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contracts, swarm: implement EIP-1577 (#19285)
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* contracts/ens: update public resolver solidity code

* contracts/ens: update public resolver, update go bindings

* update build

* fix ens.sol

* contracts/ens: change contract interface

* contracts/ens: implement public resolver changes

* contracts/ens: added ENSRegistry contract

* contracts/ens: reinstate old contract code

* contracts/ens: update README.md

* contracts/ens: added test coverage for fallback contract

* contracts/ens: added support for fallback contract

* contracts/ens: removed unused contract code

* contracts/ens: add todo and decode multicodec stub

* add encode

* vendor: add ipfs cid libraries

* contracts/ens: cid sanity tests

* contracts/ens: more cid sanity checks

* contracts/ens: wip integration

* wip

* Revert "vendor: add ipfs cid libraries"

This reverts commit 29d9b6b.

* contracts/ens: removed multiformats dependencies

* contracts/ens: added decode tests

* contracts/ens: added eip spec test, minor changes to exiting tests

* contracts/ens: moved cid decoding to own file

* contracts/ens: added unit test to encode hash to content hash

* contracts/ens: removed unused code

* contracts/ens: fix ens tests to use cid decode and encode

* contracts/ens: adjust swarm multicodecs after pr merge

* contracts/ens: fix linter error

* constracts/ens: address PR comments

* cmd, contracts: make peoples lives easier

* contracts/ens: fix linter error

* contracts/ens: address PR comments
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acud authored and nonsense committed May 8, 2019
1 parent eb1aaf3 commit 96b6679
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59 changes: 58 additions & 1 deletion cmd/swarm/hash.go
Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,13 @@ package main

import (
"context"
"encoding/hex"
"fmt"
"os"

"github.com/ethereum/go-ethereum/cmd/utils"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/contracts/ens"
"github.com/ethereum/go-ethereum/swarm/storage"
"gopkg.in/urfave/cli.v1"
)
Expand All @@ -34,7 +37,33 @@ var hashCommand = cli.Command{
Usage: "print the swarm hash of a file or directory",
ArgsUsage: "<file>",
Description: "Prints the swarm hash of file or directory",
}
Subcommands: []cli.Command{
{
CustomHelpTemplate: helpTemplate,
Name: "ens",
Usage: "converts a swarm hash to an ens EIP1577 compatible CIDv1 hash",
ArgsUsage: "<ref>",
Description: "",
Subcommands: []cli.Command{
{
Action: encodeEipHash,
CustomHelpTemplate: helpTemplate,
Name: "contenthash",
Usage: "converts a swarm hash to an ens EIP1577 compatible CIDv1 hash",
ArgsUsage: "<ref>",
Description: "",
},
{
Action: ensNodeHash,
CustomHelpTemplate: helpTemplate,
Name: "node",
Usage: "converts an ens name to an ENS node hash",
ArgsUsage: "<ref>",
Description: "",
},
},
},
}}

func hash(ctx *cli.Context) {
args := ctx.Args()
Expand All @@ -56,3 +85,31 @@ func hash(ctx *cli.Context) {
fmt.Printf("%v\n", addr)
}
}
func ensNodeHash(ctx *cli.Context) {
args := ctx.Args()
if len(args) < 1 {
utils.Fatalf("Usage: swarm hash ens node <ens name>")
}
ensName := args[0]

hash := ens.EnsNode(ensName)

stringHex := hex.EncodeToString(hash[:])
fmt.Println(stringHex)
}
func encodeEipHash(ctx *cli.Context) {
args := ctx.Args()
if len(args) < 1 {
utils.Fatalf("Usage: swarm hash ens <swarm hash>")
}
swarmHash := args[0]

hash := common.HexToHash(swarmHash)
ensHash, err := ens.EncodeSwarmHash(hash)
if err != nil {
utils.Fatalf("error converting swarm hash", err)
}

stringHex := hex.EncodeToString(ensHash)
fmt.Println(stringHex)
}
10 changes: 10 additions & 0 deletions contracts/ens/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -18,3 +18,13 @@ The go bindings for ENS contracts are generated using `abigen` via the go genera
```shell
go generate ./contracts/ens
```

## Fallback contract support

In order to better support content resolution on different service providers (such as Swarm and IPFS), [EIP-1577](https://eips.ethereum.org/EIPS/eip-1577)
was introduced and with it changes that allow applications to know _where_ content hashes are stored (i.e. if the
requested hash resides on Swarm or IPFS).

