manifest: make default trusts invalid

Refs. #3522. The core problem is the same as for groups/features: we can't
allow empty trusts when they're unmarshalled from JSON. But unlike others we
can't easily differentiate missing any value with other cases because the
default value for WildPermissionDescs is a valid thing. Adding an additional
field makes it invalid and we can build around it. Other options are
implementing custom UnmarshalJSON for Manifest (too much for this) or making
Trusts a pointer (an option, but can fail in too many ways).

Signed-off-by: Roman Khimov <roman@nspcc.ru>

pkg/core/interop/runtime/ext_test.go

@@ -715,6 +715,7 @@ func TestSystemRuntimeNotify_HFBasilisk(t *testing.T) {
 		Name:     "ctr",
 		Features: json.RawMessage("{}"),
 		Groups:   []manifest.Group{},
+		Trusts:   manifest.WildPermissionDescs{Wildcard: true},
 		ABI: manifest.ABI{
 			Methods: []manifest.Method{
 				{

pkg/core/native/management_neotest_test.go

@@ -55,6 +55,7 @@ func TestManagement_DeployUpdate_HFBasilisk(t *testing.T) {
 		Name:     "ctr",
 		Features: json.RawMessage("{}"),
 		Groups:   []manifest.Group{},
+		Trusts:   manifest.WildPermissionDescs{Wildcard: true},
 		ABI: manifest.ABI{
 			Methods: []manifest.Method{
 				{
@@ -92,6 +93,7 @@ func TestManagement_CallInTheSameBlock(t *testing.T) {
 		Name:     "ctr",
 		Features: json.RawMessage("{}"),
 		Groups:   []manifest.Group{},
+		Trusts:   manifest.WildPermissionDescs{Wildcard: true},
 		ABI: manifest.ABI{
 			Methods: []manifest.Method{
 				{

pkg/core/state/contract_test.go

@@ -58,6 +58,7 @@ func TestContractStateToFromSI(t *testing.T) {
 
 		t.Run("preserve wildcard trusts", func(t *testing.T) {
 			contract.Manifest.Trusts.Value = nil
+			contract.Manifest.Trusts.Wildcard = true
 			require.True(t, contract.Manifest.Trusts.IsWildcard())
 			actual := new(Contract)
 			item, err := contract.ToStackItem()

pkg/smartcontract/manifest/container.go

@@ -16,7 +16,8 @@ type WildStrings struct {
 
 // WildPermissionDescs represents a PermissionDescriptor set which can be a wildcard.
 type WildPermissionDescs struct {
-	Value []PermissionDesc
+	Value    []PermissionDesc
+	Wildcard bool
 }
 
 // Contains checks if v is in the container.
@@ -49,13 +50,16 @@ func (c *WildPermissionDescs) Contains(v PermissionDesc) bool {
 func (c *WildStrings) IsWildcard() bool { return c.Value == nil }
 
 // IsWildcard returns true iff the container is a wildcard.
-func (c *WildPermissionDescs) IsWildcard() bool { return c.Value == nil }
+func (c *WildPermissionDescs) IsWildcard() bool { return c.Wildcard }
 
 // Restrict transforms the container into an empty one.
 func (c *WildStrings) Restrict() { c.Value = []string{} }
 
 // Restrict transforms the container into an empty one.
-func (c *WildPermissionDescs) Restrict() { c.Value = []PermissionDesc{} }
+func (c *WildPermissionDescs) Restrict() {
+	c.Value = []PermissionDesc{}
+	c.Wildcard = false
+}
 
 // Add adds v to the container.
 func (c *WildStrings) Add(v string) { c.Value = append(c.Value, v) }
@@ -93,7 +97,8 @@ func (c *WildStrings) UnmarshalJSON(data []byte) error {
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
 func (c *WildPermissionDescs) UnmarshalJSON(data []byte) error {
-	if !bytes.Equal(data, []byte(`"*"`)) {
+	c.Wildcard = bytes.Equal(data, []byte(`"*"`))
+	if !c.Wildcard {
 		us := []PermissionDesc{}
 		if err := json.Unmarshal(data, &us); err != nil {
 			return err

pkg/smartcontract/manifest/container_test.go

@@ -24,6 +24,9 @@ func TestContainer_Restrict(t *testing.T) {
 	t.Run("PermissionDesc", func(t *testing.T) {
 		check := func(t *testing.T, u PermissionDesc) {
 			c := new(WildPermissionDescs)
+			require.False(t, c.IsWildcard())
+			require.False(t, c.Contains(u))
+			c.Wildcard = true
 			require.True(t, c.IsWildcard())
 			require.True(t, c.Contains(u))
 			c.Restrict()

pkg/smartcontract/manifest/manifest.go

@@ -124,6 +124,9 @@ func (m *Manifest) IsValid(hash util.Uint160, checkSize bool) error {
 	if err != nil {
 		return err
 	}
+	if m.Trusts.Value == nil && !m.Trusts.Wildcard {
+		return errors.New("invalid (null?) trusts")
+	}
 	if len(m.Trusts.Value) > 1 {
 		hashes := make([]PermissionDesc, len(m.Trusts.Value))
 		copy(hashes, m.Trusts.Value)
@@ -278,7 +281,7 @@ func (m *Manifest) FromStackItem(item stackitem.Item) error {
 		m.Permissions[i] = *p
 	}
 	if _, ok := str[6].(stackitem.Null); ok {
-		m.Trusts = WildPermissionDescs{Value: nil} // wildcard by default
+		m.Trusts = WildPermissionDescs{Value: nil, Wildcard: true} // wildcard by default
 	} else {
 		if str[6].Type() != stackitem.ArrayT {
 			return errors.New("invalid Trusts stackitem type")

pkg/smartcontract/manifest/manifest_test.go

@@ -212,6 +212,13 @@ func TestIsValid(t *testing.T) {
 	})
 	m.SupportedStandards = m.SupportedStandards[:1]
 
+	t.Run("invalid, no trusts", func(t *testing.T) {
+		m.Trusts.Value = nil
+		m.Trusts.Wildcard = false
+		require.Error(t, m.IsValid(contractHash, true))
+	})
+	m.Trusts.Restrict()
+
 	d := PermissionDesc{Type: PermissionHash, Value: util.Uint160{1, 2, 3}}
 	m.Trusts.Add(d)
 	t.Run("valid, with trust", func(t *testing.T) {