Merge pull request #733 from wpaulino/watch-only-account-utils

waddrmgr+wallet: support transaction creation and signing for watch-only accounts

.travis.yml

@@ -11,4 +11,3 @@ script:
   - make lint
   - make unit-race
   - make unit-cover
-  - make goveralls

Makefile

@@ -1,12 +1,10 @@
 PKG := github.com/btcsuite/btcwallet
 
-GOVERALLS_PKG := github.com/mattn/goveralls
 LINT_PKG := github.com/golangci/golangci-lint/cmd/golangci-lint
 GOACC_PKG := github.com/ory/go-acc
 GOIMPORTS_PKG := golang.org/x/tools/cmd/goimports
 
 GO_BIN := ${GOPATH}/bin
-GOVERALLS_BIN := $(GO_BIN)/goveralls
 LINT_BIN := $(GO_BIN)/golangci-lint
 GOACC_BIN := $(GO_BIN)/go-acc
 
@@ -49,10 +47,6 @@ all: build check
 # DEPENDENCIES
 # ============
 
-$(GOVERALLS_BIN):
-	@$(call print, "Fetching goveralls.")
-	go get -u $(GOVERALLS_PKG)
-
 $(LINT_BIN):
 	@$(call print, "Fetching linter")
 	$(DEPGET) $(LINT_PKG)@$(LINT_COMMIT)
@@ -97,10 +91,6 @@ unit-race:
 	@$(call print, "Running unit race tests.")
 	env CGO_ENABLED=1 GORACE="history_size=7 halt_on_errors=1" $(GOLIST) | $(XARGS) env $(GOTEST) -race
 
-goveralls: $(GOVERALLS_BIN)
-	@$(call print, "Sending coverage report.")
-	$(GOVERALLS_BIN) -coverprofile=coverage.txt -service=travis-ci
-
 # =========
 # UTILITIES
 # =========
@@ -126,7 +116,6 @@ clean:
 	unit \
 	unit-cover \
 	unit-race \
-	goveralls \
 	fmt \
 	lint \
 	clean

cmd/sweepaccount/main.go

@@ -22,6 +22,7 @@ import (
 	"github.com/btcsuite/btcwallet/netparams"
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
 	"github.com/btcsuite/btcwallet/wallet/txrules"
+	"github.com/btcsuite/btcwallet/wallet/txsizes"
 	"github.com/jessevdk/go-flags"
 )
 
@@ -190,14 +191,22 @@ func makeInputSource(outputs []btcjson.ListUnspentResult) txauthor.InputSource {
 // makeDestinationScriptSource creates a ChangeSource which is used to receive
 // all correlated previous input value.  A non-change address is created by this
 // function.
-func makeDestinationScriptSource(rpcClient *rpcclient.Client, accountName string) txauthor.ChangeSource {
+func makeDestinationScriptSource(rpcClient *rpcclient.Client, accountName string) *txauthor.ChangeSource {
-	return func() ([]byte, error) {
+
+	// GetNewAddress always returns a P2PKH address since it assumes
+	// BIP-0044.
+	newChangeScript := func() ([]byte, error) {
 		destinationAddress, err := rpcClient.GetNewAddress(accountName)
 		if err != nil {
 			return nil, err
 		}
 		return txscript.PayToAddrScript(destinationAddress)
 	}
+
+	return &txauthor.ChangeSource{
+		ScriptSize: txsizes.P2PKHPkScriptSize,
+		NewScript:  newChangeScript,
+	}
 }
 
 func main() {

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/btcsuite/btcutil/psbt v1.0.3-0.20201208143702-a53e38424cce
 	github.com/btcsuite/btcwallet/wallet/txauthor v1.0.0
 	github.com/btcsuite/btcwallet/wallet/txrules v1.0.0
+	github.com/btcsuite/btcwallet/wallet/txsizes v1.0.0
 	github.com/btcsuite/btcwallet/walletdb v1.3.4
 	github.com/btcsuite/btcwallet/wtxmgr v1.2.0
 	github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792

rpc/legacyrpc/methods.go

@@ -1293,20 +1293,14 @@ func listAllTransactions(icmd interface{}, w *wallet.Wallet) (interface{}, error
 func listUnspent(icmd interface{}, w *wallet.Wallet) (interface{}, error) {
 	cmd := icmd.(*btcjson.ListUnspentCmd)
 
-	var addresses map[string]struct{}
+	if cmd.Addresses != nil && len(*cmd.Addresses) > 0 {
-	if cmd.Addresses != nil {
+		return nil, &btcjson.RPCError{
-		addresses = make(map[string]struct{})
+			Code:    btcjson.ErrRPCInvalidParameter,
-		// confirm that all of them are good:
+			Message: "Filtering by addresses has been deprecated",
-		for _, as := range *cmd.Addresses {
-			a, err := decodeAddress(as, w.ChainParams())
-			if err != nil {
-				return nil, err
-			}
-			addresses[a.EncodeAddress()] = struct{}{}
 		}
 	}
 
-	return w.ListUnspent(int32(*cmd.MinConf), int32(*cmd.MaxConf), addresses)
+	return w.ListUnspent(int32(*cmd.MinConf), int32(*cmd.MaxConf), "")
 }
 
 // lockUnspent handles the lockunspent command.
@@ -1359,13 +1353,14 @@ func makeOutputs(pairs map[string]btcutil.Amount, chainParams *chaincfg.Params)
 // It returns the transaction hash in string format upon success
 // All errors are returned in btcjson.RPCError format
 func sendPairs(w *wallet.Wallet, amounts map[string]btcutil.Amount,
-	account uint32, minconf int32, feeSatPerKb btcutil.Amount) (string, error) {
+	keyScope waddrmgr.KeyScope, account uint32, minconf int32,
+	feeSatPerKb btcutil.Amount) (string, error) {
 
 	outputs, err := makeOutputs(amounts, w.ChainParams())
 	if err != nil {
 		return "", err
 	}
-	tx, err := w.SendOutputs(outputs, account, minconf, feeSatPerKb, "")
+	tx, err := w.SendOutputs(outputs, &keyScope, account, minconf, feeSatPerKb, "")
 	if err != nil {
 		if err == txrules.ErrAmountNegative {
 			return "", ErrNeedPositiveAmount
@@ -1433,7 +1428,7 @@ func sendFrom(icmd interface{}, w *wallet.Wallet, chainClient *chain.RPCClient)
 		cmd.ToAddress: amt,
 	}
 
-	return sendPairs(w, pairs, account, minConf,
+	return sendPairs(w, pairs, waddrmgr.KeyScopeBIP0044, account, minConf,
 		txrules.DefaultRelayFeePerKb)
 }
 
@@ -1475,7 +1470,7 @@ func sendMany(icmd interface{}, w *wallet.Wallet) (interface{}, error) {
 		pairs[k] = amt
 	}
 
-	return sendPairs(w, pairs, account, minConf, txrules.DefaultRelayFeePerKb)
+	return sendPairs(w, pairs, waddrmgr.KeyScopeBIP0044, account, minConf, txrules.DefaultRelayFeePerKb)
 }
 
 // sendToAddress handles a sendtoaddress RPC request by creating a new
@@ -1511,7 +1506,7 @@ func sendToAddress(icmd interface{}, w *wallet.Wallet) (interface{}, error) {
 	}
 
 	// sendtoaddress always spends from the default account, this matches bitcoind
-	return sendPairs(w, pairs, waddrmgr.DefaultAccountNum, 1,
+	return sendPairs(w, pairs, waddrmgr.KeyScopeBIP0044, waddrmgr.DefaultAccountNum, 1,
 		txrules.DefaultRelayFeePerKb)
 }
 

rpc/rpcserver/server.go

@@ -408,7 +408,7 @@ func (s *walletServer) GetTransactions(ctx context.Context, req *pb.GetTransacti
 
 	_ = minRecentTxs
 
-	gtr, err := s.wallet.GetTransactions(startBlock, endBlock, ctx.Done())
+	gtr, err := s.wallet.GetTransactions(startBlock, endBlock, "", ctx.Done())
 	if err != nil {
 		return nil, translateError(err)
 	}

waddrmgr/manager.go

@@ -405,6 +405,29 @@ func (m *Manager) watchOnly() bool {
 	return m.watchingOnly
 }
 
