【JS 逆向百例】当乐网登录接口参数逆向

文章目录

- 声明
- 逆向目标
- 逆向过程
- - 抓包分析
  - 参数逆向
- 完整代码
- - d_cn_encrypt.js
  - d_cn_login.py

声明

本文章中所有内容仅供学习交流，严禁用于商业用途和非法用途，否则由此产生的一切后果均与作者无关，若有侵权，请联系我立即删除！

逆向目标

目标：当乐网登录
主页：https://oauth.d.cn/auth/goLogin.html
接口：https://oauth.d.cn/auth/login

逆向参数：

Query String Parameters：

pwd:26fac08e6b524bef29c09479fdefe604ea7b2c4d7285a3e01f0969a9230a4e9af1b8ed23ca840978f61bf0e7850c72ece07dc95ef3f7484a5086284f825bd420da19ecd8b832877b113f21181bc9a22cc795c92f8d4c8dc6ca8b21309c674220e365ab67475a299277b0aa7842e09517c7ab3c5e693e51c4d9d9935f6ec430cb

逆向过程

抓包分析

随便输入一个账号密码，点击登陆，抓包定位到登录接口为 https://oauth.d.cn/auth/login ，GET 请求，Query String Parameters 里，密码 pwd 被加密处理了。

参数逆向

全局搜索 pwd 关键字，在首页就可以找到一段 submitData 提交数据的函数，埋下断点进行调试，可以发现明文密码是经过 RSA 加密后得到的：

跟进这个 rsa 加密函数：

  var rsa = function (arg) {setMaxDigits(130);var PublicExponent = "10001";var modulus = "be44aec4d73408f6b60e6fe9e3dc55d0e1dc53a1e171e071b547e2e8e0b7da01c56e8c9bcf0521568eb111adccef4e40124b76e33e7ad75607c227af8f8e0b759c30ef283be8ab17a84b19a051df5f94c07e6e7be5f77866376322aac944f45f3ab532bb6efc70c1efa524d821d16cafb580c5a901f0defddea3692a4e68e6cd";var key = new RSAKeyPair(PublicExponent, "", modulus);return encryptedString(key, arg);};

setMaxDigits 这个函数在 BigInt.js 里面可以找到，而 RSAKeyPair 和 encryptedString 都可以在 RSA.js 里面找到，由于这两个 JS 都比较复杂，所以直接将两个 JS 源码全部复制下来直接调用即可。

在本地调试的过程中发现 RSA.js 里面会提示 BarrettMu 未定义，经过调试可以发现这个函数在 Barrett.js 里面，所以直接把 Barrett.js 也全部复制下来即可。

