add more checks to zrc20 is valid

precompiles/bank/method_deposit.go

@@ -80,7 +80,7 @@ func (c *Contract) deposit(
 	//   this way we map ZRC20 addresses to cosmos denoms "zevm/0x12345".
 	// - Mint coins to the fungible module.
 	// - Send coins from fungible to the caller.
-	coinSet, err := precompiletypes.CreateCoinSet(zrc20Addr, amount)
+	coinSet, err := precompiletypes.CreateZRC20CoinSet(zrc20Addr, amount)
 	if err != nil {
 		return nil, err
 	}

precompiles/bank/method_withdraw.go

@@ -79,7 +79,7 @@ func (c *Contract) withdraw(
 		}
 	}
 
-	coinSet, err := precompiletypes.CreateCoinSet(zrc20Addr, amount)
+	coinSet, err := precompiletypes.CreateZRC20CoinSet(zrc20Addr, amount)
 	if err != nil {
 		return nil, err
 	}

precompiles/staking/method_distribute.go

@@ -42,7 +42,7 @@ func (c *Contract) distribute(
 	}
 
 	// Create the coinSet in advance, if this step fails do not lock ZRC20.
-	coinSet, err := precompiletypes.CreateCoinSet(zrc20Addr, amount)
+	coinSet, err := precompiletypes.CreateZRC20CoinSet(zrc20Addr, amount)
 	if err != nil {
 		return nil, err
 	}

precompiles/staking/method_get_validators_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"cosmossdk.io/math"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/require"
 	precompiletypes "github.com/zeta-chain/node/precompiles/types"
 	"github.com/zeta-chain/node/testutil/sample"
@@ -44,6 +45,36 @@ func Test_GetValidators(t *testing.T) {
 		require.Len(t, list, 0)
 	})
 
+	t.Run("should return an empty list for an invalid staker", func(t *testing.T) {
+		/* ARRANGE */
+		s := newTestSuite(t)
+
+		// Create validator.
+		validator := sample.Validator(t, rand.New(rand.NewSource(42)))
+		s.sdkKeepers.StakingKeeper.SetValidator(s.ctx, validator)
+
+		/* ACT */
+		// Call getRewards.
+		getValidatorsMethod := s.stkContractABI.Methods[GetValidatorsMethodName]
+
+		s.mockVMContract.Input = packInputArgs(
+			t,
+			getValidatorsMethod,
+			[]interface{}{common.Address{}}...,
+		)
+
+		bytes, err := s.stkContract.Run(s.mockEVM, s.mockVMContract, false)
+		require.NoError(t, err)
+
+		res, err := getValidatorsMethod.Outputs.Unpack(bytes)
+		require.NoError(t, err)
+		require.NotEmpty(t, res)
+
+		list, ok := res[0].([]string)
+		require.True(t, ok)
+		require.Len(t, list, 0)
+	})
+
 	t.Run("should return staker's validator list", func(t *testing.T) {
 		/* ARRANGE */
 		s := newTestSuite(t)

precompiles/types/coin.go

@@ -17,13 +17,20 @@ func ZRC20ToCosmosDenom(ZRC20Address common.Address) string {
 	return config.ZRC20DenomPrefix + ZRC20Address.String()
 }
 
-func CreateCoinSet(zrc20address common.Address, amount *big.Int) (sdk.Coins, error) {
+func CreateZRC20CoinSet(zrc20address common.Address, amount *big.Int) (sdk.Coins, error) {
 	defer func() {
 		if r := recover(); r != nil {
 			return
 		}
 	}()
 
+	if (zrc20address == common.Address{}) {
+		return nil, &ErrInvalidAddr{
+			Got:    zrc20address.String(),
+			Reason: "empty address",
+		}
+	}
+
 	denom := ZRC20ToCosmosDenom(zrc20address)
 
 	coin := sdk.NewCoin(denom, math.NewIntFromBigInt(amount))
@@ -53,5 +60,14 @@ func CreateCoinSet(zrc20address common.Address, amount *big.Int) (sdk.Coins, err
 
 // CoinIsZRC20 checks if a given coin is a ZRC20 coin based on its denomination.
 func CoinIsZRC20(denom string) bool {
-	return strings.HasPrefix(denom, config.ZRC20DenomPrefix)
+	// Fail fast if the prefix is not set.
+	if !strings.HasPrefix(denom, config.ZRC20DenomPrefix) {
+		return false
+	}
+
+	// Prefix is correctly set, extract the zrc20 address.
+	zrc20Addr := strings.TrimPrefix(denom, config.ZRC20DenomPrefix)
+
+	// Return true only if address is not empty and is a valid hex address.
+	return common.HexToAddress(zrc20Addr) != common.Address{} && common.IsHexAddress(zrc20Addr)
 }

precompiles/types/coin_test.go

@@ -20,7 +20,7 @@ func Test_createCoinSet(t *testing.T) {
 	tokenDenom := ZRC20ToCosmosDenom(tokenAddr)
 	amount := big.NewInt(100)
 
-	coinSet, err := CreateCoinSet(tokenAddr, amount)
+	coinSet, err := CreateZRC20CoinSet(tokenAddr, amount)
 	require.NoError(t, err, "createCoinSet should not return an error")
 	require.NotNil(t, coinSet, "coinSet should not be nil")
 
@@ -34,18 +34,19 @@ func Test_CoinIsZRC20(t *testing.T) {
 		denom    string
 		expected bool
 	}{
-		{"zrc20/0x0123456789abcdef", true},
-		{"zrc20/0xabcdef0123456789", true},
-		{"zrc200xabcdef", false},
-		{"foo/0x0123456789", false},
+		{"", false}, // Empty string.
+		{"zrc20/", false}, // Missing address.
+		{"zrc20/0x514910771af9ca656af840dff83e8264ecf986ca", true}, // Valid ZRC20 address.
+		{"zrc20/0xCa14007Eff0dB1f8135f4C25B34De49AB0d42766", true}, // Valid ZRC20 address.
+		{"zrc200xabcdef", false}, // Malformed prefix.
+		{"foo/0x0123456789", false}, // Invalid prefix.
+		{"ZRC20/0x0123456789abcdef", false}, // Invalid prefix.
 	}
 
 	for _, tt := range test {
 		t.Run(tt.denom, func(t *testing.T) {
 			result := CoinIsZRC20(tt.denom)
-			if result != tt.expected {
-				t.Errorf("got %v, want %v", result, tt.expected)
-			}
+			require.Equal(t, tt.expected, result, "got %v, want %v", result, tt.expected)
 		})
 	}
 }