go-ethereum/accounts/abi/packing.go
Thomas Bocek 89c6c5bb85 accounts/abi: Negative numbers not properly converted in ABI encoding
When converting a negative number e.g., -2, the resulting ABI encoding
should look as follows:
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe.
However, since the check of the type is for an uint instead of an
int, it results in the following ABI encoding:
0101010101010101010101010101010101010101010101010101010101010102. The
Ethereum ABI
(https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI) says,
that signed integers are stored in two's complement which should be
of the form ffffff.... and not 01010101..... for e.g. -1. Thus, I
removed the type check in numbers.go as well as the function S256
as I don't think they are correct. Or maybe I'm missing something?
2016-06-06 14:27:15 +02:00

66 lines
2.1 KiB
Go

// Copyright 2016 The go-ethereum Authors
// 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
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// 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/>.
package abi
import (
"reflect"
"github.com/ethereum/go-ethereum/common"
)
// packBytesSlice packs the given bytes as [L, V] as the canonical representation
// bytes slice
func packBytesSlice(bytes []byte, l int) []byte {
len := packNum(reflect.ValueOf(l))
return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
}
// packElement packs the given reflect value according to the abi specification in
// t.
func packElement(t Type, reflectValue reflect.Value) []byte {
switch t.T {
case IntTy, UintTy:
return packNum(reflectValue)
case StringTy:
return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
case AddressTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
return common.LeftPadBytes(reflectValue.Bytes(), 32)
case BoolTy:
if reflectValue.Bool() {
return common.LeftPadBytes(common.Big1.Bytes(), 32)
} else {
return common.LeftPadBytes(common.Big0.Bytes(), 32)
}
case BytesTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
case FixedBytesTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
return common.RightPadBytes(reflectValue.Bytes(), 32)
}
panic("abi: fatal error")
}