完整代码

完整代码可在 GitHub 下载：https://github.com/kuaidaili/crawler/tree/main/oauth_d_cn

d_cn_encrypt.js

var RSAAPP = {};RSAAPP.NoPadding = "NoPadding";
RSAAPP.PKCS1Padding = "PKCS1Padding";
RSAAPP.RawEncoding = "RawEncoding";
RSAAPP.NumericEncoding = "NumericEncoding"function RSAKeyPair(encryptionExponent, decryptionExponent, modulus, keylen) {this.e = biFromHex(encryptionExponent);this.d = biFromHex(decryptionExponent);this.m = biFromHex(modulus);if (typeof (keylen) != 'number') {this.chunkSize = 2 * biHighIndex(this.m);} else {this.chunkSize = keylen / 8;}this.radix = 16;this.barrett = new BarrettMu(this.m);
}function encryptedString(key, s, pad, encoding) {var a = new Array();var sl = s.length;var i, j, k;var padtype;var encodingtype;var rpad;var al;var result = "";var block;var crypt;var text;if (typeof (pad) == 'string') {if (pad == RSAAPP.NoPadding) {padtype = 1;} else if (pad == RSAAPP.PKCS1Padding) {padtype = 2;} else {padtype = 0;}} else {padtype = 0;}if (typeof (encoding) == 'string' && encoding == RSAAPP.RawEncoding) {encodingtype = 1;} else {encodingtype = 0;}if (padtype == 1) {if (sl > key.chunkSize) {sl = key.chunkSize;}} else if (padtype == 2) {if (sl > (key.chunkSize - 11)) {sl = key.chunkSize - 11;}}i = 0;if (padtype == 2) {j = sl - 1;} else {j = key.chunkSize - 1;}while (i < sl) {if (padtype) {a[j] = s.charCodeAt(i);} else {a[i] = s.charCodeAt(i);}i++;j--;}if (padtype == 1) {i = 0;}j = key.chunkSize - (sl % key.chunkSize);while (j > 0) {if (padtype == 2) {rpad = Math.floor(Math.random() * 256);while (!rpad) {rpad = Math.floor(Math.random() * 256);}a[i] = rpad;} else {a[i] = 0;}i++;j--;}if (padtype == 2) {a[sl] = 0;a[key.chunkSize - 2] = 2;a[key.chunkSize - 1] = 0;}al = a.length;for (i = 0; i < al; i += key.chunkSize) {block = new BigInt();j = 0;for (k = i; k < (i + key.chunkSize); ++j) {block.digits[j] = a[k++];block.digits[j] += a[k++] << 8;}crypt = key.barrett.powMod(block, key.e);if (encodingtype == 1) {text = biToBytes(crypt);} else {text = (key.radix == 16) ? biToHex(crypt) : biToString(crypt, key.radix);}result += text;}return result;
}function decryptedString(key, c) {var blocks = c.split(" ");var b;var i, j;var bi;var result = "";for (i = 0; i < blocks.length; ++i) {if (key.radix == 16) {bi = biFromHex(blocks[i]);} else {bi = biFromString(blocks[i], key.radix);}b = key.barrett.powMod(bi, key.d);for (j = 0; j <= biHighIndex(b); ++j) {result += String.fromCharCode(b.digits[j] & 255, b.digits[j] >> 8);}}if (result.charCodeAt(result.length - 1) == 0) {result = result.substring(0, result.length - 1);}return (result);
}var biRadixBase = 2;
var biRadixBits = 16;
var bitsPerDigit = biRadixBits;
var biRadix = 1 << 16; // = 2^16 = 65536
var biHalfRadix = biRadix >>> 1;
var biRadixSquared = biRadix * biRadix;
var maxDigitVal = biRadix - 1;
var maxInteger = 9999999999999998;
var maxDigits;
var ZERO_ARRAY;
var bigZero, bigOne;function setMaxDigits(value) {maxDigits = value;ZERO_ARRAY = new Array(maxDigits);for (var iza = 0; iza < ZERO_ARRAY.length; iza++) ZERO_ARRAY[iza] = 0;bigZero = new BigInt();bigOne = new BigInt();bigOne.digits[0] = 1;
}setMaxDigits(20);var dpl10 = 15;
var lr10 = biFromNumber(1000000000000000);function BigInt(flag) {if (typeof flag == "boolean" && flag == true) {this.digits = null;} else {this.digits = ZERO_ARRAY.slice(0);}this.isNeg = false;
