Golang btcec.S256函数代码示例

// isPubKey returns whether or not the passed public key script is a standard
// pay-to-pubkey script that pays to a valid compressed or uncompressed public
// key along with the serialized pubkey it is paying to if it is.
//
// NOTE: This function ensures the public key is actually valid since the
// compression algorithm requires valid pubkeys.  It does not support hybrid
// pubkeys.  This means that even if the script has the correct form for a
// pay-to-pubkey script, this function will only return true when it is paying
// to a valid compressed or uncompressed pubkey.
func isPubKey(script []byte) (bool, []byte) {
	// Pay-to-compressed-pubkey script.
	if len(script) == 35 && script[0] == txscript.OP_DATA_33 &&
		script[34] == txscript.OP_CHECKSIG && (script[1] == 0x02 ||
		script[1] == 0x03) {

		// Ensure the public key is valid.
		serializedPubKey := script[1:34]
		_, err := btcec.ParsePubKey(serializedPubKey, btcec.S256())
		if err == nil {
			return true, serializedPubKey
		}
	}

	// Pay-to-uncompressed-pubkey script.
	if len(script) == 67 && script[0] == txscript.OP_DATA_65 &&
		script[66] == txscript.OP_CHECKSIG && script[1] == 0x04 {

		// Ensure the public key is valid.
		serializedPubKey := script[1:66]
		_, err := btcec.ParsePubKey(serializedPubKey, btcec.S256())
		if err == nil {
			return true, serializedPubKey
		}
	}

	return false, nil
}

func TestPublicKeyIsEqual(t *testing.T) {
	pubKey1, err := btcec.ParsePubKey(
		[]byte{0x03, 0x26, 0x89, 0xc7, 0xc2, 0xda, 0xb1, 0x33,
			0x09, 0xfb, 0x14, 0x3e, 0x0e, 0x8f, 0xe3, 0x96, 0x34,
			0x25, 0x21, 0x88, 0x7e, 0x97, 0x66, 0x90, 0xb6, 0xb4,
			0x7f, 0x5b, 0x2a, 0x4b, 0x7d, 0x44, 0x8e,
		},
		btcec.S256(),
	)
	if err != nil {
		t.Fatalf("failed to parse raw bytes for pubKey1: %v", err)
	}

	pubKey2, err := btcec.ParsePubKey(
		[]byte{0x02, 0xce, 0x0b, 0x14, 0xfb, 0x84, 0x2b, 0x1b,
			0xa5, 0x49, 0xfd, 0xd6, 0x75, 0xc9, 0x80, 0x75, 0xf1,
			0x2e, 0x9c, 0x51, 0x0f, 0x8e, 0xf5, 0x2b, 0xd0, 0x21,
			0xa9, 0xa1, 0xf4, 0x80, 0x9d, 0x3b, 0x4d,
		},
		btcec.S256(),
	)
	if err != nil {
		t.Fatalf("failed to parse raw bytes for pubKey2: %v", err)
	}

	if !pubKey1.IsEqual(pubKey1) {
		t.Fatalf("value of IsEqual is incorrect, %v is "+
			"equal to %v", pubKey1, pubKey1)
	}

	if pubKey1.IsEqual(pubKey2) {
		t.Fatalf("value of IsEqual is incorrect, %v is not "+
			"equal to %v", pubKey1, pubKey2)
	}
}

// TestSigCacheAddMaxEntriesZeroOrNegative tests that if a sigCache is created
// with a max size <= 0, then no entries are added to the sigcache at all.
func TestSigCacheAddMaxEntriesZeroOrNegative(t *testing.T) {
	// Create a sigcache that can hold up to 0 entries.
	sigCache := NewSigCache(0)

	// Generate a random sigCache entry triplet.
	msg1, sig1, key1, err := genRandomSig()
	if err != nil {
		t.Errorf("unable to generate random signature test data")
	}

	// Add the triplet to the signature cache.
	sigCache.Add(*msg1, sig1, key1)

	// The generated triplet should not be found.
	sig1Copy, _ := btcec.ParseSignature(sig1.Serialize(), btcec.S256())
	key1Copy, _ := btcec.ParsePubKey(key1.SerializeCompressed(), btcec.S256())
	if sigCache.Exists(*msg1, sig1Copy, key1Copy) {
		t.Errorf("previously added signature found in sigcache, but" +
			"shouldn't have been")
	}