+// IsWatchOnlyAccount determines if the account with the given key scope is set
+// up as watch-only.
+func (m *Manager) IsWatchOnlyAccount(ns walletdb.ReadBucket, keyScope KeyScope,
+	account uint32) (bool, error) {
+
+	if m.WatchOnly() {
+		return true, nil
+	}
+
+	// Assume the default imported account has no private keys.
+	//
+	// TODO: Actually check whether it does.
+	if account == ImportedAddrAccount {
+		return true, nil
+	}
+
+	scopedMgr, err := m.FetchScopedKeyManager(keyScope)
+	if err != nil {
+		return false, err
+	}
+	return scopedMgr.IsWatchOnlyAccount(ns, account)
+}
+
 // lock performs a best try effort to remove and zero all secret keys associated
 // with the address manager.
 //
@@ -1218,7 +1241,7 @@ func (m *Manager) Unlock(ns walletdb.ReadBucket, passphrase []byte) error {
 		// We'll also derive any private keys that are pending due to
 		// them being created while the address manager was locked.
 		for _, info := range manager.deriveOnUnlock {
-			addressKey, _, err := manager.deriveKeyFromPath(
+			addressKey, _, _, err := manager.deriveKeyFromPath(
 				ns, info.managedAddr.InternalAccount(),
 				info.branch, info.index, true,
 			)
@@ -1276,6 +1299,25 @@ func ValidateAccountName(name string) error {
 	return nil
 }
 
+// LookupAccount returns the corresponding key scope and account number for the
+// account with the given name.
+func (m *Manager) LookupAccount(ns walletdb.ReadBucket, name string) (KeyScope,
+	uint32, error) {
+
+	m.mtx.RLock()
+	defer m.mtx.RUnlock()
+
+	for keyScope, scopedMgr := range m.scopedManagers {
+		acct, err := scopedMgr.LookupAccount(ns, name)
+		if err == nil {
+			return keyScope, acct, nil
+		}
+	}
+
+	str := fmt.Sprintf("account name '%s' not found", name)
+	return KeyScope{}, 0, managerError(ErrAccountNotFound, str, nil)
+}
+
 // selectCryptoKey selects the appropriate crypto key based on the key type. An
 // error is returned when an invalid key type is specified or the requested key
 // requires the manager to be unlocked when it isn't.

waddrmgr/scoped_manager.go

@@ -72,6 +72,12 @@ type DerivationPath struct {
 	// Index is the final child in the derivation path. This denotes the
 	// key index within as a child of the account and branch.
 	Index uint32
+
+	// MasterKeyFingerprint represents the fingerprint of the root key (also
+	// known as the key with derivation path m/) corresponding to the
+	// account public key. This may be required by some hardware wallets for
+	// proper identification and signing.
+	MasterKeyFingerprint uint32
 }
 
 // KeyScope represents a restricted key scope from the primary root key within
@@ -448,6 +454,7 @@ func (s *ScopedKeyManager) loadAccountInfo(ns walletdb.ReadBucket,
 		Account:              acctInfo.acctKeyPub.ChildIndex(),
 		Branch:               branch,
 		Index:                index,
+		MasterKeyFingerprint: acctInfo.masterKeyFingerprint,
 	}
 	lastExtKey, err := s.deriveKey(acctInfo, branch, index, hasPrivateKey)
 	if err != nil {
@@ -469,6 +476,7 @@ func (s *ScopedKeyManager) loadAccountInfo(ns walletdb.ReadBucket,
 		Account:              acctInfo.acctKeyPub.ChildIndex(),
 		Branch:               branch,
 		Index:                index,
+		MasterKeyFingerprint: acctInfo.masterKeyFingerprint,
 	}
 	lastIntKey, err := s.deriveKey(acctInfo, branch, index, hasPrivateKey)
 	if err != nil {
@@ -580,7 +588,7 @@ func (s *ScopedKeyManager) DeriveFromKeyPath(ns walletdb.ReadBucket,
 	watchOnly := s.rootManager.WatchOnly()
 	private := !s.rootManager.IsLocked() && !watchOnly
 
-	addrKey, _, err := s.deriveKeyFromPath(
+	addrKey, _, _, err := s.deriveKeyFromPath(
 		ns, kp.InternalAccount, kp.Branch, kp.Index, private,
 	)
 	if err != nil {
@@ -601,18 +609,18 @@ func (s *ScopedKeyManager) DeriveFromKeyPath(ns walletdb.ReadBucket,
 // This function MUST be called with the manager lock held for writes.
 func (s *ScopedKeyManager) deriveKeyFromPath(ns walletdb.ReadBucket,
 	internalAccount, branch, index uint32, private bool) (
-	*hdkeychain.ExtendedKey, *hdkeychain.ExtendedKey, error) {
+	*hdkeychain.ExtendedKey, *hdkeychain.ExtendedKey, uint32, error) {
 
 	// Look up the account key information.
 	acctInfo, err := s.loadAccountInfo(ns, internalAccount)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, 0, err
 	}
 	private = private && acctInfo.acctKeyPriv != nil
 
 	addrKey, err := s.deriveKey(acctInfo, branch, index, private)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, 0, err
 	}
 
 	acctKey := acctInfo.acctKeyPub
@@ -620,7 +628,7 @@ func (s *ScopedKeyManager) deriveKeyFromPath(ns walletdb.ReadBucket,
 		acctKey = acctInfo.acctKeyPriv
 	}
 
-	return addrKey, acctKey, nil
+	return addrKey, acctKey, acctInfo.masterKeyFingerprint, nil
 }
 
 // chainAddressRowToManaged returns a new managed address based on chained
@@ -634,7 +642,7 @@ func (s *ScopedKeyManager) chainAddressRowToManaged(ns walletdb.ReadBucket,
 	// function, we use the internal isLocked to avoid a deadlock.
 	private := !s.rootManager.isLocked() && !s.rootManager.watchOnly()
 
-	addressKey, acctKey, err := s.deriveKeyFromPath(
+	addressKey, acctKey, masterKeyFingerprint, err := s.deriveKeyFromPath(
 		ns, row.account, row.branch, row.index, private,
 	)
 	if err != nil {
@@ -651,6 +659,7 @@ func (s *ScopedKeyManager) chainAddressRowToManaged(ns walletdb.ReadBucket,
 			Account:              acctKey.ChildIndex(),
 			Branch:               row.branch,
 			Index:                row.index,
+			MasterKeyFingerprint: masterKeyFingerprint,
 		}, acctInfo,
 	)
 }
@@ -2177,6 +2186,22 @@ func (s *ScopedKeyManager) ForEachInternalActiveAddress(ns walletdb.ReadBucket,
 	return nil
 }
 
+// IsWatchOnlyAccount determines if the given account belonging to this scoped
+// manager is set up as watch-only.
+func (s *ScopedKeyManager) IsWatchOnlyAccount(ns walletdb.ReadBucket,
+	account uint32) (bool, error) {
+
+	s.mtx.Lock()
+	defer s.mtx.Unlock()
+
+	acctInfo, err := s.loadAccountInfo(ns, account)
+	if err != nil {
+		return false, err
+	}
+
+	return acctInfo.acctKeyPriv == nil, nil
+}
+
 // cloneKeyWithVersion clones an extended key to use the version corresponding
 // to the manager's key scope. This should only be used for non-watch-only
 // accounts as they are stored within the database using the legacy BIP-0044

wallet/createtx.go

@@ -15,6 +15,7 @@ import (
 	"github.com/btcsuite/btcutil"
 	"github.com/btcsuite/btcwallet/waddrmgr"
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
+	"github.com/btcsuite/btcwallet/wallet/txsizes"
 	"github.com/btcsuite/btcwallet/walletdb"
 	"github.com/btcsuite/btcwallet/wtxmgr"
 )
@@ -99,14 +100,17 @@ func (s secretSource) GetScript(addr btcutil.Address) ([]byte, error) {
 // txToOutputs creates a signed transaction which includes each output from
 // outputs.  Previous outputs to reedeem are chosen from the passed account's
 // UTXO set and minconf policy. An additional output may be added to return
-// change to the wallet.  An appropriate fee is included based on the wallet's
+// change to the wallet. This output will have an address generated from the
-// current relay fee.  The wallet must be unlocked to create the transaction.
+// given key scope and account. If a key scope is not specified, the address
+// will always be generated from the P2WKH key scope. An appropriate fee is
+// included based on the wallet's current relay fee. The wallet must be
+// unlocked to create the transaction.
 //
 // NOTE: The dryRun argument can be set true to create a tx that doesn't alter
 // the database. A tx created with this set to true will intentionally have no
 // input scripts added and SHOULD NOT be broadcasted.
-func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
+func (w *Wallet) txToOutputs(outputs []*wire.TxOut, keyScope *waddrmgr.KeyScope,
-	minconf int32, feeSatPerKb btcutil.Amount, dryRun bool) (
+	account uint32, minconf int32, feeSatPerKb btcutil.Amount, dryRun bool) (
 	tx *txauthor.AuthoredTx, err error) {
 
 	chainClient, err := w.requireChainClient()
@@ -120,7 +124,12 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
 	}
 	defer func() { _ = dbtx.Rollback() }()
 
