// New methods using proper ecdsa keys from the stdlib
func ToECDSA(prv []byte) *ecdsa.PrivateKey {
if len(prv) == 0 {
return nil
}
priv := new(ecdsa.PrivateKey)
priv.PublicKey.Curve = secp256k1.S256()
priv.D = common.BigD(prv)
priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(prv)
return priv
}
// TODO: remove after refactoring packages crypto and crypto/ecies
func hexKey(prv string) *PrivateKey {
priv := new(ecdsa.PrivateKey)
priv.PublicKey.Curve = secp256k1.S256()
priv.D, _ = new(big.Int).SetString(prv, 16)
priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(priv.D.Bytes())
return ImportECDSA(priv)
}
func ToECDSAPub(pub []byte) *ecdsa.PublicKey {
if len(pub) == 0 {
return nil
}
x, y := elliptic.Unmarshal(secp256k1.S256(), pub)
return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}
}
// Tests whether a message can be signed, and wrapped in plain-text.
func TestMessageCleartextSignRecover(t *testing.T) {
key, err := crypto.GenerateKey()
if err != nil {
t.Fatalf("failed to create crypto key: %v", err)
}
payload := []byte("hello world")
msg := NewMessage(payload)
if _, err := msg.Wrap(DefaultPoW, Options{
From: key,
}); err != nil {
t.Fatalf("failed to sign message: %v", err)
}
if msg.Flags&signatureFlag != signatureFlag {
t.Fatalf("signature flag mismatch: have %d, want %d", msg.Flags&signatureFlag, signatureFlag)
}
if bytes.Compare(msg.Payload, payload) != 0 {
t.Fatalf("payload mismatch after signing: have 0x%x, want 0x%x", msg.Payload, payload)
}
pubKey := msg.Recover()
if pubKey == nil {
t.Fatalf("failed to recover public key")
}
p1 := elliptic.Marshal(secp256k1.S256(), key.PublicKey.X, key.PublicKey.Y)
p2 := elliptic.Marshal(secp256k1.S256(), pubKey.X, pubKey.Y)
if !bytes.Equal(p1, p2) {
t.Fatalf("public key mismatch: have 0x%x, want 0x%x", p2, p1)
}
}
func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
s, err := Ecrecover(hash, sig)
if err != nil {
return nil, err
}
x, y := elliptic.Unmarshal(secp256k1.S256(), s)
return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}, nil
}
func newKey(rand io.Reader) (*Key, error) {
privateKeyECDSA, err := ecdsa.GenerateKey(secp256k1.S256(), rand)
if err != nil {
return nil, err
}
return newKeyFromECDSA(privateKeyECDSA), nil
}
func (h *encHandshake) handleAuthMsg(msg *authMsgV4, prv *ecdsa.PrivateKey) error {
// Import the remote identity.
h.initNonce = msg.Nonce[:]
h.remoteID = msg.InitiatorPubkey
rpub, err := h.remoteID.Pubkey()
if err != nil {
return fmt.Errorf("bad remoteID: %#v", err)
}
h.remotePub = ecies.ImportECDSAPublic(rpub)
// Generate random keypair for ECDH.
// If a private key is already set, use it instead of generating one (for testing).
if h.randomPrivKey == nil {
h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, secp256k1.S256(), nil)
if err != nil {
return err
}
}
// Check the signature.
token, err := h.staticSharedSecret(prv)
if err != nil {
return err
}
signedMsg := xor(token, h.initNonce)
remoteRandomPub, err := secp256k1.RecoverPubkey(signedMsg, msg.Signature[:])
if err != nil {
return err
}
h.remoteRandomPub, _ = importPublicKey(remoteRandomPub)
return nil
}
// makeAuthMsg creates the initiator handshake message.
func (h *encHandshake) makeAuthMsg(prv *ecdsa.PrivateKey, token []byte) (*authMsgV4, error) {
rpub, err := h.remoteID.Pubkey()
if err != nil {
return nil, fmt.Errorf("bad remoteID: %v", err)
}
h.remotePub = ecies.ImportECDSAPublic(rpub)
// Generate random initiator nonce.
