[#276] Merge repo with frostfs-api-go

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

api/util/signature/options.go

@@ -0,0 +1,77 @@
+package signature
+
+import (
+	"crypto/ecdsa"
+	"encoding/base64"
+	"fmt"
+
+	crypto "git.frostfs.info/TrueCloudLab/frostfs-crypto"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/api/refs"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/api/util/signature/walletconnect"
+)
+
+type cfg struct {
+	schemeFixed bool
+	scheme      refs.SignatureScheme
+}
+
+func defaultCfg() *cfg {
+	return new(cfg)
+}
+
+func verify(cfg *cfg, data []byte, sig *refs.Signature) error {
+	if !cfg.schemeFixed {
+		cfg.scheme = sig.GetScheme()
+	}
+
+	pub := crypto.UnmarshalPublicKey(sig.GetKey())
+	if pub == nil {
+		return crypto.ErrEmptyPublicKey
+	}
+
+	switch cfg.scheme {
+	case refs.ECDSA_SHA512:
+		return crypto.Verify(pub, data, sig.GetSign())
+	case refs.ECDSA_RFC6979_SHA256:
+		return crypto.VerifyRFC6979(pub, data, sig.GetSign())
+	case refs.ECDSA_RFC6979_SHA256_WALLET_CONNECT:
+		buffer := buffersPool.Get(uint32(base64.StdEncoding.EncodedLen(len(data))))
+		defer buffersPool.Put(buffer)
+		base64.StdEncoding.Encode(buffer.Data, data)
+		if !walletconnect.Verify(pub, buffer.Data, sig.GetSign()) {
+			return crypto.ErrInvalidSignature
+		}
+		return nil
+	default:
+		return fmt.Errorf("unsupported signature scheme %s", cfg.scheme)
+	}
+}
+
+func sign(cfg *cfg, key *ecdsa.PrivateKey, data []byte) ([]byte, error) {
+	switch cfg.scheme {
+	case refs.ECDSA_SHA512:
+		return crypto.Sign(key, data)
+	case refs.ECDSA_RFC6979_SHA256:
+		return crypto.SignRFC6979(key, data)
+	case refs.ECDSA_RFC6979_SHA256_WALLET_CONNECT:
+		buffer := buffersPool.Get(uint32(base64.StdEncoding.EncodedLen(len(data))))
+		defer buffersPool.Put(buffer)
+		base64.StdEncoding.Encode(buffer.Data, data)
+		return walletconnect.Sign(key, buffer.Data)
+	default:
+		panic(fmt.Sprintf("unsupported scheme %s", cfg.scheme))
+	}
+}
+
+func SignWithRFC6979() SignOption {
+	return func(c *cfg) {
+		c.schemeFixed = true
+		c.scheme = refs.ECDSA_RFC6979_SHA256
+	}
+}
+
+func SignWithWalletConnect() SignOption {
+	return func(c *cfg) {
+		c.scheme = refs.ECDSA_RFC6979_SHA256_WALLET_CONNECT
+	}
+}