SPOT will be exposed to attackers (a third user C could become its owner before user B). For this reason, if security is critical, we recommend replacing the public keys only via USB.

If user B has physical access to the device, they can connect the device via USB and execute

ant deploy

In both cases, if a customised library has been flashed to the Sun SPOT, it must be re-flashed by user B so that the library is signed using user B’s private key. This means that user B must also execute

ant flashlibrary

This command cannot be executed remotely. Note that this procedure is not necessary if the library has not been customised, as verification for the factory-installed library is handled differently.

Sharing Sun SPOTs

If you want to share Sun SPOTs between two or more SDK installations or users, you have to ensure that the SDK installations and users share the same key-pair. To do this, start by installing each SDK as normal. Then, copy the key-pair from one “master” user to each of the others. You can do this by copying the file sdk.key from the sunspotkeystore sub-directory of the “master” user’s home directory and replacing the corresponding file in each of the other user’s sunspotkeystore directories.

You then have to force the master’s public key onto each of the Sun SPOTs associated with the other installations. The simplest way to do this is to re-deploy the application via USB

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Sun Microsystems V2.0 manual Changing the owner of a Sun Spot, Sharing Sun SPOTs