updates aka procrastination

DrewML · Dec 18, 2020 · c4ccecb · c4ccecb
1 parent fed14c3
commit c4ccecb
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Showing 11 changed files with 162 additions and 141 deletions.
diff --git a/bin/aimserver b/bin/aimserver
@@ -1,3 +1,11 @@
 #!/usr/bin/env node
 
-require('../dist/cli').cli();
+const authHost = process.env.AUTH_HOST;
+const authPort = process.env.AUTH_PORT;
+
+require('../dist/cli')
+    .cli({ authHost, authPort })
+    .catch(err => {
+        console.error(err);
+        process.exit(1);
+    });
diff --git a/src/AIMAuthServer.ts b/src/AIMAuthServer.ts
@@ -1,28 +1,30 @@
 import net, { Socket, Server } from 'net';
 import assert from 'assert';
 import { Flap } from './types';
-import { buildFlap } from './serverFlaps';
-import { matchSnac, authKeyResponseSnac } from './serverSnacs';
-import {
-    parseFlap,
-    parseSnac,
-    parseAuthRequest,
-    parseMD5LoginRequest,
-} from './parsers';
+import { buildFlap, parseFlap } from './flapUtils';
+import { matchSnac, parseSnac } from './snacUtils';
+import { authKeyResponseSnac } from './serverSentSnacs';
+import { parseAuthRequest, parseMD5LoginRequest } from './clientSnacs';
 
 interface AIMAuthServerOpts {
     port?: number;
     host?: string;
 }
 
-const defaults: AIMAuthServerOpts = {
-    port: 5190,
-};
-
+/**
+ * @summary The first server an Oscar Protocol client
+ *          connects to when signing on. Confirms client
+ *          credentials, and returns a cookie and address
+ *          to contact the next service (the BOSS server)
+ */
 export class AIMAuthServer {
     private server: Server;
+    private host: string;
+    private port: number;
 
-    constructor(private opts: AIMAuthServerOpts = defaults) {
+    constructor(opts: AIMAuthServerOpts = {}) {
+        this.host = opts.host ?? '0.0.0.0';
+        this.port = opts.port ?? 5190;
         this.server = net.createServer(this.onNewConnection.bind(this));
         this.server.on('error', this.onServerError.bind(this));
     }
@@ -48,7 +50,9 @@ export class AIMAuthServer {
         socket.write(
             buildFlap({
                 channel: 1,
-                sequence: 1, // TODO: Sequence should be generated in an abstraction around socket.write
+                // TODO: Sequence numbers should be generated in an abstraction around socket.write,
+                // to prevent out-of-order sequences, which is a fatal error for an OSCAR client
+                sequence: 1,
                 data: Buffer.from([0x1]), // Flap version 1
             }),
         );
@@ -64,6 +68,7 @@ export class AIMAuthServer {
     }
 
     private onChannel2(flap: Flap, socket: Socket) {
+        console.log('channel 2 flap', flap);
         const snac = parseSnac(flap.data);
 
         if (matchSnac(snac, 'AUTH', 'MD5_AUTH_REQUEST')) {
@@ -125,10 +130,16 @@ export class AIMAuthServer {
         handler.call(this, flap, socket);
     }
 
-    listen() {
-        const { port, host } = this.opts;
-        this.server.listen(port, host, () => {
-            console.log(`AIMAuthServer: Listening on ${port}`);
+    listen(): Promise<{ host: string; port: number }> {
+        return new Promise((res) => {
+            this.server.listen(this.port, this.host, () => {
+                const address = this.server.address();
+                assert(
+                    address && typeof address !== 'string',
+                    'Unexpected net.AddressInfo in AIMAuthServer.listen',
+                );
+                res({ host: address.address, port: address.port });
+            });
         });
     }
 }

diff --git a/src/cli.ts b/src/cli.ts
@@ -1,6 +1,15 @@
 import { AIMAuthServer } from './AIMAuthServer';
 
-export function cli() {
-    const server = new AIMAuthServer();
-    server.listen();
+interface CLIOpts {
+    authHost?: string;
+    authPort?: string;
+}
+
+export async function cli(opts: CLIOpts) {
+    const authServer = new AIMAuthServer({
+        host: opts.authHost,
+        port: (opts.authPort && Number(opts.authPort)) || undefined,
+    });
+    const { host, port } = await authServer.listen();
+    console.log(`Auth Service listening on ${host}:${port}`);
 }
diff --git a/src/clientSnacs.ts b/src/clientSnacs.ts
@@ -0,0 +1,26 @@
+import { parseTLVs } from './parseTLVs';
+import { TLVS } from './constants';
+
+/**
+ * @see http://iserverd1.khstu.ru/oscar/snac_17_06.html
+ */
+export function parseAuthRequest(data: Buffer) {
+    const tlvs = parseTLVs(data);
+    const screennameTLV = tlvs.first(TLVS.SCREENNAME);
+
+    return {
+        screenname: screennameTLV.value.toString('ascii'),
+    };
+}
+
+/**
+ * @see http://iserverd1.khstu.ru/oscar/snac_17_02.html
+ */
+export function parseMD5LoginRequest(data: Buffer) {
+    const tlvs = parseTLVs(data);
+    const screenname = tlvs.first(TLVS.SCREENNAME);
+    const passwordHash = tlvs.first(TLVS.PASSWORD_HASH);
+    const clientID = tlvs.first(TLVS.CLIENT_ID_STRING);
+
+    return { screenname, passwordHash, clientID };
+}
diff --git a/src/customInspects.ts b/src/customInspects.ts
diff --git a/src/serverFlaps.ts → src/flapUtils.ts b/src/serverFlaps.ts → src/flapUtils.ts
@@ -1,4 +1,5 @@
 import { assert } from 'console';
+import { Flap } from './types';
 
