声明：本文只作学习研究，禁止用于非法用途，否则后果自负，如有侵权，请告知删除，谢谢！
项目场景：
最近看了中国新说唱，Giao哥在节目中出了一首很火的歌：画画的baby，也是搏得了厂牌主理人Gai的一笑，随后这首歌便出现了在网易云的热歌中，便去网易云上听了听，突然心血来潮，我好像还没有爬过网易云的歌，heihei，开撸（耳机里听着画画的baby~）。
解决方案：
1.直接搜歌名画画的baby，点一个进去，点击播放，看看哪个请求是加载了歌曲链接。
2.可以看到有俩个加密参数params和encSecKey，老方法ctrl+shift+f搜一下params吧，然后点一个进去，继续搜params。
3.很轻松，一搜就出来两个，主要生成方式就是下面的代码，四个参数，bqN0x(["流泪", "强"])和 bqN0x(["爱心", "女孩", "惊恐", "大笑"])看起来像两个常量，到时候直接扣他的值就行，废话不多说，直接下断点调试下。
var bVZ8R = window.asrsea(JSON.stringify(i0x), bqN0x(["流泪", "强"]), bqN0x(Wx5C.md), bqN0x(["爱心", "女孩", "惊恐", "大笑"]));
4.这里有个小问题嗷，就是这个window.asrsea会执行多次，我们要找对那个对的，怎么找呢，就是我们之前得到的有参数的那个连接 v1?csrf_token= 这个，每次执行后看看xhr那里的请求是不是这个，如果是就可以扣他加密参数了。
经过多次调试，果然bqN0x(["流泪", "强"])和 bqN0x(["爱心", "女孩", "惊恐", "大笑"])是常量，而且发现bqN0x(Wx5C.md)也是常量，具体的值给你们扣下来了，那么还有一个参数JSON.stringify(i0x)，可以从上面的图看出这个ids，就是我们请求的歌曲id（music.163.com/#/song?id=1…
bqN0x(["流泪", "强"]) = '010001'
bqN0x(Wx5C.md) = '00e0b509f6259df8642dbc35662901477df22677ec152b5ff68ace615bb7b725152b3ab17a876aea8a5aa76d2e417629ec4ee341f56135fccf695280104e0312ecbda92557c93870114af6c9d05c4f7f0c3685b7a46bee255932575cce10b424d813cfe4875d3e82047b97ddef52741d546b8e289dc6935b3ece0462db0a22b8e7'
bqN0x(["爱心", "女孩", "惊恐", "大笑"]) = '0CoJUm6Qyw8W8jud'
JSON.stringify(i0x)也帮你们扣下来了。
JSON.stringify(i0x) = {"ids":"[1474342935]","level":"standard","encodeType":"aac","csrf_token":""}
5.那么到此为，window.asrsea的四个参数我们都知道了，接下来就要扣他的方法，打个断点进去瞅瞅他的方法，就是下面的代码块，。
function d(d, e, f, g) {
var h = {}
, i = a(16);
return h.encText = b(d, g),
h.encText = b(h.encText, i),
h.encSecKey = c(i, e, f),
h
}
6.也是老办法了，把这个方法用到的函数都给他扣下来，知道你们懒，我帮你们扣好了
var CryptoJS = require('crypto-js');
function RSAKeyPair(a, b, c) {
this.e = biFromHex(a),
this.d = biFromHex(b),
this.m = biFromHex(c),
this.chunkSize = 2 * biHighIndex(this.m),
this.radix = 16,
this.barrett = new BarrettMu(this.m)
}
function twoDigit(a) {
return (10 > a ? "0" : "") + String(a)
}
function encryptedString(a, b) {
for (var f, g, h, i, j, k, l, c = new Array, d = b.length, e = 0; d > e; )
c[e] = b.charCodeAt(e),
e++;
for (; 0 != c.length % a.chunkSize; )
c[e++] = 0;
for (f = c.length,
g = "",
e = 0; f > e; e += a.chunkSize) {
for (j = new BigInt,
h = 0,
i = e; i < e + a.chunkSize; ++h)
j.digits[h] = c[i++],
j.digits[h] += c[i++] << 8;
k = a.barrett.powMod(j, a.e),
l = 16 == a.radix ? biToHex(k) : biToString(k, a.radix),
g += l + " "
}
return g.substring(0, g.length - 1)
}
function decryptedString(a, b) {
var e, f, g, h, c = b.split(" "), d = "";
for (e = 0; e < c.length; ++e)
for (h = 16 == a.radix ? biFromHex(c[e]) : biFromString(c[e], a.radix),
g = a.barrett.powMod(h, a.d),
f = 0; f <= biHighIndex(g); ++f)
d += String.fromCharCode(255 & g.digits[f], g.digits[f] >> 8);
return 0 == d.charCodeAt(d.length - 1) && (d = d.substring(0, d.length - 1)),
d
}
function setMaxDigits(a) {
maxDigits = a,
ZERO_ARRAY = new Array(maxDigits);
for (var b = 0; b < ZERO_ARRAY.length; b++)
ZERO_ARRAY[b] = 0;
bigZero = new BigInt,
bigOne = new BigInt,
bigOne.digits[0] = 1
}