The code under `contracts/ens/contract` reflects the new Public Resolver changes and the code under `fallback_contract` allows
us to support the old contract resolution in cases where the ENS name owner did not update her Resolver contract, until the migration
period ends (date arbitrarily set to June 1st, 2019).
121 changes: 121 additions & 0 deletions contracts/ens/cid.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,121 @@
// Copyright 2016 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 ens

import (
"encoding/binary"
"errors"
"fmt"

"github.com/ethereum/go-ethereum/common"
)

const (
cidv1 = 0x1

nsIpfs = 0xe3
nsSwarm = 0xe4

swarmTypecode = 0xfa //swarm manifest, see https://github.com/multiformats/multicodec/blob/master/table.csv
swarmHashtype = 0xd6 // BMT, see https://github.com/multiformats/multicodec/blob/master/table.csv

hashLength = 32
)

// deocodeEIP1577ContentHash decodes a chain-stored content hash from an ENS record according to EIP-1577
// a successful decode will result the different parts of the content hash in accordance to the CID spec
// Note: only CIDv1 is supported
func decodeEIP1577ContentHash(buf []byte) (storageNs, contentType, hashType, hashLength uint64, hash []byte, err error) {
if len(buf) < 10 {
return 0, 0, 0, 0, nil, errors.New("buffer too short")
}

storageNs, n := binary.Uvarint(buf)

buf = buf[n:]
vers, n := binary.Uvarint(buf)

if vers != 1 {
return 0, 0, 0, 0, nil, fmt.Errorf("expected cid v1, got: %d", vers)
}
buf = buf[n:]
contentType, n = binary.Uvarint(buf)

buf = buf[n:]
hashType, n = binary.Uvarint(buf)

buf = buf[n:]
hashLength, n = binary.Uvarint(buf)

hash = buf[n:]

if len(hash) != int(hashLength) {
return 0, 0, 0, 0, nil, errors.New("hash length mismatch")
}
return storageNs, contentType, hashType, hashLength, hash, nil
}

func extractContentHash(buf []byte) (common.Hash, error) {
storageNs, _ /*contentType*/, _ /* hashType*/, decodedHashLength, hashBytes, err := decodeEIP1577ContentHash(buf)

if err != nil {
return common.Hash{}, err
}

if storageNs != nsSwarm {
return common.Hash{}, errors.New("unknown storage system")
}

//todo: for the time being we implement loose enforcement for the EIP rules until ENS manager is updated
/*if contentType != swarmTypecode {
return common.Hash{}, errors.New("unknown content type")
}
if hashType != swarmHashtype {
return common.Hash{}, errors.New("unknown multihash type")
}*/

if decodedHashLength != hashLength {
return common.Hash{}, errors.New("odd hash length, swarm expects 32 bytes")
}

if len(hashBytes) != int(hashLength) {
return common.Hash{}, errors.New("hash length mismatch")
}

return common.BytesToHash(buf), nil
}

func EncodeSwarmHash(hash common.Hash) ([]byte, error) {
var cidBytes []byte
var headerBytes = []byte{
nsSwarm, //swarm namespace
cidv1, // CIDv1
swarmTypecode, // swarm hash
swarmHashtype, // swarm bmt hash
hashLength, //hash length. 32 bytes
}

varintbuf := make([]byte, binary.MaxVarintLen64)
for _, v := range headerBytes {
n := binary.PutUvarint(varintbuf, uint64(v))
cidBytes = append(cidBytes, varintbuf[:n]...)
}

cidBytes = append(cidBytes, hash[:]...)
return cidBytes, nil
}
158 changes: 158 additions & 0 deletions contracts/ens/cid_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,158 @@
// Copyright 2016 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 ens

import (
"bytes"
"encoding/binary"
"encoding/hex"
"fmt"
"testing"

