New boarding protocol (#279)

* [domain] add reverse boarding inputs in Payment struct

* [tx-builder] support reverse boarding script

* [wallet] add GetTransaction

* [api-spec][application] add reverse boarding support in covenantless

* [config] add reverse boarding config

* [api-spec] add ReverseBoardingAddress RPC

* [domain][application] support empty forfeits txs in EndFinalization events

* [tx-builder] optional connector output in round tx

* [btc-embedded] fix getTx and taproot finalizer

* whitelist ReverseBoardingAddress RPC

* [test] add reverse boarding integration test

* [client] support reverse boarding

* [sdk] support reverse boarding

* [e2e] add sleep time after faucet

* [test] run using bitcoin-core RPC

* [tx-builder] fix GetSweepInput

* [application][tx-builder] support reverse onboarding in covenant

* [cli] support reverse onboarding in covenant CLI

* [test] rework integration tests

* [sdk] remove onchain wallet, replace by onboarding address

* remove old onboarding protocols

* [sdk] Fix RegisterPayment

* [e2e] add more funds to covenant ASP

* [e2e] add sleeping time

* several fixes

* descriptor boarding

* remove boarding delay from info

* [sdk] implement descriptor boarding

* go mod tidy

* fixes and revert error msgs

* move descriptor pkg to common

* add replace in go.mod

* [sdk] fix unit tests

* rename DescriptorInput --> BoardingInput

* genrest in SDK

* remove boarding input from domain

* remove all "reverse boarding"

* rename "onboarding" ==> "boarding"

* remove outdate payment unit test

* use tmpfs docker volument for compose testing files

* several fixes

common/tree/descriptor.go

@@ -0,0 +1,52 @@
+package tree
+
+import (
+	"encoding/hex"
+
+	"github.com/ark-network/ark/common/descriptor"
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
+	"github.com/vulpemventures/go-elements/taproot"
+)
+
+func ComputeOutputScript(desc descriptor.TaprootDescriptor) ([]byte, error) {
+	leaves := make([]taproot.TapElementsLeaf, 0)
+
+	for _, l := range desc.ScriptTree {
+		script, err := l.Script(false)
+		if err != nil {
+			return nil, err
+		}
+
+		scriptBytes, err := hex.DecodeString(script)
+		if err != nil {
+			return nil, err
+		}
+
+		leaves = append(leaves, taproot.NewBaseTapElementsLeaf(scriptBytes))
+	}
+
+	taprootTree := taproot.AssembleTaprootScriptTree(
+		leaves...,
+	)
+
+	root := taprootTree.RootNode.TapHash()
+
+	internalKey, err := hex.DecodeString(desc.InternalKey.Hex)
+	if err != nil {
+		return nil, err
+	}
+
+	internalKeyParsed, err := schnorr.ParsePubKey(internalKey)
+	if err != nil {
+		return nil, err
+	}
+
+	taprootKey := taproot.ComputeTaprootOutputKey(internalKeyParsed, root[:])
+
+	outputScript, err := taprootOutputScript(taprootKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return outputScript, nil
+}

common/tree/script.go

@@ -3,6 +3,7 @@ package tree
 import (
 	"bytes"
 	"encoding/binary"
+	"encoding/hex"
 	"fmt"
 
 	"github.com/ark-network/ark/common"
@@ -62,7 +63,7 @@ func DecodeClosure(script []byte) (Closure, error) {
 		return closure, nil
 	}
 
-	return nil, fmt.Errorf("invalid closure script")
+	return nil, fmt.Errorf("invalid closure script %s", hex.EncodeToString(script))
 }
 
 func (f *ForfeitClosure) Leaf() (*taproot.TapElementsLeaf, error) {