[#274] crypto: Add WalletConnect API support

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

crypto/crypto_test.go

@@ -28,6 +28,9 @@ func TestSignature(t *testing.T) {
 		func() neofscrypto.Signer {
 			return neofsecdsa.SignerRFC6979(k.PrivateKey)
 		},
+		func() neofscrypto.Signer {
+			return neofsecdsa.SignerWalletConnect(k.PrivateKey)
+		},
 	} {
 		signer := f()
 
@@ -39,6 +42,6 @@ func TestSignature(t *testing.T) {
 		s.ReadFromV2(m)
 
 		valid := s.Verify(data)
-		require.True(t, valid)
+		require.True(t, valid, "type %T", signer)
 	}
 }

crypto/ecdsa/init.go

@@ -10,4 +10,8 @@ func init() {
 	neofscrypto.RegisterScheme(neofscrypto.ECDSA_DETERMINISTIC_SHA256, func() neofscrypto.PublicKey {
 		return new(PublicKeyRFC6979)
 	})
+
+	neofscrypto.RegisterScheme(neofscrypto.ECDSA_WALLETCONNECT, func() neofscrypto.PublicKey {
+		return new(PublicKeyWalletConnect)
+	})
 }

crypto/ecdsa/wallet_connect.go

@@ -0,0 +1,85 @@
+package neofsecdsa
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"encoding/base64"
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neofs-api-go/v2/util/signature/walletconnect"
+	neofscrypto "github.com/nspcc-dev/neofs-sdk-go/crypto"
+)
+
+// SignerWalletConnect is similar to SignerRFC6979 with 2 changes:
+// 1. The data is base64 encoded before signing/verifying.
+// 2. The signature is a concatenation of the signature itself and 16-byte salt.
+//
+// Instances MUST be initialized from ecdsa.PrivateKey using type conversion.
+type SignerWalletConnect ecdsa.PrivateKey
+
+// Scheme returns neofscrypto.ECDSA_WALLETCONNECT.
+// Implements neofscrypto.Signer.
+func (x SignerWalletConnect) Scheme() neofscrypto.Scheme {
+	return neofscrypto.ECDSA_WALLETCONNECT
+}
+
+// Sign signs data using ECDSA algorithm with SHA-512 hashing.
+// Implements neofscrypto.Signer.
+func (x SignerWalletConnect) Sign(data []byte) ([]byte, error) {
+	b64 := make([]byte, base64.StdEncoding.EncodedLen(len(data)))
+	base64.StdEncoding.Encode(b64, data)
+	return walletconnect.Sign((*ecdsa.PrivateKey)(&x), b64)
+}
+
+// Public initializes PublicKey and returns it as neofscrypto.PublicKey.
+// Implements neofscrypto.Signer.
+func (x SignerWalletConnect) Public() neofscrypto.PublicKey {
+	return (*PublicKeyWalletConnect)(&x.PublicKey)
+}
+
+// PublicKeyWalletConnect is a wrapper over ecdsa.PublicKey used for NeoFS needs.
+// Provides neofscrypto.PublicKey interface.
+//
+// Instances MUST be initialized from ecdsa.PublicKey using type conversion.
+type PublicKeyWalletConnect ecdsa.PublicKey
+
+// MaxEncodedSize returns size of the compressed ECDSA public key.
+func (x PublicKeyWalletConnect) MaxEncodedSize() int {
+	return 33
+}
+
+// Encode encodes ECDSA public key in compressed form into buf.
+// Uses exactly MaxEncodedSize bytes of the buf.
+//
+// Encode panics if buf length is less than MaxEncodedSize.
+//
+// See also Decode.
+func (x PublicKeyWalletConnect) Encode(buf []byte) int {
+	if len(buf) < 33 {
+		panic(fmt.Sprintf("too short buffer %d", len(buf)))
+	}
+
+	return copy(buf, (*keys.PublicKey)(&x).Bytes())
+}
+
+// Decode decodes compressed binary representation of the PublicKeyWalletConnect.
+//
+// See also Encode.
+func (x *PublicKeyWalletConnect) Decode(data []byte) error {
+	pub, err := keys.NewPublicKeyFromBytes(data, elliptic.P256())
+	if err != nil {
+		return err
+	}
+
+	*x = (PublicKeyWalletConnect)(*pub)
+
+	return nil
+}
+
+// Verify verifies data signature calculated by ECDSA algorithm with SHA-512 hashing.
+func (x PublicKeyWalletConnect) Verify(data, signature []byte) bool {
+	b64 := make([]byte, base64.StdEncoding.EncodedLen(len(data)))
+	base64.StdEncoding.Encode(b64, data)
+	return walletconnect.Verify((*ecdsa.PublicKey)(&x), b64, signature)
+}

crypto/signer.go

@@ -17,6 +17,7 @@ const (
 
 	ECDSA_SHA512               // ECDSA with SHA-512 hashing (FIPS 186-3)
 	ECDSA_DETERMINISTIC_SHA256 // Deterministic ECDSA with SHA-256 hashing (RFC 6979)
+	ECDSA_WALLETCONNECT        // Wallet Connect signature scheme
 )
 
 // String implements fmt.Stringer.

go.mod

@@ -10,7 +10,7 @@ require (
 	github.com/mr-tron/base58 v1.2.0
 	github.com/nspcc-dev/hrw v1.0.9
 	github.com/nspcc-dev/neo-go v0.98.2
-	github.com/nspcc-dev/neofs-api-go/v2 v2.12.2
+	github.com/nspcc-dev/neofs-api-go/v2 v2.12.3-0.20220621170933-dd233c3fbc84
 	github.com/nspcc-dev/neofs-contract v0.15.1
 	github.com/nspcc-dev/tzhash v1.5.2
 	github.com/stretchr/testify v1.7.0