"github.com/ethereum/go-ethereum/common"
)

// Tests for the decoding of the example ENS
func TestEIPSpecCidDecode(t *testing.T) {
const (
eipSpecHash = "e3010170122029f2d17be6139079dc48696d1f582a8530eb9805b561eda517e22a892c7e3f1f"
eipHash = "29f2d17be6139079dc48696d1f582a8530eb9805b561eda517e22a892c7e3f1f"
dagPb = 0x70
sha2256 = 0x12
)
b, err := hex.DecodeString(eipSpecHash)
if err != nil {
t.Fatal(err)
}
hashBytes, err := hex.DecodeString(eipHash)

if err != nil {
t.Fatal(err)
}

storageNs, contentType, hashType, hashLength, decodedHashBytes, err := decodeEIP1577ContentHash(b)

if err != nil {
t.Fatal(err)
}
if storageNs != nsIpfs {
t.Fatal("wrong ns")
}
if contentType != dagPb {
t.Fatal("should be ipfs typecode")
}
if hashType != sha2256 {
t.Fatal("should be sha2-256")
}
if hashLength != 32 {
t.Fatal("should be 32")
}
if !bytes.Equal(hashBytes, decodedHashBytes) {
t.Fatal("should be equal")
}

}
func TestManualCidDecode(t *testing.T) {
// call cid encode method with hash. expect byte slice returned, compare according to spec

for _, v := range []struct {
name string
headerBytes []byte
wantErr bool
}{
{
name: "values correct, should not fail",
headerBytes: []byte{0xe4, 0x01, 0xfa, 0xd6, 0x20},
wantErr: false,
},
{
name: "cid version wrong, should fail",
headerBytes: []byte{0xe4, 0x00, 0xfa, 0xd6, 0x20},
wantErr: true,
},
{
name: "hash length wrong, should fail",
headerBytes: []byte{0xe4, 0x01, 0xfa, 0xd6, 0x1f},
wantErr: true,
},
{
name: "values correct for ipfs, should fail",
headerBytes: []byte{0xe3, 0x01, 0x70, 0x12, 0x20},
wantErr: true,
},
{
name: "loose values for swarm, todo remove, should not fail",
headerBytes: []byte{0xe4, 0x01, 0x70, 0x12, 0x20},
wantErr: false,
},
{
name: "loose values for swarm, todo remove, should not fail",
headerBytes: []byte{0xe4, 0x01, 0x99, 0x99, 0x20},
wantErr: false,
},
} {
t.Run(v.name, func(t *testing.T) {
const eipHash = "29f2d17be6139079dc48696d1f582a8530eb9805b561eda517e22a892c7e3f1f"

var bb []byte
buf := make([]byte, binary.MaxVarintLen64)
for _, vv := range v.headerBytes {
n := binary.PutUvarint(buf, uint64(vv))
bb = append(bb, buf[:n]...)
}

h := common.HexToHash(eipHash)
bb = append(bb, h[:]...)
str := hex.EncodeToString(bb)
fmt.Println(str)
decodedHash, e := extractContentHash(bb)
switch v.wantErr {
case true:
if e == nil {
t.Fatal("the decode should fail")
}
case false:
if e != nil {
t.Fatalf("the deccode shouldnt fail: %v", e)
}
if !bytes.Equal(decodedHash[:], h[:]) {
t.Fatal("hashes not equal")
}
}
})
}
}

func TestManuelCidEncode(t *testing.T) {
// call cid encode method with hash. expect byte slice returned, compare according to spec
const eipHash = "29f2d17be6139079dc48696d1f582a8530eb9805b561eda517e22a892c7e3f1f"
cidBytes, err := EncodeSwarmHash(common.HexToHash(eipHash))
if err != nil {
t.Fatal(err)
}

// logic in extractContentHash is unit tested thoroughly
// hence we just check that the returned hash is equal
h, err := extractContentHash(cidBytes)
if err != nil {
t.Fatal(err)
}

if bytes.Equal(h[:], cidBytes) {
t.Fatal("should be equal")
}
}
23 changes: 0 additions & 23 deletions contracts/ens/contract/AbstractENS.sol

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