function BigInt(a) {
this.digits = "boolean" == typeof a && 1 == a ? null : ZERO_ARRAY.slice(0),
this.isNeg = !1
}
function biFromDecimal(a) {
for (var d, e, f, b = "-" == a.charAt(0), c = b ? 1 : 0; c < a.length && "0" == a.charAt(c); )
++c;
if (c == a.length)
d = new BigInt;
else {
for (e = a.length - c,
f = e % dpl10,
0 == f && (f = dpl10),
d = biFromNumber(Number(a.substr(c, f))),
c += f; c < a.length; )
d = biAdd(biMultiply(d, lr10), biFromNumber(Number(a.substr(c, dpl10)))),
c += dpl10;
d.isNeg = b
}
return d
}
function biCopy(a) {
var b = new BigInt(!0);
return b.digits = a.digits.slice(0),
b.isNeg = a.isNeg,
b
}
function biFromNumber(a) {
var c, b = new BigInt;
for (b.isNeg = 0 > a,
a = Math.abs(a),
c = 0; a > 0; )
b.digits[c++] = a & maxDigitVal,
a >>= biRadixBits;
return b
}
function reverseStr(a) {
var c, b = "";
for (c = a.length - 1; c > -1; --c)
b += a.charAt(c);
return b
}
function biToString(a, b) {
var d, e, c = new BigInt;
for (c.digits[0] = b,
d = biDivideModulo(a, c),
e = hexatrigesimalToChar[d[1].digits[0]]; 1 == biCompare(d[0], bigZero); )
d = biDivideModulo(d[0], c),
digit = d[1].digits[0],
e += hexatrigesimalToChar[d[1].digits[0]];
return (a.isNeg ? "-" : "") + reverseStr(e)
}
function biToDecimal(a) {
var c, d, b = new BigInt;
for (b.digits[0] = 10,
c = biDivideModulo(a, b),
d = String(c[1].digits[0]); 1 == biCompare(c[0], bigZero); )
c = biDivideModulo(c[0], b),
d += String(c[1].digits[0]);
return (a.isNeg ? "-" : "") + reverseStr(d)
}
function digitToHex(a) {
var b = 15
, c = "";
for (i = 0; 4 > i; ++i)
c += hexToChar[a & b],
a >>>= 4;
return reverseStr(c)
}
function biToHex(a) {
var d, b = "";
for (biHighIndex(a),
d = biHighIndex(a); d > -1; --d)
b += digitToHex(a.digits[d]);
return b
}
function charToHex(a) {
var h, b = 48, c = b + 9, d = 97, e = d + 25, f = 65, g = 90;
return h = a >= b && c >= a ? a - b : a >= f && g >= a ? 10 + a - f : a >= d && e >= a ? 10 + a - d : 0
}
function hexToDigit(a) {
var d, b = 0, c = Math.min(a.length, 4);
for (d = 0; c > d; ++d)
b <<= 4,
b |= charToHex(a.charCodeAt(d));
return b
}
function biFromHex(a) {
var d, e, b = new BigInt, c = a.length;
for (d = c,
e = 0; d > 0; d -= 4,
++e)
b.digits[e] = hexToDigit(a.substr(Math.max(d - 4, 0), Math.min(d, 4)));
return b
}
function biFromString(a, b) {
var g, h, i, j, c = "-" == a.charAt(0), d = c ? 1 : 0, e = new BigInt, f = new BigInt;
for (f.digits[0] = 1,
g = a.length - 1; g >= d; g--)
h = a.charCodeAt(g),
i = charToHex(h),
j = biMultiplyDigit(f, i),
e = biAdd(e, j),
f = biMultiplyDigit(f, b);
return e.isNeg = c,
e
}
function biDump(a) {
return (a.isNeg ? "-" : "") + a.digits.join(" ")
}
function biAdd(a, b) {
var c, d, e, f;
if (a.isNeg != b.isNeg)
b.isNeg = !b.isNeg,
c = biSubtract(a, b),
b.isNeg = !b.isNeg;
else {
for (c = new BigInt,
d = 0,
f = 0; f < a.digits.length; ++f)
e = a.digits[f] + b.digits[f] + d,
c.digits[f] = 65535 & e,
d = Number(e >= biRadix);
c.isNeg = a.isNeg
}
return c
}
function biSubtract(a, b) {