-	addrmgrNs, changeSource := w.addrMgrWithChangeSource(dbtx, account)
+	addrmgrNs, changeSource, err := w.addrMgrWithChangeSource(
+		dbtx, keyScope, account,
+	)
+	if err != nil {
+		return nil, err
+	}
 
 	// Get current block's height and hash.
 	bs, err := chainClient.BlockStamp()
@@ -128,14 +137,17 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
 		return nil, err
 	}
 
-	eligible, err := w.findEligibleOutputs(dbtx, account, minconf, bs)
+	eligible, err := w.findEligibleOutputs(
+		dbtx, keyScope, account, minconf, bs,
+	)
 	if err != nil {
 		return nil, err
 	}
 
 	inputSource := makeInputSource(eligible)
-	tx, err = txauthor.NewUnsignedTransaction(outputs, feeSatPerKb,
+	tx, err = txauthor.NewUnsignedTransaction(
-		inputSource, changeSource)
+		outputs, feeSatPerKb, inputSource, changeSource,
+	)
 	if err != nil {
 		return nil, err
 	}
@@ -155,6 +167,27 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
 		return tx, nil
 	}
 
+	// Before committing the transaction, we'll sign our inputs. If the
+	// inputs are part of a watch-only account, there's no private key
+	// information stored, so we'll skip signing such.
+	var watchOnly bool
+	if keyScope == nil {
+		// If a key scope wasn't specified, then coin selection was
+		// performed from the default wallet accounts (NP2WKH, P2WKH),
+		// so any key scope provided doesn't impact the result of this
+		// call.
+		watchOnly, err = w.Manager.IsWatchOnlyAccount(
+			addrmgrNs, waddrmgr.KeyScopeBIP0084, account,
+		)
+	} else {
+		watchOnly, err = w.Manager.IsWatchOnlyAccount(
+			addrmgrNs, *keyScope, account,
+		)
+	}
+	if err != nil {
+		return nil, err
+	}
+	if !watchOnly {
 		err = tx.AddAllInputScripts(secretSource{w.Manager, addrmgrNs})
 		if err != nil {
 			return nil, err
@@ -164,6 +197,7 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
 		if err != nil {
 			return nil, err
 		}
+	}
 
 	if err := dbtx.Commit(); err != nil {
 		return nil, err
@@ -193,7 +227,10 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
 	return tx, nil
 }
 
-func (w *Wallet) findEligibleOutputs(dbtx walletdb.ReadTx, account uint32, minconf int32, bs *waddrmgr.BlockStamp) ([]wtxmgr.Credit, error) {
+func (w *Wallet) findEligibleOutputs(dbtx walletdb.ReadTx,
+	keyScope *waddrmgr.KeyScope, account uint32, minconf int32,
+	bs *waddrmgr.BlockStamp) ([]wtxmgr.Credit, error) {
+
 	addrmgrNs := dbtx.ReadBucket(waddrmgrNamespaceKey)
 	txmgrNs := dbtx.ReadBucket(wtxmgrNamespaceKey)
 
@@ -239,8 +276,14 @@ func (w *Wallet) findEligibleOutputs(dbtx walletdb.ReadTx, account uint32, minco
 		if err != nil || len(addrs) != 1 {
 			continue
 		}
-		_, addrAcct, err := w.Manager.AddrAccount(addrmgrNs, addrs[0])
+		scopedMgr, addrAcct, err := w.Manager.AddrAccount(addrmgrNs, addrs[0])
-		if err != nil || addrAcct != account {
+		if err != nil {
+			continue
+		}
+		if keyScope != nil && scopedMgr.Scope() != *keyScope {
+			continue
+		}
+		if addrAcct != account {
 			continue
 		}
 		eligible = append(eligible, *output)
@@ -249,26 +292,61 @@ func (w *Wallet) findEligibleOutputs(dbtx walletdb.ReadTx, account uint32, minco
 }
 
 // addrMgrWithChangeSource returns the address manager bucket and a change
-// source function that returns change addresses from said address manager.
+// source that returns change addresses from said address manager. The change
+// addresses will come from the specified key scope and account, unless a key
+// scope is not specified. In that case, change addresses will always come from
+// the P2WKH key scope.
 func (w *Wallet) addrMgrWithChangeSource(dbtx walletdb.ReadWriteTx,
-	account uint32) (walletdb.ReadWriteBucket, txauthor.ChangeSource) {
+	changeKeyScope *waddrmgr.KeyScope, account uint32) (
+	walletdb.ReadWriteBucket, *txauthor.ChangeSource, error) {
 
+	// Determine the address type for change addresses of the given account.
+	if changeKeyScope == nil {
+		changeKeyScope = &waddrmgr.KeyScopeBIP0084
+	}
+	addrType := waddrmgr.ScopeAddrMap[*changeKeyScope].InternalAddrType
+
+	// It's possible for the account to have an address schema override, so
+	// prefer that if it exists.
 	addrmgrNs := dbtx.ReadWriteBucket(waddrmgrNamespaceKey)
-	changeSource := func() ([]byte, error) {
+	scopeMgr, err := w.Manager.FetchScopedKeyManager(*changeKeyScope)
-		// Derive the change output script. We'll use the default key
+	if err != nil {
-		// scope responsible for P2WPKH addresses to do so. As a hack to
+		return nil, nil, err
-		// allow spending from the imported account, change addresses
+	}
-		// are created from account 0.
+	accountInfo, err := scopeMgr.AccountProperties(addrmgrNs, account)
-		var changeAddr btcutil.Address
+	if err != nil {
-		var err error
+		return nil, nil, err
-		changeKeyScope := waddrmgr.KeyScopeBIP0084
+	}
+	if accountInfo.AddrSchema != nil {
+		addrType = accountInfo.AddrSchema.InternalAddrType
+	}
+
+	// Compute the expected size of the script for the change address type.
+	var scriptSize int
+	switch addrType {
+	case waddrmgr.PubKeyHash:
+		scriptSize = txsizes.P2PKHPkScriptSize
+	case waddrmgr.NestedWitnessPubKey:
+		scriptSize = txsizes.NestedP2WPKHPkScriptSize
+	case waddrmgr.WitnessPubKey:
+		scriptSize = txsizes.P2WPKHPkScriptSize
+	}
+
+	newChangeScript := func() ([]byte, error) {
+		// Derive the change output script. As a hack to allow spending
+		// from the imported account, change addresses are created from
+		// account 0.
+		var (
+			changeAddr btcutil.Address
+			err        error
+		)
 		if account == waddrmgr.ImportedAddrAccount {
 			changeAddr, err = w.newChangeAddress(
-				addrmgrNs, 0, changeKeyScope,
+				addrmgrNs, 0, *changeKeyScope,
 			)
 		} else {
 			changeAddr, err = w.newChangeAddress(
-				addrmgrNs, account, changeKeyScope,
+				addrmgrNs, account, *changeKeyScope,
 			)
 		}
 		if err != nil {
@@ -276,7 +354,11 @@ func (w *Wallet) addrMgrWithChangeSource(dbtx walletdb.ReadWriteTx,
 		}
 		return txscript.PayToAddrScript(changeAddr)
 	}
-	return addrmgrNs, changeSource
+
+	return addrmgrNs, &txauthor.ChangeSource{
+		ScriptSize: scriptSize,
+		NewScript:  newChangeScript,
+	}, nil
 }
 
