This shows how to change the verkey that the ledger associates with a DID. It builds on "Write DID and Query Its Verkey".
In case of troubles running the how-to, please read the trouble shooting section.
Setup your workstation with an indy development virtual machine (VM). See prerequisites.
In your normal workstation operating system (not the VM), open a text editor of your
choice and paste the template code of one of the available in the list bellow into
a new file and saved it as rotate_key.EXT, replacing EXT with the proper file
extension (e.g for python: rotate_key.py, for nodejs: rotate_key.js, and so on).
We will be modifying this code in later steps.
[ Python template | Java template | Node.js template | Rust template]
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 the correspondent step2 file below into your rotate_key file
instead of the Step 2 code goes here placeholder comment, and save it.
[ Python step2 | Java step2 | Node.js step2 | Rust step2]
Once we have an identity on the ledger, we can rotate its key pair.
Copy the contents of the correspondent step3 file below into your rotate_key file instead of the Step 3 code goes here placeholder comment.
[ Python step3 | Java step3 | Node.js step3 | Rust step3]
Most of the logic here should be self-explanatory. However, it's worth
explaining the paired functions replace_keys_start and replace_keys_apply.
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 replace_keys_start method tells the wallet
that an update is pending, and that it should track both the new and old keypairs
for the identity. The replace_keys_apply 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 file below into your rotate_key file instead of
the Step 4 code goes here placeholder comment.
[ Python step4 | Java step4 | Node.js step4 | Rust step4]
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.
[ Python complete | Java complete | Node.js complete | Rust complete]
You might try the "Save a Schema and Cred Def" how-to.