89c6c5bb85
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?
119 lines
3.8 KiB
Go
119 lines
3.8 KiB
Go
// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package abi
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import (
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"fmt"
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"reflect"
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"strings"
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"github.com/ethereum/go-ethereum/crypto"
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)
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// Callable method given a `Name` and whether the method is a constant.
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// If the method is `Const` no transaction needs to be created for this
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// particular Method call. It can easily be simulated using a local VM.
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// For example a `Balance()` method only needs to retrieve something
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// from the storage and therefor requires no Tx to be send to the
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// network. A method such as `Transact` does require a Tx and thus will
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// be flagged `true`.
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// Input specifies the required input parameters for this gives method.
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type Method struct {
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Name string
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Const bool
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Inputs []Argument
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Outputs []Argument
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}
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func (m Method) pack(method Method, args ...interface{}) ([]byte, error) {
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// Make sure arguments match up and pack them
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if len(args) != len(method.Inputs) {
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return nil, fmt.Errorf("argument count mismatch: %d for %d", len(args), len(method.Inputs))
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}
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// variable input is the output appended at the end of packed
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// output. This is used for strings and bytes types input.
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var variableInput []byte
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var ret []byte
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for i, a := range args {
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input := method.Inputs[i]
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// pack the input
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packed, err := input.Type.pack(reflect.ValueOf(a))
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if err != nil {
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return nil, fmt.Errorf("`%s` %v", method.Name, err)
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}
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// check for a slice type (string, bytes, slice)
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if input.Type.requiresLengthPrefix() {
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// calculate the offset
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offset := len(method.Inputs)*32 + len(variableInput)
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// set the offset
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ret = append(ret, packNum(reflect.ValueOf(offset))...)
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// Append the packed output to the variable input. The variable input
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// will be appended at the end of the input.
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variableInput = append(variableInput, packed...)
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} else {
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// append the packed value to the input
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ret = append(ret, packed...)
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}
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}
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// append the variable input at the end of the packed input
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ret = append(ret, variableInput...)
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return ret, nil
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}
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// Sig returns the methods string signature according to the ABI spec.
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//
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// Example
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//
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// function foo(uint32 a, int b) = "foo(uint32,int256)"
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//
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// Please note that "int" is substitute for its canonical representation "int256"
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func (m Method) Sig() string {
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types := make([]string, len(m.Inputs))
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i := 0
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for _, input := range m.Inputs {
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types[i] = input.Type.String()
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i++
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}
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return fmt.Sprintf("%v(%v)", m.Name, strings.Join(types, ","))
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}
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func (m Method) String() string {
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inputs := make([]string, len(m.Inputs))
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for i, input := range m.Inputs {
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inputs[i] = fmt.Sprintf("%v %v", input.Name, input.Type)
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}
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outputs := make([]string, len(m.Outputs))
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for i, output := range m.Outputs {
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if len(output.Name) > 0 {
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outputs[i] = fmt.Sprintf("%v ", output.Name)
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}
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outputs[i] += output.Type.String()
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}
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constant := ""
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if m.Const {
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constant = "constant "
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}
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return fmt.Sprintf("function %v(%v) %sreturns(%v)", m.Name, strings.Join(inputs, ", "), constant, strings.Join(outputs, ", "))
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}
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func (m Method) Id() []byte {
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return crypto.Keccak256([]byte(m.Sig()))[:4]
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}
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