 // validateMsgTx verifies transaction input scripts for tx.  All previous output

wallet/createtx_test.go

@@ -34,7 +34,8 @@ func TestTxToOutputsDryRun(t *testing.T) {
 	defer cleanup()
 
 	// Create an address we can use to send some coins to.
-	addr, err := w.CurrentAddress(0, waddrmgr.KeyScopeBIP0044)
+	keyScope := waddrmgr.KeyScopeBIP0049Plus
+	addr, err := w.CurrentAddress(0, keyScope)
 	if err != nil {
 		t.Fatalf("unable to get current address: %v", addr)
 	}
@@ -70,7 +71,7 @@ func TestTxToOutputsDryRun(t *testing.T) {
 
 	// First do a few dry-runs, making sure the number of addresses in the
 	// database us not inflated.
-	dryRunTx, err := w.txToOutputs(txOuts, 0, 1, 1000, true)
+	dryRunTx, err := w.txToOutputs(txOuts, nil, 0, 1, 1000, true)
 	if err != nil {
 		t.Fatalf("unable to author tx: %v", err)
 	}
@@ -85,7 +86,7 @@ func TestTxToOutputsDryRun(t *testing.T) {
 		t.Fatalf("expected 1 address, found %v", len(addresses))
 	}
 
-	dryRunTx2, err := w.txToOutputs(txOuts, 0, 1, 1000, true)
+	dryRunTx2, err := w.txToOutputs(txOuts, nil, 0, 1, 1000, true)
 	if err != nil {
 		t.Fatalf("unable to author tx: %v", err)
 	}
@@ -118,7 +119,7 @@ func TestTxToOutputsDryRun(t *testing.T) {
 
 	// Now we do a proper, non-dry run. This should add a change address
 	// to the database.
-	tx, err := w.txToOutputs(txOuts, 0, 1, 1000, false)
+	tx, err := w.txToOutputs(txOuts, nil, 0, 1, 1000, false)
 	if err != nil {
 		t.Fatalf("unable to author tx: %v", err)
 	}

wallet/psbt.go

@@ -12,8 +12,10 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/btcsuite/btcutil/psbt"
+	"github.com/btcsuite/btcwallet/waddrmgr"
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
 	"github.com/btcsuite/btcwallet/wallet/txrules"
+	"github.com/btcsuite/btcwallet/walletdb"
 	"github.com/btcsuite/btcwallet/wtxmgr"
 )
 
@@ -24,17 +26,22 @@ import (
 // is created and the index -1 is returned.
 //
 // NOTE: If the packet doesn't contain any inputs, coin selection is performed
-// automatically. If the packet does contain any inputs, it is assumed that full
+// automatically, only selecting inputs from the account based on the given key
-// coin selection happened externally and no additional inputs are added. If the
+// scope and account number. If a key scope is not specified, then inputs from
-// specified inputs aren't enough to fund the outputs with the given fee rate,
+// accounts matching the account number provided across all key scopes may be
-// an error is returned.
+// selected. This is done to handle the default account case, where a user wants
+// to fund a PSBT with inputs regardless of their type (NP2WKH, P2WKH, etc.). If
+// the packet does contain any inputs, it is assumed that full coin selection
+// happened externally and no additional inputs are added. If the specified
+// inputs aren't enough to fund the outputs with the given fee rate, an error is
+// returned.
 //
 // NOTE: A caller of the method should hold the global coin selection lock of
 // the wallet. However, no UTXO specific lock lease is acquired for any of the
 // selected/validated inputs by this method. It is in the caller's
 // responsibility to lock the inputs before handing the partial transaction out.
-func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
+func (w *Wallet) FundPsbt(packet *psbt.Packet, keyScope *waddrmgr.KeyScope,
-	feeSatPerKB btcutil.Amount) (int32, error) {
+	account uint32, feeSatPerKB btcutil.Amount) (int32, error) {
 
 	// Make sure the packet is well formed. We only require there to be at
 	// least one output but not necessarily any inputs.
@@ -70,7 +77,7 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 	addInputInfo := func(inputs []*wire.TxIn) error {
 		packet.Inputs = make([]psbt.PInput, len(inputs))
 		for idx, in := range inputs {
-			tx, utxo, _, err := w.FetchInputInfo(
+			tx, utxo, derivationPath, _, err := w.FetchInputInfo(
 				&in.PreviousOutPoint,
 			)
 			if err != nil {
@@ -91,10 +98,27 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 			}
 			packet.Inputs[idx].SighashType = txscript.SigHashAll
 
+			// Include the derivation path for each input.
+			packet.Inputs[idx].Bip32Derivation = []*psbt.Bip32Derivation{
+				derivationPath,
+			}
+
 			// We don't want to include the witness or any script
-			// just yet.
+			// on the unsigned TX just yet.
 			packet.UnsignedTx.TxIn[idx].Witness = wire.TxWitness{}
 			packet.UnsignedTx.TxIn[idx].SignatureScript = nil
+
+			// For nested P2WKH we need to add the redeem script to
+			// the input, otherwise an offline wallet won't be able
+			// to sign for it. For normal P2WKH this will be nil.
+			addr, witnessProgram, _, err := w.scriptForOutput(utxo)
+			if err != nil {
+				return fmt.Errorf("error fetching UTXO "+
+					"script: %v", err)
+			}
+			if addr.AddrType() == waddrmgr.NestedWitnessPubKey {
+				packet.Inputs[idx].RedeemScript = witnessProgram
+			}
 		}
 
 		return nil
@@ -108,8 +132,8 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 		// includes everything we need, specifically fee estimation and
 		// change address creation.
 		tx, err = w.CreateSimpleTx(
-			account, packet.UnsignedTx.TxOut, 1, feeSatPerKB,
+			keyScope, account, packet.UnsignedTx.TxOut, 1,
-			false,
+			feeSatPerKB, false,
 		)
 		if err != nil {
 			return 0, fmt.Errorf("error creating funding TX: %v",
@@ -161,7 +185,12 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 		if err != nil {
 			return 0, err
 		}
-		_, changeSource := w.addrMgrWithChangeSource(dbtx, account)
+		_, changeSource, err := w.addrMgrWithChangeSource(
+			dbtx, keyScope, account,
+		)
+		if err != nil {
+			return 0, err
+		}
 
 		// Ask the txauthor to create a transaction with our selected
 		// coins. This will perform fee estimation and add a change
@@ -227,7 +256,9 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 //
 // NOTE: This method does NOT publish the transaction after it's been finalized
 // successfully.
-func (w *Wallet) FinalizePsbt(packet *psbt.Packet) error {
+func (w *Wallet) FinalizePsbt(keyScope *waddrmgr.KeyScope, account uint32,
+	packet *psbt.Packet) error {
+
 	// Let's check that this is actually something we can and want to sign.
 	// We need at least one input and one output.
 	err := psbt.VerifyInputOutputLen(packet, true, true)
@@ -259,7 +290,7 @@ func (w *Wallet) FinalizePsbt(packet *psbt.Packet) error {
 		// We can only sign this input if it's ours, so we try to map it
 		// to a coin we own. If we can't, then we'll continue as it
 		// isn't our input.
-		fullTx, txOut, _, err := w.FetchInputInfo(
+		fullTx, txOut, _, _, err := w.FetchInputInfo(
 			&txIn.PreviousOutPoint,
 		)
 		if err != nil {
@@ -298,8 +329,37 @@ func (w *Wallet) FinalizePsbt(packet *psbt.Packet) error {
 			}
 		}
 
