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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