lnd/lnrpc/walletrpc/walletkit_util.go
ziggie 7b68289a7a
walletrpc: add sign/verify methods
Adding the grpc functionality to sign and verify messages with
single addresses
2023-01-24 09:22:05 +01:00

99 lines
2.5 KiB
Go

package walletrpc
import (
"bytes"
"fmt"
"strconv"
"strings"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/lnrpc"
)
// AccountsToWatchOnly converts the accounts returned by the walletkit's
// ListAccounts RPC into a struct that can be used to create a watch-only
// wallet.
func AccountsToWatchOnly(exported []*Account) ([]*lnrpc.WatchOnlyAccount,
error) {
result := make([]*lnrpc.WatchOnlyAccount, len(exported))
for idx, acct := range exported {
parsedPath, err := parseDerivationPath(acct.DerivationPath)
if err != nil {
return nil, fmt.Errorf("error parsing derivation path "+
"of account %d: %v", idx, err)
}
if len(parsedPath) < 3 {
return nil, fmt.Errorf("derivation path of account %d "+
"has invalid derivation path, need at least "+
"path of depth 3, instead has depth %d", idx,
len(parsedPath))
}
result[idx] = &lnrpc.WatchOnlyAccount{
Purpose: parsedPath[0],
CoinType: parsedPath[1],
Account: parsedPath[2],
Xpub: acct.ExtendedPublicKey,
}
}
return result, nil
}
// parseDerivationPath parses a path in the form of m/x'/y'/z'/a/b into a slice
// of [x, y, z, a, b], meaning that the apostrophe is ignored and 2^31 is _not_
// added to the numbers.
func parseDerivationPath(path string) ([]uint32, error) {
path = strings.TrimSpace(path)
if len(path) == 0 {
return nil, fmt.Errorf("path cannot be empty")
}
if !strings.HasPrefix(path, "m/") {
return nil, fmt.Errorf("path must start with m/")
}
// Just the root key, no path was provided. This is valid but not useful
// in most cases.
rest := strings.ReplaceAll(path, "m/", "")
if rest == "" {
return []uint32{}, nil
}
parts := strings.Split(rest, "/")
indices := make([]uint32, len(parts))
for i := 0; i < len(parts); i++ {
part := parts[i]
if strings.Contains(parts[i], "'") {
part = strings.TrimRight(parts[i], "'")
}
parsed, err := strconv.ParseInt(part, 10, 32)
if err != nil {
return nil, fmt.Errorf("could not parse part \"%s\": "+
"%v", part, err)
}
indices[i] = uint32(parsed)
}
return indices, nil
}
// doubleHashMessage creates the double hash (sha256) of a message
// prepended with a specified prefix.
func doubleHashMessage(prefix string, msg string) ([]byte, error) {
var buf bytes.Buffer
err := wire.WriteVarString(&buf, 0, prefix)
if err != nil {
return nil, err
}
err = wire.WriteVarString(&buf, 0, msg)
if err != nil {
return nil, err
}
digest := chainhash.DoubleHashB(buf.Bytes())
return digest, nil
}