native: implement CryptoLib contract

pkg/interop/native/crypto/crypto.go

@@ -0,0 +1,34 @@
+package crypto
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+)
+
+// Hash represents CryptoLib contract hash.
+const Hash = "\x1b\xf5\x75\xab\x11\x89\x68\x84\x13\x61\x0a\x35\xa1\x28\x86\xcd\xe0\xb6\x6c\x72"
+
+// NamedCurve represents named elliptic curve.
+type NamedCurve byte
+
+// Various named elliptic curves.
+const (
+	Secp256k1 NamedCurve = 22
+	Secp256r1 NamedCurve = 23
+)
+
+// Sha256 calls `sha256` method of native CryptoLib contract and computes SHA256 hash of b.
+func Sha256(b []byte) interop.Hash256 {
+	return contract.Call(interop.Hash160(Hash), "sha256", contract.NoneFlag, b).(interop.Hash256)
+}
+
+// Ripemd160 calls `ripemd160` method of native CryptoLib contract and computes RIPEMD160 hash of b.
+func Ripemd160(b []byte) interop.Hash160 {
+	return contract.Call(interop.Hash160(Hash), "ripemd160", contract.NoneFlag, b).(interop.Hash160)
+}
+
+// VerifyWithECDsa calls `verifyWithECDsa` method of native CryptoLib contract and checks that sig is
+// correct msg's signature for a given pub (serialized public key on a given curve).
+func VerifyWithECDsa(msg []byte, pub interop.PublicKey, sig interop.Signature, curve NamedCurve) bool {
+	return contract.Call(interop.Hash160(Hash), "verifyWithECDsa", contract.NoneFlag, msg, pub, sig, curve).(bool)
+}