package state import ( "errors" "math" "math/big" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest" "github.com/nspcc-dev/neo-go/pkg/smartcontract/nef" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm/emit" "github.com/nspcc-dev/neo-go/pkg/vm/opcode" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" ) // Contract holds information about a smart contract in the NEO blockchain. type Contract struct { ContractBase UpdateCounter uint16 `json:"updatecounter"` } // ContractBase represents a part shared by native and user-deployed contracts. type ContractBase struct { ID int32 `json:"id"` Hash util.Uint160 `json:"hash"` NEF nef.File `json:"nef"` Manifest manifest.Manifest `json:"manifest"` } // NativeContract holds information about the native contract. type NativeContract struct { ContractBase UpdateHistory []uint32 `json:"updatehistory"` } // ToStackItem converts state.Contract to stackitem.Item. func (c *Contract) ToStackItem() (stackitem.Item, error) { rawNef, err := c.NEF.Bytes() if err != nil { return nil, err } m, err := c.Manifest.ToStackItem() if err != nil { return nil, err } return stackitem.NewArray([]stackitem.Item{ stackitem.Make(c.ID), stackitem.Make(c.UpdateCounter), stackitem.NewByteArray(c.Hash.BytesBE()), stackitem.NewByteArray(rawNef), m, }), nil } // FromStackItem fills Contract's data from the given stack itemized contract // representation. func (c *Contract) FromStackItem(item stackitem.Item) error { arr, ok := item.Value().([]stackitem.Item) if !ok { return errors.New("not an array") } bi, ok := arr[0].Value().(*big.Int) if !ok { return errors.New("ID is not an integer") } if !bi.IsInt64() || bi.Int64() > math.MaxInt32 || bi.Int64() < math.MinInt32 { return errors.New("ID not in int32 range") } c.ID = int32(bi.Int64()) bi, ok = arr[1].Value().(*big.Int) if !ok { return errors.New("UpdateCounter is not an integer") } if !bi.IsUint64() || bi.Uint64() > math.MaxUint16 { return errors.New("UpdateCounter not in uint16 range") } c.UpdateCounter = uint16(bi.Uint64()) bytes, err := arr[2].TryBytes() if err != nil { return err } c.Hash, err = util.Uint160DecodeBytesBE(bytes) if err != nil { return err } bytes, err = arr[3].TryBytes() if err != nil { return err } c.NEF, err = nef.FileFromBytes(bytes) if err != nil { return err } m := new(manifest.Manifest) err = m.FromStackItem(arr[4]) if err != nil { return err } c.Manifest = *m return nil } // CreateContractHash creates a deployed contract hash from the transaction sender // and the contract script. func CreateContractHash(sender util.Uint160, checksum uint32, name string) util.Uint160 { w := io.NewBufBinWriter() emit.Opcodes(w.BinWriter, opcode.ABORT) emit.Bytes(w.BinWriter, sender.BytesBE()) emit.Int(w.BinWriter, int64(checksum)) emit.String(w.BinWriter, name) if w.Err != nil { panic(w.Err) } return hash.Hash160(w.Bytes()) }