From 37f9d25ba027356457953eab5f181c98b46e9988 Mon Sep 17 00:00:00 2001 From: Daniel Perez Date: Fri, 4 Mar 2022 13:39:09 +0100 Subject: [PATCH] signer/fourbyte: add support for nested types in selectors (#24407) This replaces the simple selector parser in signer/fourbyte with one that can actually handle most types. The new parser is added in accounts/abi to also make it useable elsewhere. --- accounts/abi/selector_parser.go | 152 +++++++++++++++++++++++++++ accounts/abi/selector_parser_test.go | 54 ++++++++++ signer/fourbyte/abi.go | 36 +------ 3 files changed, 210 insertions(+), 32 deletions(-) create mode 100644 accounts/abi/selector_parser.go create mode 100644 accounts/abi/selector_parser_test.go diff --git a/accounts/abi/selector_parser.go b/accounts/abi/selector_parser.go new file mode 100644 index 000000000..75609b28a --- /dev/null +++ b/accounts/abi/selector_parser.go @@ -0,0 +1,152 @@ +package abi + +import ( + "fmt" +) + +type SelectorMarshaling struct { + Name string `json:"name"` + Type string `json:"type"` + Inputs []ArgumentMarshaling `json:"inputs"` +} + +func isDigit(c byte) bool { + return c >= '0' && c <= '9' +} + +func isAlpha(c byte) bool { + return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') +} + +func isIdentifierSymbol(c byte) bool { + return c == '$' || c == '_' +} + +func parseToken(unescapedSelector string, isIdent bool) (string, string, error) { + if len(unescapedSelector) == 0 { + return "", "", fmt.Errorf("empty token") + } + firstChar := unescapedSelector[0] + position := 1 + if !(isAlpha(firstChar) || (isIdent && isIdentifierSymbol(firstChar))) { + return "", "", fmt.Errorf("invalid token start: %c", firstChar) + } + for position < len(unescapedSelector) { + char := unescapedSelector[position] + if !(isAlpha(char) || isDigit(char) || (isIdent && isIdentifierSymbol(char))) { + break + } + position++ + } + return unescapedSelector[:position], unescapedSelector[position:], nil +} + +func parseIdentifier(unescapedSelector string) (string, string, error) { + return parseToken(unescapedSelector, true) +} + +func parseElementaryType(unescapedSelector string) (string, string, error) { + parsedType, rest, err := parseToken(unescapedSelector, false) + if err != nil { + return "", "", fmt.Errorf("failed to parse elementary type: %v", err) + } + // handle arrays + for len(rest) > 0 && rest[0] == '[' { + parsedType = parsedType + string(rest[0]) + rest = rest[1:] + for len(rest) > 0 && isDigit(rest[0]) { + parsedType = parsedType + string(rest[0]) + rest = rest[1:] + } + if len(rest) == 0 || rest[0] != ']' { + return "", "", fmt.Errorf("failed to parse array: expected ']', got %c", unescapedSelector[0]) + } + parsedType = parsedType + string(rest[0]) + rest = rest[1:] + } + return parsedType, rest, nil +} + +func parseCompositeType(unescapedSelector string) ([]interface{}, string, error) { + if len(unescapedSelector) == 0 || unescapedSelector[0] != '(' { + return nil, "", fmt.Errorf("expected '(', got %c", unescapedSelector[0]) + } + parsedType, rest, err := parseType(unescapedSelector[1:]) + if err != nil { + return nil, "", fmt.Errorf("failed to parse type: %v", err) + } + result := []interface{}{parsedType} + for len(rest) > 0 && rest[0] != ')' { + parsedType, rest, err = parseType(rest[1:]) + if err != nil { + return nil, "", fmt.Errorf("failed to parse type: %v", err) + } + result = append(result, parsedType) + } + if len(rest) == 0 || rest[0] != ')' { + return nil, "", fmt.Errorf("expected ')', got '%s'", rest) + } + return result, rest[1:], nil +} + +func parseType(unescapedSelector string) (interface{}, string, error) { + if len(unescapedSelector) == 0 { + return nil, "", fmt.Errorf("empty type") + } + if unescapedSelector[0] == '(' { + return parseCompositeType(unescapedSelector) + } else { + return parseElementaryType(unescapedSelector) + } +} + +func assembleArgs(args []interface{}) ([]ArgumentMarshaling, error) { + arguments := make([]ArgumentMarshaling, 0) + for i, arg := range args { + // generate dummy name to avoid unmarshal issues + name := fmt.Sprintf("name%d", i) + if s, ok := arg.(string); ok { + arguments = append(arguments, ArgumentMarshaling{name, s, s, nil, false}) + } else if components, ok := arg.([]interface{}); ok { + subArgs, err := assembleArgs(components) + if err != nil { + return nil, fmt.Errorf("failed to assemble components: %v", err) + } + arguments = append(arguments, ArgumentMarshaling{name, "tuple", "tuple", subArgs, false}) + } else { + return nil, fmt.Errorf("failed to assemble args: unexpected type %T", arg) + } + } + return arguments, nil +} + +// ParseSelector converts a method selector into a struct that can be JSON encoded +// and consumed by other functions in this package. +// Note, although uppercase letters are not part of the ABI spec, this function +// still accepts it as the general format is valid. +func ParseSelector(unescapedSelector string) (SelectorMarshaling, error) { + name, rest, err := parseIdentifier(unescapedSelector) + if err != nil { + return SelectorMarshaling{}, fmt.Errorf("failed