[#273] status: Support signature status

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

client/status/common.go

@@ -123,3 +123,54 @@ func (x WrongMagicNumber) CorrectMagic() (magic uint64, ok int8) {
 
 	return
 }
+
+// SignatureVerification describes failure status related to signature verification.
+// Instances provide Status and StatusV2 interfaces.
+type SignatureVerification struct {
+	v2 status.Status
+}
+
+func (x SignatureVerification) Error() string {
+	return errMessageStatusV2(
+		globalizeCodeV2(status.SignatureVerificationFail, status.GlobalizeCommonFail),
+		x.v2.Message(),
+	)
+}
+
+// implements local interface defined in FromStatusV2 func.
+func (x *SignatureVerification) fromStatusV2(st *status.Status) {
+	x.v2 = *st
+}
+
+// ToStatusV2 implements StatusV2 interface method.
+// If the value was returned by FromStatusV2, returns the source message.
+// Otherwise, returns message with
+//  * code: SIGNATURE_VERIFICATION_FAIL;
+//  * string message: written message via SetMessage or
+//    "signature verification failed" as a default message;
+//  * details: empty.
+func (x SignatureVerification) ToStatusV2() *status.Status {
+	x.v2.SetCode(globalizeCodeV2(status.SignatureVerificationFail, status.GlobalizeCommonFail))
+
+	if x.v2.Message() == "" {
+		x.v2.SetMessage("signature verification failed")
+	}
+
+	return &x.v2
+}
+
+// SetMessage writes signature verification failure message.
+// Message should be used for debug purposes only.
+//
+// See also Message.
+func (x *SignatureVerification) SetMessage(v string) {
+	x.v2.SetMessage(v)
+}
+
+// Message returns status message. Zero status returns empty message.
+// Message should be used for debug purposes only.
+//
+// See also SetMessage.
+func (x SignatureVerification) Message() string {
+	return x.v2.Message()
+}

client/status/common_test.go

@@ -50,3 +50,42 @@ func TestWrongMagicNumber_CorrectMagic(t *testing.T) {
 	_, ok = st.CorrectMagic()
 	require.EqualValues(t, -1, ok)
 }
+
+func TestSignatureVerification(t *testing.T) {
+	t.Run("default", func(t *testing.T) {
+		var st apistatus.SignatureVerification
+
+		require.Empty(t, st.Message())
+	})
+
+	t.Run("custom message", func(t *testing.T) {
+		var st apistatus.SignatureVerification
+		msg := "some message"
+
+		st.SetMessage(msg)
+
+		stV2 := st.ToStatusV2()
+
+		require.Equal(t, msg, st.Message())
+		require.Equal(t, msg, stV2.Message())
+	})
+
+	t.Run("empty to V2", func(t *testing.T) {
+		var st apistatus.SignatureVerification
+
+		stV2 := st.ToStatusV2()
+
+		require.Equal(t, "signature verification failed", stV2.Message())
+	})
+
+	t.Run("non-empty to V2", func(t *testing.T) {
+		var st apistatus.SignatureVerification
+		msg := "some other msg"
+
+		st.SetMessage(msg)
+
+		stV2 := st.ToStatusV2()
+
+		require.Equal(t, msg, stV2.Message())
+	})
+}

client/status/v2.go

@@ -31,7 +31,8 @@ type StatusV2 interface {
 //   * status.OK: *SuccessDefaultV2 (this also includes nil argument).
 //
 // Common failures:
-//   * status.Internal: *ServerInternal.
+//   * status.Internal: *ServerInternal;
+//   * status.SignatureVerificationFail: *SignatureVerification.
 //
 // Object failures:
 //   * object.StatusLocked: *ObjectLocked;
@@ -55,6 +56,8 @@ func FromStatusV2(st *status.Status) Status {
 			decoder = new(ServerInternal)
 		case status.WrongMagicNumber:
 			decoder = new(WrongMagicNumber)
+		case status.SignatureVerificationFail:
+			decoder = new(SignatureVerification)
 		}
 	case object.LocalizeFailStatus(&code):
 		switch code {