}function biFromDecimal(s) {var isNeg = s.charAt(0) == '-';var i = isNeg ? 1 : 0;var result;// Skip leading zeros.while (i < s.length && s.charAt(i) == '0') ++i;if (i == s.length) {result = new BigInt();} else {var digitCount = s.length - i;var fgl = digitCount % dpl10;if (fgl == 0) fgl = dpl10;result = biFromNumber(Number(s.substr(i, fgl)));i += fgl;while (i < s.length) {result = biAdd(biMultiply(result, lr10), biFromNumber(Number(s.substr(i, dpl10))));i += dpl10;}result.isNeg = isNeg;}return result;
}function biCopy(bi) {var result = new BigInt(true);result.digits = bi.digits.slice(0);result.isNeg = bi.isNeg;return result;
}function biFromNumber(i) {var result = new BigInt();result.isNeg = i < 0;i = Math.abs(i);var j = 0;while (i > 0) {result.digits[j++] = i & maxDigitVal;i >>= biRadixBits;}return result;
}function reverseStr(s) {var result = "";for (var i = s.length - 1; i > -1; --i) {result += s.charAt(i);}return result;
}var hexatrigesimalToChar = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z');function biToString(x, radix) {var b = new BigInt();b.digits[0] = radix;var qr = biDivideModulo(x, b);var result = hexatrigesimalToChar[qr[1].digits[0]];while (biCompare(qr[0], bigZero) == 1) {qr = biDivideModulo(qr[0], b);digit = qr[1].digits[0];result += hexatrigesimalToChar[qr[1].digits[0]];}return (x.isNeg ? "-" : "") + reverseStr(result);
}function biToDecimal(x) {var b = new BigInt();b.digits[0] = 10;var qr = biDivideModulo(x, b);var result = String(qr[1].digits[0]);while (biCompare(qr[0], bigZero) == 1) {qr = biDivideModulo(qr[0], b);result += String(qr[1].digits[0]);}return (x.isNeg ? "-" : "") + reverseStr(result);
}var hexToChar = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f');function digitToHex(n) {var mask = 0xf;var result = "";for (i = 0; i < 4; ++i) {result += hexToChar[n & mask];n >>>= 4;}return reverseStr(result);
}function biToHex(x) {var result = "";var n = biHighIndex(x);for (var i = biHighIndex(x); i > -1; --i) {result += digitToHex(x.digits[i]);}return result;
}function charToHex(c) {var ZERO = 48;var NINE = ZERO + 9;var littleA = 97;var littleZ = littleA + 25;var bigA = 65;var bigZ = 65 + 25;var result;if (c >= ZERO && c <= NINE) {result = c - ZERO;} else if (c >= bigA && c <= bigZ) {result = 10 + c - bigA;} else if (c >= littleA && c <= littleZ) {result = 10 + c - littleA;} else {result = 0;}return result;
}function hexToDigit(s) {var result = 0;var sl = Math.min(s.length, 4);for (var i = 0; i < sl; ++i) {result <<= 4;result |= charToHex(s.charCodeAt(i))}return result;
}function biFromHex(s) {var result = new BigInt();var sl = s.length;for (var i = sl,j = 0; i > 0; i -= 4, ++j) {result.digits[j] = hexToDigit(s.substr(Math.max(i - 4, 0), Math.min(i, 4)));}return result;
}function biFromString(s, radix) {var isNeg = s.charAt(0) == '-';var istop = isNeg ? 1 : 0;var result = new BigInt();var place = new BigInt();place.digits[0] = 1; // radix^0for (var i = s.length - 1; i >= istop; i--) {var c = s.charCodeAt(i);var digit = charToHex(c);var biDigit = biMultiplyDigit(place, digit);result = biAdd(result, biDigit);place = biMultiplyDigit(place, radix);}result.isNeg = isNeg;return result;
}function biToBytes(x)
// Returns a string containing raw bytes.
{var result = "";for (var i = biHighIndex(x); i > -1; --i) {result += digitToBytes(x.digits[i]);}return result;
}function digitToBytes(n)
// Convert two-byte digit to string containing both bytes.