	// There shouldn't be any entries in the sigCache.
	if len(sigCache.validSigs) != 0 {
		t.Errorf("%v items found in sigcache, no items should have"+
			"been added", len(sigCache.validSigs))
	}
}

// GetIdentity returns the public identity corresponding to the given address
// if it exists.
func (c *Client) GetIdentity(address string) (*identity.Public, error) {
	addr, err := bmutil.DecodeAddress(address)
	if err != nil {
		return nil, fmt.Errorf("Address decode failed: %v", addr)
	}

	res, err := c.bmd.GetIdentity(context.Background(), &pb.GetIdentityRequest{
		Address: address,
	})
	if grpc.Code(err) == codes.NotFound {
		return nil, ErrIdentityNotFound
	} else if err != nil {
		return nil, err
	}

	signKey, err := btcec.ParsePubKey(res.SigningKey, btcec.S256())
	if err != nil {
		return nil, err
	}
	encKey, err := btcec.ParsePubKey(res.EncryptionKey, btcec.S256())
	if err != nil {
		return nil, err
	}

	return identity.NewPublic(signKey, encKey,
		&pow.Data{
			res.NonceTrials,
			res.ExtraBytes,
		}, addr.Version, addr.Stream), nil
}

//Deriving Child public Key from Public Parent Key
func (parent *ExtendedPublicKey) CKDpub(index uint32) (*ExtendedPublicKey, error) {
	if index >= HardenedKeyIndex {
		return nil, nil
	}
	// let I = HMAC-SHA512(Key = cpar, Data = serP(Kpar) || ser32(i)).
	//serP(P): serializes the coordinate pair P = (x,y) as a byte sequence using SEC1's
	//compressed form: (0x02 or 0x03) || ser256(x)  <-- done above
	//, where the header byte depends on the parity of the omitted y coordinate.
	data := make([]byte, 37)
	copy(data[0:], parent.PublicKey)
	binary.BigEndian.PutUint32(data[33:], index)
	hmac512 := hmac.New(sha512.New, parent.Chaincode)
	hmac512.Write(data)
	raw := hmac512.Sum(nil)
	//child Chaincode is the right 32 bytes of the result
	childChaincode := raw[32:]
	// The returned child key Ki is point(parse256(IL)) + Kpar
	leftX, leftY := Point(raw[:32])
	x1 := new(big.Int).SetBytes(leftX)
	y1 := new(big.Int).SetBytes(leftY)
	x2 := new(big.Int).SetBytes(parent.X)
	y2 := new(big.Int).SetBytes(parent.Y)
	childX, childY := btcec.S256().Add(x1, y1, x2, y2)
	ParentFingerPrint := parent.GetFingerPrint()
	depthBytes := []byte{parent.Depth}
	depthInt := new(big.Int).SetBytes(depthBytes)
	depthInt.Add(depthInt, big.NewInt(1))
	depth := depthInt.Bytes()
	publicKey := btcec.PublicKey{Curve: btcec.S256(), X: childX, Y: childY}
	childExtendedPublicKey := NewExtendedPublicKey(childX.Bytes(), childY.Bytes(), depth[len(depth)-1], ParentFingerPrint, index, childChaincode, publicKey.SerializeCompressed())

	return childExtendedPublicKey, nil
}

func TestEncodeDecodeWIF(t *testing.T) {
	priv1, _ := btcec.PrivKeyFromBytes(btcec.S256(), []byte{
		0x0c, 0x28, 0xfc, 0xa3, 0x86, 0xc7, 0xa2, 0x27,
		0x60, 0x0b, 0x2f, 0xe5, 0x0b, 0x7c, 0xae, 0x11,
		0xec, 0x86, 0xd3, 0xbf, 0x1f, 0xbe, 0x47, 0x1b,
		0xe8, 0x98, 0x27, 0xe1, 0x9d, 0x72, 0xaa, 0x1d})

	priv2, _ := btcec.PrivKeyFromBytes(btcec.S256(), []byte{
		0xdd, 0xa3, 0x5a, 0x14, 0x88, 0xfb, 0x97, 0xb6,
		0xeb, 0x3f, 0xe6, 0xe9, 0xef, 0x2a, 0x25, 0x81,
		0x4e, 0x39, 0x6f, 0xb5, 0xdc, 0x29, 0x5f, 0xe9,
		0x94, 0xb9, 0x67, 0x89, 0xb2, 0x1a, 0x03, 0x98})

