From 64114460adde54f8e0606b778ef99d8abcf7e1ae Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 25 Jan 2017 02:31:40 -0800
Subject: [PATCH] socks: refactor addr parsing.

---
 lib/net/socks.js | 96 ++++++++++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 43 deletions(-)

diff --git a/lib/net/socks.js b/lib/net/socks.js
index 3cb9129a..f1e02008 100644
--- a/lib/net/socks.js
+++ b/lib/net/socks.js
@@ -410,7 +410,7 @@ SOCKS.prototype.sendProxy = function sendProxy() {
 };
 
 SOCKS.prototype.handleProxy = function handleProxy(data) {
-  var br, len, host, port, msg;
+  var addr, msg;
 
   if (data.length < 6) {
     this.error('Bad packet size for SOCKS connect.');
@@ -433,45 +433,18 @@ SOCKS.prototype.handleProxy = function handleProxy(data) {
     return;
   }
 
-  br = new BufferReader(data);
-  br.seek(3);
-
-  switch (br.readU8()) {
-    case 0x01:
-      if (br.left() < 6) {
-        this.error('Bad packet length for SOCKS connect.');
-        return;
-      }
-      host = IP.toString(br.readBytes(4));
-      port = br.readU16BE();
-      break;
-    case 0x03:
-      len = br.readU8();
-      if (br.left() < len + 2) {
-        this.error('Bad packet length for SOCKS connect.');
-        return;
-      }
-      host = br.readString(len, 'utf8');
-      port = br.readU16BE();
-      break;
-    case 0x04:
-      if (br.left() < 18) {
-        this.error('Bad packet length for SOCKS connect.');
-        return;
-      }
-      host = IP.toString(br.readBytes(16));
-      port = br.readU16BE();
-      break;
-    default:
-      this.error('Unknown SOCKS address type: %d.', data[4]);
-      return;
+  try {
+    addr = parseAddr(data, 3);
+  } catch (e) {
+    this.error(e);
+    return;
   }
 
   this.state = SOCKS.states.PROXY_DONE;
   this.stopTimeout();
   this.proxied = true;
 
-  this.emit('proxied', host, port);
+  this.emit('proxy address', addr);
   this.emit('proxy', this.socket);
 };
 
@@ -494,9 +467,9 @@ SOCKS.prototype.sendResolve = function sendResolve() {
 };
 
 SOCKS.prototype.handleResolve = function handleResolve(data) {
-  var ip, msg;
+  var addr, msg;
 
-  if (data.length !== 10) {
+  if (data.length < 6) {
     this.error('Bad packet size for tor resolve.');
     return;
   }
@@ -513,17 +486,12 @@ SOCKS.prototype.handleResolve = function handleResolve(data) {
   }
 
   if (data[2] !== 0x00) {
-    this.error('Unknown tor resolve error: %d.', data[2]);
-    return;
-  }
-
-  if (data[3] !== 0x01) {
     this.error('Tor resolve failed (padding).');
     return;
   }
 
   try {
-    ip = IP.toString(data.slice(4, 8));
+    addr = parseAddr(data, 3);
   } catch (e) {
     this.error(e);
     return;
@@ -533,7 +501,7 @@ SOCKS.prototype.handleResolve = function handleResolve(data) {
 
   this.destroy();
 
-  this.emit('resolve', [ip]);
+  this.emit('resolve', [addr.host]);
 };
 
 SOCKS.resolve = function resolve(options) {
@@ -690,6 +658,48 @@ function parseProxy(host) {
   };
 }
 
+function parseAddr(data, offset) {
+  var br = new BufferReader(data);
+  var type, len, host, port;
+
+  if (br.left() < offset + 2)
+    throw new Error('Bad SOCKS address length.');
+
+  br.seek(offset);
+
+  type = br.readU8();
+
+  switch (type) {
+    case 0x01:
+      if (br.left() < 6)
+        throw new Error('Bad SOCKS ipv4 length.');
+
+      host = IP.toString(br.readBytes(4));
+      port = br.readU16BE();
+      break;
+    case 0x03:
+      len = br.readU8();
+
+      if (br.left() < len + 2)
+        throw new Error('Bad SOCKS domain length.');
+
+      host = br.readString(len, 'utf8');
+      port = br.readU16BE();
+      break;
+    case 0x04:
+      if (br.left() < 18)
+        throw new Error('Bad SOCKS ipv6 length.');
+
+      host = IP.toString(br.readBytes(16));
+      port = br.readU16BE();
+      break;
+    default:
+      throw new Error('Unknown SOCKS address type: ' + type + '.');
+  }
+
+  return { host: host, port: port };
+}
+
 /*
  * Expose
  */