Add v2 version to go module name

Replace all elements from `v2` to root directory.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

signature/sign_test.go

@@ -0,0 +1,72 @@
+package signature
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/accounting"
+	"github.com/nspcc-dev/neofs-api-go/v2/session"
+	crypto "github.com/nspcc-dev/neofs-crypto"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBalanceResponse(t *testing.T) {
+	dec := new(accounting.Decimal)
+	dec.SetValue(100)
+
+	body := new(accounting.BalanceResponseBody)
+	body.SetBalance(dec)
+
+	meta := new(session.ResponseMetaHeader)
+	meta.SetTTL(1)
+
+	req := new(accounting.BalanceResponse)
+	req.SetBody(body)
+	req.SetMetaHeader(meta)
+
+	// verify unsigned request
+	require.Error(t, VerifyServiceMessage(req))
+
+	key, err := crypto.LoadPrivateKey("Kwk6k2eC3L3QuPvD8aiaNyoSXgQ2YL1bwS5CP1oKoA9waeAze97s")
+	require.NoError(t, err)
+
+	// sign request
+	require.NoError(t, SignServiceMessage(key, req))
+
+	// verification must pass
+	require.NoError(t, VerifyServiceMessage(req))
+
+	// add level to meta header matryoshka
+	meta = new(session.ResponseMetaHeader)
+	meta.SetOrigin(req.GetMetaHeader())
+	req.SetMetaHeader(meta)
+
+	// sign request
+	require.NoError(t, SignServiceMessage(key, req))
+
+	// verification must pass
+	require.NoError(t, VerifyServiceMessage(req))
+
+	// corrupt body
+	dec.SetValue(dec.GetValue() + 1)
+
+	// verification must fail
+	require.Error(t, VerifyServiceMessage(req))
+
+	// restore body
+	dec.SetValue(dec.GetValue() - 1)
+
+	// corrupt meta header
+	meta.SetTTL(meta.GetTTL() + 1)
+
+	// verification must fail
+	require.Error(t, VerifyServiceMessage(req))
+
+	// restore meta header
+	meta.SetTTL(meta.GetTTL() - 1)
+
+	// corrupt origin verification header
+	req.GetVerificationHeader().SetOrigin(nil)
+
+	// verification must fail
+	require.Error(t, VerifyServiceMessage(req))
+}