JD之log值 2022.03.22——开源

机器兔

大佬帮找个JS算法
https://bbs.125.la/forum.php?mod=viewthread&tid=14721694
(出处: 精易论坛)

@果心豆腐酱

前几天看到有人求此算法，当时我是真没看到这个包，，，今天突然又看了一眼，嗯，既然看到了就好办了。
理论上来说，所有算法都可以分析、逆向、推理等，能加密亦可解密；




首先我开始打算通过hook，但是由于混淆太严重，导致hook失败；


然后我是通过程序发起定位追踪得到的位子，在进行单步走定位；首先打开谷歌开发者工具，我就不多说了；


先观察程序发起调用的全部js文件(共2个)：图1
文件1：vendor.1e2b8531.js
文件2：index.d43de3f0.js
2个文件全部打开，在文件每个里搜索关键词：log
文件1里没有搜到；在搜文件2，好，文件2里搜到了很多；那么我们就定位核心文件为：文件2
data: {"redPacketId":"441595068","followShop":0,"random":"88812911","log":"需要的","sceneid":"JLHBhPageh5"}



接下来，看图2
首先打开跟进程序发起的第1个函数；下上断点之后，点击网页上的“为他助力”，上看看、下看看发现没用看到log这个密文，那么说明我们所定位的位子不准确；
好，那么我们把这个断点取消，在进行打开跟进程序发起的第2个函数，以此类推，一直找到为止，不要说找不到，只是你没看到而已；



接下来，看图3
经过不断找呀找~~~!找到了，在第9个函数mt()50764位子；
然后下断点，在去网页上点击“为他助力”



图4
根据图4所得到的定位我们接下来进行单步跟踪到函数内，按快捷键F11，走11下到图5位子


图5
那么这个log密文必然就是这个函数内所计算加密而成的 => var c = u(t, e, n);
然后我们单步跳过也就是快捷键F10，按1下走到图6位子


图6
smashUtils.get_risk_result(i);
那么这个函数就是核心了，log运算的过程就在此；核心函数范围：38727~39008行
此js并不难，难点却在switch里绕来绕去，在加混淆有点厉害。
如有任何不懂的，可通过聊天私信




图7
图文教到此结束



提示下，此本版务必通过 http://127.0.0.1/Index.html 才可以正常运算，不支持脱机工作，免费的凑合用吧,我特么的用了2天时间。。。；

卧槽~又长姿势了！源码在此~！
Index.rar (60.8 KB, 下载次数: 264)

2022-3-22 21:02 上传

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机器兔

有人说算法最后字符串一样的问题;
确实是一个bug,是因为函数以及变量声明引用重复导致冲突；



首先找到这个 s 函数位子;


