multi: add bitcoin-descriptors to genimportscript

btc/bitcoind.go

@@ -17,6 +17,7 @@ const (
 	FormatCli          = "bitcoin-cli"
 	FormatCliWatchOnly = "bitcoin-cli-watchonly"
 	FormatImportwallet = "bitcoin-importwallet"
+	FormatDescriptors  = "bitcoin-descriptors"
 	FormatElectrum     = "electrum"
 )
 
@@ -40,6 +41,9 @@ func ParseFormat(format string) (KeyExporter, error) {
 	case FormatImportwallet:
 		return &ImportWallet{}, nil
 
+	case FormatDescriptors:
+		return &Descriptors{}, nil
+
 	case FormatElectrum:
 		return &Electrum{}, nil
 
@@ -179,19 +183,14 @@ func (c *CliWatchOnly) Format(hdKey *hdkeychain.ExtendedKey,
 	if err != nil {
 		return "", fmt.Errorf("could not create address: %w", err)
 	}
-	addrP2TR, err := lnd.P2TRAddr(pubKey, params)
-	if err != nil {
-		return "", fmt.Errorf("could not create address: %w", err)
-	}
 
 	flags := ""
 	if params.Net == wire.TestNet || params.Net == wire.TestNet3 {
 		flags = " -testnet"
 	}
 	return fmt.Sprintf("bitcoin-cli%s importpubkey %x \"%s/%d/%d/\" "+
-		"false # addr=%s,%s,%s,%s", flags, pubKey.SerializeCompressed(),
-		path, branch, index, addrP2PKH, addrP2WKH, addrNP2WKH,
-		addrP2TR), nil
+		"false # addr=%s,%s,%s", flags, pubKey.SerializeCompressed(),
+		path, branch, index, addrP2PKH, addrP2WKH, addrNP2WKH), nil
 }
 
 func (c *CliWatchOnly) Trailer(birthdayBlock uint32) string {
@@ -276,3 +275,40 @@ func (p *Electrum) Format(hdKey *hdkeychain.ExtendedKey,
 func (p *Electrum) Trailer(_ uint32) string {
 	return ""
 }
+
+type Descriptors struct{}
+
+func (d *Descriptors) Header() string {
+	return "# Paste the following lines into a command line window."
+}
+
+func (d *Descriptors) Format(hdKey *hdkeychain.ExtendedKey,
+	params *chaincfg.Params, path string, branch, index uint32) (string,
+	error) {
+
+	privKey, err := hdKey.ECPrivKey()
+	if err != nil {
+		return "", fmt.Errorf("could not derive private key: %w", err)
+	}
+	wif, err := btcutil.NewWIF(privKey, params, true)
+	if err != nil {
+		return "", fmt.Errorf("could not encode WIF: %w", err)
+	}
+
+	np2wkh := makeDescriptor("sh(wpkh(%s))", wif.String())
+	p2wkh := makeDescriptor("wpkh(%s)", wif.String())
+	p2tr := makeDescriptor("tr(%s)", wif.String())
+
+	return fmt.Sprintf("bitcoin-cli importdescriptors '[%s,%s,%s]'",
+		np2wkh, p2wkh, p2tr), nil
+}
+
+func (d *Descriptors) Trailer(birthdayBlock uint32) string {
+	return fmt.Sprintf("bitcoin-cli rescanblockchain %d\n", birthdayBlock)
+}
+
+func makeDescriptor(format, wif string) string {
+	descriptor := fmt.Sprintf(format, wif)
+	return fmt.Sprintf("{\"desc\":\"%s\",\"timestamp\":\"now\"}",
+		DescriptorSumCreate(descriptor))
+}

