From 8d8b4d1526690839eec1c13e3617c843d8a2d780 Mon Sep 17 00:00:00 2001
From: oatmealine <krakaka088@gmail.com>
Date: Sun, 26 Jan 2020 23:26:12 +0300
Subject: [PATCH] download level added

---
 src/downloadGJLevel22.ts | 38 ++++++++++++++++++++++++++++++++++++++
 src/hash.ts              | 17 +++++++++++++++++
 src/index.ts             |  5 ++++-
 src/xor.ts               | 11 +++++++++++
 4 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 src/downloadGJLevel22.ts
 create mode 100644 src/xor.ts

diff --git a/src/downloadGJLevel22.ts b/src/downloadGJLevel22.ts
new file mode 100644
index 0000000..4cfbcae
--- /dev/null
+++ b/src/downloadGJLevel22.ts
@@ -0,0 +1,38 @@
+import * as xor from './xor';
+import * as hashes from './hash';
+
+module.exports = (app) : void => {
+	app.post('/' + app.get('config').addtopath + 'database/downloadGJLevel22.php', async (req, res) => {
+		let level = await app.get('db').collection('levels').findOneAndUpdate({
+			id: Number(req.body.levelID)
+		}, {
+			$inc: {downloads: 1}
+		});
+
+		if (level.value == null) return res.status(200).send('-1');
+
+		level = level.value;
+
+		let gameVer = Number(req.body.gameVersion || 1);
+		let xor_pw = level.password;
+
+		let description = level.description;
+
+		if (gameVer > 19) {
+			if (level.password != 0)
+				xor_pw = xor.encode(String(level.password), '26364');
+		} else {
+			description = Buffer.from(description, 'base64').toString('utf8');
+		}
+
+		let response = `1:${level.id}:2:${level.name}:3:${description}:4:${level.level_data}:5:${1 /* level version, placeholder*/}:6:${level.user_id}:8:10:9:${level.difficulty}:10:${level.downloads}:11:1:12:${level.audio_track}:13:${level.game_version}:14:${level.likes}:17:${Number(level.difficulty >= 60)}:43:${Math.max((level.difficulty-60)/10, 0)}:25:${Number(level.auto)}:18:${level.stars}:19:${Number(level.featured)}:42:${Number(level.epic)}:45:${level.objects}:15:${level.length}:30:${level.original}:31:1:28:${0 /* upload date */}:29:${0 /* update date*/}:35:${level.song_id}:36:${level.extra_data}:37:${level.coins}:38:${Number(level.rated_coins)}:39:${level.requested_stars}:46:1:47:2:48:1:40:${Number(level.ldm)}:27:${xor_pw}`;
+
+		response += `#${hashes.hashLevel(level.level_data)}#`;
+		level.demon = level.difficulty >= 60;
+		let extraData = ['user_id', 'stars', 'demon', 'id', 'rated_coins', 'featured'].map(key => Number(level[key])).join(',');
+		extraData += `,${level.password},${0 /* featured id */}`;
+		response += `${hashes.hashSolo2(extraData)}#${extraData}`;
+
+		res.status(200).send(response);
+	});
+};
\ No newline at end of file
diff --git a/src/hash.ts b/src/hash.ts
index c2d4efb..1ed53bb 100644
--- a/src/hash.ts
+++ b/src/hash.ts
@@ -6,4 +6,21 @@ export function hashLevels(levels : any[]) : string {
 	let shasum = crypto.createHash('sha1');
 	shasum.update(c + 'xI25fpAapCQg');
 	return shasum.digest('hex');
+}
+
+export function hashLevel(level : string) : string {
+	let data = '';
+	let l = Math.floor(level.length / 40);
+	for (let i = 0; i < 40; i++)
+		data += level[i * l];
+	
+	let shasum = crypto.createHash('sha1');
+	shasum.update(data + 'xI25fpAapCQg');
+	return shasum.digest('hex');
+}
+
+export function hashSolo2(data : string) : string {
+	let shasum = crypto.createHash('sha1');
+	shasum.update(data + 'xI25fpAapCQg');
+	return shasum.digest('hex');
 }
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index 991dceb..51245ed 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -27,8 +27,11 @@ dbClient.connect((err) => {
 
 	require('./getGJLevels21')(app);
 	require('./uploadGJLevel21')(app);
+	require('./downloadGJLevel22')(app);
 
 	app.get('*', (req, res) => res.status(404).send('wrong page dumbass'));
 
-	app.listen(config.port);
+	app.listen(config.port, () => {
+		console.log(`expressjs server launched on port ${config.port}, gdps should now function properly`);
+	});
 });
\ No newline at end of file
diff --git a/src/xor.ts b/src/xor.ts
new file mode 100644
index 0000000..70087fa
--- /dev/null
+++ b/src/xor.ts
@@ -0,0 +1,11 @@
+export function encode(str : string, key : string) : string {
+	return Buffer.from(Array.from(
+		str,
+		(c : string, i) => String.fromCharCode(c.charCodeAt(0) ^ key.charCodeAt(i % key.length))
+	).join('')).toString('base64');
+}
+
+export function decode(str : string, key : string) : string {
+	str = Buffer.from(str, 'base64').toString('utf8');
+	return Array(str.length).fill(0).map((_, i) => String.fromCharCode(str.charCodeAt(i) ^ key.charCodeAt(i % key.length))).join('');
+}
\ No newline at end of file