	wif1, err := NewWIF(priv1, &chaincfg.MainNetParams, false)
	if err != nil {
		t.Fatal(err)
	}
	wif2, err := NewWIF(priv2, &chaincfg.TestNet3Params, true)
	if err != nil {
		t.Fatal(err)
	}

	tests := []struct {
		wif     *WIF
		encoded string
	}{
		{
			wif1,
			"5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ",
		},
		{
			wif2,
			"cV1Y7ARUr9Yx7BR55nTdnR7ZXNJphZtCCMBTEZBJe1hXt2kB684q",
		},
	}

	for _, test := range tests {
		// Test that encoding the WIF structure matches the expected string.
		s := test.wif.String()
		if s != test.encoded {
			t.Errorf("TestEncodeDecodePrivateKey failed: want '%s', got '%s'",
				test.encoded, s)
			continue
		}

		// Test that decoding the expected string results in the original WIF
		// structure.
		w, err := DecodeWIF(test.encoded)
		if err != nil {
			t.Error(err)
			continue
		}
		if got := w.String(); got != test.encoded {
			t.Errorf("NewWIF failed: want '%v', got '%v'", test.wif, got)
		}
	}
}

// Verifies a hash using DER encoded signature
func verifyECDSA(pubKey, signature, hash []byte) (bool, error) {
	sig, err := btcec.ParseDERSignature(signature, btcec.S256())
	if err != nil {
		return false, err
	}
	pk, err := btcec.ParsePubKey(pubKey, btcec.S256())
	if err != nil {
		return false, nil
	}
	return sig.Verify(hash, pk), nil
}

// NewKeyFromString returns a new extended key instance from a base58-encoded
// extended key.
func NewKeyFromString(key string) (*ExtendedKey, error) {
	// The base58-decoded extended key must consist of a serialized payload
	// plus an additional 4 bytes for the checksum.
	decoded := base58.Decode(key)
	if len(decoded) != serializedKeyLen+4 {
		return nil, ErrInvalidKeyLen
	}

	// The serialized format is:
	//   version (4) || depth (1) || parent fingerprint (4)) ||
	//   child num (4) || chain code (32) || key data (33) || checksum (4)

	// Split the payload and checksum up and ensure the checksum matches.
	payload := decoded[:len(decoded)-4]
	checkSum := decoded[len(decoded)-4:]
	expectedCheckSum := chainhash.DoubleHashB(payload)[:4]
	if !bytes.Equal(checkSum, expectedCheckSum) {
		return nil, ErrBadChecksum
	}

	// Deserialize each of the payload fields.
	version := payload[:4]
	depth := uint16(payload[4:5][0])
	parentFP := payload[5:9]
	childNum := binary.BigEndian.Uint32(payload[9:13])
	chainCode := payload[13:45]
	keyData := payload[45:78]

	// The key data is a private key if it starts with 0x00.  Serialized
	// compressed pubkeys either start with 0x02 or 0x03.
	isPrivate := keyData[0] == 0x00
	if isPrivate {
		// Ensure the private key is valid.  It must be within the range
		// of the order of the secp256k1 curve and not be 0.
		keyData = keyData[1:]
		keyNum := new(big.Int).SetBytes(keyData)
		if keyNum.Cmp(btcec.S256().N) >= 0 || keyNum.Sign() == 0 {
			return nil, ErrUnusableSeed
		}
	} else {
		// Ensure the public key parses correctly and is actually on the
		// secp256k1 curve.
		_, err := btcec.ParsePubKey(keyData, btcec.S256())
		if err != nil {
			return nil, err
		}
	}

	return newExtendedKey(version, keyData, chainCode, parentFP, depth,
		childNum, isPrivate), nil
}

// TestSigCacheAddEvictEntry tests the eviction case where a new signature
// triplet is added to a full signature cache which should trigger randomized
// eviction, followed by adding the new element to the cache.
func TestSigCacheAddEvictEntry(t *testing.T) {
	// Create a sigcache that can hold up to 100 entries.
	sigCacheSize := uint(100)
	sigCache := NewSigCache(sigCacheSize)

