package core import ( "bytes" "errors" "fmt" "sort" "github.com/nspcc-dev/neo-go/pkg/core/interop" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" ) const ( // MaxContractDescriptionLen is the maximum length for contract description. MaxContractDescriptionLen = 65536 // MaxContractScriptSize is the maximum script size for a contract. MaxContractScriptSize = 1024 * 1024 // MaxContractParametersNum is the maximum number of parameters for a contract. MaxContractParametersNum = 252 // MaxContractStringLen is the maximum length for contract metadata strings. MaxContractStringLen = 252 ) var errGasLimitExceeded = errors.New("gas limit exceeded") // storageFind finds stored key-value pair. func storageFind(ic *interop.Context, v *vm.VM) error { stcInterface := v.Estack().Pop().Value() stc, ok := stcInterface.(*StorageContext) if !ok { return fmt.Errorf("%T is not a StorageContext", stcInterface) } prefix := v.Estack().Pop().Bytes() siMap, err := ic.DAO.GetStorageItemsWithPrefix(stc.ID, prefix) if err != nil { return err } filteredMap := stackitem.NewMap() for k, v := range siMap { filteredMap.Add(stackitem.NewByteArray(append(prefix, []byte(k)...)), stackitem.NewByteArray(v.Value)) } sort.Slice(filteredMap.Value().([]stackitem.MapElement), func(i, j int) bool { return bytes.Compare(filteredMap.Value().([]stackitem.MapElement)[i].Key.Value().([]byte), filteredMap.Value().([]stackitem.MapElement)[j].Key.Value().([]byte)) == -1 }) item := vm.NewMapIterator(filteredMap) v.Estack().PushVal(item) return nil } // createContractStateFromVM pops all contract state elements from the VM // evaluation stack, does a lot of checks and returns Contract if it // succeeds. func createContractStateFromVM(ic *interop.Context, v *vm.VM) (*state.Contract, error) { script := v.Estack().Pop().Bytes() if len(script) > MaxContractScriptSize { return nil, errors.New("the script is too big") } manifestBytes := v.Estack().Pop().Bytes() if len(manifestBytes) > manifest.MaxManifestSize { return nil, errors.New("manifest is too big") } if !v.AddGas(util.Fixed8(StoragePrice * (len(script) + len(manifestBytes)))) { return nil, errGasLimitExceeded } var m manifest.Manifest err := m.UnmarshalJSON(manifestBytes) if err != nil { return nil, err } return &state.Contract{ Script: script, Manifest: m, }, nil } // contractCreate creates a contract. func contractCreate(ic *interop.Context, v *vm.VM) error { newcontract, err := createContractStateFromVM(ic, v) if err != nil { return err } contract, err := ic.DAO.GetContractState(newcontract.ScriptHash()) if contract != nil { return errors.New("contract already exists") } id, err := ic.DAO.GetNextContractID() if err != nil { return err } newcontract.ID = id if err := ic.DAO.PutNextContractID(id); err != nil { return err } if err := ic.DAO.PutContractState(newcontract); err != nil { return err } v.Estack().PushVal(stackitem.NewInterop(newcontract)) return nil } // contractUpdate migrates a contract. func contractUpdate(ic *interop.Context, v *vm.VM) error { contract, err := ic.DAO.GetContractState(v.GetCurrentScriptHash()) if contract == nil { return errors.New("contract doesn't exist") } newcontract, err := createContractStateFromVM(ic, v) if err != nil { return err } if newcontract.Script != nil { if l := len(newcontract.Script); l == 0 || l > MaxContractScriptSize { return errors.New("invalid script len") } h := newcontract.ScriptHash() if h.Equals(contract.ScriptHash()) { return errors.New("the script is the same") } else if _, err := ic.DAO.GetContractState(h); err == nil { return errors.New("contract already exists") } newcontract.ID = contract.ID if err := ic.DAO.PutContractState(newcontract); err != nil { return err } if err := ic.DAO.DeleteContractState(contract.ScriptHash()); err != nil { return err } } if !newcontract.HasStorage() { siMap, err := ic.DAO.GetStorageItems(contract.ID) if err != nil { return err } if len(siMap) != 0 { return errors.New("old contract shouldn't have storage") } } v.Estack().PushVal(stackitem.NewInterop(contract)) return contractDestroy(ic, v) } // runtimeSerialize serializes top stack item into a ByteArray. func runtimeSerialize(_ *interop.Context, v *vm.VM) error { return vm.RuntimeSerialize(v) } // runtimeDeserialize deserializes ByteArray from a stack into an item. func runtimeDeserialize(_ *interop.Context, v *vm.VM) error { return vm.RuntimeDeserialize(v) }