Only allow deposit messages from monomer

The important change is in helpers/ante.go.

Before, we were only blocking deposit transactions from the Monomer mempool.
This meant that standard auth txs could contain deposit messages, minting arbitrary amounts of eth.
We fix this by checking for deposit messages in all transactions in helpers/ante.go.

mempool/mempool.go

@@ -8,7 +8,6 @@ import (
 
 	comettypes "github.com/cometbft/cometbft/types"
 	dbm "github.com/cosmos/cosmos-db"
-	"github.com/polymerdao/monomer"
 	"github.com/polymerdao/monomer/utils"
 )
 
@@ -39,13 +38,6 @@ func (p *Pool) Enqueue(userTxn comettypes.Tx) (err error) {
 	// Unfortunately, comet's DB interface doesn't support it.
 	// Moving to a different DB interface is left for future work.
 
-	// Attempt to adapt the Cosmos transaction to an Ethereum deposit transaction.
-	// If the adaptation succeeds, it indicates that the
-	// user transaction is a deposit transaction, which is not allowed in the pool.
-	if _, err := monomer.GetDepositTxs(userTxn); err == nil {
-		return errors.New("deposit txs are not allowed in the pool")
-	}
-
 	batch := p.db.NewBatch()
 	defer func() {
 		err = utils.WrapCloseErr(err, batch)

mempool/mempool_test.go

@@ -4,8 +4,6 @@ import (
 	"testing"
 
 	comettypes "github.com/cometbft/cometbft/types"
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/polymerdao/monomer"
 	"github.com/polymerdao/monomer/mempool"
 	"github.com/polymerdao/monomer/testutils"
 	"github.com/stretchr/testify/assert"
@@ -24,18 +22,6 @@ func TestMempool(t *testing.T) {
 		require.Error(t, err)
 	})
 
-	t.Run("deposit transaction", func(t *testing.T) {
-		l1AttributesTx, depositTx, _ := testutils.GenerateEthTxs(t)
-		l1AttributesTxBytes, err := l1AttributesTx.MarshalBinary()
-		require.NoError(t, err)
-		depositTxBytes, err := depositTx.MarshalBinary()
-		require.NoError(t, err)
-
-		cosmosTxs, err := monomer.AdaptPayloadTxsToCosmosTxs([]hexutil.Bytes{l1AttributesTxBytes, depositTxBytes})
-		require.NoError(t, err)
-		require.ErrorContains(t, pool.Enqueue(cosmosTxs[0]), "deposit txs are not allowed in the pool")
-	})
-
 	// enqueue multiple to empty
 	for i := byte(0); i < 3; i++ {
 		require.NoError(t, pool.Enqueue(comettypes.Tx([]byte{i})))

x/rollup/tx/helpers/ante.go

@@ -1,6 +1,7 @@
 package helpers
 
 import (
+	"errors"
 	"fmt"
 
 	sdktypes "github.com/cosmos/cosmos-sdk/types"
@@ -43,6 +44,12 @@ func (a *AnteHandler) AnteHandle(
 		}
 		return newCtx, err
 	default: // Unfortunately, the Cosmos SDK does not export its default tx type.
+		for _, msg := range tx.GetMsgs() {
+			if _, ok := msg.(rolluptypes.DepositMsg); ok {
+				return ctx, errors.New("transaction contains deposit message")
+			}
+		}
+
 		newCtx, err := a.authAnteHandler(ctx, tx, simulate)
 		if err != nil {
 			return newCtx, fmt.Errorf("auth ante handle: %v", err)

x/rollup/types/deposit_msg.go

@@ -0,0 +1,8 @@
+package types
+
+type DepositMsg interface {
+	isDeposit()
+}
+
+func (*MsgSetL1Attributes) isDeposit()  {}
+func (*MsgApplyUserDeposit) isDeposit() {}