41 lines
1.2 KiB
JavaScript
41 lines
1.2 KiB
JavaScript
const express = require("express");
|
|
const request = require("request");
|
|
const log = require("./log")
|
|
const app = express();
|
|
const port = 9000;
|
|
const { getDecryptionArray } = require("./decode");
|
|
const { Transform } = require("stream");
|
|
function xorTransform(decryptionArray) {
|
|
let processedBytes = 0;
|
|
return new Transform({
|
|
transform(chunk, encoding, callback) {
|
|
if (processedBytes < decryptionArray.length) {
|
|
let remaining = Math.min(
|
|
decryptionArray.length - processedBytes,
|
|
chunk.length
|
|
);
|
|
for (let i = 0; i < remaining; i++) {
|
|
chunk[i] = chunk[i] ^ decryptionArray[processedBytes + i];
|
|
}
|
|
processedBytes += remaining;
|
|
}
|
|
this.push(chunk);
|
|
callback();
|
|
},
|
|
});
|
|
}
|
|
|
|
app.get("/download", (req, res) => {
|
|
const { url, decodeKey } = req.query;
|
|
log.info(`download url:${url}`);
|
|
log.info(`download decodeKey:${decodeKey}`);
|
|
let xorStream = xorTransform(
|
|
getDecryptionArray(decodeURIComponent(decodeKey))
|
|
);
|
|
request(decodeURIComponent(url)).pipe(xorStream).pipe(res);
|
|
});
|
|
|
|
app.listen(port, () => {
|
|
log.info(`Example app listening at http://localhost:${port}`);
|
|
});
|