h.initNonce = make([]byte, shaLen)
if _, err := rand.Read(h.initNonce); err != nil {
return nil, err
}
// Generate random keypair to for ECDH.
h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, secp256k1.S256(), nil)
if err != nil {
return nil, err
}
// Sign known message: static-shared-secret ^ nonce
token, err = h.staticSharedSecret(prv)
if err != nil {
return nil, err
}
signed := xor(token, h.initNonce)
signature, err := crypto.Sign(signed, h.randomPrivKey.ExportECDSA())
if err != nil {
return nil, err
}
msg := new(authMsgV4)
copy(msg.Signature[:], signature)
copy(msg.InitiatorPubkey[:], crypto.FromECDSAPub(&prv.PublicKey)[1:])
copy(msg.Nonce[:], h.initNonce)
msg.Version = 4
return msg, nil
}
// Tests whether a message can be properly signed and encrypted.
func TestMessageFullCrypto(t *testing.T) {
fromKey, err := crypto.GenerateKey()
if err != nil {
t.Fatalf("failed to create sender crypto key: %v", err)
}
toKey, err := crypto.GenerateKey()
if err != nil {
t.Fatalf("failed to create recipient crypto key: %v", err)
}
payload := []byte("hello world")
msg := NewMessage(payload)
envelope, err := msg.Wrap(DefaultPoW, Options{
From: fromKey,
To: &toKey.PublicKey,
})
if err != nil {
t.Fatalf("failed to encrypt message: %v", err)
}
if msg.Flags&signatureFlag != signatureFlag {
t.Fatalf("signature flag mismatch: have %d, want %d", msg.Flags&signatureFlag, signatureFlag)
}
if len(msg.Signature) == 0 {
t.Fatalf("no signature found for signed message")
}
out, err := envelope.Open(toKey)
if err != nil {
t.Fatalf("failed to open encrypted message: %v", err)
}
if !bytes.Equal(out.Payload, payload) {
t.Errorf("payload mismatch: have 0x%x, want 0x%x", out.Payload, payload)
}
pubKey := out.Recover()
if pubKey == nil {
t.Fatalf("failed to recover public key")
}
p1 := elliptic.Marshal(secp256k1.S256(), fromKey.PublicKey.X, fromKey.PublicKey.Y)
p2 := elliptic.Marshal(secp256k1.S256(), pubKey.X, pubKey.Y)
if !bytes.Equal(p1, p2) {
t.Fatalf("public key mismatch: have 0x%x, want 0x%x", p2, p1)
}
}
// 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: secp256k1.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("id is invalid secp256k1 curve point")
}
return p, nil
}
// Benchmark the generation of S256 shared keys.
func BenchmarkGenSharedKeyS256(b *testing.B) {
prv, err := GenerateKey(rand.Reader, secp256k1.S256(), nil)
if err != nil {
fmt.Println(err.Error())
b.FailNow()
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
_, err := prv.GenerateShared(&prv.PublicKey, 16, 16)
if err != nil {
fmt.Println(err.Error())
b.FailNow()
}
}
}
// NewKeyForDirectICAP generates a 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(secp256k1.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
}
func GenerateKey() (*ecdsa.PrivateKey, error) {
return ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
}
func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
if pub == nil || pub.X == nil || pub.Y == nil {
return nil
}
return elliptic.Marshal(secp256k1.S256(), pub.X, pub.Y)
}
import (
"crypto"
"crypto/aes"
"crypto/cipher"
"crypto/elliptic"
"crypto/sha256"
"crypto/sha512"
"fmt"
"hash"
"github.com/expanse-project/go-expanse/crypto/secp256k1"
)
var (
DefaultCurve = secp256k1.S256()
ErrUnsupportedECDHAlgorithm = fmt.Errorf("ecies: unsupported ECDH algorithm")
ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters")
)
type ECIESParams struct {
Hash func() hash.Hash // hash function
hashAlgo crypto.Hash
Cipher func([]byte) (cipher.Block, error) // symmetric cipher
BlockSize int // block size of symmetric cipher
KeyLen int // length of symmetric key
}
// Standard ECIES parameters:
// * ECIES using AES128 and HMAC-SHA-256-16
// * ECIES using AES256 and HMAC-SHA-256-32