{var c1 = String.fromCharCode(n & 0xff);n >>>= 8;var c2 = String.fromCharCode(n & 0xff);return c2 + c1;
}function biDump(b) {return (b.isNeg ? "-" : "") + b.digits.join(" ");
}function biAdd(x, y) {var result;if (x.isNeg != y.isNeg) {y.isNeg = !y.isNeg;result = biSubtract(x, y);y.isNeg = !y.isNeg;} else {result = new BigInt();var c = 0;var n;for (var i = 0; i < x.digits.length; ++i) {n = x.digits[i] + y.digits[i] + c;result.digits[i] = n & 0xffff;c = Number(n >= biRadix);}result.isNeg = x.isNeg;}return result;
}function biSubtract(x, y) {var result;if (x.isNeg != y.isNeg) {y.isNeg = !y.isNeg;result = biAdd(x, y);y.isNeg = !y.isNeg;} else {result = new BigInt();var n, c;c = 0;for (var i = 0; i < x.digits.length; ++i) {n = x.digits[i] - y.digits[i] + c;result.digits[i] = n & 0xffff;// Stupid non-conforming modulus operation.if (result.digits[i] < 0) result.digits[i] += biRadix;c = 0 - Number(n < 0);}// Fix up the negative sign, if any.if (c == -1) {c = 0;for (var i = 0; i < x.digits.length; ++i) {n = 0 - result.digits[i] + c;result.digits[i] = n & 0xffff;// Stupid non-conforming modulus operation.if (result.digits[i] < 0) result.digits[i] += biRadix;c = 0 - Number(n < 0);}// Result is opposite sign of arguments.result.isNeg = !x.isNeg;} else {// Result is same sign.result.isNeg = x.isNeg;}}return result;
}function biHighIndex(x) {var result = x.digits.length - 1;while (result > 0 && x.digits[result] == 0) --result;return result;
}function biNumBits(x) {var n = biHighIndex(x);var d = x.digits[n];var m = (n + 1) * bitsPerDigit;var result;for (result = m; result > m - bitsPerDigit; --result) {if ((d & 0x8000) != 0) break;d <<= 1;}return result;
}function biMultiply(x, y) {var result = new BigInt();var c;var n = biHighIndex(x);var t = biHighIndex(y);var u, uv, k;for (var i = 0; i <= t; ++i) {c = 0;k = i;for (j = 0; j <= n; ++j, ++k) {uv = result.digits[k] + x.digits[j] * y.digits[i] + c;result.digits[k] = uv & maxDigitVal;c = uv >>> biRadixBits;}result.digits[i + n + 1] = c;}// Someone give me a logical xor, please.result.isNeg = x.isNeg != y.isNeg;return result;
}function biMultiplyDigit(x, y) {var n, c, uv;result = new BigInt();n = biHighIndex(x);c = 0;for (var j = 0; j <= n; ++j) {uv = result.digits[j] + x.digits[j] * y + c;result.digits[j] = uv & maxDigitVal;c = uv >>> biRadixBits;}result.digits[1 + n] = c;return result;
}function arrayCopy(src, srcStart, dest, destStart, n) {var m = Math.min(srcStart + n, src.length);for (var i = srcStart,j = destStart; i < m; ++i, ++j) {dest[j] = src[i];}
}var highBitMasks = new Array(0x0000, 0x8000, 0xC000, 0xE000, 0xF000, 0xF800, 0xFC00, 0xFE00, 0xFF00, 0xFF80, 0xFFC0, 0xFFE0, 0xFFF0, 0xFFF8, 0xFFFC, 0xFFFE, 0xFFFF);function biShiftLeft(x, n) {var digitCount = Math.floor(n / bitsPerDigit);var result = new BigInt();arrayCopy(x.digits, 0, result.digits, digitCount, result.digits.length - digitCount);var bits = n % bitsPerDigit;var rightBits = bitsPerDigit - bits;for (var i = result.digits.length - 1,i1 = i - 1; i > 0; --i, --i1) {result.digits[i] = ((result.digits[i] << bits) & maxDigitVal) | ((result.digits[i1] & highBitMasks[bits]) >>> (rightBits));}result.digits[0] = ((result.digits[i] << bits) & maxDigitVal);result.isNeg = x.isNeg;return result;
