From 78745551c077bf54151202138c2629f288769561 Mon Sep 17 00:00:00 2001 From: Determinant Date: Tue, 15 Sep 2020 23:55:34 -0400 Subject: WIP: geth-tavum --- accounts/abi/unpack.go | 295 ------------------------------------------------- 1 file changed, 295 deletions(-) delete mode 100644 accounts/abi/unpack.go (limited to 'accounts/abi/unpack.go') diff --git a/accounts/abi/unpack.go b/accounts/abi/unpack.go deleted file mode 100644 index d3cd310..0000000 --- a/accounts/abi/unpack.go +++ /dev/null @@ -1,295 +0,0 @@ -// Copyright 2017 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 . - -package abi - -import ( - "encoding/binary" - "fmt" - "math/big" - "reflect" - - "github.com/ava-labs/go-ethereum/common" -) - -var ( - maxUint256 = big.NewInt(0).Add( - big.NewInt(0).Exp(big.NewInt(2), big.NewInt(256), nil), - big.NewInt(-1)) - maxInt256 = big.NewInt(0).Add( - big.NewInt(0).Exp(big.NewInt(2), big.NewInt(255), nil), - big.NewInt(-1)) -) - -// reads the integer based on its kind -func readInteger(typ byte, kind reflect.Kind, b []byte) interface{} { - switch kind { - case reflect.Uint8: - return b[len(b)-1] - case reflect.Uint16: - return binary.BigEndian.Uint16(b[len(b)-2:]) - case reflect.Uint32: - return binary.BigEndian.Uint32(b[len(b)-4:]) - case reflect.Uint64: - return binary.BigEndian.Uint64(b[len(b)-8:]) - case reflect.Int8: - return int8(b[len(b)-1]) - case reflect.Int16: - return int16(binary.BigEndian.Uint16(b[len(b)-2:])) - case reflect.Int32: - return int32(binary.BigEndian.Uint32(b[len(b)-4:])) - case reflect.Int64: - return int64(binary.BigEndian.Uint64(b[len(b)-8:])) - default: - // the only case lefts for integer is int256/uint256. - // big.SetBytes can't tell if a number is negative, positive on itself. - // On EVM, if the returned number > max int256, it is negative. - ret := new(big.Int).SetBytes(b) - if typ == UintTy { - return ret - } - - if ret.Cmp(maxInt256) > 0 { - ret.Add(maxUint256, big.NewInt(0).Neg(ret)) - ret.Add(ret, big.NewInt(1)) - ret.Neg(ret) - } - return ret - } -} - -// reads a bool -func readBool(word []byte) (bool, error) { - for _, b := range word[:31] { - if b != 0 { - return false, errBadBool - } - } - switch word[31] { - case 0: - return false, nil - case 1: - return true, nil - default: - return false, errBadBool - } -} - -// A function type is simply the address with the function selection signature at the end. -// This enforces that standard by always presenting it as a 24-array (address + sig = 24 bytes) -func readFunctionType(t Type, word []byte) (funcTy [24]byte, err error) { - if t.T != FunctionTy { - return [24]byte{}, fmt.Errorf("abi: invalid type in call to make function type byte array") - } - if garbage := binary.BigEndian.Uint64(word[24:32]); garbage != 0 { - err = fmt.Errorf("abi: got improperly encoded function type, got %v", word) - } else { - copy(funcTy[:], word[0:24]) - } - return -} - -// through reflection, creates a fixed array to be read from -func readFixedBytes(t Type, word []byte) (interface{}, error) { - if t.T != FixedBytesTy { - return nil, fmt.Errorf("abi: invalid type in call to make fixed byte array") - } - // convert - array := reflect.New(t.Type).Elem() - - reflect.Copy(array, reflect.ValueOf(word[0:t.Size])) - return array.Interface(), nil - -} - -// iteratively unpack elements -func forEachUnpack(t Type, output []byte, start, size int) (interface{}, error) { - if size < 0 { - return nil, fmt.Errorf("cannot marshal input to array, size is negative (%d)", size) - } - if start+32*size > len(output) { - return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), start+32*size) - } - - // this value will become our slice or our array, depending on the type - var refSlice reflect.Value - - if t.T == SliceTy { - // declare our slice - refSlice = reflect.MakeSlice(t.Type, size, size) - } else if t.T == ArrayTy { - // declare our array - refSlice = reflect.New(t.Type).Elem() - } else { - return nil, fmt.Errorf("abi: invalid type in array/slice unpacking stage") - } - - // Arrays have packed elements, resulting in longer unpack steps. - // Slices have just 32 bytes per element (pointing to the contents). - elemSize := getTypeSize(*t.Elem) - - for i, j := start, 0; j < size; i, j = i+elemSize, j+1 { - inter, err := toGoType(i, *t.Elem, output) - if err != nil { - return nil, err - } - - // append the item to our reflect slice - refSlice.Index(j).Set(reflect.ValueOf(inter)) - } - - // return the interface - return refSlice.Interface(), nil -} - -func forTupleUnpack(t Type, output []byte) (interface{}, error) { - retval := reflect.New(t.Type).Elem() - virtualArgs := 0 - for index, elem := range t.TupleElems { - marshalledValue, err := toGoType((index+virtualArgs)*32, *elem, output) - if elem.T == ArrayTy && !isDynamicType(*elem) { - // If we have a static array, like [3]uint256, these are coded as - // just like uint256,uint256,uint256. - // This means that we need to add two 'virtual' arguments when - // we count the index from now on. - // - // Array values nested multiple levels deep are also encoded inline: - // [2][3]uint256: uint256,uint256,uint256,uint256,uint256,uint256 - // - // Calculate the full array size to get the correct offset for the next argument. - // Decrement it by 1, as the normal index increment is still applied. - virtualArgs += getTypeSize(*elem)/32 - 1 - } else if elem.T == TupleTy && !isDynamicType(*elem) { - // If we have a static tuple, like (uint256, bool, uint256), these are - // coded as just like uint256,bool,uint256 - virtualArgs += getTypeSize(*elem)/32 - 1 - } - if err != nil { - return nil, err - } - retval.Field(index).Set(reflect.ValueOf(marshalledValue)) - } - return retval.Interface(), nil -} - -// toGoType parses the output bytes and recursively assigns the value of these bytes -// into a go type with accordance with the ABI spec. -func toGoType(index int, t Type, output []byte) (interface{}, error) { - if index+32 > len(output) { - return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32) - } - - var ( - returnOutput []byte - begin, length int - err error - ) - - // if we require a length prefix, find the beginning word and size returned. - if t.requiresLengthPrefix() { - begin, length, err = lengthPrefixPointsTo(index, output) - if err != nil { - return nil, err - } - } else { - returnOutput = output[index : index+32] - } - - switch t.T { - case TupleTy: - if isDynamicType(t) { - begin, err := tuplePointsTo(index, output) - if err != nil { - return nil, err - } - return forTupleUnpack(t, output[begin:]) - } else { - return forTupleUnpack(t, output[index:]) - } - case SliceTy: - return forEachUnpack(t, output[begin:], 0, length) - case ArrayTy: - if isDynamicType(*t.Elem) { - offset := int64(binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:])) - return forEachUnpack(t, output[offset:], 0, t.Size) - } - return forEachUnpack(t, output[index:], 0, t.Size) - case StringTy: // variable arrays are written at the end of the return bytes - return string(output[begin : begin+length]), nil - case IntTy, UintTy: - return readInteger(t.T, t.Kind, returnOutput), nil - case BoolTy: - return readBool(returnOutput) - case AddressTy: - return common.BytesToAddress(returnOutput), nil - case HashTy: - return common.BytesToHash(returnOutput), nil - case BytesTy: - return output[begin : begin+length], nil - case FixedBytesTy: - return readFixedBytes(t, returnOutput) - case FunctionTy: - return readFunctionType(t, returnOutput) - default: - return nil, fmt.Errorf("abi: unknown type %v", t.T) - } -} - -// interprets a 32 byte slice as an offset and then determines which indice to look to decode the type. -func lengthPrefixPointsTo(index int, output []byte) (start int, length int, err error) { - bigOffsetEnd := big.NewInt(0).SetBytes(output[index : index+32]) - bigOffsetEnd.Add(bigOffsetEnd, common.Big32) - outputLength := big.NewInt(int64(len(output))) - - if bigOffsetEnd.Cmp(outputLength) > 0 { - return 0, 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", bigOffsetEnd, outputLength) - } - - if bigOffsetEnd.BitLen() > 63 { - return 0, 0, fmt.Errorf("abi offset larger than int64: %v", bigOffsetEnd) - } - - offsetEnd := int(bigOffsetEnd.Uint64()) - lengthBig := big.NewInt(0).SetBytes(output[offsetEnd-32 : offsetEnd]) - - totalSize := big.NewInt(0) - totalSize.Add(totalSize, bigOffsetEnd) - totalSize.Add(totalSize, lengthBig) - if totalSize.BitLen() > 63 { - return 0, 0, fmt.Errorf("abi: length larger than int64: %v", totalSize) - } - - if totalSize.Cmp(outputLength) > 0 { - return 0, 0, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %v require %v", outputLength, totalSize) - } - start = int(bigOffsetEnd.Uint64()) - length = int(lengthBig.Uint64()) - return -} - -// tuplePointsTo resolves the location reference for dynamic tuple. -func tuplePointsTo(index int, output []byte) (start int, err error) { - offset := big.NewInt(0).SetBytes(output[index : index+32]) - outputLen := big.NewInt(int64(len(output))) - - if offset.Cmp(big.NewInt(int64(len(output)))) > 0 { - return 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", offset, outputLen) - } - if offset.BitLen() > 63 { - return 0, fmt.Errorf("abi offset larger than int64: %v", offset) - } - return int(offset.Uint64()), nil -} -- cgit v1.2.3