lx-music-desktop/src/renderer/utils/musicSdk/mg/mrc.js
2022-10-29 11:36:35 +08:00

105 lines
3.1 KiB
JavaScript

// const key = 'karakal@123Qcomyidongtiantianhaoting'
const DELTA = 2654435769n
const MIN_LENGTH = 32
// const SPECIAL_CHAR = '0'
const keyArr = [
27303562373562475n,
18014862372307051n,
22799692160172081n,
34058940340699235n,
30962724186095721n,
27303523720101991n,
27303523720101998n,
31244139033526382n,
28992395054481524n,
]
const teaDecrypt = (data, key) => {
const length = data.length
const lengthBitint = BigInt(length)
if (length >= 1) {
// let j = data[data.length - 1];
let j2 = data[0]
let j3 = toLong((6n + (52n / lengthBitint)) * DELTA)
while (true) {
let j4 = j3
if (j4 == 0n) break
let j5 = toLong(3n & toLong(j4 >> 2n))
let j6 = lengthBitint
while (true) {
j6--
if (j6 > 0n) {
let j7 = data[(j6 - 1n)]
let i = j6
j2 = toLong(data[i] - (toLong(toLong(j2 ^ j4) + toLong(j7 ^ key[toLong(toLong(3n & j6) ^ j5)])) ^ toLong(toLong(toLong(j7 >> 5n) ^ toLong(j2 << 2n)) + toLong(toLong(j2 >> 3n) ^ toLong(j7 << 4n)))))
data[i] = j2
} else break
}
let j8 = data[lengthBitint - 1n]
j2 = toLong(data[0n] - toLong(toLong(toLong(key[toLong(toLong(j6 & 3n) ^ j5)] ^ j8) + toLong(j2 ^ j4)) ^ toLong(toLong(toLong(j8 >> 5n) ^ toLong(j2 << 2n)) + toLong(toLong(j2 >> 3n) ^ toLong(j8 << 4n)))))
data[0] = j2
j3 = toLong(j4 - DELTA)
}
}
return data
}
const longArrToString = (data) => {
const arrayList = []
for (const j of data) arrayList.push(longToBytes(j).toString('utf16le'))
return arrayList.join('')
}
// https://stackoverflow.com/a/29132118
const longToBytes = (l) => {
const result = Buffer.alloc(8)
for (let i = 0; i < 8; i++) {
result[i] = parseInt(l & 0xFFn)
l >>= 8n
}
return result
}
const toBigintArray = (data) => {
const length = Math.floor(data.length / 16)
const jArr = Array(length)
for (let i = 0; i < length; i++) {
jArr[i] = toLong(data.substring(i * 16, (i * 16) + 16))
}
return jArr
}
// https://github.com/lyswhut/lx-music-desktop/issues/445#issuecomment-1139338682
const MAX = 9223372036854775807n
const MIN = -9223372036854775808n
const toLong = str => {
const num = typeof str == 'string' ? BigInt('0x' + str) : str
if (num > MAX) return toLong(num - (1n << 64n))
else if (num < MIN) return toLong(num + (1n << 64n))
return num
}
export const decrypt = (data) => {
// console.log(data.length)
// -3551594764563790630
// console.log(toLongArrayFromArr(Buffer.from(key)))
// console.log(teaDecrypt(toBigintArray(data), keyArr))
// console.log(longArrToString(teaDecrypt(toBigintArray(data), keyArr)))
// console.log(toByteArray(teaDecrypt(toBigintArray(data), keyArr)))
return (data == null || data.length < MIN_LENGTH)
? data
: longArrToString(teaDecrypt(toBigintArray(data), keyArr))
}
// console.log(14895149309145760986n - )
// console.log(toLong('14895149309145760986'))
// console.log(decrypt(str))
// console.log(decrypt(str))
// console.log(toByteArray([6048138644744000495n]))
// console.log(toByteArray([16325999628386395n]))
// console.log(toLong(90994076459972177136n))