btc/descriptors.go

@@ -0,0 +1,83 @@
+package btc
+
+import (
+	"strings"
+)
+
+var (
+	inputCharset = "0123456789()[],'/*abcdefgh@:$%{}IJKLMNOPQRSTUVWXYZ" +
+		"&+-.;<=>?!^_|~ijklmnopqrstuvwxyzABCDEFGH`#\\\"\\\\ "
+	checksumCharset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+	generator       = []uint64{
+		0xf5dee51989, 0xa9fdca3312, 0x1bab10e32d, 0x3706b1677a,
+		0x644d626ffd,
+	}
+)
+
+func descriptorSumPolymod(symbols []uint64) uint64 {
+	chk := uint64(1)
+	for _, value := range symbols {
+		top := chk >> 35
+		chk = (chk&0x7ffffffff)<<5 ^ value
+		for i := 0; i < 5; i++ {
+			if (top>>i)&1 != 0 {
+				chk ^= generator[i]
+			}
+		}
+	}
+	return chk
+}
+
+func descriptorSumExpand(s string) []uint64 {
+	groups := []uint64{}
+	symbols := []uint64{}
+	for _, c := range s {
+		v := strings.IndexRune(inputCharset, c)
+		if v < 0 {
+			return nil
+		}
+		symbols = append(symbols, uint64(v&31))
+		groups = append(groups, uint64(v>>5))
+		if len(groups) == 3 {
+			symbols = append(
+				symbols, groups[0]*9+groups[1]*3+groups[2],
+			)
+			groups = []uint64{}
+		}
+	}
+	if len(groups) == 1 {
+		symbols = append(symbols, groups[0])
+	} else if len(groups) == 2 {
+		symbols = append(symbols, groups[0]*3+groups[1])
+	}
+	return symbols
+}
+
+func DescriptorSumCreate(s string) string {
+	symbols := append(descriptorSumExpand(s), 0, 0, 0, 0, 0, 0, 0, 0)
+	checksum := descriptorSumPolymod(symbols) ^ 1
+	builder := strings.Builder{}
+	for i := 0; i < 8; i++ {
+		builder.WriteByte(checksumCharset[(checksum>>(5*(7-i)))&31])
+	}
+	return s + "#" + builder.String()
+}
+
+func DescriptorSumCheck(s string, require bool) bool {
+	if !strings.Contains(s, "#") {
+		return !require
+	}
+	if s[len(s)-9] != '#' {
+		return false
+	}
+	for _, c := range s[len(s)-8:] {
+		if !strings.ContainsRune(checksumCharset, c) {
+			return false
+		}
+	}
+	symbols := append(
+		descriptorSumExpand(s[:len(s)-9]),
+		uint64(strings.Index(checksumCharset, s[len(s)-8:])),
+	)
+	return descriptorSumPolymod(symbols) == 1
+}

btc/descriptors_test.go

@@ -0,0 +1,27 @@
+package btc
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var testCases = []struct {
+	descriptor  string
+	expectedSum string
+}{{
+	descriptor:  "addr(mkmZxiEcEd8ZqjQWVZuC6so5dFMKEFpN2j)",
+	expectedSum: "#02wpgw69",
+}, {
+	descriptor:  "tr(cRhCT5vC5NdnSrQ2Jrah6NPCcth41uT8DWFmA6uD8R4x2ufucnYX)",
+	expectedSum: "#gwfmkgga",
+}}
+
+func TestDescriptorSum(t *testing.T) {
+	for _, tc := range testCases {
+		sum := DescriptorSumCreate(tc.descriptor)
+		require.Equal(t, tc.descriptor+tc.expectedSum, sum)
+
+		DescriptorSumCheck(sum, true)
+	}
+}

