p2p/discover: add NodeID.Pubkey

This commit is contained in:
Felix Lange 2015-03-02 15:26:24 +01:00
parent d344054e5a
commit 2c505efd1e
2 changed files with 33 additions and 0 deletions

View File

@ -7,6 +7,7 @@ import (
"errors"
"fmt"
"io"
"math/big"
"math/rand"
"net"
"net/url"
@ -14,6 +15,7 @@ import (
"strings"
"time"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/secp256k1"
"github.com/ethereum/go-ethereum/rlp"
)
@ -187,6 +189,19 @@ func PubkeyID(pub *ecdsa.PublicKey) NodeID {
return id
}
// Pubkey returns the public key represented by the node ID.
// It returns an error if the ID is not a point on the curve.
func (id NodeID) Pubkey() (*ecdsa.PublicKey, error) {
p := &ecdsa.PublicKey{Curve: crypto.S256(), X: new(big.Int), Y: new(big.Int)}
half := len(id) / 2
p.X.SetBytes(id[:half])
p.Y.SetBytes(id[half:])
if !p.Curve.IsOnCurve(p.X, p.Y) {
return nil, errors.New("not a point on the S256 curve")
}
return p, nil
}
// recoverNodeID computes the public key used to sign the
// given hash from the signature.
func recoverNodeID(hash, sig []byte) (id NodeID, err error) {

View File

@ -133,6 +133,24 @@ func TestNodeID_recover(t *testing.T) {
if pub != recpub {
t.Errorf("recovered wrong pubkey:\ngot: %v\nwant: %v", recpub, pub)
}
ecdsa, err := pub.Pubkey()
if err != nil {
t.Errorf("Pubkey error: %v", err)
}
if !reflect.DeepEqual(ecdsa, &prv.PublicKey) {
t.Errorf("Pubkey mismatch:\n got: %#v\n want: %#v", ecdsa, &prv.PublicKey)
}
}
func TestNodeID_pubkeyBad(t *testing.T) {
ecdsa, err := NodeID{}.Pubkey()
if err == nil {
t.Error("expected error for zero ID")
}
if ecdsa != nil {
t.Error("expected nil result")
}
}
func TestNodeID_distcmp(t *testing.T) {