Indy-SDK Developer Walkthrough #2, Java Edition
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Setup your workstation with an indy development virtual machine (VM). See prerequisites.
In your normal workstation operating system (not the VM), open a java editor of your choice and paste the code from template.java into a new doc. We will be modifying this code in later steps.
Save the doc as RotateKey.java.
This how-to builds on the work in "Write DID and Query Verkey". Rather than duplicate our explanation of those steps here, we will simply copy that code as our starting point.
Copy the contents of step2.java into
RotateKey.java on top of the Step 2 code goes here placeholder comment.
Save the updated version of RotateKey.java.
Once we have an identity on the ledger, we can rotate its key pair.
Copy the contents of step3.java into
RotateKey.java on top of the Step 3 code goes here placeholder comment.
Save the updated version of RotateKey.java.
Most of the logic here should be self-explanatory. However, it's worth
explaining the paired functions replaceKeysStart() and replaceKeysApply().
When we submit the update transaction to the ledger, we have to sign it
using the current signing key; the ledger will verify this using the
verkey that it recognizes. Yet we have to specify the new verkey value
in the transaction itself. The replaceKeysStart() method tells the wallet
that an update is pending, and that it should track both the new and old keypairs
for the identity. The replaceKeysApply() resolves the pending status
so the new value becomes canonical in the local wallet (after it has
already become canonical on the ledger).
Now we can query the ledger to see which verkey it has on record for the identity.
Copy the contents of step4.java into
RotateKey.java on top of the Step 4 code goes here placeholder comment.
Save the updated version of RotateKey.java.
Only a handful of lines of code matter to our goal here; the rest of this block is comments and boilerplate cleanup (which you should not omit!).
Run the completed demo and observe the whole sequence.
TBD