cmd/chantools/genimportscript.go

@@ -41,7 +41,9 @@ imported into other software like bitcoind.
 The following script formats are currently supported:
 * bitcoin-cli: Creates a list of bitcoin-cli importprivkey commands that can
   be used in combination with a bitcoind full node to recover the funds locked
-  in those private keys.
+  in those private keys. NOTE: This will only work for legacy wallets and only
+  for legacy, p2sh-segwit and bech32 (p2pkh, np2wkh and p2wkh) addresses. Use
+  bitcoin-descriptors and a descriptor wallet for bech32m (p2tr).
 * bitcoin-cli-watchonly: Does the same as bitcoin-cli but with the
   bitcoin-cli importpubkey command. That means, only the public keys are 
   imported into bitcoind to watch the UTXOs of those keys. The funds cannot be
@@ -49,7 +51,12 @@ The following script formats are currently supported:
 * bitcoin-importwallet: Creates a text output that is compatible with
   bitcoind's importwallet command.
 * electrum: Creates a text output that contains one private key per line with
-  the address type as the prefix, the way Electrum expects them.`,
+  the address type as the prefix, the way Electrum expects them.
+* bitcoin-descriptors: Create a list of bitcoin-cli importdescriptors commands
+  that can be used in combination with a bitcoind full node that has a
+  descriptor wallet to recover the funds locked in those private keys.
+  NOTE: This will only work for descriptor wallets and only for
+  p2sh-segwit, bech32 and bech32m (np2wkh, p2wkh and p2tr) addresses.`,
 		Example: `chantools genimportscript --format bitcoin-cli \
 	--recoverywindow 5000`,
 		RunE: cc.Execute,
@@ -58,7 +65,8 @@ The following script formats are currently supported:
 		&cc.Format, "format", "bitcoin-importwallet", "format of the "+
 			"generated import script; currently supported are: "+
 			"bitcoin-importwallet, bitcoin-cli, "+
-			"bitcoin-cli-watchonly and electrum",
+			"bitcoin-cli-watchonly, bitcoin-descriptors and "+
+			"electrum",
 	)
 	cc.cmd.Flags().BoolVar(
 		&cc.LndPaths, "lndpaths", false, "use all derivation paths "+

doc/chantools_genimportscript.md

@@ -11,7 +11,9 @@ imported into other software like bitcoind.
 The following script formats are currently supported:
 * bitcoin-cli: Creates a list of bitcoin-cli importprivkey commands that can
   be used in combination with a bitcoind full node to recover the funds locked
-  in those private keys.
+  in those private keys. NOTE: This will only work for legacy wallets and only
+  for legacy, p2sh-segwit and bech32 (p2pkh, np2wkh and p2wkh) addresses. Use
+  bitcoin-descriptors and a descriptor wallet for bech32m (p2tr).
 * bitcoin-cli-watchonly: Does the same as bitcoin-cli but with the
   bitcoin-cli importpubkey command. That means, only the public keys are 
   imported into bitcoind to watch the UTXOs of those keys. The funds cannot be
@@ -20,6 +22,11 @@ The following script formats are currently supported:
   bitcoind's importwallet command.
 * electrum: Creates a text output that contains one private key per line with
   the address type as the prefix, the way Electrum expects them.
+* bitcoin-descriptors: Create a list of bitcoin-cli importdescriptors commands
+  that can be used in combination with a bitcoind full node that has a
+  descriptor wallet to recover the funds locked in those private keys.
+  NOTE: This will only work for descriptor wallets and only for
+  p2sh-segwit, bech32 and bech32m (np2wkh, p2wkh and p2tr) addresses.
 
 ```
 chantools genimportscript [flags]
@@ -37,7 +44,7 @@ chantools genimportscript --format bitcoin-cli \
 ```
       --bip39                   read a classic BIP39 seed and passphrase from the terminal instead of asking for lnd seed format or providing the --rootkey flag
       --derivationpath string   use one specific derivation path; specify the first levels of the derivation path before any internal/external branch; Cannot be used in conjunction with --lndpaths
-      --format string           format of the generated import script; currently supported are: bitcoin-importwallet, bitcoin-cli, bitcoin-cli-watchonly and electrum (default "bitcoin-importwallet")
+      --format string           format of the generated import script; currently supported are: bitcoin-importwallet, bitcoin-cli, bitcoin-cli-watchonly, bitcoin-descriptors and electrum (default "bitcoin-importwallet")
   -h, --help                    help for genimportscript
       --lndpaths                use all derivation paths that lnd used; results in a large number of results; cannot be used in conjunction with --derivationpath
       --recoverywindow uint32   number of keys to scan per internal/external branch; output will consist of double this amount of keys (default 2500)