-		// Finally, we'll sign the input as is, and populate the input
+		// Finally, if the input doesn't belong to a watch-only account,
-		// with the witness and sigScript (if needed).
+		// then we'll sign it as is, and populate the input with the
+		// witness and sigScript (if needed).
+		watchOnly := false
+		err = walletdb.View(w.db, func(tx walletdb.ReadTx) error {
+			ns := tx.ReadBucket(waddrmgrNamespaceKey)
+			var err error
+			if keyScope == nil {
+				// If a key scope wasn't specified, then coin
+				// selection was performed from the default
+				// wallet accounts (NP2WKH, P2WKH), so any key
+				// scope provided doesn't impact the result of
+				// this call.
+				watchOnly, err = w.Manager.IsWatchOnlyAccount(
+					ns, waddrmgr.KeyScopeBIP0084, account,
+				)
+			} else {
+				watchOnly, err = w.Manager.IsWatchOnlyAccount(
+					ns, *keyScope, account,
+				)
+			}
+			return err
+		})
+		if err != nil {
+			return fmt.Errorf("unable to determine if account is "+
+				"watch-only: %v", err)
+		}
+		if watchOnly {
+			continue
+		}
+
 		witness, sigScript, err := w.ComputeInputScript(
 			tx, signOutput, idx, sigHashes, in.SighashType, nil,
 		)

wallet/psbt_test.go

@@ -219,7 +219,7 @@ func TestFundPsbt(t *testing.T) {
 		tc := tc
 		t.Run(tc.name, func(t *testing.T) {
 			changeIndex, err := w.FundPsbt(
-				tc.packet, 0, tc.feeRateSatPerKB,
+				tc.packet, nil, 0, tc.feeRateSatPerKB,
 			)
 
 			// In any case, unlock the UTXO before continuing, we
@@ -391,7 +391,7 @@ func TestFinalizePsbt(t *testing.T) {
 	}
 
 	// Finalize it to add all witness data then extract the final TX.
-	err = w.FinalizePsbt(packet)
+	err = w.FinalizePsbt(nil, 0, packet)
 	if err != nil {
 		t.Fatalf("error finalizing PSBT packet: %v", err)
 	}

wallet/signer.go

@@ -5,6 +5,8 @@
 package wallet
 
 import (
+	"fmt"
+
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
@@ -12,6 +14,71 @@ import (
 	"github.com/btcsuite/btcwallet/waddrmgr"
 )
 
+// scriptForOutput returns the address, witness program and redeem script for a
+// given UTXO. An error is returned if the UTXO does not belong to our wallet or
+// it is not a managed pubKey address.
+func (w *Wallet) scriptForOutput(output *wire.TxOut) (
+	waddrmgr.ManagedPubKeyAddress, []byte, []byte, error) {
+
+	// First make sure we can sign for the input by making sure the script
+	// in the UTXO belongs to our wallet and we have the private key for it.
+	walletAddr, err := w.fetchOutputAddr(output.PkScript)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	pubKeyAddr, ok := walletAddr.(waddrmgr.ManagedPubKeyAddress)
+	if !ok {
+		return nil, nil, nil, fmt.Errorf("address %s is not a "+
+			"p2wkh or np2wkh address", walletAddr.Address())
+	}
+
+	var (
+		witnessProgram []byte
+		sigScript      []byte
+	)
+
+	switch {
+	// If we're spending p2wkh output nested within a p2sh output, then
+	// we'll need to attach a sigScript in addition to witness data.
+	case walletAddr.AddrType() == waddrmgr.NestedWitnessPubKey:
+		pubKey := pubKeyAddr.PubKey()
+		pubKeyHash := btcutil.Hash160(pubKey.SerializeCompressed())
+
+		// Next, we'll generate a valid sigScript that will allow us to
+		// spend the p2sh output. The sigScript will contain only a
+		// single push of the p2wkh witness program corresponding to
+		// the matching public key of this address.
+		p2wkhAddr, err := btcutil.NewAddressWitnessPubKeyHash(
+			pubKeyHash, w.chainParams,
+		)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		witnessProgram, err = txscript.PayToAddrScript(p2wkhAddr)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+
+		bldr := txscript.NewScriptBuilder()
+		bldr.AddData(witnessProgram)
+		sigScript, err = bldr.Script()
+		if err != nil {
+			return nil, nil, nil, err
+		}
+
+	// Otherwise, this is a regular p2wkh output, so we include the
+	// witness program itself as the subscript to generate the proper
+	// sighash digest. As part of the new sighash digest algorithm, the
+	// p2wkh witness program will be expanded into a regular p2kh
+	// script.
+	default:
+		witnessProgram = output.PkScript
+	}
+
+	return pubKeyAddr, witnessProgram, sigScript, nil
+}
+
 // PrivKeyTweaker is a function type that can be used to pass in a callback for
 // tweaking a private key before it's used to sign an input.
 type PrivKeyTweaker func(*btcec.PrivateKey) (*btcec.PrivateKey, error)
@@ -25,62 +92,16 @@ func (w *Wallet) ComputeInputScript(tx *wire.MsgTx, output *wire.TxOut,
 	hashType txscript.SigHashType, tweaker PrivKeyTweaker) (wire.TxWitness,
 	[]byte, error) {
 
-	// First make sure we can sign for the input by making sure the script
+	walletAddr, witnessProgram, sigScript, err := w.scriptForOutput(output)
-	// in the UTXO belongs to our wallet and we have the private key for it.
-	walletAddr, err := w.fetchOutputAddr(output.PkScript)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	pka := walletAddr.(waddrmgr.ManagedPubKeyAddress)
+	privKey, err := walletAddr.PrivKey()
-	privKey, err := pka.PrivKey()
 	if err != nil {
 		return nil, nil, err
 	}
 
-	var (
-		witnessProgram []byte
-		sigScript      []byte
-	)
-
-	switch {
-	// If we're spending p2wkh output nested within a p2sh output, then
-	// we'll need to attach a sigScript in addition to witness data.
-	case pka.AddrType() == waddrmgr.NestedWitnessPubKey:
-		pubKey := privKey.PubKey()
-		pubKeyHash := btcutil.Hash160(pubKey.SerializeCompressed())
-
-		// Next, we'll generate a valid sigScript that will allow us to
-		// spend the p2sh output. The sigScript will contain only a
-		// single push of the p2wkh witness program corresponding to
-		// the matching public key of this address.
-		p2wkhAddr, err := btcutil.NewAddressWitnessPubKeyHash(
-			pubKeyHash, w.chainParams,
-		)
-		if err != nil {
-			return nil, nil, err
-		}
-		witnessProgram, err = txscript.PayToAddrScript(p2wkhAddr)
-		if err != nil {
-			return nil, nil, err
-		}
-
-		bldr := txscript.NewScriptBuilder()
-		bldr.AddData(witnessProgram)
-		sigScript, err = bldr.Script()
-		if err != nil {
-			return nil, nil, err
-		}
-
-	// Otherwise, this is a regular p2wkh output, so we include the
-	// witness program itself as the subscript to generate the proper
-	// sighash digest. As part of the new sighash digest algorithm, the
-	// p2wkh witness program will be expanded into a regular p2kh
-	// script.
-	default:
-		witnessProgram = output.PkScript
-	}
-
 	// If we need to maybe tweak our private key, do it now.
 	if tweaker != nil {
 		privKey, err = tweaker(privKey)

wallet/txauthor/author.go

@@ -60,8 +60,15 @@ type AuthoredTx struct {
 	ChangeIndex     int // negative if no change
 }
 
-// ChangeSource provides P2PKH change output scripts for transaction creation.
+// ChangeSource provides change output scripts for transaction creation.
-type ChangeSource func() ([]byte, error)
+type ChangeSource struct {
+	// NewScript is a closure that produces unique change output scripts per
+	// invocation.
+	NewScript func() ([]byte, error)
+
+	// ScriptSize is the size in bytes of scripts produced by `NewScript`.
+	ScriptSize int
+}
 
 // NewUnsignedTransaction creates an unsigned transaction paying to one or more
 // non-change outputs.  An appropriate transaction fee is included based on the
@@ -84,10 +91,12 @@ type ChangeSource func() ([]byte, error)
 //
 // BUGS: Fee estimation may be off when redeeming non-compressed P2PKH outputs.
 func NewUnsignedTransaction(outputs []*wire.TxOut, feeRatePerKb btcutil.Amount,
-	fetchInputs InputSource, fetchChange ChangeSource) (*AuthoredTx, error) {
+	fetchInputs InputSource, changeSource *ChangeSource) (*AuthoredTx, error) {
 
 	targetAmount := SumOutputValues(outputs)
-	estimatedSize := txsizes.EstimateVirtualSize(0, 1, 0, outputs, true)
+	estimatedSize := txsizes.EstimateVirtualSize(
+		0, 1, 0, outputs, changeSource.ScriptSize,
+	)
 	targetFee := txrules.FeeForSerializeSize(feeRatePerKb, estimatedSize)
 
 	for {
@@ -115,8 +124,9 @@ func NewUnsignedTransaction(outputs []*wire.TxOut, feeRatePerKb btcutil.Amount,
 			}
 		}
 
