From 4996d5cb07bcfc7f906c78d442adc9efa7fd2369 Mon Sep 17 00:00:00 2001
From: Lev Rusanov <30170278+JDM170@users.noreply.github.com>
Date: Sat, 11 Jun 2022 10:46:55 +0700
Subject: [PATCH] added decoder.js

Signed-off-by: Lev Rusanov <30170278+JDM170@users.noreply.github.com>
---
 decoder.js | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 decoder.js

diff --git a/decoder.js b/decoder.js
new file mode 100644
index 0000000..e1d6136
--- /dev/null
+++ b/decoder.js
@@ -0,0 +1,79 @@
+const chalk = require('chalk');
+const yargs = require('yargs/yargs')
+const { hideBin } = require('yargs/helpers')
+const fs = require('fs');
+const path = require('path');
+const ora = require('ora');
+const glob = require("glob");
+const tea = require('mta-tea');
+const crypto = require('crypto');
+
+const error = chalk.bold.red;
+
+const argv = yargs(hideBin(process.argv))
+.usage('Usage: $0 -pass [pass] -res [path]')
+.example('$0 -pass encryptme -res resourceName', 'Encrypt resourceName')
+.options('pass', {
+    alias: 'p',
+    describe: 'Password for the encryption',
+    type: 'string',
+    coerce: arg =>
+    arg && arg.length >= 6 ? arg : undefined
+})
+.options('res', {
+    alias: 'r',
+    describe: 'Resource folder path',
+    type: 'string',
+    coerce: arg =>
+    arg && fs.existsSync(path.resolve(__dirname, arg)) && fs.lstatSync(path.resolve(__dirname, arg)).isDirectory() ? arg : undefined
+})
+.demandOption(['pass'], error("Include password with 6 symbols or more!"))
+.demandOption(['res'], error("Incorrect or no resource folder selected!"))
+.argv;
+
+const blockSize = 12; // encoded block length
+const encodeSize = 3000; // encoded byte count
+const decodeSize = blockSize * encodeSize;
+
+let getDirectories = (src, callback) => {
+    glob(src + '/**/*', callback);
+}
+
+const extensions = ['.colrw', '.colc', '.txdrw', '.txdc', '.dffrw', '.dffc']
+
+let spinner = ora('Getting files list').start();
+getDirectories(argv.res, (err, res) => {
+    if (err) {
+        spinner.fail('Something went wrong!')
+    } else {
+        let files = res.filter(element => fs.lstatSync(path.resolve(__dirname, element)).isFile() && extensions.includes(path.extname(element)))
+        spinner.succeed()
+
+        spinner = ora('Decoding files').start();
+        files.forEach(file => {
+            const newFilePath = file + '.dec';
+
+            // Decoding first $decodeSize bytes from file
+            const key = crypto.createHash('md5').update(argv.pass).digest('hex').substring(0, 16);
+            const data = fs.readFileSync(file);
+            const encodedPart = data.toString().substring(0, decodeSize);
+            let decoded = [];
+            for (let i = 0; i < decodeSize; i += blockSize)
+                decoded.push(tea.decode(encodedPart.substring(i, i + blockSize), key));
+
+            // Checking the file for existence, if the file exists - deleting it
+            try {
+                fs.accessSync(newFilePath);
+                fs.rmSync(newFilePath);
+            } catch (err) {
+                // console.log("access err: " + err);
+            }
+
+            let fd = fs.openSync(newFilePath, 'a+'); // Open file
+            fs.writeSync(fd, Buffer.from(decoded), 0); // Writing decoded part in start of file
+            fs.writeSync(fd, data, decodeSize, data.length - decodeSize); // Writing original part after decoded part
+            fs.closeSync(fd); // Close file
+        });
+        spinner.succeed()
+    }
+})