6286c255f1
This applies spec changes from ethereum/EIPs#1049 and adds support for pluggable identity schemes. Some care has been taken to make the "v4" scheme standalone. It uses public APIs only and could be moved out of package enr at any time. A couple of minor changes were needed to make identity schemes work: - The sequence number is now updated in Set instead of when signing. - Record is now copy-safe, i.e. calling Set on a shallow copy doesn't modify the record it was copied from.
145 lines
3.8 KiB
Go
145 lines
3.8 KiB
Go
// Copyright 2017 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 enr
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import (
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"crypto/ecdsa"
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"fmt"
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"io"
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"net"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/rlp"
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)
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// Entry is implemented by known node record entry types.
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//
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// To define a new entry that is to be included in a node record,
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// create a Go type that satisfies this interface. The type should
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// also implement rlp.Decoder if additional checks are needed on the value.
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type Entry interface {
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ENRKey() string
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}
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type generic struct {
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key string
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value interface{}
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}
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func (g generic) ENRKey() string { return g.key }
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func (g generic) EncodeRLP(w io.Writer) error {
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return rlp.Encode(w, g.value)
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}
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func (g *generic) DecodeRLP(s *rlp.Stream) error {
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return s.Decode(g.value)
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}
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// WithEntry wraps any value with a key name. It can be used to set and load arbitrary values
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// in a record. The value v must be supported by rlp. To use WithEntry with Load, the value
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// must be a pointer.
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func WithEntry(k string, v interface{}) Entry {
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return &generic{key: k, value: v}
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}
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// TCP is the "tcp" key, which holds the TCP port of the node.
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type TCP uint16
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func (v TCP) ENRKey() string { return "tcp" }
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// UDP is the "udp" key, which holds the UDP port of the node.
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type UDP uint16
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func (v UDP) ENRKey() string { return "udp" }
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// ID is the "id" key, which holds the name of the identity scheme.
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type ID string
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const IDv4 = ID("v4") // the default identity scheme
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func (v ID) ENRKey() string { return "id" }
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// IP is the "ip" key, which holds the IP address of the node.
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type IP net.IP
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func (v IP) ENRKey() string { return "ip" }
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// EncodeRLP implements rlp.Encoder.
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func (v IP) EncodeRLP(w io.Writer) error {
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if ip4 := net.IP(v).To4(); ip4 != nil {
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return rlp.Encode(w, ip4)
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}
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return rlp.Encode(w, net.IP(v))
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}
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// DecodeRLP implements rlp.Decoder.
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func (v *IP) DecodeRLP(s *rlp.Stream) error {
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if err := s.Decode((*net.IP)(v)); err != nil {
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return err
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}
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if len(*v) != 4 && len(*v) != 16 {
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return fmt.Errorf("invalid IP address, want 4 or 16 bytes: %v", *v)
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}
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return nil
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}
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// Secp256k1 is the "secp256k1" key, which holds a public key.
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type Secp256k1 ecdsa.PublicKey
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func (v Secp256k1) ENRKey() string { return "secp256k1" }
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// EncodeRLP implements rlp.Encoder.
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func (v Secp256k1) EncodeRLP(w io.Writer) error {
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return rlp.Encode(w, crypto.CompressPubkey((*ecdsa.PublicKey)(&v)))
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}
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// DecodeRLP implements rlp.Decoder.
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func (v *Secp256k1) DecodeRLP(s *rlp.Stream) error {
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buf, err := s.Bytes()
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if err != nil {
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return err
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}
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pk, err := crypto.DecompressPubkey(buf)
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if err != nil {
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return err
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}
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*v = (Secp256k1)(*pk)
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return nil
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}
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// KeyError is an error related to a key.
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type KeyError struct {
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Key string
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Err error
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}
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// Error implements error.
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func (err *KeyError) Error() string {
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if err.Err == errNotFound {
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return fmt.Sprintf("missing ENR key %q", err.Key)
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}
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return fmt.Sprintf("ENR key %q: %v", err.Key, err.Err)
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}
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// IsNotFound reports whether the given error means that a key/value pair is
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// missing from a record.
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func IsNotFound(err error) bool {
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kerr, ok := err.(*KeyError)
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return ok && kerr.Err == errNotFound
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}
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