var c, d, e, f;
if (a.isNeg != b.isNeg)
b.isNeg = !b.isNeg,
c = biAdd(a, b),
b.isNeg = !b.isNeg;
else {
for (c = new BigInt,
e = 0,
f = 0; f < a.digits.length; ++f)
d = a.digits[f] - b.digits[f] + e,
c.digits[f] = 65535 & d,
c.digits[f] < 0 && (c.digits[f] += biRadix),
e = 0 - Number(0 > d);
if (-1 == e) {
for (e = 0,
f = 0; f < a.digits.length; ++f)
d = 0 - c.digits[f] + e,
c.digits[f] = 65535 & d,
c.digits[f] < 0 && (c.digits[f] += biRadix),
e = 0 - Number(0 > d);
c.isNeg = !a.isNeg
} else
c.isNeg = a.isNeg
}
return c
}
function biHighIndex(a) {
for (var b = a.digits.length - 1; b > 0 && 0 == a.digits[b]; )
--b;
return b
}
function biNumBits(a) {
var e, b = biHighIndex(a), c = a.digits[b], d = (b + 1) * bitsPerDigit;
for (e = d; e > d - bitsPerDigit && 0 == (32768 & c); --e)
c <<= 1;
return e
}
function biMultiply(a, b) {
var d, h, i, k, c = new BigInt, e = biHighIndex(a), f = biHighIndex(b);
for (k = 0; f >= k; ++k) {
for (d = 0,
i = k,
j = 0; e >= j; ++j,
++i)
h = c.digits[i] + a.digits[j] * b.digits[k] + d,
c.digits[i] = h & maxDigitVal,
d = h >>> biRadixBits;
c.digits[k + e + 1] = d
}
return c.isNeg = a.isNeg != b.isNeg,
c
}
function biMultiplyDigit(a, b) {
var c, d, e, f;
for (result = new BigInt,
c = biHighIndex(a),
d = 0,
f = 0; c >= f; ++f)
e = result.digits[f] + a.digits[f] * b + d,
result.digits[f] = e & maxDigitVal,
d = e >>> biRadixBits;
return result.digits[1 + c] = d,
result
}
function arrayCopy(a, b, c, d, e) {
var g, h, f = Math.min(b + e, a.length);
for (g = b,
h = d; f > g; ++g,
++h)
c[h] = a[g]
}
function biShiftLeft(a, b) {
var e, f, g, h, c = Math.floor(b / bitsPerDigit), d = new BigInt;
for (arrayCopy(a.digits, 0, d.digits, c, d.digits.length - c),
e = b % bitsPerDigit,
f = bitsPerDigit - e,
g = d.digits.length - 1,
h = g - 1; g > 0; --g,
--h)
d.digits[g] = d.digits[g] << e & maxDigitVal | (d.digits[h] & highBitMasks[e]) >>> f;
return d.digits[0] = d.digits[g] << e & maxDigitVal,
d.isNeg = a.isNeg,
d
}
function biShiftRight(a, b) {
var e, f, g, h, c = Math.floor(b / bitsPerDigit), d = new BigInt;
for (arrayCopy(a.digits, c, d.digits, 0, a.digits.length - c),
e = b % bitsPerDigit,
f = bitsPerDigit - e,
g = 0,
h = g + 1; g < d.digits.length - 1; ++g,
++h)
d.digits[g] = d.digits[g] >>> e | (d.digits[h] & lowBitMasks[e]) << f;
return d.digits[d.digits.length - 1] >>>= e,
d.isNeg = a.isNeg,
d
}
function biMultiplyByRadixPower(a, b) {
var c = new BigInt;
return arrayCopy(a.digits, 0, c.digits, b, c.digits.length - b),
c
}
function biDivideByRadixPower(a, b) {
var c = new BigInt;
return arrayCopy(a.digits, b, c.digits, 0, c.digits.length - b),
c
}
function biModuloByRadixPower(a, b) {
var c = new BigInt;
return arrayCopy(a.digits, 0, c.digits, 0, b),
c
}
function biCompare(a, b) {
if (a.isNeg != b.isNeg)
return 1 - 2 * Number(a.isNeg);
for (var c = a.digits.length - 1; c >= 0; --c)
if (a.digits[c] != b.digits[c])
return a.isNeg ? 1 - 2 * Number(a.digits[c] > b.digits[c]) : 1 - 2 * Number(a.digits[c] < b.digits[c]);