-		maxSignedSize := txsizes.EstimateVirtualSize(p2pkh, p2wpkh,
+		maxSignedSize := txsizes.EstimateVirtualSize(
-			nested, outputs, true)
+			p2pkh, p2wpkh, nested, outputs, changeSource.ScriptSize,
+		)
 		maxRequiredFee := txrules.FeeForSerializeSize(feeRatePerKb, maxSignedSize)
 		remainingAmount := inputAmount - targetAmount
 		if remainingAmount < maxRequiredFee {
@@ -130,18 +140,16 @@ func NewUnsignedTransaction(outputs []*wire.TxOut, feeRatePerKb btcutil.Amount,
 			TxOut:    outputs,
 			LockTime: 0,
 		}
+
 		changeIndex := -1
 		changeAmount := inputAmount - targetAmount - maxRequiredFee
 		if changeAmount != 0 && !txrules.IsDustAmount(changeAmount,
-			txsizes.P2WPKHPkScriptSize, txrules.DefaultRelayFeePerKb) {
+			changeSource.ScriptSize, txrules.DefaultRelayFeePerKb) {
-			changeScript, err := fetchChange()
+
+			changeScript, err := changeSource.NewScript()
 			if err != nil {
 				return nil, err
 			}
-			if len(changeScript) > txsizes.P2WPKHPkScriptSize {
-				return nil, errors.New("fee estimation requires change " +
-					"scripts no larger than P2WPKH output scripts")
-			}
 			change := wire.NewTxOut(int64(changeAmount), changeScript)
 			l := len(outputs)
 			unsignedTransaction.TxOut = append(outputs[:l:l], change)

wallet/txauthor/author_test.go

@@ -61,7 +61,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 			Outputs:        p2pkhOutputs(1e6),
 			RelayFee:       1e3,
 			ChangeAmount: 1e8 - 1e6 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6), true)),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6), txsizes.P2WPKHPkScriptSize)),
 			InputCount: 1,
 		},
 		2: {
@@ -69,7 +69,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 			Outputs:        p2pkhOutputs(1e6),
 			RelayFee:       1e4,
 			ChangeAmount: 1e8 - 1e6 - txrules.FeeForSerializeSize(1e4,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6), true)),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6), txsizes.P2WPKHPkScriptSize)),
 			InputCount: 1,
 		},
 		3: {
@@ -77,7 +77,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 			Outputs:        p2pkhOutputs(1e6, 1e6, 1e6),
 			RelayFee:       1e4,
 			ChangeAmount: 1e8 - 3e6 - txrules.FeeForSerializeSize(1e4,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6, 1e6, 1e6), true)),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6, 1e6, 1e6), txsizes.P2WPKHPkScriptSize)),
 			InputCount: 1,
 		},
 		4: {
@@ -85,7 +85,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 			Outputs:        p2pkhOutputs(1e6, 1e6, 1e6),
 			RelayFee:       2.55e3,
 			ChangeAmount: 1e8 - 3e6 - txrules.FeeForSerializeSize(2.55e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6, 1e6, 1e6), true)),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(1e6, 1e6, 1e6), txsizes.P2WPKHPkScriptSize)),
 			InputCount: 1,
 		},
 
@@ -93,7 +93,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		5: {
 			UnspentOutputs: p2pkhOutputs(1e8),
 			Outputs: p2pkhOutputs(1e8 - 545 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     1e3,
 			ChangeAmount: 545,
 			InputCount:   1,
@@ -101,7 +101,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		6: {
 			UnspentOutputs: p2pkhOutputs(1e8),
 			Outputs: p2pkhOutputs(1e8 - 546 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     1e3,
 			ChangeAmount: 546,
 			InputCount:   1,
@@ -111,7 +111,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		7: {
 			UnspentOutputs: p2pkhOutputs(1e8),
 			Outputs: p2pkhOutputs(1e8 - 1392 - txrules.FeeForSerializeSize(2.55e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     2.55e3,
 			ChangeAmount: 1392,
 			InputCount:   1,
@@ -119,7 +119,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		8: {
 			UnspentOutputs: p2pkhOutputs(1e8),
 			Outputs: p2pkhOutputs(1e8 - 1393 - txrules.FeeForSerializeSize(2.55e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     2.55e3,
 			ChangeAmount: 1393,
 			InputCount:   1,
@@ -131,7 +131,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		9: {
 			UnspentOutputs: p2pkhOutputs(1e8, 1e8),
 			Outputs: p2pkhOutputs(1e8 - 546 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     1e3,
 			ChangeAmount: 546,
 			InputCount:   1,
@@ -145,7 +145,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		10: {
 			UnspentOutputs: p2pkhOutputs(1e8, 1e8),
 			Outputs: p2pkhOutputs(1e8 - 545 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), true))),
+				txsizes.EstimateVirtualSize(1, 0, 0, p2pkhOutputs(0), txsizes.P2WPKHPkScriptSize))),
 			RelayFee:     1e3,
 			ChangeAmount: 545,
 			InputCount:   1,
@@ -157,7 +157,7 @@ func TestNewUnsignedTransaction(t *testing.T) {
 			Outputs:        p2pkhOutputs(1e8),
 			RelayFee:       1e3,
 			ChangeAmount: 1e8 - txrules.FeeForSerializeSize(1e3,
-				txsizes.EstimateVirtualSize(2, 0, 0, p2pkhOutputs(1e8), true)),
+				txsizes.EstimateVirtualSize(2, 0, 0, p2pkhOutputs(1e8), txsizes.P2WPKHPkScriptSize)),
 			InputCount: 2,
 		},
 
@@ -172,9 +172,12 @@ func TestNewUnsignedTransaction(t *testing.T) {
 		},
 	}
 
-	changeSource := func() ([]byte, error) {
+	changeSource := &ChangeSource{
+		NewScript: func() ([]byte, error) {
 			// Only length matters for these tests.
 			return make([]byte, txsizes.P2WPKHPkScriptSize), nil
+		},
+		ScriptSize: txsizes.P2WPKHPkScriptSize,
 	}
 
 	for i, test := range tests {

wallet/txsizes/size.go

@@ -82,6 +82,16 @@ const (
 	//   - 4 bytes sequence
 	RedeemP2WPKHInputSize = 32 + 4 + 1 + RedeemP2WPKHScriptSize + 4
 
+	// NestedP2WPKHPkScriptSize is the size of a transaction output script
+	// that pays to a pay-to-witness-key hash nested in P2SH (P2SH-P2WPKH).
+	// It is calculated as:
+	//
+	//   - OP_HASH160
+	//   - OP_DATA_20
+	//   - 20 bytes script hash
+	//   - OP_EQUAL
+	NestedP2WPKHPkScriptSize = 1 + 1 + 20 + 1
+
 	// RedeemNestedP2WPKHScriptSize is the worst case size of a transaction
 	// input script that redeems a pay-to-witness-key hash nested in P2SH
 	// (P2SH-P2WPKH). It is calculated as:
@@ -150,12 +160,14 @@ func EstimateSerializeSize(inputCount int, txOuts []*wire.TxOut, addChangeOutput
 // from txOuts. The estimate is incremented for an additional P2PKH
 // change output if addChangeOutput is true.
 func EstimateVirtualSize(numP2PKHIns, numP2WPKHIns, numNestedP2WPKHIns int,
-	txOuts []*wire.TxOut, addChangeOutput bool) int {
+	txOuts []*wire.TxOut, changeScriptSize int) int {
-	changeSize := 0
 	outputCount := len(txOuts)
-	if addChangeOutput {
+
-		// We are always using P2WPKH as change output.
+	changeOutputSize := 0
-		changeSize = P2WPKHOutputSize
+	if changeScriptSize > 0 {
+		changeOutputSize = 8 +
+			wire.VarIntSerializeSize(uint64(changeScriptSize)) +
+			changeScriptSize
 		outputCount++
 	}
 
@@ -170,7 +182,7 @@ func EstimateVirtualSize(numP2PKHIns, numP2WPKHIns, numNestedP2WPKHIns int,
 		numP2WPKHIns*RedeemP2WPKHInputSize +
 		numNestedP2WPKHIns*RedeemNestedP2WPKHInputSize +
 		SumOutputSerializeSizes(txOuts) +
-		changeSize
+		changeOutputSize
 
