common, crypto: add ICAP functions

This commit is contained in:
Gustav Simonsson 2015-10-06 18:39:42 +02:00
parent 44fd395141
commit 2db9798646
5 changed files with 314 additions and 0 deletions

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@ -27,6 +27,9 @@ var (
BigTrue = Big1
BigFalse = Big0
Big32 = big.NewInt(32)
Big36 = big.NewInt(36)
Big97 = big.NewInt(97)
Big98 = big.NewInt(98)
Big256 = big.NewInt(0xff)
Big257 = big.NewInt(257)
MaxBig = String2Big("0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")

190
common/icap.go Normal file
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@ -0,0 +1,190 @@
// 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 <http://www.gnu.org/licenses/>.
// 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, "")
}

91
common/icap_test.go Normal file
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@ -0,0 +1,91 @@
// 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 <http://www.gnu.org/licenses/>.
package common
import "testing"
/* More test vectors:
https://github.com/ethereum/web3.js/blob/master/test/iban.fromAddress.js
https://github.com/ethereum/web3.js/blob/master/test/iban.toAddress.js
https://github.com/ethereum/web3.js/blob/master/test/iban.isValid.js
https://github.com/ethereum/libethereum/blob/develop/test/libethcore/icap.cpp
*/
type icapTest struct {
name string
addr string
icap string
}
var icapOKTests = []icapTest{
{"Direct1", "0x52dc504a422f0e2a9e7632a34a50f1a82f8224c7", "XE499OG1EH8ZZI0KXC6N83EKGT1BM97P2O7"},
{"Direct2", "0x11c5496aee77c1ba1f0854206a26dda82a81d6d8", "XE1222Q908LN1QBBU6XUQSO1OHWJIOS46OO"},
{"DirectZeroPrefix", "0x00c5496aee77c1ba1f0854206a26dda82a81d6d8", "XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS"},
{"DirectDoubleZeroPrefix", "0x0000a5327eab78357cbf2ae8f3d49fd9d90c7d22", "XE0600DQK33XDTYUCRI0KYM5ELAKXDWWF6"},
}
var icapInvalidTests = []icapTest{
{"DirectInvalidCheckSum", "", "XE7438O073KYGTWWZN0F2WZ0R8PX5ZPPZS"},
{"DirectInvalidCountryCode", "", "XD7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS"},
{"DirectInvalidLength36", "", "XE499OG1EH8ZZI0KXC6N83EKGT1BM97P2O77"},
{"DirectInvalidLength33", "", "XE499OG1EH8ZZI0KXC6N83EKGT1BM97P2"},
{"IndirectInvalidCheckSum", "", "XE35ETHXREGGOPHERSSS"},
{"IndirectInvalidAssetIdentifier", "", "XE34ETHXREGGOPHERSSS"},
{"IndirectInvalidLength19", "", "XE34ETHXREGGOPHERSS"},
{"IndirectInvalidLength21", "", "XE34ETHXREGGOPHERSSSS"},
}
func TestICAPOK(t *testing.T) {
for _, test := range icapOKTests {
decodeEncodeTest(HexToAddress(test.addr), test.icap, t)
}
}
func TestICAPInvalid(t *testing.T) {
for _, test := range icapInvalidTests {
failedDecodingTest(test.icap, t)
}
}
func decodeEncodeTest(addr0 Address, icap0 string, t *testing.T) {
icap1, err := AddressToICAP(addr0)
if err != nil {
t.Errorf("ICAP encoding failed: %s", err)
}
if icap1 != icap0 {
t.Errorf("ICAP mismatch: have: %s want: %s", icap1, icap0)
}
addr1, err := ICAPToAddress(icap0)
if err != nil {
t.Errorf("ICAP decoding failed: %s", err)
}
if addr1 != addr0 {
t.Errorf("Address mismatch: have: %x want: %x", addr1, addr0)
}
}
func failedDecodingTest(icap string, t *testing.T) {
addr, err := ICAPToAddress(icap)
if err == nil {
t.Errorf("Expected ICAP decoding to fail.")
}
if addr != (Address{}) {
t.Errorf("Expected empty Address on failed ICAP decoding.")
}
}

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@ -22,6 +22,7 @@ import (
"encoding/hex"
"encoding/json"
"io"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/pborman/uuid"
@ -143,3 +144,24 @@ func NewKey(rand io.Reader) *Key {
return NewKeyFromECDSA(privateKeyECDSA)
}
// generate key whose address fits into < 155 bits so it can fit into
// the Direct ICAP spec. for simplicity and easier compatibility with
// other libs, we retry until the first byte is 0.
func NewKeyForDirectICAP(rand io.Reader) *Key {
randBytes := make([]byte, 64)
_, err := rand.Read(randBytes)
if err != nil {
panic("key generation: could not read from random source: " + err.Error())
}
reader := bytes.NewReader(randBytes)
privateKeyECDSA, err := ecdsa.GenerateKey(S256(), reader)
if err != nil {
panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
}
key := NewKeyFromECDSA(privateKeyECDSA)
if !strings.HasPrefix(key.Address.Hex(), "0x00") {
return NewKeyForDirectICAP(rand)
}
return key
}

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@ -20,6 +20,7 @@ import (
"encoding/hex"
"fmt"
"reflect"
"strings"
"testing"
"github.com/ethereum/go-ethereum/common"
@ -223,3 +224,10 @@ func loadKeyStoreTestV1(file string, t *testing.T) map[string]KeyStoreTestV1 {
}
return tests
}
func TestKeyForDirectICAP(t *testing.T) {
key := NewKeyForDirectICAP(randentropy.Reader)
if !strings.HasPrefix(key.Address.Hex(), "0x00") {
t.Errorf("Expected first address byte to be zero, have: %s", key.Address.Hex())
}
}