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

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

api/util/signature/data.go

@@ -0,0 +1,93 @@
+package signature
+
+import (
+	"crypto/ecdsa"
+
+	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/pool"
+)
+
+const poolSliceMaxSize = 128 * 1024
+
+var buffersPool = pool.NewBufferPool(poolSliceMaxSize)
+
+type DataSource interface {
+	ReadSignedData([]byte) ([]byte, error)
+	SignedDataSize() int
+}
+
+type DataWithSignature interface {
+	DataSource
+	GetSignature() *refs.Signature
+	SetSignature(*refs.Signature)
+}
+
+type SignOption func(*cfg)
+
+type KeySignatureHandler func(*refs.Signature)
+
+type KeySignatureSource func() *refs.Signature
+
+func SignDataWithHandler(key *ecdsa.PrivateKey, src DataSource, handler KeySignatureHandler, opts ...SignOption) error {
+	if key == nil {
+		return crypto.ErrEmptyPrivateKey
+	}
+
+	cfg := defaultCfg()
+
+	for i := range opts {
+		opts[i](cfg)
+	}
+
+	buffer := buffersPool.Get(uint32(src.SignedDataSize()))
+	defer buffersPool.Put(buffer)
+
+	data, err := src.ReadSignedData(buffer.Data)
+	if err != nil {
+		return err
+	}
+
+	sigData, err := sign(cfg, key, data)
+	if err != nil {
+		return err
+	}
+
+	sig := new(refs.Signature)
+	sig.SetScheme(cfg.scheme)
+	sig.SetKey(crypto.MarshalPublicKey(&key.PublicKey))
+	sig.SetSign(sigData)
+	handler(sig)
+
+	return nil
+}
+
+func VerifyDataWithSource(dataSrc DataSource, sigSrc KeySignatureSource, opts ...SignOption) error {
+	buffer := buffersPool.Get(uint32(dataSrc.SignedDataSize()))
+	defer buffersPool.Put(buffer)
+
+	data, err := dataSrc.ReadSignedData(buffer.Data)
+	if err != nil {
+		return err
+	}
+
+	return VerifyDataSlice(data, sigSrc, opts...)
+}
+
+func SignData(key *ecdsa.PrivateKey, v DataWithSignature, opts ...SignOption) error {
+	return SignDataWithHandler(key, v, v.SetSignature, opts...)
+}
+
+func VerifyData(src DataWithSignature, opts ...SignOption) error {
+	return VerifyDataWithSource(src, src.GetSignature, opts...)
+}
+
+func VerifyDataSlice(data []byte, sigSrc KeySignatureSource, opts ...SignOption) error {
+	cfg := defaultCfg()
+
+	for i := range opts {
+		opts[i](cfg)
+	}
+
+	return verify(cfg, data, sigSrc())
+}