Wallet sync fixes (#32)

* moves wallet functionality to wallet.go

* changeAddress NPE avoided

* log -> print

---------

Co-authored-by: dpiatkivskyi <dmytro.piatkikvskyi@gmailcom>

run/btcwallet.go

@@ -183,8 +183,9 @@ func doInit(config *BtcwalletConfig) (*wallet.Wallet, error) {
 		if err != nil && !strings.Contains(err.Error(), "already exists") {
 			return nil, fmt.Errorf("cannot import change address: %w", err)
 		}
-		log.Infof("Change address: %s", changeAddress)
-
+		if changeAddress != nil {
+			log.Infof("Change address: %s", changeAddress.Address())
+		}
 		if changeAddressKey == nil {
 			return nil, fmt.Errorf("change key is nil")
 		}

wallet/wallet.go

@@ -11,6 +11,9 @@ import (
 	"errors"
 	"fmt"
 	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stroomnetwork/frost/crypto"
 	"sort"
 	"sync"
 	"sync/atomic"
@@ -4145,3 +4148,113 @@ func OpenWithRetry(db walletdb.DB, pubPass []byte, cbs *waddrmgr.OpenCallbacks,
 
 	return w, nil
 }
+
+func (w *Wallet) GenerateAndImportKeyWithCheck(btcAddr, ethAddr string) (*btcec.PublicKey, error) {
+
+	key, importedAddress, err := w.GenerateKeyFromEthAddressAndImport(ethAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	if importedAddress != nil {
+		address := importedAddress.Address().String()
+		if btcAddr != "" && address != btcAddr {
+			return nil, fmt.Errorf("address mismatch: %s != %s", address, btcAddr)
+		}
+	}
+
+	return key, nil
+}
+
+func (w *Wallet) GenerateKeyFromEthAddressAndImport(ethAddr string) (*btcec.PublicKey, waddrmgr.ManagedAddress, error) {
+
+	lc, err := w.lcFromEthAddr(ethAddr)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	pubKey := lc.GetCombinedPubKey()
+	importedAddress, err := w.ImportPublicKeyReturnAddress(pubKey, waddrmgr.TaprootPubKey)
+	if err != nil {
+		return pubKey, importedAddress, err
+	}
+
+	if importedAddress == nil {
+		return pubKey, nil, fmt.Errorf("imported address is nil")
+	}
+
+	err = w.AddressMapStorage.SetEthAddress(importedAddress.Address().String(), ethAddr)
+	if err != nil {
+		return pubKey, nil, err
+	}
+
+	fmt.Printf("Imported address %s with eth address %s\n", importedAddress.Address(), ethAddr)
+
+	return pubKey, importedAddress, nil
+}
+
+func (w *Wallet) lcFromEthAddr(ethAddrStr string) (*crypto.LinearCombination, error) {
+	ethAddr := common.HexToAddress(ethAddrStr)
+
+	uint256Ty, _ := abi.NewType("uint256", "uint256", nil)
+	addressTy, _ := abi.NewType("address", "address", nil)
+
+	arguments := abi.Arguments{
+		{
+			Type: uint256Ty,
+		},
+		{
+			Type: uint256Ty,
+		},
+		{
+			Type: addressTy,
+		},
+	}
+
+	if w.Pk1 == nil {
+		return nil, fmt.Errorf("missing pk1")
+	}
+	if w.Pk2 == nil {
+		return nil, fmt.Errorf("missing pk2")
+	}
+
+	b1, _ := arguments.Pack(
+		w.Pk1.X(),
+		w.Pk1.Y(),
+		ethAddr,
+	)
+	h1 := crypto.Sha256(b1)
+	c1FromAddr, _ := crypto.PrivKeyFromBytes(h1[:])
+
+	b2, _ := arguments.Pack(
+		w.Pk2.X(),
+		w.Pk2.Y(),
+		ethAddr,
+	)
+	h2 := crypto.Sha256(b2)
+	c2FromAddr, _ := crypto.PrivKeyFromBytes(h2[:])
+
+	lc, err := crypto.NewLinearCombination(
+		[]*btcec.PublicKey{w.Pk1, w.Pk2},
+		[]*btcec.PrivateKey{c1FromAddr, c2FromAddr},
+		crypto.PrivKeyFromInt(0),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return lc, nil
+}
+
+func (w *Wallet) GetSignerPublicKeys() (*btcec.PublicKey, *btcec.PublicKey, error) {
+
+	if w.Pk1 == nil {
+		return nil, nil, fmt.Errorf("missing pk1")
+	}
+
+	if w.Pk2 == nil {
+		return nil, nil, fmt.Errorf("missing pk2")
+	}
+
+	return w.Pk1, w.Pk2, nil
+}