AST|【2021-09-24】Babel AST for-switch简单控制流 babel|Babel

【AST|【2021-09-24】Babel AST for-switch简单控制流】学习文章：https://mp.weixin.qq.com/s/nzbKgYEyE1AhJ3v82rxtkA

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js混淆和ast反混淆脚本

const fs = require('fs'); const TNT = require("@babel/types"); const { parse } = require("@babel/parser"); const traverse = require("@babel/traverse").default; const generator = require("@babel/generator").default; let ast = parse(` function $_FIn(e, t, r) { var $_CGFHG = 10; for (; $_CGFHG !== 9; ) { switch ($_CGFHG) { case 10: var n = e["split"]("."), i = n[0] || "div", o = new $_EHB(n)["$_GFS"](1)["$_GGD"](function(e, t, r) { var $_DBIK = cZBsG.$_CN, $_DBHT = ["$_DCBG"].cancat($_DBIK); $_DBHT.shift(); return PREFIX + e; })["$_GHx"](" "), s = new $_EJo(i); return r("." + n[1], s), "input" == i && s["$_GIU"]({ "type": "hidden", "name": o }), s["$_GJa"]({ "className": o }), $_DHf(t) ? s["$_HAZ"](t) : new $_EIz(t)["$_HBY"](function(e, t) { var $_DCDu = cZBsG.$_CN, $_DCCF = ["$_DCGs"].concat(s_DCDu); $_DCCF.shift(); s["$_HCj"]($_FIn(e, t, r)); }), s; $_CGFHG = 9; break; }} }`) traverse(ast, {FunctionDeclaration(path) {let Body = path.get('body').node.body // 第一步：判断函数下面两个子节点是否是var for if (!Body || Body.length != 2 || !TNT.isVariableDeclaration(Body[0]) || !TNT.isForStatement(Body[1])) return; let num = Body[1].test.right.value; // 9 【for语句: $_CGFHG !== 9】 let forBlockName = Body[1].test.left.name; // $_CGFHG 【for语句: $_CGFHG !== 9】// 第二步：查看for语句前面是否存在该变量 let isExist = Body[0].declarations.filter(item => item.id.name === forBlockName) let switchBody = Body[1].body.body; if (!isExist || switchBody.length !== 1 || switchBody[0].cases.length !== 1 || switchBody[0].discriminant.name !== forBlockName) return; // 第三步：【case语句: $_CGFHG = 9; 】 let consequents = switchBody[0].cases[0].consequent; // case语句下面的全部节点 let lastNode = consequents[consequents.length - 2] // 排除break语句后当作最后一个节点 if (TNT.isExpressionStatement(lastNode)) { // 排除【$_CGFHG = 9; 】和 break语句 var { operator, left, right } = lastNode.expression; if (operator == "=" && left.name == forBlockName && right.value =https://www.it610.com/article/= num) {path.get("body").node.body = consequents.slice(0, consequents.indexOf(lastNode)); } } }, })let { code } = generator(ast, { retainLines: false, jsescOption: { minimal: true, } }) fs.writeFileSync("_result_.js", code, "utf-8")

学习目标【还没写出来】

还原前：function Y3s(L8s, T8s, B8s) {var g8s = 2; for (; g8s !== 17; ) {switch (g8s) {case 11: k3s[O3s] = r3s(k3s[O3s - 1], k3s[O3s - 1])[q8s[86]](); g8s = 10; break; case 20: c3s = h3s[q8s[88]][q8s[89]](L8s[q8s[90]](V3s) ^ k3s[O3s][q8s[91]](Z3s)) + c3s; g8s = 19; break; case 13: O3s = 0; g8s = 12; break; case 6: Z3s = 0; g8s = 14; break; case 9: var V3s = L8s[q8s[84]] - 1 , Z3s = 0; g8s = 8; break; case 7: g8s = Z3s === u3s ? 6 : 20; break; case 12: g8s = k3s[q8s[85]] < B8s ? 11 : 10; break; case 2: var c3s = q8s[81]; var O3s = 0; var k3s = []; k3s[O3s] = T8s[q8s[82]](); var u3s = k3s[O3s][q8s[83]]; g8s = 9; break; case 10: u3s = k3s[O3s][q8s[87]]; g8s = 20; break; case 8: g8s = V3s >= 0 ? 7 : 18; break; case 14: g8s = ++O3s === B8s ? 13 : 12; break; case 18: return c3s; break; case 19: --V3s, ++Z3s; g8s = 8; break; } } }还原后:function Y3s(L8s, T8s, B8s) {var c3s = q8s[81]; var O3s = 0; var k3s = []; k3s[O3s] = T8s[q8s[82]](); var u3s = k3s[O3s][q8s[83]]; var V3s = L8s[q8s[84]] - 1 , Z3s = 0; while (V3s >= 0) {if (Z3s === u3s) {Z3s = 0; if (++O3s === B8s) {O3s = 0; }if (k3s[q8s[85]] < B8s) {k3s[O3s] = r3s(k3s[O3s - 1], k3s[O3s - 1])[q8s[86]](); }u3s = k3s[O3s][q8s[87]]; }c3s = h3s[q8s[88]][q8s[89]](L8s[q8s[90]](V3s) ^ k3s[O3s][q8s[91]](Z3s)) + c3s; --V3s, ++Z3s; }return c3s; }