native: implement CryptoLib contract

pkg/core/native/crypto.go

@@ -0,0 +1,138 @@
+package native
+
+import (
+	"crypto/elliptic"
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcd/btcec"
+	"github.com/nspcc-dev/neo-go/pkg/core/interop"
+	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
+)
+
+// Crypto represents CryptoLib contract.
+type Crypto struct {
+	interop.ContractMD
+}
+
+// NamedCurve identifies named elliptic curves.
+type NamedCurve byte
+
+// Various named elliptic curves.
+const (
+	Secp256k1 NamedCurve = 22
+	Secp256r1 NamedCurve = 23
+)
+
+const cryptoContractID = -3
+
+func newCrypto() *Crypto {
+	c := &Crypto{ContractMD: *interop.NewContractMD(nativenames.CryptoLib, cryptoContractID)}
+	defer c.UpdateHash()
+
+	desc := newDescriptor("sha256", smartcontract.ByteArrayType,
+		manifest.NewParameter("data", smartcontract.ByteArrayType))
+	md := newMethodAndPrice(c.sha256, 1<<15, callflag.NoneFlag)
+	c.AddMethod(md, desc)
+
+	desc = newDescriptor("ripemd160", smartcontract.ByteArrayType,
+		manifest.NewParameter("data", smartcontract.ByteArrayType))
+	md = newMethodAndPrice(c.ripemd160, 1<<15, callflag.NoneFlag)
+	c.AddMethod(md, desc)
+
+	desc = newDescriptor("verifyWithECDsa", smartcontract.BoolType,
+		manifest.NewParameter("message", smartcontract.ByteArrayType),
+		manifest.NewParameter("pubkey", smartcontract.ByteArrayType),
+		manifest.NewParameter("signature", smartcontract.ByteArrayType),
+		manifest.NewParameter("curve", smartcontract.IntegerType))
+	md = newMethodAndPrice(c.verifyWithECDsa, 1<<15, callflag.NoneFlag)
+	c.AddMethod(md, desc)
+	return c
+}
+
+func (c *Crypto) sha256(_ *interop.Context, args []stackitem.Item) stackitem.Item {
+	bs, err := args[0].TryBytes()
+	if err != nil {
+		panic(err)
+	}
+	return stackitem.NewByteArray(hash.Sha256(bs).BytesBE())
+}
+
+func (c *Crypto) ripemd160(_ *interop.Context, args []stackitem.Item) stackitem.Item {
+	bs, err := args[0].TryBytes()
+	if err != nil {
+		panic(err)
+	}
+	return stackitem.NewByteArray(hash.RipeMD160(bs).BytesBE())
+}
+
+func (c *Crypto) verifyWithECDsa(_ *interop.Context, args []stackitem.Item) stackitem.Item {
+	msg, err := args[0].TryBytes()
+	if err != nil {
+		panic(fmt.Errorf("invalid message stackitem: %w", err))
+	}
+	hashToCheck := hash.Sha256(msg)
+	pubkey, err := args[1].TryBytes()
+	if err != nil {
+		panic(fmt.Errorf("invalid pubkey stackitem: %w", err))
+	}
+	signature, err := args[2].TryBytes()
+	if err != nil {
+		panic(fmt.Errorf("invalid signature stackitem: %w", err))
+	}
+	curve, err := curveFromStackitem(args[3])
+	if err != nil {
+		panic(fmt.Errorf("invalid curve stackitem: %w", err))
+	}
+	pkey, err := keys.NewPublicKeyFromBytes(pubkey, curve)
+	if err != nil {
+		panic(fmt.Errorf("failed to decode pubkey: %w", err))
+	}
+	res := pkey.Verify(signature, hashToCheck.BytesBE())
+	return stackitem.NewBool(res)
+}
+
+func curveFromStackitem(si stackitem.Item) (elliptic.Curve, error) {
+	curve, err := si.TryInteger()
+	if err != nil {
+		return nil, err
+	}
+	if !curve.IsInt64() {
+		return nil, errors.New("not an int64")
+	}
+	c := curve.Int64()
+	switch c {
+	case int64(Secp256k1):
+		return btcec.S256(), nil
+	case int64(Secp256r1):
+		return elliptic.P256(), nil
+	default:
+		return nil, errors.New("unsupported curve type")
+	}
+}
+
+// Metadata implements Contract interface.
+func (c *Crypto) Metadata() *interop.ContractMD {
+	return &c.ContractMD
+}
+
+// Initialize implements Contract interface.
+func (c *Crypto) Initialize(ic *interop.Context) error {
+	return nil
+}
+
+// OnPersist implements Contract interface.
+func (c *Crypto) OnPersist(ic *interop.Context) error {
+	return nil
+}
+
+// PostPersist implements Contract interface.
+func (c *Crypto) PostPersist(ic *interop.Context) error {
+	return nil
+}