initial version

README.md

@@ -1,2 +1,11 @@
 # anti-sni-filter-socks5-proxy
-Socks5 Proxy - bypass SNI/Host checking censorship.
+* Socks5 Proxy - bypass SNI/Host checking censorship.
+* works with HTTP/HTTPS filtering at Korea.
+
+# run
+
+work and tested python2.
+
+```
+python socks5proxy.py
+```

socks5proxy.py

@@ -0,0 +1,106 @@
+#!/usr/bin/python
+# -*- coding:utf-8 -*-
+#
+# Socks5 Proxy Service with Avoid SNI based Contents Filtering.
+# This sample is for test purpose.
+# - code by Jioh L. Jung(ziozzang@gmail.com)
+#
+# Threaded Socks5 Server in Python
+#
+# Source: http://xiaoxia.org/2011/03/29/written-by-python-socks5-server/
+#
+#
+
+#from gevent import monkey
+#monkey.patch_all()
+
+import socket, os, sys, select, SocketServer, struct, time
+
+class ThreadingTCPServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer): pass
+class Socks5Server(SocketServer.StreamRequestHandler):
+    def handle_tcp(self, sock, remote):
+        fdset = [sock, remote]
+        self.marked = False
+        self.sent = False
+        self.reqtype = None
+        self.cbuf = None
+
+        # Basic Loop for contents passing.
+        while True:
+            r, w, e = select.select(fdset, [], [])
+            if sock in r:
+                buf = sock.recv(4096)
+                if not self.marked:
+                    # build Packet Filter Marking
+                    self.marked = True
+                    if len(buf) == 0:
+                        break
+                    if buf[0] ==  '\x16': # TLS start
+                        p = min(len(buf) / 5, 100) # Tricky Code. split by specific size or split by some...
+                        self.sent = True
+                        remote.send(buf[:p])
+                        if remote.send(buf[p:]) <= 0: break
+                    elif  buf[0].lower() >= ord('a')  or buf[0].lower() <= ord('z'):
+                        # Generic HTTP?
+                        lp = buf.lower().find("host:")
+                        if lp != -1:
+                            self.sent = True
+                            remote.send(buf[:lp+4])
+                            if remote.send(buf[p+4:]) <= 0: break
+                    if not self.sent:
+                        self.sent = True
+                        if remote.send(buf) <= 0: break
+                else:
+                    if remote.send(buf) <= 0: break
+
+            if remote in r:
+                buf = remote.recv(4096)
+                # no filtering
+
+                if not buf: break
+                if sock.send(buf) <= 0: break
+    def handle(self):
+        try:
+            #>> 'socks connection from ', self.client_address
+            sock = self.connection
+            # 1. Version
+            sock.recv(262)
+            sock.send(b"\x05\x00");
+            # 2. Request
+            data = self.rfile.read(4)
+            mode = ord(data[1])
+            addrtype = ord(data[3])
+            if addrtype == 1:       # IPv4
+                addr = socket.inet_ntoa(self.rfile.read(4))
+            elif addrtype == 3:     # Domain name
+                addr = self.rfile.read(ord(sock.recv(1)[0]))
+            port = struct.unpack('>H', self.rfile.read(2))
+            reply = b"\x05\x00\x00\x01"
+            try:
+                if mode == 1:  # 1. Tcp connect
+                    self.addr = addr
+                    self.port = port[0]
+                    remote = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                    remote.connect((addr, port[0]))
+                    #>> 'Tcp connect to', addr, port[0]
+                else:
+                    reply = b"\x05\x07\x00\x01" # Command not supported
+                local = remote.getsockname()
+                reply += socket.inet_aton(local[0]) + struct.pack(">H", local[1])
+            except socket.error:
+                # Connection refused
+                reply = '\x05\x05\x00\x01\x00\x00\x00\x00\x00\x00'
+            sock.send(reply)
+            # 3. Transfering
+            if reply[1] == '\x00':  # Success
+                if mode == 1:    # 1. Tcp connect
+                    self.handle_tcp(sock, remote)
+        except socket.error:
+            pass
+            #print 'socket error'
+def main():
+    server = ThreadingTCPServer(('', 1080), Socks5Server)
+    server.serve_forever()
+
+if __name__ == '__main__':
+    main()