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accounts/abi: Negative numbers not properly converted in ABI encoding

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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?
This commit is contained in:
Thomas Bocek
2016-06-02 18:43:27 +02:00
parent 16a23ff740
commit 89c6c5bb85
4 changed files with 10 additions and 64 deletions
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26
accounts/abi/numbers_test.go
View File

@ -26,48 +26,28 @@ import (
func TestNumberTypes(t *testing.T) {
ubytes := make([]byte, 32)
ubytes[31] = 1
sbytesmin := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
unsigned := U256(big.NewInt(1))
if !bytes.Equal(unsigned, ubytes) {
t.Errorf("expected %x got %x", ubytes, unsigned)
}
signed := S256(big.NewInt(1))
if !bytes.Equal(signed, ubytes) {
t.Errorf("expected %x got %x", ubytes, unsigned)
}
signed = S256(big.NewInt(-1))
if !bytes.Equal(signed, sbytesmin) {
t.Errorf("expected %x got %x", ubytes, unsigned)
}
}
func TestPackNumber(t *testing.T) {
ubytes := make([]byte, 32)
ubytes[31] = 1
sbytesmin := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
maxunsigned := []byte{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}
packed := packNum(reflect.ValueOf(1), IntTy)
packed := packNum(reflect.ValueOf(1))
if !bytes.Equal(packed, ubytes) {
t.Errorf("expected %x got %x", ubytes, packed)
}
packed = packNum(reflect.ValueOf(-1), IntTy)
if !bytes.Equal(packed, sbytesmin) {
t.Errorf("expected %x got %x", ubytes, packed)
}
packed = packNum(reflect.ValueOf(1), UintTy)
if !bytes.Equal(packed, ubytes) {
t.Errorf("expected %x got %x", ubytes, packed)
}
packed = packNum(reflect.ValueOf(-1), UintTy)
packed = packNum(reflect.ValueOf(-1))
if !bytes.Equal(packed, maxunsigned) {
t.Errorf("expected %x got %x", maxunsigned, packed)
}
packed = packNum(reflect.ValueOf("string"), UintTy)
packed = packNum(reflect.ValueOf("string"))
if packed != nil {
t.Errorf("expected 'string' to pack to nil. got %x instead", packed)
}