user: Refactor constructors of Signer instances

Previously, package provided constructors for `Signer` instances with
RFC 6979 signature scheme only. User may need to construct any `Signer`
instance (other scheme or even custom implementation).

Add generic constructor `NewSigner` accepting split `neofscrypto.Signer`
and `user.ID`. Add two constructors from standard `ecdsa.PrivateKey`
with an explanation that the user ID is resolved automatically.

Signed-off-by: Leonard Lyubich <[email protected]>

client/example_container_put_test.go

@@ -25,7 +25,7 @@ func ExampleClient_ContainerPut() {
 		panic(err)
 	}
 
-	signer := user.NewSignerRFC6979(key.PrivateKey)
+	signer := user.NewAutoIDSignerRFC6979(key.PrivateKey)
 	// take account from user's signer
 	accountID = signer.UserID()
 

crypto/test/tests.go

@@ -30,5 +30,5 @@ func RandomSignerRFC6979(tb testing.TB) user.Signer {
 	p, err := keys.NewPrivateKey()
 	require.NoError(tb, err)
 
-	return user.NewSignerRFC6979(p.PrivateKey)
+	return user.NewAutoIDSignerRFC6979(p.PrivateKey)
 }

object/slicer/slicer_test.go

@@ -163,7 +163,7 @@ func randomInput(tb testing.TB, size, sizeLimit uint64) (input, slicer.Options)
 	}
 
 	var in input
-	in.signer = user.NewSignerRFC6979(*key)
+	in.signer = user.NewAutoIDSigner(*key)
 	in.container = cidtest.ID()
 	in.currentEpoch = rand.Uint64()
 	if sizeLimit > 0 {

pool/example_pool_test.go

@@ -13,7 +13,7 @@ import (
 func ExampleNew_easiestWay() {
 	// Signer generation, like example.
 	pk, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	signer := user.NewSignerRFC6979(*pk)
+	signer := user.NewAutoIDSignerRFC6979(*pk)
 
 	pool, _ := New(NewFlatNodeParams([]string{"grpc://localhost:8080", "grpcs://localhost:8081"}), signer, DefaultOptions())
 	_ = pool
@@ -24,7 +24,7 @@ func ExampleNew_easiestWay() {
 func ExampleNew_adjustingParameters() {
 	// Signer generation, like example.
 	pk, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	signer := user.NewSignerRFC6979(*pk)
+	signer := user.NewAutoIDSignerRFC6979(*pk)
 
 	opts := DefaultOptions()
 	opts.SetErrorThreshold(10)

user/signer.go

@@ -8,43 +8,51 @@ import (
 	neofsecdsa "github.com/nspcc-dev/neofs-sdk-go/crypto/ecdsa"
 )
 
-// Signer is an interface of entities that can be used for signing operations
-// in NeoFS. It is the same as [neofscrypto.Signer], but has an extra method to retrieve [ID].
+// Signer represents a NeoFS user authorized by a digital signature.
 type Signer interface {
+	// Signer signs data on behalf of the user.
 	neofscrypto.Signer
-
+	// UserID returns ID of the associated user.
 	UserID() ID
 }
 
-// SignerRFC6979 wraps [ecdsa.PrivateKey] and represents signer based on deterministic
-// ECDSA with SHA-256 hashing (RFC 6979). Provides [Signer] interface.
+type signer struct {
+	neofscrypto.Signer
+	usr ID
+}
+
+func (s signer) UserID() ID {
+	return s.usr
+}
+
+// NewSigner combines provided [neofscrypto.Signer] and [ID] into [Signer].
 //
-// Instances SHOULD be initialized with [NewSignerRFC6979] or [NewSignerRFC6979WithID].
-type SignerRFC6979 struct {
-	neofsecdsa.SignerRFC6979
-	userID ID
+// See also [NewAutoIDSigner].
+func NewSigner(s neofscrypto.Signer, usr ID) Signer {
+	return signer{
+		Signer: s,
+		usr:    usr,
+	}
 }
 
-// NewSignerRFC6979 is a constructor for [SignerRFC6979].
-func NewSignerRFC6979(pk ecdsa.PrivateKey) *SignerRFC6979 {
+func newAutoResolvedSigner(s neofscrypto.Signer, pubKey ecdsa.PublicKey) Signer {
 	var id ID
-	id.SetScriptHash((*keys.PublicKey)(&pk.PublicKey).GetScriptHash())
+	id.SetScriptHash((*keys.PublicKey)(&pubKey).GetScriptHash())
 
-	return &SignerRFC6979{
-		userID:        id,
-		SignerRFC6979: neofsecdsa.SignerRFC6979(pk),
-	}
+	return NewSigner(s, id)
 }
 
-// NewSignerRFC6979WithID is a constructor for [SignerRFC6979] where you may specify [ID] associated with this signer.
-func NewSignerRFC6979WithID(pk ecdsa.PrivateKey, id ID) *SignerRFC6979 {
-	return &SignerRFC6979{
-		SignerRFC6979: neofsecdsa.SignerRFC6979(pk),
-		userID:        id,
-	}
+// NewAutoIDSigner returns [Signer] with neofscrypto.ECDSA_SHA512
+// signature scheme and user [ID] automatically resolved from the ECDSA public
+// key.
+//
+// See also [NewAutoIDSignerRFC6979].
+func NewAutoIDSigner(key ecdsa.PrivateKey) Signer {
+	return newAutoResolvedSigner(neofsecdsa.Signer(key), key.PublicKey)
 }
 
-// UserID returns the [ID] using script hash calculated for the given key.
-func (s SignerRFC6979) UserID() ID {
-	return s.userID
+// NewAutoIDSignerRFC6979 is an analogue of [NewAutoIDSigner] but with
+// [neofscrypto.ECDSA_DETERMINISTIC_SHA256] signature scheme.
+func NewAutoIDSignerRFC6979(key ecdsa.PrivateKey) Signer {
+	return newAutoResolvedSigner(neofsecdsa.SignerRFC6979(key), key.PublicKey)
 }

waiter/example_waiter_test.go

@@ -24,7 +24,7 @@ func ExampleNewWaiter() {
 		panic(err)
 	}
 
-	signer := user.NewSignerRFC6979(key.PrivateKey)
+	signer := user.NewAutoIDSignerRFC6979(key.PrivateKey)
 
 	account := signer.UserID()