to parse selector '%s': %v", unescapedSelector, err) + } + args := []interface{}{} + if len(rest) >= 2 && rest[0] == '(' && rest[1] == ')' { + rest = rest[2:] + } else { + args, rest, err = parseCompositeType(rest) + if err != nil { + return SelectorMarshaling{}, fmt.Errorf("failed to parse selector '%s': %v", unescapedSelector, err) + } + } + if len(rest) > 0 { + return SelectorMarshaling{}, fmt.Errorf("failed to parse selector '%s': unexpected string '%s'", unescapedSelector, rest) + } + + // Reassemble the fake ABI and constuct the JSON + fakeArgs, err := assembleArgs(args) + if err != nil { + return SelectorMarshaling{}, fmt.Errorf("failed to parse selector: %v", err) + } + + return SelectorMarshaling{name, "function", fakeArgs}, nil +} diff --git a/accounts/abi/selector_parser_test.go b/accounts/abi/selector_parser_test.go new file mode 100644 index 000000000..9720c9d53 --- /dev/null +++ b/accounts/abi/selector_parser_test.go @@ -0,0 +1,54 @@ +package abi + +import ( + "fmt" + "log" + "reflect" + "testing" +) + +func TestParseSelector(t *testing.T) { + mkType := func(types ...interface{}) []ArgumentMarshaling { + var result []ArgumentMarshaling + for i, typeOrComponents := range types { + name := fmt.Sprintf("name%d", i) + if typeName, ok := typeOrComponents.(string); ok { + result = append(result, ArgumentMarshaling{name, typeName, typeName, nil, false}) + } else if components, ok := typeOrComponents.([]ArgumentMarshaling); ok { + result = append(result, ArgumentMarshaling{name, "tuple", "tuple", components, false}) + } else { + log.Fatalf("unexpected type %T", typeOrComponents) + } + } + return result + } + tests := []struct { + input string + name string + args []ArgumentMarshaling + }{ + {"noargs()", "noargs", []ArgumentMarshaling{}}, + {"simple(uint256,uint256,uint256)", "simple", mkType("uint256", "uint256", "uint256")}, + {"other(uint256,address)", "other", mkType("uint256", "address")}, + {"withArray(uint256[],address[2],uint8[4][][5])", "withArray", mkType("uint256[]", "address[2]", "uint8[4][][5]")}, + {"singleNest(bytes32,uint8,(uint256,uint256),address)", "singleNest", mkType("bytes32", "uint8", mkType("uint256", "uint256"), "address")}, + {"multiNest(address,(uint256[],uint256),((address,bytes32),uint256))", "multiNest", + mkType("address", mkType("uint256[]", "uint256"), mkType(mkType("address", "bytes32"), "uint256"))}, + } + for i, tt := range tests { + selector, err := ParseSelector(tt.input) + if err != nil { + t.Errorf("test %d: failed to parse selector '%v': %v", i, tt.input, err) + } + if selector.Name != tt.name { + t.Errorf("test %d: unexpected function name: '%s' != '%s'", i, selector.Name, tt.name) + } + + if selector.Type != "function" { + t.Errorf("test %d: unexpected type: '%s' != '%s'", i, selector.Type, "function") + } + if !reflect.DeepEqual(selector.Inputs, tt.args) { + t.Errorf("test %d: unexpected args: '%v' != '%v'", i, selector.Inputs, tt.args) + } + } +} diff --git a/signer/fourbyte/abi.go b/signer/fourbyte/abi.go index d8fbabd3b..352abc59e 100644 --- a/signer/fourbyte/abi.go +++ b/signer/fourbyte/abi.go @@ -20,7 +20,6 @@ import ( "bytes" "encoding/json" "fmt" - "regexp" "strings" "github.com/ethereum/go-ethereum/accounts/abi" @@ -75,42 +74,15 @@ func verifySelector(selector string, calldata []byte) (*decodedCallData, error) return parseCallData(calldata, string(abidata)) } -// selectorRegexp is used to validate that a 4byte database selector corresponds -// to a valid ABI function declaration. -// -// Note, although uppercase letters are not part of the ABI spec, this regexp -// still accepts it as the general format is valid. It will be rejected later -// by the type checker. -var selectorRegexp = regexp.MustCompile(`^([^\)]+)\(([A-Za-z0-9,\[\]]*)\)`) - // parseSelector converts a method selector into an ABI JSON spec. The returned // data is a valid JSON string which can be consumed by the standard abi package. func parseSelector(unescapedSelector string) ([]byte, error) { - // Define a tiny fake ABI struct for JSON marshalling - type fakeArg struct { - Type string `json:"type"` + selector, err := abi.ParseSelector(unescapedSelector) + if err != nil { + return nil, fmt.Errorf("failed to parse selector: %v", err) } - type fakeABI struct { - Name string `json:"name"` - Type string `json:"type"` - Inputs []fakeArg `json:"inputs"` - } - // Validate the unescapedSelector and extract it's components - groups := selectorRegexp.FindStringSubmatch(unescapedSelector) - if len(groups) != 3 { - return nil, fmt.Errorf("invalid selector %q (%v matches)", unescapedSelector, len(groups)) - } - name := groups[1] - args := groups[2] - // Reassemble the fake ABI and constuct the JSON - arguments := make([]fakeArg, 0) - if len(args) > 0 { - for _, arg := range strings.Split(args, ",") { - arguments = append(arguments, fakeArg{arg}) - } - } - return json.Marshal([]fakeABI{{name, "function", arguments}}) + return json.Marshal([]abi.SelectorMarshaling{selector}) } // parseCallData matches the provided call data against the ABI definition and