improve loan approval and verify proof

Author: keithsue

Diff for: api/side/lending/tx.pulsar.go

@@ -99,8 +99,8 @@ message MsgApprove {
 
     string relayer = 1;
     string deposit_tx_id =2;
-    uint64 height = 3;
-    string poof = 4;
+    string block_hash = 3;
+    repeated string proof = 4;
 }
 
 message MsgApproveResponse {

Diff for: proto/side/lending/tx.proto

@@ -14,10 +14,11 @@ type (
 		storeKey storetypes.StoreKey
 		memKey   storetypes.StoreKey
 
-		bankKeeper    types.BankKeeper
-		oracleKeeper  types.OracleKeeper
-		auctionKeeper types.AuctionKeeper
-		dlcKeeper     types.DLCKeeper
+		bankKeeper      types.BankKeeper
+		oracleKeeper    types.OracleKeeper
+		auctionKeeper   types.AuctionKeeper
+		dlcKeeper       types.DLCKeeper
+		btcbridgeKeeper types.BtcBridgeKeeper
 
 		authority string
 	}
@@ -30,18 +31,20 @@ func NewKeeper(
 	bankKeeper types.BankKeeper,
 	oracleKeeper types.OracleKeeper,
 	auctionKeeper types.AuctionKeeper,
-	dlckeeper types.DLCKeeper,
+	dlcKeeper types.DLCKeeper,
+	btcbridgeKeeper types.BtcBridgeKeeper,
 	authority string,
 ) Keeper {
 	return Keeper{
-		cdc:           cdc,
-		storeKey:      storeKey,
-		memKey:        memKey,
-		bankKeeper:    bankKeeper,
-		oracleKeeper:  oracleKeeper,
-		auctionKeeper: auctionKeeper,
-		dlcKeeper:     dlckeeper,
-		authority:     authority,
+		cdc:             cdc,
+		storeKey:        storeKey,
+		memKey:          memKey,
+		bankKeeper:      bankKeeper,
+		oracleKeeper:    oracleKeeper,
+		auctionKeeper:   auctionKeeper,
+		dlcKeeper:       dlcKeeper,
+		btcbridgeKeeper: btcbridgeKeeper,
+		authority:       authority,
 	}
 }
 
@@ -76,6 +79,10 @@ func (k Keeper) DLCKeeper() types.DLCKeeper {
 	return k.dlcKeeper
 }
 
+func (k Keeper) BtcBridgeKeeper() types.BtcBridgeKeeper {
+	return k.btcbridgeKeeper
+}
+
 func (k Keeper) SetPool(ctx sdk.Context, pool types.LendingPool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&pool)

Diff for: x/lending/keeper/keeper.go

@@ -152,13 +152,15 @@ func (m msgServer) Approve(goCtx context.Context, msg *types.MsgApprove) (*types
 		return nil, types.ErrDepositTxNotExists
 	}
 
-	// verify merkle proof
-	// verify(msg.Height, msg.DepositTxId, msg.Poof)
-
 	log := m.GetDepositLog(ctx, msg.DepositTxId)
 	if !m.HasLoan(ctx, log.VaultAddress) {
 		return nil, types.ErrLoanNotExists
 	}
+
+	if _, _, err := m.btcbridgeKeeper.ValidateTransaction(ctx, log.DepositTx, "", msg.BlockHash, msg.Proof); err != nil {
+		return nil, types.ErrInvalidProof
+	}
+
 	loan := m.GetLoan(ctx, log.VaultAddress)
 
 	loan.Status = types.LoanStatus_Approve
@@ -167,8 +169,8 @@ func (m msgServer) Approve(goCtx context.Context, msg *types.MsgApprove) (*types
 	m.EmitEvent(ctx, msg.Relayer,
 		sdk.NewAttribute("vault", loan.VaultAddress),
 		sdk.NewAttribute("deposit_tx", msg.DepositTxId),
-		sdk.NewAttribute("proof", msg.Poof),
-		sdk.NewAttribute("height", fmt.Sprint(msg.Height)),
+		sdk.NewAttribute("proof", fmt.Sprintf("%s", msg.Proof)),
+		sdk.NewAttribute("block_hash", msg.BlockHash),
 	)
 
 	return &types.MsgApproveResponse{}, nil

Diff for: x/lending/keeper/msg_server.go

@@ -31,7 +31,7 @@ var (
 	ErrLoanNotExists          = errorsmod.Register(ModuleName, 3009, "loan not exists")
 
 	ErrEmptyDepositTx     = errorsmod.Register(ModuleName, 4001, "invalid deposit tx")
-	ErrEmptyPoof          = errorsmod.Register(ModuleName, 4002, "invalid proof")
+	ErrInvalidProof       = errorsmod.Register(ModuleName, 4002, "invalid proof")
 	ErrDepositTxNotExists = errorsmod.Register(ModuleName, 4002, "deposit not exists")
 
 	ErrEmptyLoanSecret    = errorsmod.Register(ModuleName, 5001, "invalid loan secret")

Diff for: x/lending/types/errors.go

@@ -4,11 +4,13 @@ import (
 	"context"
 
 	sdkmath "cosmossdk.io/math"
+	"github.com/btcsuite/btcd/btcutil"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 	banktype "github.com/cosmos/cosmos-sdk/x/bank/types"
 
 	auctiontypes "github.com/sideprotocol/side/x/auction/types"
+	btcbridgetypes "github.com/sideprotocol/side/x/btcbridge/types"
 	dlctypes "github.com/sideprotocol/side/x/dlc/types"
 )
 
@@ -51,3 +53,9 @@ type AuctionKeeper interface {
 type DLCKeeper interface {
 	GetEvent(ctx sdk.Context, id uint64) *dlctypes.DLCPriceEvent
 }
+
+// BtcBridgeKeeper defines the expected BtcBridge keeper interface
+type BtcBridgeKeeper interface {
+	ValidateTransaction(ctx sdk.Context, tx string, prevTx string, blockHash string, proof []string) (*btcutil.Tx, *btcutil.Tx, error)
+	GetFeeRate(ctx sdk.Context) *btcbridgetypes.FeeRate
+}

Diff for: x/lending/types/expected_keepers.go

@@ -6,12 +6,12 @@ import (
 
 var _ sdk.Msg = &MsgApprove{}
 
-func NewMsgDeposit(relayer string, DepositTxId string, height uint64, proof string) *MsgApprove {
+func NewMsgDeposit(relayer string, depositTxId string, blockHash string, proof []string) *MsgApprove {
 	return &MsgApprove{
 		Relayer:     relayer,
-		DepositTxId: DepositTxId,
-		Height:      height,
-		Poof:        proof,
+		DepositTxId: depositTxId,
+		BlockHash:   blockHash,
+		Proof:       proof,
 	}
 }
 
@@ -21,8 +21,8 @@ func (m *MsgApprove) ValidateBasic() error {
 		return ErrEmptyDepositTx
 	}
 
-	if len(m.Poof) == 0 {
-		return ErrEmptyPoof
+	if len(m.Proof) == 0 {
+		return ErrInvalidProof
 	}
 
 	return nil