Provide dedicated descriptors for change addresses with tapret

[crisdut]

Discussed in #53

^{Originally posted by crisdut October 12, 2022}
According to this comment, the descriptor change is provided by the same wallet used to provide the inputs.

I think the command line needs an optional parameter to allow choose your change descriptor.

This important feature for TapRet commitments, because always we need a TapTree to add commitment.

TapRet commitment user case (example):

1. We create a Taptree output descriptor with OP_CHECKSIG.

change_desc="tr(A,pk(B))#mjnpzw6a"

2. We construct a PSBT file.

btc-cold construct --input  <INPUTS> <WALLET_FILE> <PSBT_FILE> <FEE> --allow-tapret-path 1 --account-file <ACCOUNT_FILE> --change $change_desc 

3. After RGB finalize, the Taptree is updated with the commitment script

4. If we want to spend the bitcoins of the output descriptor, we need to create a new wallet based on the script of the step 1

btc-cold create  $change_desc <WALLET_FILE> --account-file <ACCOUNT_FILE>

5. Use the new wallet to construct a new PSBT file.

Does make sense?

I will start work on this issue.

[dr-orlovsky]

You are right about that existance of tapret commiments makes it harder to deal with change outputs; but I do not agree that this should be addressed by creating a dedicated descriptor. Instead, my plan was to support extended descriptor format supporting tapret fragment and a list of tweaks which should be looked for at specific indexes.

[dr-orlovsky]

Like I did in this early prototype concept: https://github.com/BP-WG/stingerjet-docs

See the end of the README, the taprets final section of a sample.

[dr-orlovsky]

Just not to duplicate messages I propose to continue discussion on the proper way of supporting tapret commitments in wallet descriptors in #53

Closing in favor of issue which tracks the status (#58)

[crisdut]

Just not to duplicate messages I propose to continue discussion on the proper way of supporting tapret commitments in wallet descriptors in #53

Ok, I'm sorry.

I created an issue just because I started implementation of the solution.