改为如下

再将这里的s改为我们刚才改的即可




然后在将下面这个a声明变量放入 var e6 函数头部；

[JavaScript] 纯文本查看 复制代码

var a = {"0":0,"1":1996959894,"2":-301047508,"3":-1727442502,"4":124634137,"5":1886057615,"6":-379345611,"7":-1637575261,"8":249268274,"9":2044508324,"10":-522852066,"11":-1747789432,"12":162941995,"13":2125561021,"14":-407360249,"15":-1866523247,"16":498536548,"17":1789927666,"18":-205950648,"19":-2067906082,"20":450548861,"21":1843258603,"22":-187386543,"23":-2083289657,"24":325883990,"25":1684777152,"26":-43845254,"27":-1973040660,"28":335633487,"29":1661365465,"30":-99664541,"31":-1928851979,"32":997073096,"33":1281953886,"34":-715111964,"35":-1570279054,"36":1006888145,"37":1258607687,"38":-770865667,"39":-1526024853,"40":901097722,"41":1119000684,"42":-608450090,"43":-1396901568,"44":853044451,"45":1172266101,"46":-589951537,"47":-1412350631,"48":651767980,"49":1373503546,"50":-925412992,"51":-1076862698,"52":565507253,"53":1454621731,"54":-809855591,"55":-1195530993,"56":671266974,"57":1594198024,"58":-972236366,"59":-1324619484,"60":795835527,"61":1483230225,"62":-1050600021,"63":-1234817731,"64":1994146192,"65":31158534,"66":-1731059524,"67":-271249366,"68":1907459465,"69":112637215,"70":-1614814043,"71":-390540237,"72":2013776290,"73":251722036,"74":-1777751922,"75":-519137256,"76":2137656763,"77":141376813,"78":-1855689577,"79":-429695999,"80":1802195444,"81":476864866,"82":-2056965928,"83":-228458418,"84":1812370925,"85":453092731,"86":-2113342271,"87":-183516073,"88":1706088902,"89":314042704,"90":-1950435094,"91":-54949764,"92":1658658271,"93":366619977,"94":-1932296973,"95":-69972891,"96":1303535960,"97":984961486,"98":-1547960204,"99":-725929758,"100":1256170817,"101":1037604311,"102":-1529756563,"103":-740887301,"104":1131014506,"105":879679996,"106":-1385723834,"107":-631195440,"108":1141124467,"109":855842277,"110":-1442165665,"111":-586318647,"112":1342533948,"113":654459306,"114":-1106571248,"115":-921952122,"116":1466479909,"117":544179635,"118":-1184443383,"119":-832445281,"120":1591671054,"121":702138776,"122":-1328506846,"123":-942167884,"124":1504918807,"125":783551873,"126":-1212326853,"127":-1061524307,"128":-306674912,"129":-1698712650,"130":62317068,"131":1957810842,"132":-355121351,"133":-1647151185,"134":81470997,"135":1943803523,"136":-480048366,"137":-1805370492,"138":225274430,"139":2053790376,"140":-468791541,"141":-1828061283,"142":167816743,"143":2097651377,"144":-267414716,"145":-2029476910,"146":503444072,"147":1762050814,"148":-144550051,"149":-2140837941,"150":426522225,"151":1852507879,"152":-19653770,"153":-1982649376,"154":282753626,"155":1742555852,"156":-105259153,"157":-1900089351,"158":397917763,"159":1622183637,"160":-690576408,"161":-1580100738,"162":953729732,"163":1340076626,"164":-776247311,"165":-1497606297,"166":1068828381,"167":1219638859,"168":-670225446,"169":-1358292148,"170":906185462,"171":1090812512,"172":-547295293,"173":-1469587627,"174":829329135,"175":1181335161,"176":-882789492,"177":-1134132454,"178":628085408,"179":1382605366,"180":-871598187,"181":-1156888829,"182":570562233,"183":1426400815,"184":-977650754,"185":-1296233688,"186":733239954,"187":1555261956,"188":-1026031705,"189":-1244606671,"190":752459403,"191":1541320221,"192":-1687895376,"193":-328994266,"194":1969922972,"195":40735498,"196":-1677130071,"197":-351390145,"198":1913087877,"199":83908371,"200":-1782625662,"201":-491226604,"202":2075208622,"203":213261112,"204":-1831694693,"205":-438977011,"206":2094854071,"207":198958881,"208":-2032938284,"209":-237706686,"210":1759359992,"211":534414190,"212":-2118248755,"213":-155638181,"214":1873836001,"215":414664567,"216":-2012718362,"217":-15766928,"218":1711684554,"219":285281116,"220":-1889165569,"221":-127750551,"222":1634467795,"223":376229701,"224":-1609899400,"225":-686959890,"226":1308918612,"227":956543938,"228":-1486412191,"229":-799009033,"230":1231636301,"231":1047427035,"232":-1362007478,"233":-640263460,"234":1088359270,"235":936918000,"236":-1447252397,"237":-558129467,"238":1202900863,"239":817233897,"240":-1111625188,"241":-893730166,"242":1404277552,"243":615818150,"244":-1160759803,"245":-841546093,"246":1423857449,"247":601450431,"248":-1285129682,"249":-1000256840,"250":1567103746,"251":711928724,"252":-1274298825,"253":-1022587231,"254":1510334235,"255":755167117};

最后测试运行结果如下：

13824055147

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wpzyan123

支持开源~！感谢分享

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111111111111111111111111

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