Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fix: ignore possible dead branches for control flow object checks #45

Draft
wants to merge 2 commits into
base: master
Choose a base branch
from
Draft

fix: ignore possible dead branches for control flow object checks #45

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e06593d
fix: ignore possible dead branches for control flow object checks
j4k0xb Jan 3, 2024
dfe0c75
refactor
j4k0xb Jan 3, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 27 additions & 5 deletions packages/webcrack/src/deobfuscate/control-flow-object.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
import type { Binding, NodePath } from '@babel/traverse';
import * as t from '@babel/types';
import type { FunctionExpression } from '@babel/types';
import * as t from '@babel/types';
import * as m from '@codemod/matchers';
import type { Transform } from '../ast-utils';
import {
Expand Down Expand Up @@ -104,6 +104,20 @@ export default {
m.capture(m.objectExpression(objectProperties)),
);

const anyMemberAccess = constMemberExpression(m.identifier(), propertyName);
const deadBranchTest = m.or(
m.callExpression(anyMemberAccess, [anyMemberAccess, anyMemberAccess]),
m.binaryExpression(
m.or('===', '!=='),
m.stringLiteral(),
m.stringLiteral(),
),
);
const deadBranchMatcher = m.or(
m.ifStatement(deadBranchTest),
m.conditionalExpression(deadBranchTest),
);

function isConstantBinding(binding: Binding) {
// Workaround because sometimes babel treats the VariableDeclarator/binding itself as a violation
return binding.constant || binding.constantViolations[0] === binding.path;
Expand All @@ -116,9 +130,13 @@ export default {
// would have generated the code (no reassignments, etc.)
const binding = path.scope.getBinding(varId.current!.name);
if (!binding) return changes;
if (!isConstantBinding(binding)) return changes;
const isInDeadBranchMaybe = binding.constantViolations.every((path) =>
findParent(path, deadBranchMatcher),
);
if (!isInDeadBranchMaybe && !isConstantBinding(binding)) return changes;
if (!transformObjectKeys(binding)) return changes;
if (!isReadonlyObject(binding, memberAccess)) return changes;
if (!isInDeadBranchMaybe && !isReadonlyObject(binding, memberAccess))
return changes;

const props = new Map(
objectProperties.current!.map((p) => [
Expand All @@ -133,13 +151,17 @@ export default {
// Have to loop backwards because we might replace a node that
// contains another reference to the binding (https://github.com/babel/babel/issues/12943)
[...binding.referencePaths].reverse().forEach((ref) => {
const memberPath = ref.parentPath as NodePath<t.MemberExpression>;
const memberPath = ref.parentPath;

// It should always be a MemberExpression unless when dead code injection is enabled
if (!t.isMemberExpression(memberPath?.node)) return;

const propName = getPropName(memberPath.node.property)!;
const value = props.get(propName)!;

if (t.isStringLiteral(value)) {
memberPath.replaceWith(value);
} else {
} else if (t.isFunctionExpression(value)) {
inlineFunction(
value,
memberPath.parentPath as NodePath<t.CallExpression>,
Expand Down