return 0
}
function biDivideModulo(a, b) {
var f, g, h, i, j, k, l, m, n, o, p, q, r, s, c = biNumBits(a), d = biNumBits(b), e = b.isNeg;
if (d > c)
return a.isNeg ? (f = biCopy(bigOne),
f.isNeg = !b.isNeg,
a.isNeg = !1,
b.isNeg = !1,
g = biSubtract(b, a),
a.isNeg = !0,
b.isNeg = e) : (f = new BigInt,
g = biCopy(a)),
new Array(f,g);
for (f = new BigInt,
g = a,
h = Math.ceil(d / bitsPerDigit) - 1,
i = 0; b.digits[h] < biHalfRadix; )
b = biShiftLeft(b, 1),
++i,
++d,
h = Math.ceil(d / bitsPerDigit) - 1;
for (g = biShiftLeft(g, i),
c += i,
j = Math.ceil(c / bitsPerDigit) - 1,
k = biMultiplyByRadixPower(b, j - h); -1 != biCompare(g, k); )
++f.digits[j - h],
g = biSubtract(g, k);
for (l = j; l > h; --l) {
for (m = l >= g.digits.length ? 0 : g.digits[l],
n = l - 1 >= g.digits.length ? 0 : g.digits[l - 1],
o = l - 2 >= g.digits.length ? 0 : g.digits[l - 2],
p = h >= b.digits.length ? 0 : b.digits[h],
q = h - 1 >= b.digits.length ? 0 : b.digits[h - 1],
f.digits[l - h - 1] = m == p ? maxDigitVal : Math.floor((m * biRadix + n) / p),
r = f.digits[l - h - 1] * (p * biRadix + q),
s = m * biRadixSquared + (n * biRadix + o); r > s; )
--f.digits[l - h - 1],
r = f.digits[l - h - 1] * (p * biRadix | q),
s = m * biRadix * biRadix + (n * biRadix + o);
k = biMultiplyByRadixPower(b, l - h - 1),
g = biSubtract(g, biMultiplyDigit(k, f.digits[l - h - 1])),
g.isNeg && (g = biAdd(g, k),
--f.digits[l - h - 1])
}
return g = biShiftRight(g, i),
f.isNeg = a.isNeg != e,
a.isNeg && (f = e ? biAdd(f, bigOne) : biSubtract(f, bigOne),
b = biShiftRight(b, i),
g = biSubtract(b, g)),
0 == g.digits[0] && 0 == biHighIndex(g) && (g.isNeg = !1),
new Array(f,g)
}
function biDivide(a, b) {
return biDivideModulo(a, b)[0]
}
function biModulo(a, b) {
return biDivideModulo(a, b)[1]
}
function biMultiplyMod(a, b, c) {
return biModulo(biMultiply(a, b), c)
}
function biPow(a, b) {
for (var c = bigOne, d = a; ; ) {
if (0 != (1 & b) && (c = biMultiply(c, d)),
b >>= 1,
0 == b)
break;
d = biMultiply(d, d)
}
return c
}
function biPowMod(a, b, c) {
for (var d = bigOne, e = a, f = b; ; ) {
if (0 != (1 & f.digits[0]) && (d = biMultiplyMod(d, e, c)),
f = biShiftRight(f, 1),
0 == f.digits[0] && 0 == biHighIndex(f))
break;
e = biMultiplyMod(e, e, c)
}
return d
}
function BarrettMu(a) {
this.modulus = biCopy(a),
this.k = biHighIndex(this.modulus) + 1;
var b = new BigInt;
b.digits[2 * this.k] = 1,
this.mu = biDivide(b, this.modulus),
this.bkplus1 = new BigInt,
this.bkplus1.digits[this.k + 1] = 1,
this.modulo = BarrettMu_modulo,
this.multiplyMod = BarrettMu_multiplyMod,
this.powMod = BarrettMu_powMod
}
function BarrettMu_modulo(a) {
var i, b = biDivideByRadixPower(a, this.k - 1), c = biMultiply(b, this.mu), d = biDivideByRadixPower(c, this.k + 1), e = biModuloByRadixPower(a, this.k + 1), f = biMultiply(d, this.modulus), g = biModuloByRadixPower(f, this.k + 1), h = biSubtract(e, g);
for (h.isNeg && (h = biAdd(h, this.bkplus1)),
i = biCompare(h, this.modulus) >= 0; i; )
