Use bip322 to build pop through bitcoind (#186)

* Use bip322 to build pop through bitcoind

babylonclient/pop.go

@@ -3,10 +3,13 @@ package babylonclient
 import (
 	"fmt"
 
+	"github.com/babylonchain/babylon/crypto/bip322"
 	bbn "github.com/babylonchain/babylon/types"
 	btcstypes "github.com/babylonchain/babylon/x/btcstaking/types"
 	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/wire"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
@@ -23,6 +26,8 @@ type BabylonPop struct {
 	BtcSig  []byte
 }
 
+// NewBabylonPop Generic constructor for BabylonPop that do as little validation
+// as possible. It assumes passed btcSigOverBbnAddr is matching the popType `t`
 func NewBabylonPop(t BabylonBtcPopType, btcSigOverBbnAddr []byte) (*BabylonPop, error) {
 	if len(btcSigOverBbnAddr) == 0 {
 		return nil, fmt.Errorf("cannot create BabylonPop with empty signatures")
@@ -34,6 +39,39 @@ func NewBabylonPop(t BabylonBtcPopType, btcSigOverBbnAddr []byte) (*BabylonPop,
 	}, nil
 }
 
+// NewBabylonBip322Pop build proper BabylonPop in BIP322 style, it verifies the
+// the bip322 signature validity
+func NewBabylonBip322Pop(
+	msg []byte,
+	w wire.TxWitness,
+	a btcutil.Address) (*BabylonPop, error) {
+	// TODO: bip322.Verify does not use it last parameter and this parameter should
+	// be removed from the function signature upstream.
+	// after that, we can remove the nil parameter here
+	if err := bip322.Verify(msg, w, a, nil); err != nil {
+		return nil, fmt.Errorf("invalid bip322 pop parameters: %w", err)
+	}
+
+	serializedWitness, err := bip322.SerializeWitness(w)
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to serialize bip322 witness: %w", err)
+	}
+
+	bip322Sig := btcstypes.BIP322Sig{
+		Sig:     serializedWitness,
+		Address: a.EncodeAddress(),
+	}
+
+	m, err := bip322Sig.Marshal()
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to serialize btcstypes.BIP322Sig proto: %w", err)
+	}
+
+	return NewBabylonPop(Bip322Type, m)
+}
+
 func NewBTCSigType(t BabylonBtcPopType) (btcstypes.BTCSigType, error) {
 	switch t {
 	case SchnorrType:

staker/stakerapp.go

@@ -8,9 +8,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	pv "github.com/cosmos/relayer/v2/relayer/provider"
-	"go.uber.org/zap"
-
 	"github.com/avast/retry-go/v4"
 	staking "github.com/babylonchain/babylon/btcstaking"
 	cl "github.com/babylonchain/btc-staker/babylonclient"
@@ -21,6 +18,8 @@ import (
 	"github.com/babylonchain/btc-staker/types"
 	"github.com/babylonchain/btc-staker/utils"
 	"github.com/babylonchain/btc-staker/walletcontroller"
+	pv "github.com/cosmos/relayer/v2/relayer/provider"
+	"go.uber.org/zap"
 
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcec/v2/schnorr"
@@ -1274,28 +1273,6 @@ func (app *StakerApp) BabylonController() cl.BabylonClient {
 	return app.babylonClient
 }
 
-// Generate proof of possessions for staker address.
-// Requires btc wallet to be unlocked!
-func (app *StakerApp) generatePop(stakerPrivKey *btcec.PrivateKey) (*cl.BabylonPop, error) {
-	// build proof of possession, no point moving forward if staker does not have all
-	// the necessary keys
-	babylonAddrHash := tmhash.Sum(app.babylonClient.GetKeyAddress().Bytes())
-	btcSig, err := schnorr.Sign(stakerPrivKey, babylonAddrHash)
-	if err != nil {
-		return nil, err
-	}
-
-	pop, err := cl.NewBabylonPop(
-		cl.SchnorrType,
-		btcSig.Serialize(),
-	)
-	if err != nil {
-		return nil, fmt.Errorf("failed to generate pop: %w", err)
-	}
-
-	return pop, nil
-}
-
 func GetMinStakingTime(p *cl.StakingParams) uint32 {
 	// Actual minimum staking time in babylon is k+w, but setting it to that would
 	// result in delegation which have voting power for 0 btc blocks.
@@ -1450,21 +1427,32 @@ func (app *StakerApp) StakeFunds(
 
 	// build proof of possesion, no point moving forward if staker do not have all
 	// the necessary keys
-	stakerPrivKey, err := app.wc.DumpPrivateKey(stakerAddress)
+	stakerPubKey, err := app.wc.AddressPublicKey(stakerAddress)
 
 	if err != nil {
 		return nil, err
 	}
 
-	// We build pop ourselves so no need to verify it
-	pop, err := app.generatePop(stakerPrivKey)
+	babylonAddrHash := tmhash.Sum(app.babylonClient.GetKeyAddress().Bytes())
+
+	sig, err := app.wc.SignBip322NativeSegwit(babylonAddrHash, stakerAddress)
+
+	if err != nil {
+		return nil, err
+	}
+
+	pop, err := cl.NewBabylonBip322Pop(
+		babylonAddrHash,
+		sig,
+		stakerAddress,
+	)
 
 	if err != nil {
 		return nil, err
 	}
 
 	stakingInfo, err := staking.BuildStakingInfo(
-		stakerPrivKey.PubKey(),
+		stakerPubKey,
 		fpPks,
 		params.CovenantPks,
 		params.CovenantQuruomThreshold,

walletcontroller/client.go

@@ -99,13 +99,25 @@ func (w *RpcWalletController) UnlockWallet(timoutSec int64) error {
 }
 
 func (w *RpcWalletController) AddressPublicKey(address btcutil.Address) (*btcec.PublicKey, error) {
-	privKey, err := w.DumpPrivKey(address)
+	encoded := address.EncodeAddress()
+
+	info, err := w.GetAddressInfo(encoded)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if info.PubKey == nil {
+		return nil, fmt.Errorf("address %s has no public key", encoded)
+	}
+
+	decodedHex, err := hex.DecodeString(*info.PubKey)
 
 	if err != nil {
 		return nil, err
 	}
 
-	return privKey.PrivKey.PubKey(), nil
+	return btcec.ParsePubKey(decodedHex)
 }
 
 func (w *RpcWalletController) DumpPrivateKey(address btcutil.Address) (*btcec.PrivateKey, error) {