package smartcontract import ( "encoding/hex" "errors" "strconv" "strings" "unicode/utf8" "github.com/CityOfZion/neo-go/pkg/crypto" "github.com/CityOfZion/neo-go/pkg/crypto/keys" "github.com/CityOfZion/neo-go/pkg/io" "github.com/CityOfZion/neo-go/pkg/util" ) // ParamType represents the Type of the contract parameter. type ParamType byte // A list of supported smart contract parameter types. const ( SignatureType ParamType = iota BoolType IntegerType Hash160Type Hash256Type ByteArrayType PublicKeyType StringType ArrayType ) // PropertyState represents contract properties (flags). type PropertyState byte // List of supported properties. const ( HasStorage PropertyState = 1 << iota HasDynamicInvoke IsPayable NoProperties = 0 ) // Parameter represents a smart contract parameter. type Parameter struct { // Type of the parameter. Type ParamType `json:"type"` // The actual value of the parameter. Value interface{} `json:"value"` } func (pt ParamType) String() string { switch pt { case SignatureType: return "Signature" case BoolType: return "Boolean" case IntegerType: return "Integer" case Hash160Type: return "Hash160" case Hash256Type: return "Hash256" case ByteArrayType: return "ByteArray" case PublicKeyType: return "PublicKey" case StringType: return "String" case ArrayType: return "Array" default: return "" } } // MarshalJSON implements the json.Marshaler interface. func (pt ParamType) MarshalJSON() ([]byte, error) { return []byte(`"` + pt.String() + `"`), nil } // EncodeBinary implements io.Serializable interface. func (pt ParamType) EncodeBinary(w *io.BinWriter) { w.WriteLE(pt) } // DecodeBinary implements io.Serializable interface. func (pt *ParamType) DecodeBinary(r *io.BinReader) { r.ReadLE(pt) } // NewParameter returns a Parameter with proper initialized Value // of the given ParamType. func NewParameter(t ParamType) Parameter { return Parameter{ Type: t, Value: nil, } } // parseParamType is a user-friendly string to ParamType converter, it's // case-insensitive and makes the following conversions: // signature -> SignatureType // bool -> BoolType // int -> IntegerType // hash160 -> Hash160Type // hash256 -> Hash256Type // bytes -> ByteArrayType // key -> PublicKeyType // string -> StringType // anything else generates an error. func parseParamType(typ string) (ParamType, error) { switch strings.ToLower(typ) { case "signature": return SignatureType, nil case "bool": return BoolType, nil case "int": return IntegerType, nil case "hash160": return Hash160Type, nil case "hash256": return Hash256Type, nil case "bytes": return ByteArrayType, nil case "key": return PublicKeyType, nil case "string": return StringType, nil default: // We deliberately don't support array here. return 0, errors.New("wrong or unsupported parameter type") } } // adjustValToType is a value type-checker and converter. func adjustValToType(typ ParamType, val string) (interface{}, error) { switch typ { case SignatureType: b, err := hex.DecodeString(val) if err != nil { return nil, err } if len(b) != 64 { return nil, errors.New("not a signature") } return val, nil case BoolType: switch val { case "true": return true, nil case "false": return false, nil default: return nil, errors.New("invalid boolean value") } case IntegerType: return strconv.Atoi(val) case Hash160Type: u, err := crypto.Uint160DecodeAddress(val) if err == nil { return hex.EncodeToString(u.BytesBE()), nil } b, err := hex.DecodeString(val) if err != nil { return nil, err } if len(b) != 20 { return nil, errors.New("not a hash160") } return val, nil case Hash256Type: b, err := hex.DecodeString(val) if err != nil { return nil, err } if len(b) != 32 { return nil, errors.New("not a hash256") } return val, nil case ByteArrayType: _, err := hex.DecodeString(val) if err != nil { return nil, err } return val, nil case PublicKeyType: _, err := keys.NewPublicKeyFromString(val) if err != nil { return nil, err } return val, nil case StringType: return val, nil default: return nil, errors.New("unsupported parameter type") } } // inferParamType tries to infer the value type from its contents. It returns // IntegerType for anything that looks like decimal integer (can be converted // with strconv.Atoi), BoolType for true and false values, Hash160Type for // addresses and hex strings encoding 20 bytes long values, PublicKeyType for // valid hex-encoded public keys, Hash256Type for hex-encoded 32 bytes values, // SignatureType for hex-encoded 64 bytes values, ByteArrayType for any other // valid hex-encoded values and StringType for anything else. func inferParamType(val string) ParamType { var err error _, err = strconv.Atoi(val) if err == nil { return IntegerType } if val == "true" || val == "false" { return BoolType } _, err = crypto.Uint160DecodeAddress(val) if err == nil { return Hash160Type } _, err = keys.NewPublicKeyFromString(val) if err == nil { return PublicKeyType } unhexed, err := hex.DecodeString(val) if err == nil { switch len(unhexed) { case 20: return Hash160Type case 32: return Hash256Type case 64: return SignatureType default: return ByteArrayType } } // Anything can be a string. return StringType } // NewParameterFromString returns a new Parameter initialized from the given // string in neo-go-specific format. It is intended to be used in user-facing // interfaces and has some heuristics in it to simplify parameter passing. Exact // syntax is documented in the cli documentation. func NewParameterFromString(in string) (*Parameter, error) { var ( char rune val string err error r *strings.Reader buf strings.Builder escaped bool hadType bool res = &Parameter{} ) r = strings.NewReader(in) for char, _, err = r.ReadRune(); err == nil && char != utf8.RuneError; char, _, err = r.ReadRune() { if char == '\\' && !escaped { escaped = true continue } if char == ':' && !escaped && !hadType { typStr := buf.String() res.Type, err = parseParamType(typStr) if err != nil { return nil, err } buf.Reset() hadType = true continue } escaped = false // We don't care about length and it never fails. _, _ = buf.WriteRune(char) } if char == utf8.RuneError { return nil, errors.New("bad UTF-8 string") } // The only other error `ReadRune` returns is io.EOF, which is fine and // expected, so we don't check err here. val = buf.String() if !hadType { res.Type = inferParamType(val) } res.Value, err = adjustValToType(res.Type, val) if err != nil { return nil, err } return res, nil } // ContextItem represents a transaction context item. type ContextItem struct { Script util.Uint160 Parameters []Parameter Signatures []Signature } // Signature represents a transaction signature. type Signature struct { Data []byte PublicKey []byte } // ParameterContext holds the parameter context. type ParameterContext struct{}