 	// If this transaction has any witness inputs, we must count the
 	// witness data.

wallet/txsizes/size_test.go

@@ -163,8 +163,12 @@ func TestEstimateVirtualSize(t *testing.T) {
 			t.Fatalf("unable to get test tx: %v", err)
 		}
 
+		changeScriptSize := 0
+		if test.change {
+			changeScriptSize = P2WPKHPkScriptSize
+		}
 		est := EstimateVirtualSize(test.p2pkhIns, test.p2wpkhIns,
-			test.nestedp2wpkhIns, tx.TxOut, test.change)
+			test.nestedp2wpkhIns, tx.TxOut, changeScriptSize)
 
 		if est != test.result {
 			t.Fatalf("expected estimated vsize to be %d, "+

wallet/utxos.go

@@ -11,6 +11,8 @@ import (
 
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil/hdkeychain"
+	"github.com/btcsuite/btcutil/psbt"
 	"github.com/btcsuite/btcwallet/waddrmgr"
 	"github.com/btcsuite/btcwallet/walletdb"
 )
@@ -105,15 +107,15 @@ func (w *Wallet) UnspentOutputs(policy OutputSelectionPolicy) ([]*TransactionOut
 // full transaction, the target txout and the number of confirmations are
 // returned. Otherwise, a non-nil error value of ErrNotMine is returned instead.
 func (w *Wallet) FetchInputInfo(prevOut *wire.OutPoint) (*wire.MsgTx,
-	*wire.TxOut, int64, error) {
+	*wire.TxOut, *psbt.Bip32Derivation, int64, error) {
 
 	// We manually look up the output within the tx store.
 	txid := &prevOut.Hash
 	txDetail, err := UnstableAPI(w).TxDetails(txid)
 	if err != nil {
-		return nil, nil, 0, err
+		return nil, nil, nil, 0, err
 	} else if txDetail == nil {
-		return nil, nil, 0, ErrNotMine
+		return nil, nil, nil, 0, ErrNotMine
 	}
 
 	// With the output retrieved, we'll make an additional check to ensure
@@ -122,19 +124,25 @@ func (w *Wallet) FetchInputInfo(prevOut *wire.OutPoint) (*wire.MsgTx,
 	// like in the event of us being the sender of the transaction.
 	numOutputs := uint32(len(txDetail.TxRecord.MsgTx.TxOut))
 	if prevOut.Index >= numOutputs {
-		return nil, nil, 0, fmt.Errorf("invalid output index %v for "+
+		return nil, nil, nil, 0, fmt.Errorf("invalid output index %v for "+
 			"transaction with %v outputs", prevOut.Index,
 			numOutputs)
 	}
 	pkScript := txDetail.TxRecord.MsgTx.TxOut[prevOut.Index].PkScript
-	if _, err := w.fetchOutputAddr(pkScript); err != nil {
+	addr, err := w.fetchOutputAddr(pkScript)
-		return nil, nil, 0, err
+	if err != nil {
+		return nil, nil, nil, 0, err
 	}
+	pubKeyAddr, ok := addr.(waddrmgr.ManagedPubKeyAddress)
+	if !ok {
+		return nil, nil, nil, 0, err
+	}
+	keyScope, derivationPath, _ := pubKeyAddr.DerivationInfo()
 
 	// Determine the number of confirmations the output currently has.
 	_, currentHeight, err := w.chainClient.GetBestBlock()
 	if err != nil {
-		return nil, nil, 0, fmt.Errorf("unable to retrieve current "+
+		return nil, nil, nil, 0, fmt.Errorf("unable to retrieve current "+
 			"height: %v", err)
 	}
 	confs := int64(0)
@@ -145,6 +153,16 @@ func (w *Wallet) FetchInputInfo(prevOut *wire.OutPoint) (*wire.MsgTx,
 	return &txDetail.TxRecord.MsgTx, &wire.TxOut{
 			Value:    txDetail.TxRecord.MsgTx.TxOut[prevOut.Index].Value,
 			PkScript: pkScript,
+		}, &psbt.Bip32Derivation{
+			PubKey:               pubKeyAddr.PubKey().SerializeCompressed(),
+			MasterKeyFingerprint: derivationPath.MasterKeyFingerprint,
+			Bip32Path: []uint32{
+				keyScope.Purpose + hdkeychain.HardenedKeyStart,
+				keyScope.Coin + hdkeychain.HardenedKeyStart,
+				derivationPath.Account,
+				derivationPath.Branch,
+				derivationPath.Index,
+			},
 		}, confs, nil
 }
 

wallet/utxos_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil/hdkeychain"
 	"github.com/btcsuite/btcwallet/waddrmgr"
 )
 
@@ -43,7 +44,7 @@ func TestFetchInputInfo(t *testing.T) {
 		Hash:  incomingTx.TxHash(),
 		Index: 0,
 	}
-	tx, out, confirmations, err := w.FetchInputInfo(prevOut)
+	tx, out, derivationPath, confirmations, err := w.FetchInputInfo(prevOut)
 	if err != nil {
 		t.Fatalf("error fetching input info: %v", err)
 	}
@@ -54,6 +55,34 @@ func TestFetchInputInfo(t *testing.T) {
 		t.Fatalf("unexpected TX out, got %v wanted %v",
 			tx.TxOut[prevOut.Index].PkScript, utxOut)
 	}
+	if len(derivationPath.Bip32Path) != 5 {
+		t.Fatalf("expected derivation path of length %v, got %v", 3,
+			len(derivationPath.Bip32Path))
+	}
+	if derivationPath.Bip32Path[0] !=
+		waddrmgr.KeyScopeBIP0084.Purpose+hdkeychain.HardenedKeyStart {
+		t.Fatalf("expected purpose %v, got %v",
+			waddrmgr.KeyScopeBIP0084.Purpose,
+			derivationPath.Bip32Path[0])
+	}
+	if derivationPath.Bip32Path[1] !=
+		waddrmgr.KeyScopeBIP0084.Coin+hdkeychain.HardenedKeyStart {
+		t.Fatalf("expected coin type %v, got %v",
+			waddrmgr.KeyScopeBIP0084.Coin,
+			derivationPath.Bip32Path[1])
+	}
+	if derivationPath.Bip32Path[2] != hdkeychain.HardenedKeyStart {
+		t.Fatalf("expected account %v, got %v",
+			hdkeychain.HardenedKeyStart, derivationPath.Bip32Path[2])
+	}
+	if derivationPath.Bip32Path[3] != 0 {
+		t.Fatalf("expected branch %v, got %v", 0,
+			derivationPath.Bip32Path[3])
+	}
+	if derivationPath.Bip32Path[4] != 0 {
+		t.Fatalf("expected index %v, got %v", 0,
+			derivationPath.Bip32Path[4])
+	}
 	if confirmations != int64(0-testBlockHeight) {
 		t.Fatalf("unexpected number of confirmations, got %d wanted %d",
 			confirmations, 0-testBlockHeight)

wallet/wallet.go

@@ -1125,6 +1125,7 @@ func logFilterBlocksResp(block wtxmgr.BlockMeta,
 
 type (
 	createTxRequest struct {
+		keyScope    *waddrmgr.KeyScope
 		account     uint32
 		outputs     []*wire.TxOut
 		minconf     int32
@@ -1159,8 +1160,10 @@ out:
 				txr.resp <- createTxResponse{nil, err}
 				continue
 			}
-			tx, err := w.txToOutputs(txr.outputs, txr.account,
+			tx, err := w.txToOutputs(
-				txr.minconf, txr.feeSatPerKB, txr.dryRun)
+				txr.outputs, txr.keyScope, txr.account,
+				txr.minconf, txr.feeSatPerKB, txr.dryRun,
+			)
 			heldUnlock.release()
 			txr.resp <- createTxResponse{tx, err}
 		case <-quit:
@@ -1170,20 +1173,25 @@ out:
 	w.wg.Done()
 }
 
