eth2util: new deposit message with amount

cmd/addvalidators.go

@@ -244,7 +244,7 @@ func writeDepositDatas(ctx context.Context, clusterDir string, numOps int, secre
 
 	var depositDatas []eth2p0.DepositData
 	for i, val := range vals {
-		depositMsg, err := deposit.NewMessage(eth2p0.BLSPubKey(val.PublicKey), val.WithdrawalAddress)
+		depositMsg, err := deposit.NewMessage(eth2p0.BLSPubKey(val.PublicKey), val.WithdrawalAddress, deposit.MaxValidatorAmount)
 		if err != nil {
 			return errors.Wrap(err, "new deposit message")
 		}

cmd/createcluster.go

@@ -379,7 +379,7 @@ func signDepositDatas(secrets []tbls.PrivateKey, withdrawalAddresses []string, n
 			return nil, errors.Wrap(err, "secret to pubkey")
 		}
 
-		msg, err := deposit.NewMessage(eth2p0.BLSPubKey(pk), withdrawalAddr)
+		msg, err := deposit.NewMessage(eth2p0.BLSPubKey(pk), withdrawalAddr, deposit.MaxValidatorAmount)
 		if err != nil {
 			return nil, err
 		}

dkg/dkg.go

@@ -720,7 +720,7 @@ func signDepositMsgs(shares []share, shareIdx int, withdrawalAddresses []string,
 			return nil, nil, err
 		}
 
-		msg, err := deposit.NewMessage(pubkey, withdrawalHex)
+		msg, err := deposit.NewMessage(pubkey, withdrawalHex, deposit.MaxValidatorAmount)
 		if err != nil {
 			return nil, nil, err
 		}

dkg/dkg_internal_test.go

@@ -137,7 +137,7 @@ func TestValidSignatures(t *testing.T) {
 	withdrawalAddr := testutil.RandomETHAddress()
 	network := eth2util.Goerli.Name
 
-	msg, err := deposit.NewMessage(eth2Pubkey, withdrawalAddr)
+	msg, err := deposit.NewMessage(eth2Pubkey, withdrawalAddr, deposit.MaxValidatorAmount)
 	require.NoError(t, err)
 	sigRoot, err := deposit.GetMessageSigningRoot(msg, network)
 	require.NoError(t, err)

eth2util/deposit/deposit.go

@@ -19,12 +19,15 @@ import (
 )
 
 var (
+	// Minimum allowed deposit amount (1ETH).
+	MinValidatorAmount = eth2p0.Gwei(1000000000)
+
+	// Maximum allowed deposit amount (32ETH).
+	MaxValidatorAmount = eth2p0.Gwei(32000000000)
+
 	// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/validator.md#eth1_address_withdrawal_prefix
 	eth1AddressWithdrawalPrefix = []byte{0x01}
 
-	// the amount of ether in gwei required to activate a validator.
-	validatorAmt = eth2p0.Gwei(32000000000)
-
 	// DOMAIN_DEPOSIT. See spec: https://benjaminion.xyz/eth2-annotated-spec/phase0/beacon-chain/#domain-types
 	depositDomainType = eth2p0.DomainType([4]byte{0x03, 0x00, 0x00, 0x00})
 
@@ -33,16 +36,24 @@ var (
 )
 
 // NewMessage returns a deposit message created using the provided parameters.
-func NewMessage(pubkey eth2p0.BLSPubKey, withdrawalAddr string) (eth2p0.DepositMessage, error) {
+func NewMessage(pubkey eth2p0.BLSPubKey, withdrawalAddr string, amount eth2p0.Gwei) (eth2p0.DepositMessage, error) {
 	creds, err := withdrawalCredsFromAddr(withdrawalAddr)
 	if err != nil {
 		return eth2p0.DepositMessage{}, err
 	}
 
+	if amount < MinValidatorAmount {
+		return eth2p0.DepositMessage{}, errors.New("deposit message minimum amount must be >= 1ETH", z.U64("amount", uint64(amount)))
+	}
+
+	if amount > MaxValidatorAmount {
+		return eth2p0.DepositMessage{}, errors.New("deposit message maximum amount must <= 32ETH", z.U64("amount", uint64(amount)))
+	}
+
 	return eth2p0.DepositMessage{
 		PublicKey:             pubkey,
 		WithdrawalCredentials: creds[:],
-		Amount:                validatorAmt,
+		Amount:                amount,
 	}, nil
 }
 
@@ -87,7 +98,7 @@ func MarshalDepositData(depositDatas []eth2p0.DepositData, network string) ([]by
 		ddList = append(ddList, depositDataJSON{
 			PubKey:                fmt.Sprintf("%x", depositData.PublicKey),
 			WithdrawalCredentials: fmt.Sprintf("%x", depositData.WithdrawalCredentials),
-			Amount:                uint64(validatorAmt),
+			Amount:                uint64(depositData.Amount),
 			Signature:             fmt.Sprintf("%x", depositData.Signature),
 			DepositMessageRoot:    fmt.Sprintf("%x", msgRoot),
 			DepositDataRoot:       fmt.Sprintf("%x", dataRoot),

eth2util/deposit/deposit_test.go

@@ -18,6 +18,31 @@ import (
 
 //go:generate go test . -run=TestMarshalDepositData -update -clean
 
+func TestNewMessage(t *testing.T) {
+	const privKey = "01477d4bfbbcebe1fef8d4d6f624ecbb6e3178558bb1b0d6286c816c66842a6d"
+	const addr = "0x321dcb529f3945bc94fecea9d3bc5caf35253b94"
+	amount := deposit.MaxValidatorAmount
+	_, pubKey := GetKeys(t, privKey)
+
+	msg, err := deposit.NewMessage(pubKey, addr, amount)
+
+	require.NoError(t, err)
+	require.Equal(t, pubKey, msg.PublicKey)
+	require.Equal(t, amount, msg.Amount)
+
+	t.Run("amount below minimum", func(t *testing.T) {
+		_, err := deposit.NewMessage(pubKey, addr, deposit.MinValidatorAmount-1)
+
+		require.ErrorContains(t, err, "deposit message minimum amount must be >= 1ETH")
+	})
+
+	t.Run("amount above maximum", func(t *testing.T) {
+		_, err := deposit.NewMessage(pubKey, addr, deposit.MaxValidatorAmount+1)
+
+		require.ErrorContains(t, err, "deposit message maximum amount must <= 32ETH")
+	})
+}
+
 func TestMarshalDepositData(t *testing.T) {
 	privKeys := []string{
 		"01477d4bfbbcebe1fef8d4d6f624ecbb6e3178558bb1b0d6286c816c66842a6d",
@@ -39,7 +64,7 @@ func TestMarshalDepositData(t *testing.T) {
 	for i := 0; i < len(privKeys); i++ {
 		sk, pk := GetKeys(t, privKeys[i])
 
-		msg, err := deposit.NewMessage(pk, withdrawalAddrs[i])
+		msg, err := deposit.NewMessage(pk, withdrawalAddrs[i], deposit.MaxValidatorAmount)
 		require.NoError(t, err)
 
 		sigRoot, err := deposit.GetMessageSigningRoot(msg, network)