	// Fill the sigcache up with some random sig triplets.
	for i := uint(0); i < sigCacheSize; i++ {
		msg, sig, key, err := genRandomSig()
		if err != nil {
			t.Fatalf("unable to generate random signature test data")
		}

		sigCache.Add(*msg, sig, key)

		sigCopy, _ := btcec.ParseSignature(sig.Serialize(), btcec.S256())
		keyCopy, _ := btcec.ParsePubKey(key.SerializeCompressed(), btcec.S256())
		if !sigCache.Exists(*msg, sigCopy, keyCopy) {
			t.Errorf("previously added item not found in signature" +
				"cache")
		}
	}

	// The sigcache should now have sigCacheSize entries within it.
	if uint(len(sigCache.validSigs)) != sigCacheSize {
		t.Fatalf("sigcache should now have %v entries, instead it has %v",
			sigCacheSize, len(sigCache.validSigs))
	}

	// Add a new entry, this should cause eviction of a randomly chosen
	// previously entry.
	msgNew, sigNew, keyNew, err := genRandomSig()
	if err != nil {
		t.Fatalf("unable to generate random signature test data")
	}
	sigCache.Add(*msgNew, sigNew, keyNew)

	// The sigcache should still have sigCache entries.
	if uint(len(sigCache.validSigs)) != sigCacheSize {
		t.Fatalf("sigcache should now have %v entries, instead it has %v",
			sigCacheSize, len(sigCache.validSigs))
	}

	// The entry added above should be found within the sigcache.
	sigNewCopy, _ := btcec.ParseSignature(sigNew.Serialize(), btcec.S256())
	keyNewCopy, _ := btcec.ParsePubKey(keyNew.SerializeCompressed(), btcec.S256())
	if !sigCache.Exists(*msgNew, sigNewCopy, keyNewCopy) {
		t.Fatalf("previously added item not found in signature cache")
	}
}

func (pubKey PubKeySecp256k1) VerifyBytes(msg []byte, sig_ Signature) bool {
	pub__, err := secp256k1.ParsePubKey(append([]byte{0x04}, pubKey[:]...), secp256k1.S256())
	if err != nil {
		return false
	}
	sig, ok := sig_.(SignatureSecp256k1)
	if !ok {
		return false
	}
	sig__, err := secp256k1.ParseDERSignature(sig[:], secp256k1.S256())
	if err != nil {
		return false
	}
	return sig__.Verify(Sha256(msg), pub__)
}

// PrivKey returns the private key for the address.  It can fail if the address
// manager is watching-only or locked, or the address does not have any keys.
//
// This is part of the ManagedPubKeyAddress interface implementation.
func (a *managedAddress) PrivKey() (*btcec.PrivateKey, error) {
	// No private keys are available for a watching-only address manager.
	if a.manager.watchingOnly {
		return nil, managerError(ErrWatchingOnly, errWatchingOnly, nil)
	}

	a.manager.mtx.Lock()
	defer a.manager.mtx.Unlock()

	// Account manager must be unlocked to decrypt the private key.
	if a.manager.locked {
		return nil, managerError(ErrLocked, errLocked, nil)
	}

	// Decrypt the key as needed.  Also, make sure it's a copy since the
	// private key stored in memory can be cleared at any time.  Otherwise
	// the returned private key could be invalidated from under the caller.
	privKeyCopy, err := a.unlock(a.manager.cryptoKeyPriv)
	if err != nil {
		return nil, err
	}

	privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), privKeyCopy)
	zero.Bytes(privKeyCopy)
	return privKey, nil
}

// This example demonstrates signing a message with a secp256k1 private key that
// is first parsed form raw bytes and serializing the generated signature.
func Example_signMessage() {
	// Decode a hex-encoded private key.
	pkBytes, err := hex.DecodeString("22a47fa09a223f2aa079edf85a7c2d4f87" +
		"20ee63e502ee2869afab7de234b80c")
	if err != nil {
		fmt.Println(err)
		return
	}
	privKey, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), pkBytes)

	// Sign a message using the private key.
	message := "test message"
	messageHash := wire.DoubleSha256([]byte(message))
	signature, err := privKey.Sign(messageHash)
	if err != nil {
		fmt.Println(err)
		return
	}