}var lowBitMasks = new Array(0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF);function biShiftRight(x, n) {var digitCount = Math.floor(n / bitsPerDigit);var result = new BigInt();arrayCopy(x.digits, digitCount, result.digits, 0, x.digits.length - digitCount);var bits = n % bitsPerDigit;var leftBits = bitsPerDigit - bits;for (var i = 0,i1 = i + 1; i < result.digits.length - 1; ++i, ++i1) {result.digits[i] = (result.digits[i] >>> bits) | ((result.digits[i1] & lowBitMasks[bits]) << leftBits);}result.digits[result.digits.length - 1] >>>= bits;result.isNeg = x.isNeg;return result;
}function biMultiplyByRadixPower(x, n) {var result = new BigInt();arrayCopy(x.digits, 0, result.digits, n, result.digits.length - n);return result;
}function biDivideByRadixPower(x, n) {var result = new BigInt();arrayCopy(x.digits, n, result.digits, 0, result.digits.length - n);return result;
}function biModuloByRadixPower(x, n) {var result = new BigInt();arrayCopy(x.digits, 0, result.digits, 0, n);return result;
}function biCompare(x, y) {if (x.isNeg != y.isNeg) {return 1 - 2 * Number(x.isNeg);}for (var i = x.digits.length - 1; i >= 0; --i) {if (x.digits[i] != y.digits[i]) {if (x.isNeg) {return 1 - 2 * Number(x.digits[i] > y.digits[i]);} else {return 1 - 2 * Number(x.digits[i] < y.digits[i]);}}}return 0;
}function biDivideModulo(x, y) {var nb = biNumBits(x);var tb = biNumBits(y);var origYIsNeg = y.isNeg;var q, r;if (nb < tb) {// |x| < |y|if (x.isNeg) {q = biCopy(bigOne);q.isNeg = !y.isNeg;x.isNeg = false;y.isNeg = false;r = biSubtract(y, x);// Restore signs, 'cause they're references.x.isNeg = true;y.isNeg = origYIsNeg;} else {q = new BigInt();r = biCopy(x);}return new Array(q, r);}q = new BigInt();r = x;// Normalize Y.var t = Math.ceil(tb / bitsPerDigit) - 1;var lambda = 0;while (y.digits[t] < biHalfRadix) {y = biShiftLeft(y, 1);++lambda;++tb;t = Math.ceil(tb / bitsPerDigit) - 1;}// Shift r over to keep the quotient constant. We'll shift the// remainder back at the end.r = biShiftLeft(r, lambda);nb += lambda; // Update the bit count for x.var n = Math.ceil(nb / bitsPerDigit) - 1;var b = biMultiplyByRadixPower(y, n - t);while (biCompare(r, b) != -1) {++q.digits[n - t];r = biSubtract(r, b);}for (var i = n; i > t; --i) {var ri = (i >= r.digits.length) ? 0 : r.digits[i];var ri1 = (i - 1 >= r.digits.length) ? 0 : r.digits[i - 1];var ri2 = (i - 2 >= r.digits.length) ? 0 : r.digits[i - 2];var yt = (t >= y.digits.length) ? 0 : y.digits[t];var yt1 = (t - 1 >= y.digits.length) ? 0 : y.digits[t - 1];if (ri == yt) {q.digits[i - t - 1] = maxDigitVal;} else {q.digits[i - t - 1] = Math.floor((ri * biRadix + ri1) / yt);}var c1 = q.digits[i - t - 1] * ((yt * biRadix) + yt1);var c2 = (ri * biRadixSquared) + ((ri1 * biRadix) + ri2);while (c1 > c2) {--q.digits[i - t - 1];c1 = q.digits[i - t - 1] * ((yt * biRadix) | yt1);c2 = (ri * biRadix * biRadix) + ((ri1 * biRadix) + ri2);}b = biMultiplyByRadixPower(y, i - t - 1);r = biSubtract(r, biMultiplyDigit(b, q.digits[i - t - 1]));if (r.isNeg) {r = biAdd(r, b);--q.digits[i - t - 1];}}r = biShiftRight(r, lambda);// Fiddle with the signs and stuff to make sure that 0 <= r < y.q.isNeg = x.isNeg != origYIsNeg;if (x.isNeg) {if (origYIsNeg) {q = biAdd(q, bigOne);} else {q = biSubtract(q, bigOne);}y = biShiftRight(y, lambda);r = biSubtract(y, r);}// Check for the unbelievably stupid degenerate case of r == -0.if (r.digits[0] == 0 && biHighIndex(r) == 0) r.isNeg = false;return new Array(q, r);
}function biDivide(x, y) {return biDivideModulo(x, y)[0];
