Merge pull request #2380 from CortexFoundation/dev

error when packing negative values in unsigned types

Author: ucwong

accounts/abi/error_handling.go

@@ -1,5 +1,5 @@
 // Copyright 2016 The go-ethereum Authors
-// This file is part of The go-ethereum library.
+// This file is part of the go-ethereum library.
 //
 // The go-ethereum library is free software: you can redistribute it and/or modify
 // it under the terms of the GNU Lesser General Public License as published by
@@ -12,7 +12,7 @@
 // GNU Lesser General Public License for more details.
 //
 // You should have received a copy of the GNU Lesser General Public License
-// along with The go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 package abi
 
@@ -23,15 +23,16 @@ import (
 )
 
 var (
-	errBadBool   = errors.New("abi: improperly encoded boolean value")
-	errBadUint8  = errors.New("abi: improperly encoded uint8 value")
-	errBadUint16 = errors.New("abi: improperly encoded uint16 value")
-	errBadUint32 = errors.New("abi: improperly encoded uint32 value")
-	errBadUint64 = errors.New("abi: improperly encoded uint64 value")
-	errBadInt8   = errors.New("abi: improperly encoded int8 value")
-	errBadInt16  = errors.New("abi: improperly encoded int16 value")
-	errBadInt32  = errors.New("abi: improperly encoded int32 value")
-	errBadInt64  = errors.New("abi: improperly encoded int64 value")
+	errBadBool     = errors.New("abi: improperly encoded boolean value")
+	errBadUint8    = errors.New("abi: improperly encoded uint8 value")
+	errBadUint16   = errors.New("abi: improperly encoded uint16 value")
+	errBadUint32   = errors.New("abi: improperly encoded uint32 value")
+	errBadUint64   = errors.New("abi: improperly encoded uint64 value")
+	errBadInt8     = errors.New("abi: improperly encoded int8 value")
+	errBadInt16    = errors.New("abi: improperly encoded int16 value")
+	errBadInt32    = errors.New("abi: improperly encoded int32 value")
+	errBadInt64    = errors.New("abi: improperly encoded int64 value")
+	errInvalidSign = errors.New("abi: negatively-signed value cannot be packed into uint parameter")
 )
 
 // formatSliceString formats the reflection kind with the given slice size
@@ -84,6 +85,6 @@ func typeCheck(t Type, value reflect.Value) error {
 }
 
 // typeErr returns a formatted type casting error.
-func typeErr(expected, got any) error {
+func typeErr(expected, got interface{}) error {
 	return fmt.Errorf("abi: cannot use %v as type %v as argument", got, expected)
 }

accounts/abi/pack.go

@@ -1,5 +1,5 @@
 // Copyright 2016 The go-ethereum Authors
-// This file is part of The go-ethereum library.
+// This file is part of the go-ethereum library.
 //
 // The go-ethereum library is free software: you can redistribute it and/or modify
 // it under the terms of the GNU Lesser General Public License as published by
@@ -12,7 +12,7 @@
 // GNU Lesser General Public License for more details.
 //
 // You should have received a copy of the GNU Lesser General Public License
-// along with The go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 package abi
 
@@ -37,7 +37,16 @@ func packBytesSlice(bytes []byte, l int) []byte {
 // t.
 func packElement(t Type, reflectValue reflect.Value) ([]byte, error) {
 	switch t.T {
-	case IntTy, UintTy:
+	case UintTy:
+		// make sure to not pack a negative value into a uint type.
+		if reflectValue.Kind() == reflect.Ptr {
+			val := new(big.Int).Set(reflectValue.Interface().(*big.Int))
+			if val.Sign() == -1 {
+				return nil, errInvalidSign
+			}
+		}
+		return packNum(reflectValue), nil
+	case IntTy:
 		return packNum(reflectValue), nil
 	case StringTy:
 		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len()), nil
@@ -57,7 +66,7 @@ func packElement(t Type, reflectValue reflect.Value) ([]byte, error) {
 			reflectValue = mustArrayToByteSlice(reflectValue)
 		}
 		if reflectValue.Type() != reflect.TypeOf([]byte{}) {
-			return []byte{}, errors.New("Bytes type is neither slice nor array")
+			return []byte{}, errors.New("bytes type is neither slice nor array")
 		}
 		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len()), nil
 	case FixedBytesTy, FunctionTy:
@@ -66,7 +75,7 @@ func packElement(t Type, reflectValue reflect.Value) ([]byte, error) {
 		}
 		return common.RightPadBytes(reflectValue.Bytes(), 32), nil
 	default:
-		return []byte{}, fmt.Errorf("Could not pack element, unknown type: %v", t.T)
+		return []byte{}, fmt.Errorf("could not pack element, unknown type: %v", t.T)
 	}
 }
 

accounts/abi/pack_test.go

@@ -178,6 +178,11 @@ func TestMethodPack(t *testing.T) {
 	if !bytes.Equal(packed, sig) {
 		t.Errorf("expected %x got %x", sig, packed)
 	}
+
+	// test that we can't pack a negative value for a parameter that is specified as a uint
+	if _, err := abi.Pack("send", big.NewInt(-1)); err == nil {
+		t.Fatal("expected error when trying to pack negative big.Int into uint256 value")
+	}
 }
 
 func TestPackNumber(t *testing.T) {