h = biSubtract(h, this.modulus),
i = biCompare(h, this.modulus) >= 0;
return h
}
function BarrettMu_multiplyMod(a, b) {
var c = biMultiply(a, b);
return this.modulo(c)
}
function BarrettMu_powMod(a, b) {
var d, e, c = new BigInt;
for (c.digits[0] = 1,
d = a,
e = b; ; ) {
if (0 != (1 & e.digits[0]) && (c = this.multiplyMod(c, d)),
e = biShiftRight(e, 1),
0 == e.digits[0] && 0 == biHighIndex(e))
break;
d = this.multiplyMod(d, d)
}
return c
}
var maxDigits, ZERO_ARRAY, bigZero, bigOne, dpl10, lr10, hexatrigesimalToChar, hexToChar, highBitMasks, lowBitMasks, biRadixBase = 2, biRadixBits = 16, bitsPerDigit = biRadixBits, biRadix = 65536, biHalfRadix = biRadix >>> 1, biRadixSquared = biRadix * biRadix, maxDigitVal = biRadix - 1, maxInteger = 9999999999999998;
setMaxDigits(20),
dpl10 = 15,
lr10 = biFromNumber(1e15),
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"),
hexToChar = new Array("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"),
highBitMasks = new Array(0,32768,49152,57344,61440,63488,64512,65024,65280,65408,65472,65504,65520,65528,65532,65534,65535),
lowBitMasks = new Array(0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535);
function a(a) {
var d, e, b = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", c = "";
for (d = 0; a > d; d += 1)
e = Math.random() * b.length,
e = Math.floor(e),
c += b.charAt(e);
return c
}
function b(a, b) {
var c = CryptoJS.enc.Utf8.parse(b)
, d = CryptoJS.enc.Utf8.parse("0102030405060708")
, e = CryptoJS.enc.Utf8.parse(a)
, f = CryptoJS.AES.encrypt(e, c, {
iv: d,
mode: CryptoJS.mode.CBC
});
return f.toString()
}
function c(a, b, c) {
var d, e;
return setMaxDigits(131),
d = new RSAKeyPair(b, "", c),
e = encryptedString(d, a)
}
function d(d, e, f, g) {
var h = {}
, i = a(16);
return h.encText = b(d, g),
h.encText = b(h.encText, i),
h.encSecKey = c(i, e, f),
h
}
function e(a, b, d, e) {
var f = {};
return f.encText = c(a + e, b, d),
f
}
console.log(d('{"ids":"[1474342935]","level":"standard","encodeType":"aac","csrf_token":""}',"010001","00e0b509f6259df8642dbc35662901477df22677ec152b5ff68ace615bb7b725152b3ab17a876aea8a5aa76d2e417629ec4ee341f56135fccf695280104e0312ecbda92557c93870114af6c9d05c4f7f0c3685b7a46bee255932575cce10b424d813cfe4875d3e82047b97ddef52741d546b8e289dc6935b3ece0462db0a22b8e7","0CoJUm6Qyw8W8jud"))
还好，也就500行不到，这个要导一个包crypto-js，就是前端常用的CryptoJS加密库，好了运行一下
{
encText: 'qK68Bxksw4t5nrGsr4F87ll7LRD6fBwVGTwboDLLgCi9Q0ZA4xAaY3ykWYP8gjGms6jJG9/ofip1SEj1NZnl5kFUQJzoHQ7L2UiNFn6aBLyrJrir1N6cR+ERlpsMzaNEMUSE7+dMa0LHiZLZikI+KQ==',
encSecKey: '216b24bc85908b17c74d234394b7680f5fa8271edc76072c6739fee8782157f1a1236c758bfc6d77c65ffe9f58d0b0ad58e412fca6414d2d9bf8650b378397e353f67edfe42f4a4279731b6554c4034fb499af4c0ac90e596cf95aaf1baef56e003dc1660225d12d0c186bc
e0cfb39a71814e543f38555d6556d788071baec3d'
}
7.目测没问题，在用参数去请求下，这里的encText就是参数params，encSecKey就是参数encSecKey，没问题了，请求这个链接（如果失效了并不是不可用，因为链接是动态的过几天就会失效）就能一起下载画画的baby了！
ps:各位觉得有帮助的可以给博主点个赞哦！有问题的直接下方评论秒回！