}function biModulo(x, y) {return biDivideModulo(x, y)[1];
}function biMultiplyMod(x, y, m) {return biModulo(biMultiply(x, y), m);
}function biPow(x, y) {var result = bigOne;var a = x;while (true) {if ((y & 1) != 0) result = biMultiply(result, a);y >>= 1;if (y == 0) break;a = biMultiply(a, a);}return result;
}function biPowMod(x, y, m) {var result = bigOne;var a = x;var k = y;while (true) {if ((k.digits[0] & 1) != 0) result = biMultiplyMod(result, a, m);k = biShiftRight(k, 1);if (k.digits[0] == 0 && biHighIndex(k) == 0) break;a = biMultiplyMod(a, a, m);}return result;
}function BarrettMu(m) {this.modulus = biCopy(m);this.k = biHighIndex(this.modulus) + 1;var b2k = new BigInt();b2k.digits[2 * this.k] = 1; // b2k = b^(2k)this.mu = biDivide(b2k, this.modulus);this.bkplus1 = new BigInt();this.bkplus1.digits[this.k + 1] = 1; // bkplus1 = b^(k+1)this.modulo = BarrettMu_modulo;this.multiplyMod = BarrettMu_multiplyMod;this.powMod = BarrettMu_powMod;
}function BarrettMu_modulo(x) {var q1 = biDivideByRadixPower(x, this.k - 1);var q2 = biMultiply(q1, this.mu);var q3 = biDivideByRadixPower(q2, this.k + 1);var r1 = biModuloByRadixPower(x, this.k + 1);var r2term = biMultiply(q3, this.modulus);var r2 = biModuloByRadixPower(r2term, this.k + 1);var r = biSubtract(r1, r2);if (r.isNeg) {r = biAdd(r, this.bkplus1);}var rgtem = biCompare(r, this.modulus) >= 0;while (rgtem) {r = biSubtract(r, this.modulus);rgtem = biCompare(r, this.modulus) >= 0;}return r;
}function BarrettMu_multiplyMod(x, y) {/*x = this.modulo(x);y = this.modulo(y);*/var xy = biMultiply(x, y);return this.modulo(xy);
}function BarrettMu_powMod(x, y) {var result = new BigInt();result.digits[0] = 1;var a = x;var k = y;while (true) {if ((k.digits[0] & 1) != 0) result = this.multiplyMod(result, a);k = biShiftRight(k, 1);if (k.digits[0] == 0 && biHighIndex(k) == 0) break;a = this.multiplyMod(a, a);}return result;
}function getEncryptedPassword (arg) {setMaxDigits(130);var PublicExponent = "10001";var modulus = "be44aec4d73408f6b60e6fe9e3dc55d0e1dc53a1e171e071b547e2e8e0b7da01c56e8c9bcf0521568eb111adccef4e40124b76e33e7ad75607c227af8f8e0b759c30ef283be8ab17a84b19a051df5f94c07e6e7be5f77866376322aac944f45f3ab532bb6efc70c1efa524d821d16cafb580c5a901f0defddea3692a4e68e6cd";var key = new RSAKeyPair(PublicExponent, "", modulus);return encryptedString(key, arg);
}// 测试样例
// console.log(getEncryptedPassword("2543534534"))

d_cn_login.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-import execjs
import requestsdef get_encrypted_password(password):with open('d_cn_encrypt.js', 'r', encoding='utf-8') as f:weibo_js = f.read()encrypted_password = execjs.compile(weibo_js).call('getEncryptedPassword', password)return encrypted_passworddef login(encrypted_password, username):login_url = 'https://oauth.d.cn/auth/login'headers = {'Host': 'oauth.d.cn','Referer': 'https://oauth.d.cn/auth/goLogin.html','sec-ch-ua': '" Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"','User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'}params = {'display': 'web','name': username,'pwd': encrypted_password,'to': 'https%3A%2F%2Fwww.d.cn%2F'}response = requests.get(url=login_url, params=params, headers=headers).json()print(response)def main():username = input('请输入登录账号: ')password = input('请输入登录密码: ')encrypted_password = get_encrypted_password(password)login(encrypted_password, username)if __name__ == '__main__':main()