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https://github.com/luxfi/precompile.git
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zeekay
3da812d7d9
CalculateFunctionSelector keccaks the whole string, so a signature carrying stray whitespace or a copy-paste artefact yields a selector nobody will ever send. The regex matched a substring, so the panic that exists to catch exactly that never fired. Anchored. Every caller is a package initialiser over a literal, so this is a boot failure on a constant, unreachable from calldata. RequireGasLimit's nil check was dead: a nil interface satisfies no interface, so the assertion below already answered it.
76 lines
2.6 KiB
Go
76 lines
2.6 KiB
Go
// Copyright (C) 2019-2025, Lux Industries, Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package contract
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import (
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"errors"
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"fmt"
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"regexp"
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"strings"
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"github.com/luxfi/crypto"
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"github.com/luxfi/geth/accounts/abi"
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)
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// Shared error sentinels for all precompiles.
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var (
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ErrOutOfGas = errors.New("out of gas")
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ErrInvalidInput = errors.New("invalid input")
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ErrInvalidOp = errors.New("invalid operation")
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)
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// Gas costs for stateful precompiles
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const (
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WriteGasCostPerSlot = 20_000
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ReadGasCostPerSlot = 5_000
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// Per LOG operation.
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LogGas uint64 = 375 // from params/protocol_params.go
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// Gas cost of single topic of the LOG. Should be multiplied by the number of topics.
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LogTopicGas uint64 = 375 // from params/protocol_params.go
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// Per byte cost in a LOG operation's data. Should be multiplied by the byte size of the data.
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LogDataGas uint64 = 8 // from params/protocol_params.go
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)
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// functionSignatureRegex matches a whole canonical Solidity signature and
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// nothing else. The anchors are load-bearing: keccak hashes the entire string,
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// so a signature carrying stray whitespace or a copy-paste artefact would pass
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// an unanchored check and yield a selector no caller will ever send. The panic
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// below exists to catch exactly that at boot.
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var functionSignatureRegex = regexp.MustCompile(`^\w+\((\w*|(\w+,)+\w+)\)$`)
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// CalculateFunctionSelector returns the 4 byte function selector that results from [functionSignature]
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// Ex. the function setBalance(addr address, balance uint256) should be passed in as the string:
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// "setBalance(address,uint256)"
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//
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// Panics on a signature that is not exactly one canonical Solidity signature.
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// Every caller is a package-level initialiser over a string literal, so the
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// panic is a boot failure on a constant, never reachable from calldata.
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func CalculateFunctionSelector(functionSignature string) []byte {
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if !functionSignatureRegex.MatchString(functionSignature) {
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panic(fmt.Errorf("invalid function signature: %q", functionSignature))
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}
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hash := crypto.Keccak256([]byte(functionSignature))
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return hash[:4]
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}
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// DeductGas checks if [suppliedGas] is sufficient against [requiredGas] and deducts [requiredGas] from [suppliedGas].
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func DeductGas(suppliedGas uint64, requiredGas uint64) (uint64, error) {
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if suppliedGas < requiredGas {
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return 0, ErrOutOfGas
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}
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return suppliedGas - requiredGas, nil
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}
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// ParseABI parses the given ABI string and returns the parsed ABI.
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// If the ABI is invalid, it panics.
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func ParseABI(rawABI string) abi.ABI {
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parsed, err := abi.JSON(strings.NewReader(rawABI))
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if err != nil {
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panic(err)
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}
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return parsed
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}
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