import { injectable, inject } from 'inversify';
import { ServiceIdentifiers } from '../../container/ServiceIdentifiers';
import * as escodegen from 'escodegen';
import * as estraverse from 'estraverse';
import * as ESTree from 'estree';
import { IOptions } from '../../interfaces/options/IOptions';
import { IObfuscatorReplacer } from '../../interfaces/node-transformers/IObfuscatorReplacer';
import { NodeObfuscatorsReplacers } from '../../enums/container/NodeObfuscatorsReplacers';
import { NodeType } from '../../enums/NodeType';
import { AbstractNodeTransformer } from '../AbstractNodeTransformer';
import { Node } from '../../node/Node';
@injectable()
export class MemberExpressionObfuscator extends AbstractNodeTransformer {
/**
* @type {IObfuscatorReplacer}
*/
private readonly stringLiteralReplacer: IObfuscatorReplacer;
/**
* @param replacersFactory
* @param options
*/
constructor(
@inject(ServiceIdentifiers['Factory<IObfuscatorReplacer>']) replacersFactory: (replacer: NodeObfuscatorsReplacers) => IObfuscatorReplacer,
@inject(ServiceIdentifiers.IOptions) options: IOptions
) {
super(options);
this.stringLiteralReplacer = replacersFactory(NodeObfuscatorsReplacers.StringLiteralReplacer);
}
/**
* @param memberExpressionNode
*/
public transformNode (memberExpressionNode: ESTree.MemberExpression): void {
estraverse.traverse(memberExpressionNode.property, {
enter: (node: ESTree.Node, parentNode: ESTree.Node): any => {
if (Node.isLiteralNode(node)) {
this.obfuscateLiteralProperty(node);
return;
}
if (Node.isIdentifierNode(node)) {
if (memberExpressionNode.computed) {
return;
}
memberExpressionNode.computed = true;
this.obfuscateIdentifierProperty(node);
}
}
});
}
/**
* replaces:
* object.identifier = 1;
*
* on:
* object[_0x23d45[25]] = 1;
*
* and skip:
* object[identifier] = 1;
*
* @param node
*/
private obfuscateIdentifierProperty (node: ESTree.Identifier): void {
const nodeValue: string = node.name;
const literalNode: ESTree.Literal = {
raw: `'${nodeValue}'`,
'x-verbatim-property': {
content: this.stringLiteralReplacer.replace(nodeValue),
precedence: escodegen.Precedence.Primary
},
type: NodeType.Literal,
value: nodeValue
};
delete node.name;
Object.assign(node, literalNode);
}
/**
* replaces:
* object['literal'] = 1;
*
* on:
* object[_0x23d45[25]] = 1;
*
* @param node
*/
private obfuscateLiteralProperty (node: ESTree.Literal): void {
if (typeof node.value === 'string' && !node['x-verbatim-property']) {
node['x-verbatim-property'] = {
content : this.stringLiteralReplacer.replace(node.value),
precedence: escodegen.Precedence.Primary
};
}
}
}
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