105 lines
2.3 KiB
JavaScript
105 lines
2.3 KiB
JavaScript
class RC4 {
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constructor(key) {
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this.key = Buffer.isBuffer(key) ? key : Buffer.from(key, "utf8")
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this.s = new Array(256)
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this.init()
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}
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init() {
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for (let i = 0; i < 256; i++) {
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this.s[i] = i
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}
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let j = 0
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for (let i = 0; i < 256; i++) {
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j = (j + this.s[i] + this.key[i % this.key.length]) % 256
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this.swap(i, j)
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}
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}
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swap(i, j) {
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const temp = this.s[i]
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this.s[i] = this.s[j]
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this.s[j] = temp
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}
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encrypt(data) {
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const input = Buffer.isBuffer(data) ? data : Buffer.from(data, "utf8")
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const output = Buffer.alloc(input.length)
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let i = 0,
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j = 0
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for (let k = 0; k < input.length; k++) {
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i = (i + 1) % 256
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j = (j + this.s[i]) % 256
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this.swap(i, j)
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const keystream = this.s[(this.s[i] + this.s[j]) % 256]
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output[k] = input[k] ^ keystream
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}
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return output
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}
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decrypt(data) {
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return this.encrypt(data)
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}
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}
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class Crypto {
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constructor(config) {
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this.config = config
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this.rc4 = new RC4(config.rc4Key)
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this.nonce = Buffer.from(config.nonce, "utf8")
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}
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encrypt(data) {
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if (!this.config.enabled) return data
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const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data)
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return this.rc4.encrypt(buffer)
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}
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decrypt(data) {
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if (!this.config.enabled) return data
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const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data)
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return this.rc4.decrypt(buffer)
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}
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generateNonce() {
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const timestamp = Date.now()
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const high = Math.floor(timestamp / 0x100000000) >>> 0
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const low = (timestamp >>> 0)
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const random = Math.floor(Math.random() * 0xffffffff) >>> 0
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const nonceBuffer = Buffer.alloc(16)
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nonceBuffer.writeUInt32BE(high, 0)
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nonceBuffer.writeUInt32BE(low, 4)
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nonceBuffer.writeUInt32BE(random, 8)
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nonceBuffer.writeUInt32BE((random ^ low) >>> 0, 12)
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return nonceBuffer
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}
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hash(data) {
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const crypto = require("crypto")
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return crypto.createHash("sha256").update(data).digest()
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}
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xorWithNonce(data) {
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const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data)
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const result = Buffer.alloc(buffer.length)
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for (let i = 0; i < buffer.length; i++) {
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result[i] = buffer[i] ^ this.nonce[i % this.nonce.length]
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}
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return result
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}
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}
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module.exports = { RC4, Crypto }
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