 interface BuildFlapOpts {
     channel: number;
@@ -17,3 +18,20 @@ export function buildFlap({ channel, sequence, data }: BuildFlapOpts) {
 
     return Buffer.concat([buf, data]);
 }
+
+/**
+ * @see https://en.wikipedia.org/wiki/OSCAR_protocol#FLAP_header
+ */
+export function parseFlap(rawFlap: Buffer): Flap {
+    const id = rawFlap.readUInt8(0);
+    assert(id === 0x2a, 'Unexpected Flap ID');
+
+    const flap: Flap = {
+        channel: rawFlap.readUInt8(1),
+        sequence: rawFlap.readUInt16BE(2),
+        byteLength: rawFlap.readUInt16BE(4),
+        data: rawFlap.subarray(6),
+    };
+
+    return flap;
+}
diff --git a/src/parseTLVs.ts b/src/parseTLVs.ts
@@ -0,0 +1,34 @@
+import assert from 'assert';
+import { TLV } from './types';
+import { MultiMap } from './MultiMap';
+
+/**
+ * @see http://iserverd1.khstu.ru/oscar/basic.html#b0003
+ */
+export function parseTLVs(data: Buffer) {
+    const tlvs = new MultiMap<number, TLV>();
+
+    for (let cursor = 0; cursor < data.byteLength /* */; ) {
+        const type = data.readUInt16BE(cursor);
+
+        const lengthStart = cursor + 2;
+        const length = data.readUInt16BE(lengthStart);
+
+        const valueStart = lengthStart + 2;
+        const valueEnd = valueStart + length;
+        // A TLV's value can be 0 bytes. Odd that they're
+        // not just excluded from the request, but ¯\_(ツ)_/¯
+        const value = length
+            ? data.subarray(valueStart, valueEnd)
+            : // Empty buffer so we don't have to explicitly handle
+              // a null/undefined anywhere a TLV type propagates
+              Buffer.alloc(0);
+
+        tlvs.set(type, { type, length, value });
+
+        cursor = valueEnd;
+        assert(cursor <= data.byteLength, 'Overflow that should never happen');
+    }
+
+    return tlvs;
+}
diff --git a/src/parsers.ts b/src/parsers.ts
diff --git a/src/serverSentSnacs.ts b/src/serverSentSnacs.ts
@@ -0,0 +1,22 @@
+import assert from 'assert';
+import { buildSnac } from './snacUtils';
+
+/**
+ * @see http://iserverd1.khstu.ru/oscar/snac_17_07.html
+ * @param authKey Key for client to use when encrypting password. Size should not exceed u32 int
+ * @param reqID   SNAC Request ID from client auth request
+ */
+export function authKeyResponseSnac(authKey: string, reqID: number) {
+    assert(authKey.length < 0xffff, 'authKey size exceeds u32 int');
+
+    const authKeyBuf = Buffer.from(authKey, 'ascii');
+    const authKeyLen = Buffer.alloc(32);
+    authKeyLen.writeUInt32BE(authKeyBuf.byteLength, 0);
+
+    return buildSnac({
+        family: 0x17,
+        subtype: 0x7,
+        reqID,
+        data: Buffer.concat([authKeyLen, authKeyBuf]),
+    });
+}
diff --git a/src/serverSnacs.ts → src/snacUtils.ts b/src/serverSnacs.ts → src/snacUtils.ts
@@ -1,4 +1,3 @@
-import assert from 'assert';
 import { Snac } from './types';
 import { SNACS } from './constants';
 
@@ -44,21 +43,14 @@ export function buildSnac({
 }
 
 /**
- * @see http://iserverd1.khstu.ru/oscar/snac_17_07.html
- * @param authKey Key for client to use when encrypting password. Size should not exceed u32 int
- * @param reqID   SNAC Request ID from client auth request
+ * @see http://web.archive.org/web/20080308233204/http://dev.aol.com/aim/oscar/#SNAC
  */
-export function authKeyResponseSnac(authKey: string, reqID: number) {
-    assert(authKey.length < 0xffff, 'authKey size exceeds u32 int');
-
-    const authKeyBuf = Buffer.from(authKey, 'ascii');
-    const authKeyLen = Buffer.alloc(32);
-    authKeyLen.writeUInt32BE(authKeyBuf.byteLength, 0);
-
-    return buildSnac({
-        family: 0x17,
-        subtype: 0x7,
-        reqID,
-        data: Buffer.concat([authKeyLen, authKeyBuf]),
-    });
+export function parseSnac(rawSnac: Buffer): Snac {
+    return {
+        family: rawSnac.readUInt16BE(0),
+        subtype: rawSnac.readUInt16BE(2),
+        flags: rawSnac.readUInt16BE(4),
+        requestID: rawSnac.readUInt32BE(6),
+        data: rawSnac.subarray(10),
+    };
 }
diff --git a/src/types.ts b/src/types.ts
@@ -19,6 +19,9 @@ export interface Snac {
     data: Buffer;
 }
 
+/**
+ * @see http://iserverd1.khstu.ru/oscar/basic.html#b0003
+ */
 export interface TLV {
     type: number;
     length: number;