Files
openclaw/apps/macos/Sources/OpenClaw/ExecShellWrapperParser.swift
Pavan Kumar Gondhi fc065b2693 Harden macOS shell wrapper allowlist parsing [AI] (#78518)
* fix: harden shell wrapper allowlist parsing

* fix: harden shell wrapper approval binding

* docs: add changelog entry for PR merge

---------

Co-authored-by: Ishaan <ishaan@Ishaans-Mac-mini.local>
2026-05-08 10:18:41 +05:30

205 lines
7.3 KiB
Swift

import Foundation
enum ExecShellWrapperParser {
struct ParsedShellWrapper {
let isWrapper: Bool
let command: String?
static let notWrapper = ParsedShellWrapper(isWrapper: false, command: nil)
static let blockedWrapper = ParsedShellWrapper(isWrapper: true, command: nil)
}
private enum Kind: Equatable {
case posix
case cmd
case powershell
}
private struct WrapperSpec {
let kind: Kind
let names: Set<String>
}
private static let posixInlineFlags = Set(["-lc", "-c", "--command"])
private static let powershellInlineFlags = Set(["-c", "-command", "--command"])
private static let wrapperSpecs: [WrapperSpec] = [
WrapperSpec(kind: .posix, names: ["ash", "sh", "bash", "zsh", "dash", "ksh", "fish"]),
WrapperSpec(kind: .cmd, names: ["cmd.exe", "cmd"]),
WrapperSpec(kind: .powershell, names: ["powershell", "powershell.exe", "pwsh", "pwsh.exe"]),
]
private static let loginStartupShellNames = Set(["ash", "bash", "dash", "fish", "ksh", "sh", "zsh"])
static func extract(command: [String], rawCommand: String?) -> ParsedShellWrapper {
let trimmedRaw = rawCommand?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
let preferredRaw = trimmedRaw.isEmpty ? nil : trimmedRaw
return self.extract(
command: command,
preferredRaw: preferredRaw,
failClosedOnStartupWrappers: false,
depth: 0)
}
static func extractForAllowlist(command: [String], rawCommand: String?) -> ParsedShellWrapper {
let trimmedRaw = rawCommand?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
let preferredRaw = trimmedRaw.isEmpty ? nil : trimmedRaw
return self.extract(
command: command,
preferredRaw: preferredRaw,
failClosedOnStartupWrappers: true,
depth: 0)
}
private static func extract(
command: [String],
preferredRaw: String?,
failClosedOnStartupWrappers: Bool,
depth: Int) -> ParsedShellWrapper
{
guard depth < ExecEnvInvocationUnwrapper.maxWrapperDepth else {
return .notWrapper
}
guard let token0 = command.first?.trimmingCharacters(in: .whitespacesAndNewlines), !token0.isEmpty else {
return .notWrapper
}
let base0 = ExecCommandToken.basenameLower(token0)
if base0 == "env" {
guard let unwrapped = ExecEnvInvocationUnwrapper.unwrap(command) else {
return .notWrapper
}
return self.extract(
command: unwrapped,
preferredRaw: preferredRaw,
failClosedOnStartupWrappers: failClosedOnStartupWrappers,
depth: depth + 1)
}
guard let spec = self.wrapperSpecs.first(where: { $0.names.contains(base0) }) else {
return .notWrapper
}
if spec.kind == .posix,
base0 == "fish",
ExecInlineCommandParser.hasFishAttachedCommandOption(command)
{
return .blockedWrapper
}
let includeLegacyLoginInlineForm = failClosedOnStartupWrappers &&
!self.legacyLoginInlinePayloadMatchesRaw(
command: command,
spec: spec,
base0: base0,
preferredRaw: preferredRaw)
if self.startupWrapperRequiresFullArgv(
command: command,
spec: spec,
base0: base0,
includeLegacyLoginInlineForm: includeLegacyLoginInlineForm)
{
return .blockedWrapper
}
guard let payload = self.extractPayload(command: command, spec: spec) else {
return .notWrapper
}
let normalized = failClosedOnStartupWrappers ? payload : preferredRaw ?? payload
return ParsedShellWrapper(isWrapper: true, command: normalized)
}
private static func startupWrapperRequiresFullArgv(
command: [String],
spec: WrapperSpec,
base0: String,
includeLegacyLoginInlineForm: Bool) -> Bool
{
guard spec.kind == .posix else {
return false
}
if base0 == "fish",
ExecInlineCommandParser.hasFishInitCommandOption(command)
{
return true
}
if self.loginStartupShellNames.contains(base0),
ExecInlineCommandParser.hasPosixLoginStartupBeforeInlineCommand(
command,
flags: self.posixInlineFlags)
{
return includeLegacyLoginInlineForm || !self.isLegacyShLoginInlineForm(command, base0: base0)
}
return ExecInlineCommandParser.hasPosixInteractiveStartupBeforeInlineCommand(
command,
flags: self.posixInlineFlags)
}
private static func isLegacyLoginInlineForm(_ command: [String]) -> Bool {
guard command.count > 1 else {
return false
}
return command[1].trimmingCharacters(in: .whitespacesAndNewlines) == "-lc"
}
private static func isLegacyShLoginInlineForm(_ command: [String], base0: String) -> Bool {
base0 == "sh" && self.isLegacyLoginInlineForm(command)
}
private static func legacyLoginInlinePayloadMatchesRaw(
command: [String],
spec: WrapperSpec,
base0: String,
preferredRaw: String?) -> Bool
{
guard let preferredRaw,
base0 == "sh",
self.isLegacyLoginInlineForm(command),
let payload = self.extractPayload(command: command, spec: spec)
else {
return false
}
return payload == preferredRaw.trimmingCharacters(in: .whitespacesAndNewlines)
}
private static func extractPayload(command: [String], spec: WrapperSpec) -> String? {
switch spec.kind {
case .posix:
self.extractPosixInlineCommand(command)
case .cmd:
self.extractCmdInlineCommand(command)
case .powershell:
self.extractPowerShellInlineCommand(command)
}
}
private static func extractPosixInlineCommand(_ command: [String]) -> String? {
ExecInlineCommandParser.extractInlineCommand(
command,
flags: self.posixInlineFlags,
allowCombinedC: true)
}
private static func extractCmdInlineCommand(_ command: [String]) -> String? {
guard let idx = command
.firstIndex(where: { $0.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() == "/c" })
else {
return nil
}
let tail = command.suffix(from: command.index(after: idx)).joined(separator: " ")
let payload = tail.trimmingCharacters(in: .whitespacesAndNewlines)
return payload.isEmpty ? nil : payload
}
private static func extractPowerShellInlineCommand(_ command: [String]) -> String? {
for idx in 1..<command.count {
let token = command[idx].trimmingCharacters(in: .whitespacesAndNewlines).lowercased()
if token.isEmpty { continue }
if token == "--" { break }
if self.powershellInlineFlags.contains(token) {
return ExecInlineCommandParser.extractInlineCommand(
command,
flags: self.powershellInlineFlags,
allowCombinedC: false)
}
}
return nil
}
}