	// Serialize and display the signature.
	fmt.Printf("Serialized Signature: %x\n", signature.Serialize())

	// Verify the signature for the message using the public key.
	verified := signature.Verify(messageHash, pubKey)
	fmt.Printf("Signature Verified? %v\n", verified)

	// Output:
	// Serialized Signature: 304402201008e236fa8cd0f25df4482dddbb622e8a8b26ef0ba731719458de3ccd93805b022032f8ebe514ba5f672466eba334639282616bb3c2f0ab09998037513d1f9e3d6d
	// Signature Verified? true
}

func TestScalarMult(t *testing.T) {
	// Strategy for this test:
	// Get a random exponent from the generator point at first
	// This creates a new point which is used in the next iteration
	// Use another random exponent on the new point.
	// We use BaseMult to verify by multiplying the previous exponent
	// and the new random exponent together (mod N)
	s256 := btcec.S256()
	x, y := s256.Gx, s256.Gy
	exponent := big.NewInt(1)
	for i := 0; i < 1024; i++ {
		data := make([]byte, 32)
		_, err := rand.Read(data)
		if err != nil {
			t.Fatalf("failed to read random data at %d", i)
			break
		}
		x, y = s256.ScalarMult(x, y, data)
		exponent.Mul(exponent, new(big.Int).SetBytes(data))
		xWant, yWant := s256.ScalarBaseMult(exponent.Bytes())
		if x.Cmp(xWant) != 0 || y.Cmp(yWant) != 0 {
			t.Fatalf("%d: bad output for %X: got (%X, %X), want (%X, %X)", i, data, x, y, xWant, yWant)
			break
		}
	}
}

// NewMaster creates a new master node for use in creating a hierarchical
// deterministic key chain.  The seed must be between 128 and 512 bits and
// should be generated by a cryptographically secure random generation source.
//
// NOTE: There is an extremely small chance (< 1 in 2^127) the provided seed
// will derive to an unusable secret key.  The ErrUnusable error will be
// returned if this should occur, so the caller must check for it and generate a
// new seed accordingly.
func NewMaster(seed []byte, net *chaincfg.Params) (*ExtendedKey, error) {
	// Per [BIP32], the seed must be in range [MinSeedBytes, MaxSeedBytes].
	if len(seed) < MinSeedBytes || len(seed) > MaxSeedBytes {
		return nil, ErrInvalidSeedLen
	}

	// First take the HMAC-SHA512 of the master key and the seed data:
	//   I = HMAC-SHA512(Key = "Bitcoin seed", Data = S)
	hmac512 := hmac.New(sha512.New, masterKey)
	hmac512.Write(seed)
	lr := hmac512.Sum(nil)

	// Split "I" into two 32-byte sequences Il and Ir where:
	//   Il = master secret key
	//   Ir = master chain code
	secretKey := lr[:len(lr)/2]
	chainCode := lr[len(lr)/2:]

	// Ensure the key in usable.
	secretKeyNum := new(big.Int).SetBytes(secretKey)
	if secretKeyNum.Cmp(btcec.S256().N) >= 0 || secretKeyNum.Sign() == 0 {
		return nil, ErrUnusableSeed
	}

	parentFP := []byte{0x00, 0x00, 0x00, 0x00}
	return newExtendedKey(net.HDPrivateKeyID[:], secretKey, chainCode,
		parentFP, 0, 0, true), nil
}

// pubKeyBytes returns bytes for the serialized compressed public key associated
// with this extended key in an efficient manner including memoization as
// necessary.
//
// When the extended key is already a public key, the key is simply returned as
// is since it's already in the correct form.  However, when the extended key is
// a private key, the public key will be calculated and memoized so future
// accesses can simply return the cached result.
func (k *ExtendedKey) pubKeyBytes() []byte {
	// Just return the key if it's already an extended public key.
	if !k.isPrivate {
		return k.key
	}

	// This is a private extended key, so calculate and memoize the public
	// key if needed.
	if len(k.pubKey) == 0 {
		pkx, pky := btcec.S256().ScalarBaseMult(k.key)
		pubKey := btcec.PublicKey{Curve: btcec.S256(), X: pkx, Y: pky}
		k.pubKey = pubKey.SerializeCompressed()
	}

	return k.pubKey
}