From 5c8fe28b725bd9b128edceae3215132ea741641b Mon Sep 17 00:00:00 2001 From: Felix Lange Date: Sun, 26 Feb 2017 22:21:51 +0100 Subject: common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import --- common/icap.go | 190 --------------------------------------------------------- 1 file changed, 190 deletions(-) delete mode 100644 common/icap.go (limited to 'common/icap.go') diff --git a/common/icap.go b/common/icap.go deleted file mode 100644 index a36e669b3..000000000 --- a/common/icap.go +++ /dev/null @@ -1,190 +0,0 @@ -// Copyright 2015 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 . - -// Spec at https://github.com/ethereum/wiki/wiki/ICAP:-Inter-exchange-Client-Address-Protocol - -package common - -import ( - "errors" - "math/big" - "strconv" - "strings" -) - -var ( - Base36Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" - ICAPLengthError = errors.New("Invalid ICAP length") - ICAPEncodingError = errors.New("Invalid ICAP encoding") - ICAPChecksumError = errors.New("Invalid ICAP checksum") - ICAPCountryCodeError = errors.New("Invalid ICAP country code") - ICAPAssetIdentError = errors.New("Invalid ICAP asset identifier") - ICAPInstCodeError = errors.New("Invalid ICAP institution code") - ICAPClientIdentError = errors.New("Invalid ICAP client identifier") -) - -func ICAPToAddress(s string) (Address, error) { - switch len(s) { - case 35: // "XE" + 2 digit checksum + 31 base-36 chars of address - return parseICAP(s) - case 34: // "XE" + 2 digit checksum + 30 base-36 chars of address - return parseICAP(s) - case 20: // "XE" + 2 digit checksum + 3-char asset identifier + - // 4-char institution identifier + 9-char institution client identifier - return parseIndirectICAP(s) - default: - return Address{}, ICAPLengthError - } -} - -func parseICAP(s string) (Address, error) { - if !strings.HasPrefix(s, "XE") { - return Address{}, ICAPCountryCodeError - } - if err := validCheckSum(s); err != nil { - return Address{}, err - } - // checksum is ISO13616, Ethereum address is base-36 - bigAddr, _ := new(big.Int).SetString(s[4:], 36) - return BigToAddress(bigAddr), nil -} - -func parseIndirectICAP(s string) (Address, error) { - if !strings.HasPrefix(s, "XE") { - return Address{}, ICAPCountryCodeError - } - if s[4:7] != "ETH" { - return Address{}, ICAPAssetIdentError - } - if err := validCheckSum(s); err != nil { - return Address{}, err - } - // TODO: integrate with ICAP namereg - return Address{}, errors.New("not implemented") -} - -func AddressToICAP(a Address) (string, error) { - enc := base36Encode(a.Big()) - // zero padd encoded address to Direct ICAP length if needed - if len(enc) < 30 { - enc = join(strings.Repeat("0", 30-len(enc)), enc) - } - icap := join("XE", checkDigits(enc), enc) - return icap, nil -} - -// TODO: integrate with ICAP namereg when it's available -func AddressToIndirectICAP(a Address, instCode string) (string, error) { - // return addressToIndirectICAP(a, instCode) - return "", errors.New("not implemented") -} - -func addressToIndirectICAP(a Address, instCode string) (string, error) { - // TODO: add addressToClientIdent which grabs client ident from ICAP namereg - //clientIdent := addressToClientIdent(a) - clientIdent := "todo" - return clientIdentToIndirectICAP(instCode, clientIdent) -} - -func clientIdentToIndirectICAP(instCode, clientIdent string) (string, error) { - if len(instCode) != 4 || !validBase36(instCode) { - return "", ICAPInstCodeError - } - if len(clientIdent) != 9 || !validBase36(instCode) { - return "", ICAPClientIdentError - } - - // currently ETH is only valid asset identifier - s := join("ETH", instCode, clientIdent) - return join("XE", checkDigits(s), s), nil -} - -// https://en.wikipedia.org/wiki/International_Bank_Account_Number#Validating_the_IBAN -func validCheckSum(s string) error { - s = join(s[4:], s[:4]) - expanded, err := iso13616Expand(s) - if err != nil { - return err - } - checkSumNum, _ := new(big.Int).SetString(expanded, 10) - if checkSumNum.Mod(checkSumNum, Big97).Cmp(Big1) != 0 { - return ICAPChecksumError - } - return nil -} - -func checkDigits(s string) string { - expanded, _ := iso13616Expand(strings.Join([]string{s, "XE00"}, "")) - num, _ := new(big.Int).SetString(expanded, 10) - num.Sub(Big98, num.Mod(num, Big97)) - - checkDigits := num.String() - // zero padd checksum - if len(checkDigits) == 1 { - checkDigits = join("0", checkDigits) - } - return checkDigits -} - -// not base-36, but expansion to decimal literal: A = 10, B = 11, ... Z = 35 -func iso13616Expand(s string) (string, error) { - var parts []string - if !validBase36(s) { - return "", ICAPEncodingError - } - for _, c := range s { - i := uint64(c) - if i >= 65 { - parts = append(parts, strconv.FormatUint(uint64(c)-55, 10)) - } else { - parts = append(parts, string(c)) - } - } - return join(parts...), nil -} - -func base36Encode(i *big.Int) string { - var chars []rune - x := new(big.Int) - for { - x.Mod(i, Big36) - chars = append(chars, rune(Base36Chars[x.Uint64()])) - i.Div(i, Big36) - if i.Cmp(Big0) == 0 { - break - } - } - // reverse slice - for i, j := 0, len(chars)-1; i < j; i, j = i+1, j-1 { - chars[i], chars[j] = chars[j], chars[i] - } - return string(chars) -} - -func validBase36(s string) bool { - for _, c := range s { - i := uint64(c) - // 0-9 or A-Z - if i < 48 || (i > 57 && i < 65) || i > 90 { - return false - } - } - return true -} - -func join(s ...string) string { - return strings.Join(s, "") -} -- cgit