-// CreateSimpleTx creates a new signed transaction spending unspent P2PKH
+// CreateSimpleTx creates a new signed transaction spending unspent outputs with
-// outputs with at least minconf confirmations spending to any number of
+// at least minconf confirmations spending to any number of address/amount
-// address/amount pairs.  Change and an appropriate transaction fee are
+// pairs. Only unspent outputs belonging to the given key scope and account will
-// automatically included, if necessary.  All transaction creation through this
+// be selected, unless a key scope is not specified. In that case, inputs from all
-// function is serialized to prevent the creation of many transactions which
+// accounts may be selected, no matter what key scope they belong to. This is
-// spend the same outputs.
+// done to handle the default account case, where a user wants to fund a PSBT
+// with inputs regardless of their type (NP2WKH, P2WKH, etc.). Change and an
+// appropriate transaction fee are automatically included, if necessary. All
+// transaction creation through this function is serialized to prevent the
+// creation of many transactions which spend the same outputs.
 //
 // NOTE: The dryRun argument can be set true to create a tx that doesn't alter
 // the database. A tx created with this set to true SHOULD NOT be broadcasted.
-func (w *Wallet) CreateSimpleTx(account uint32, outputs []*wire.TxOut,
+func (w *Wallet) CreateSimpleTx(keyScope *waddrmgr.KeyScope, account uint32,
-	minconf int32, satPerKb btcutil.Amount, dryRun bool) (
+	outputs []*wire.TxOut, minconf int32, satPerKb btcutil.Amount,
-	*txauthor.AuthoredTx, error) {
+	dryRun bool) (*txauthor.AuthoredTx, error) {
 
 	req := createTxRequest{
+		keyScope:    keyScope,
 		account:     account,
 		outputs:     outputs,
 		minconf:     minconf,
@@ -1754,6 +1762,46 @@ func (w *Wallet) AccountProperties(scope waddrmgr.KeyScope, acct uint32) (*waddr
 	return props, err
 }
 
+// AccountPropertiesByName returns the properties of an account by its name. It
+// first fetches the desynced information from the address manager, then updates
+// the indexes based on the address pools.
+func (w *Wallet) AccountPropertiesByName(scope waddrmgr.KeyScope,
+	name string) (*waddrmgr.AccountProperties, error) {
+
+	manager, err := w.Manager.FetchScopedKeyManager(scope)
+	if err != nil {
+		return nil, err
+	}
+
+	var props *waddrmgr.AccountProperties
+	err = walletdb.View(w.db, func(tx walletdb.ReadTx) error {
+		waddrmgrNs := tx.ReadBucket(waddrmgrNamespaceKey)
+		acct, err := manager.LookupAccount(waddrmgrNs, name)
+		if err != nil {
+			return err
+		}
+		props, err = manager.AccountProperties(waddrmgrNs, acct)
+		return err
+	})
+	return props, err
+}
+
+// LookupAccount returns the corresponding key scope and account number for the
+// account with the given name.
+func (w *Wallet) LookupAccount(name string) (waddrmgr.KeyScope, uint32, error) {
+	var (
+		keyScope waddrmgr.KeyScope
+		account  uint32
+	)
+	err := walletdb.View(w.db, func(tx walletdb.ReadTx) error {
+		ns := tx.ReadBucket(waddrmgrNamespaceKey)
+		var err error
+		keyScope, account, err = w.Manager.LookupAccount(ns, name)
+		return err
+	})
+	return keyScope, account, err
+}
+
 // RenameAccount sets the name for an account number to newName.
 func (w *Wallet) RenameAccount(scope waddrmgr.KeyScope, account uint32, newName string) error {
 	manager, err := w.Manager.FetchScopedKeyManager(scope)
@@ -2178,7 +2226,9 @@ type GetTransactionsResult struct {
 // Transaction results are organized by blocks in ascending order and unmined
 // transactions in an unspecified order.  Mined transactions are saved in a
 // Block structure which records properties about the block.
-func (w *Wallet) GetTransactions(startBlock, endBlock *BlockIdentifier, cancel <-chan struct{}) (*GetTransactionsResult, error) {
+func (w *Wallet) GetTransactions(startBlock, endBlock *BlockIdentifier,
+	accountName string, cancel <-chan struct{}) (*GetTransactionsResult, error) {
+
 	var start, end int32 = 0, -1
 
 	w.chainClientLock.Lock()
@@ -2500,7 +2550,7 @@ func (s creditSlice) Swap(i, j int) {
 // contained within it will be considered.  If we know nothing about a
 // transaction an empty array will be returned.
 func (w *Wallet) ListUnspent(minconf, maxconf int32,
-	addresses map[string]struct{}) ([]*btcjson.ListUnspentResult, error) {
+	accountName string) ([]*btcjson.ListUnspentResult, error) {
 
 	var results []*btcjson.ListUnspentResult
 	err := walletdb.View(w.db, func(tx walletdb.ReadTx) error {
@@ -2509,7 +2559,7 @@ func (w *Wallet) ListUnspent(minconf, maxconf int32,
 
 		syncBlock := w.Manager.SyncedTo()
 
-		filter := len(addresses) != 0
+		filter := accountName != ""
 		unspent, err := w.TxStore.UnspentOutputs(txmgrNs)
 		if err != nil {
 			return err
@@ -2548,7 +2598,7 @@ func (w *Wallet) ListUnspent(minconf, maxconf int32,
 			//
 			// This will be unnecessary once transactions and outputs are
 			// grouped under the associated account in the db.
-			acctName := defaultAccountName
+			outputAcctName := defaultAccountName
 			sc, addrs, _, err := txscript.ExtractPkScriptAddrs(
 				output.PkScript, w.chainParams)
 			if err != nil {
@@ -2559,22 +2609,15 @@ func (w *Wallet) ListUnspent(minconf, maxconf int32,
 				if err == nil {
 					s, err := smgr.AccountName(addrmgrNs, acct)
 					if err == nil {
-						acctName = s
+						outputAcctName = s
 					}
 				}
 			}
 
-			if filter {
+			if filter && outputAcctName != accountName {
-				for _, addr := range addrs {
-					_, ok := addresses[addr.EncodeAddress()]
-					if ok {
-						goto include
-					}
-				}
 				continue
 			}
 
-		include:
 			// At the moment watch-only addresses are not supported, so all
 			// recorded outputs that are not multisig are "spendable".
 			// Multisig outputs are only "spendable" if all keys are
@@ -2614,7 +2657,7 @@ func (w *Wallet) ListUnspent(minconf, maxconf int32,
 			result := &btcjson.ListUnspentResult{
 				TxID:          output.OutPoint.Hash.String(),
 				Vout:          output.OutPoint.Index,
-				Account:       acctName,
+				Account:       outputAcctName,
 				ScriptPubKey:  hex.EncodeToString(output.PkScript),
 				Amount:        output.Amount.ToBTC(),
 				Confirmations: int64(confs),
@@ -3104,10 +3147,16 @@ func (w *Wallet) TotalReceivedForAddr(addr btcutil.Address, minConf int32) (btcu
 	return amount, err
 }
 
-// SendOutputs creates and sends payment transactions. It returns the
+// SendOutputs creates and sends payment transactions. Coin selection is
-// transaction upon success.
+// performed by the wallet, choosing inputs that belong to the given key scope
-func (w *Wallet) SendOutputs(outputs []*wire.TxOut, account uint32,
+// and account, unless a key scope is not specified. In that case, inputs from
-	minconf int32, satPerKb btcutil.Amount, label string) (*wire.MsgTx, error) {
+// accounts matching the account number provided across all key scopes may be
+// selected. This is done to handle the default account case, where a user wants
+// to fund a PSBT with inputs regardless of their type (NP2WKH, P2WKH, etc.). It
+// returns the transaction upon success.
+func (w *Wallet) SendOutputs(outputs []*wire.TxOut, keyScope *waddrmgr.KeyScope,
+	account uint32, minconf int32, satPerKb btcutil.Amount,
+	label string) (*wire.MsgTx, error) {
 
 	// Ensure the outputs to be created adhere to the network's consensus
 	// rules.
@@ -3125,7 +3174,7 @@ func (w *Wallet) SendOutputs(outputs []*wire.TxOut, account uint32,
 	// continue to re-broadcast the transaction upon restarts until it has
 	// been confirmed.
 	createdTx, err := w.CreateSimpleTx(
-		account, outputs, minconf, satPerKb, false,
+		keyScope, account, outputs, minconf, satPerKb, false,
 	)
 	if err != nil {
 		return nil, err