non-mandatory-script-verify-flag error when broadcasting tx with electrum

[zoedberg]

I've discovered a bug while developing the rgb-integrations-tests. When broadcasting a TX I receive a non-mandatory-script-verify-flag error. Here some info I've gathered:

• appears when broadcasting via electrum (doesn't appear when using esplora as indexer)
• happens when the transfer type is witness
• happens when sending an asset received back, after several other transfers (including at least a blank transition)
  • if the sending wallet is tapret the error is Protocol(Object {"code": Number(2), "message": String("non-mandatory-script-verify-flag (Invalid Schnorr signature)")})
  • if the sending wallet is opret the error is Protocol(Object {"code": Number(2), "message": String("non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation)")})
• it may be related to the fact that descriptor-wallet is using an old rust-bitcoin version and/or the fact that when converting the psbt returned from the pay method we cast it from v2 to v0 (because of descriptor-wallet not supporting v2)

For more info on the code that triggers the issue, see the PR RGB-WG/rgb-tests#2 (using RUST_BACKTRACE=1 it's possible to see that the error arises from the last transfer of the transfer_loop test)

@dr-orlovsky I know descriptor-wallet will be eventually replaced by bp-wallet, but currently there are no other libraries we can use to use RGB with tapret1st, so either we fix this or we complete work on bp-wallet to completely drop descriptor-wallet.

[dr-orlovsky]

I had four times tried to update descriptor wallet bitcoin dependency, but failed spending couple of days with no success - too many API breaking changes in bitcoin + conflicts with strict types used in descriptor wallet which were rewritten after. I will give it another try, but if I'll fail, it will be probably faster for me to complete signing in bp-wallet.

[dr-orlovsky]

I have failed updating descriptor-wallet to latest rust-bitcoin (it was something like 6th attempt already), so I ended up adding signing abilities to BP libraries.

Here is WIP:

• Signing abilities: adding necessary types and logic to consensus bp-core#101
• Signing abilities: Xprivs, derivation, signing traits and test signer bp-std#31
• Add hot wallet bp-wallet#43
• Add hot wallet bp-wallet#51

Next I will try to add this functionality to bp cli to test it UPD: new PR to bp-wallet is added above

[zoedberg]

Closing this since we can now drop descriptor-wallet, which has been deprecated in favor of bp-wallet. I've opened BP-WG/bp-wallet#62 to track this issue (since it happens also there)