[Session String Generator] Fix mtcute serialization

grammyjs · Mar 20, 2024 · dc39157 · dc39157
1 parent bb02fcd
commit dc39157
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Showing 3 changed files with 79 additions and 20 deletions.
diff --git a/islands/SessionStringGenerator.tsx b/islands/SessionStringGenerator.tsx
@@ -266,13 +266,12 @@ async function generateSessionString(library: ValidLibrary) {
       const me = await client.getMe();
       sessionString.value = serializeMtcute(
         testMode,
-        dcId,
-        ip,
-        80,
+        { id: dcId, ip, port: 80 },
+        null,
         me.id,
         me.isBot,
         authKey,
-      ); // TODO: tests
+      );
       return;
     }
     case "mtkruto":

diff --git a/lib/session_string.tsx b/lib/session_string.tsx
@@ -238,31 +238,60 @@ export function deserializePyrogram(string: string): CommonSessionStringFormat {
  */
 export function serializeMtcute(
   testMode: boolean,
-  dcId: number,
-  ip: string,
-  port: number,
+  primaryDc: MtcuteDC,
+  mediaDc: MtcuteDC | null,
   userId: number,
   isBot: boolean,
   authKey: Uint8Array,
 ) {
   const writer = new TLRawWriter();
   writer.write(new Uint8Array([0x03])); // version
-  writer.writeInt32(
-    MTCUTE_HAS_SELF_FLAG | (testMode ? MTCUTE_TEST_MODE_FLAG : 0),
-  ); // flags
 
-  writer.write(new Uint8Array([0x01])); // dc_version
-  writer.writeBytes(new Uint8Array([dcId])); // dc_id
-  writer.writeInt32(ip.includes(":") ? MTCUTE_IPV6_FLAG : 0); // dc_flags
-  writer.writeString(ip); // dc_ip
-  writer.writeInt32(port); // dc_port
+  let flags = MTCUTE_HAS_SELF_FLAG;
+  if (mediaDc != null) {
+    flags |= MTCUTE_MEDIA_DC_FLAG;
+  }
+  if (testMode) {
+    flags |= MTCUTE_TEST_MODE_FLAG;
+  }
+  writer.writeInt32(flags); // flags
+
+  writer.writeBytes(serializeMtcuteDc(primaryDc));
+  if (mediaDc != null) {
+    writer.writeBytes(serializeMtcuteDc(mediaDc));
+  }
 
   writer.writeInt64(BigInt(userId)); // user_id
-  writer.write(new Uint8Array([isBot ? 1 : 0])); // is_bot
-  writer.write(authKey); // authKey
+  writer.writeInt32(isBot ? 0x997275b5 : 0xbc799737, false); // is_bot
+  writer.writeBytes(authKey); // authKey
 
   return base64EncodeUrlSafe(writer.buffer);
 }
+function serializeMtcuteDc(dc: MtcuteDC) {
+  const writer = new TLRawWriter();
+  writer.write(new Uint8Array([0x01])); // dc_version
+  writer.write(new Uint8Array([dc.id])); // dc_id
+  let flags = 0;
+  if (dc.ip.includes(":")) {
+    flags |= MTCUTE_DC_IPV6_FLAG;
+  }
+  if (dc.media) {
+    flags |= MTCUTE_DC_MEDIA_FLAG;
+  }
+  writer.write(new Uint8Array([flags])); // dc_flags
+  writer.writeString(dc.ip); // dc_ip
+  writer.writeInt32(dc.port); // dc_port
+  return writer.buffer;
+}
+export interface MtcuteDC {
+  id: number;
+  ip: string;
+  port: number;
+  media?: true;
+}
 const MTCUTE_HAS_SELF_FLAG = 1;
-const MTCUTE_TEST_MODE_FLAG = 2; // TODO: flag 4?
-const MTCUTE_IPV6_FLAG = 1;
+const MTCUTE_TEST_MODE_FLAG = 2;
+const MTCUTE_MEDIA_DC_FLAG = 4;
+
+const MTCUTE_DC_IPV6_FLAG = 1;
+const MTCUTE_DC_MEDIA_FLAG = 2;
diff --git a/lib/session_string_test.tsx b/lib/session_string_test.tsx
@@ -1,4 +1,5 @@
 import { assertEquals } from "$std/assert/mod.ts";
+import { serializeMtcute } from "./session_string.tsx";
 import { deserializeTelethon } from "./session_string.tsx";
 import {
   deserializeGramjs,
@@ -47,7 +48,7 @@ Deno.test("Telethon", async (t) => {
   const serialized =
     "1AwAAAAAAUAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
 
-  await t.step("serializeTelethon", () => {
+  await t.step("serialize", () => {
     assertEquals(
       serializeTelethon(dc, ip, port, authKey),
       serialized,
@@ -85,3 +86,33 @@ Deno.test("GramJS", async (t) => {
     assertEquals(deserialized.authKey, authKey);
   });
 });
+
+Deno.test("mtcute", async (t) => {
+  const serialized =
+    "AwUAAAAXAQIADjE0OS4xNTQuMTY3LjUwALsBAAAXAQICDzE0OS4xNTQuMTY3LjIyMrsBAAA5MAAAAAAAADeXebwgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+  const primaryDc = { id: 2, ip: "149.154.167.50", port: 443 } as const;
+  const mediaDc = {
+    id: 2,
+    ip: "149.154.167.222",
+    port: 443,
+    media: true,
+  } as const;
+  const isBot = false;
+  const userId = 12345;
+  const testMode = false;
+  const authKey = new Uint8Array(32);
+
+  await t.step("serialize", () => {
+    assertEquals(
+      serializeMtcute(
+        testMode,
+        primaryDc,
+        mediaDc,
+        userId,
+        isBot,
+        authKey,
+      ),
+      serialized,
+    );
+  });
+});