impl

shadowsocks/encrypt.py

@@ -32,6 +32,9 @@ def random_string(length):
     return M2Crypto.Rand.rand_bytes(length)
 
 
+cached_tables = {}
+
+
 def get_table(key):
     m = hashlib.md5()
     m.update(key)
@@ -42,12 +45,9 @@ def get_table(key):
         table.sort(lambda x, y: int(a % (ord(x) + i) - a % (ord(y) + i)))
     return table
 
-encrypt_table = None
-decrypt_table = None
-
 
 def init_table(key, method=None):
-    if method == 'table':
+    if method is not None and method == 'table':
         method = None
     if method:
         try:
@@ -57,10 +57,12 @@ def init_table(key, method=None):
                           'default method')
             sys.exit(1)
     if not method:
-        global encrypt_table, decrypt_table
+        if key in cached_tables:
+            return cached_tables[key]
         encrypt_table = ''.join(get_table(key))
         decrypt_table = string.maketrans(encrypt_table,
                                          string.maketrans('', ''))
+        cached_tables[key] = [encrypt_table, decrypt_table]
     else:
         try:
             Encryptor(key, method)  # test if the settings if OK
@@ -116,9 +118,10 @@ class Encryptor(object):
         self.iv_sent = False
         self.cipher_iv = ''
         self.decipher = None
-        if method is not None:
+        if method:
             self.cipher = self.get_cipher(key, method, 1, iv=random_string(32))
         else:
+            self.encrypt_table, self.decrypt_table = init_table(key)
             self.cipher = None
 
     def get_cipher_len(self, method):
@@ -150,8 +153,8 @@ class Encryptor(object):
     def encrypt(self, buf):
         if len(buf) == 0:
             return buf
-        if self.method is None:
-            return string.translate(buf, encrypt_table)
+        if not self.method:
+            return string.translate(buf, self.encrypt_table)
         else:
             if self.iv_sent:
                 return self.cipher.update(buf)
@@ -162,8 +165,8 @@ class Encryptor(object):
     def decrypt(self, buf):
         if len(buf) == 0:
             return buf
-        if self.method is None:
-            return string.translate(buf, decrypt_table)
+        if not self.method:
+            return string.translate(buf, self.decrypt_table)
         else:
             if self.decipher is None:
                 decipher_iv_len = self.get_cipher_len(self.method)[1]
@@ -174,3 +177,34 @@ class Encryptor(object):
                 if len(buf) == 0:
                     return buf
             return self.decipher.update(buf)
+
+
+def encrypt_all(password, method, op, data):
+    if method is not None and method.lower() == 'table':
+        method = None
+    if not method:
+        [encrypt_table, decrypt_table] = init_table(password)
+        if op:
+            return string.translate(encrypt_table, data)
+        else:
+            return string.translate(decrypt_table, data)
+    else:
+        import M2Crypto.EVP
+        result = []
+        method = method.lower()
+        (key_len, iv_len) = method_supported[method]
+        (key, _) = EVP_BytesToKey(password, key_len, iv_len)
+        if op:
+            iv = random_string(iv_len)
+            result.append(iv)
+        else:
+            iv = data[:iv_len]
+            data = data[iv_len:]
+        cipher = M2Crypto.EVP.Cipher(method.replace('-', '_'), key, iv, op,
+                                       key_as_bytes=0, d='md5', salt=None, i=1,
+                                       padding=1)
+        result.append(cipher.update(data))
+        f = cipher.final()
+        if f:
+            result.append(f)
+        return ''.join(result)

shadowsocks/server.py

@@ -215,7 +215,7 @@ def main():
                      tuple(server.server_address[:2]))
         threading.Thread(target=server.serve_forever).start()
         udprelay.UDPRelay(SERVER, int(port), None, None, key, METHOD,
-                          int(TIMEOUT), False)
+                          int(TIMEOUT), False).start()
 
 
 if __name__ == '__main__':

shadowsocks/udprelay.py

@@ -68,7 +68,48 @@
 
 import threading
 import socket
-import event
+import logging
+import struct
+import eventloop
+
+BUF_SIZE = 65536
+
+
+def parse_header(data):
+    addrtype = ord(data[0])
+    dest_addr = None
+    dest_port = None
+    header_length = 0
+    if addrtype == 1:
+        if len(data) >= 7:
+            dest_addr = socket.inet_ntoa(data[1:5])
+            dest_port = struct.unpack('>H', data[5:7])[0]
+            header_length = 7
+        else:
+            logging.warn('[udp] header is too short')
+    elif addrtype == 3:
+        if len(data) > 2:
+            addrlen = ord(data[1])
+            if len(data) >= 2 + addrlen:
+                dest_addr = data[2:2 + addrlen]
+                dest_port = struct.unpack('>H', data[2 + addrlen:4 + addrlen])[0]
+                header_length = 4 + addrlen
+            else:
+                logging.warn('[udp] header is too short')
+        else:
+            logging.warn('[udp] header is too short')
+    elif addrtype == 4:
+        if len(data) >= 19:
+            dest_addr = socket.inet_ntop(socket.AF_INET6, data[1:17])
+            dest_port = struct.unpack('>H', data[17:19])[0]
+            header_length = 19
+        else:
+            logging.warn('[udp] header is too short')
+    else:
+        logging.warn('unsupported addrtype %d' % addrtype)
+    if dest_addr is None:
+        return None
+    return (addrtype, dest_addr, dest_port, header_length)
 
 
 class UDPRelay(object):
@@ -83,25 +124,37 @@ class UDPRelay(object):
         self._method = method
         self._timeout = timeout
         self._is_local = is_local
-        self._eventloop = event.EventLoop()
+        self._eventloop = eventloop.EventLoop()
         self._cache = {}  # TODO replace this dictionary with an LRU cache
 
-    def _handle_server(self, addr, sock, data):
-        # TODO
-        pass
-
-    def _handle_client(self, addr, sock, data):
+    def _handle_server(self):
+        server = self._server_socket
+        data = server.recvfrom(BUF_SIZE)
+        if self._is_local:
+            frag = ord(data[2])
+            if frag != 0:
+                logging.warn('drop a message since frag is not 0')
+            else:
+                data = data[3:]
+        else:
+            decrypt
+        
+
+    def _handle_client(self, sock):
         # TODO
         pass
 
     def _run(self):
-        eventloop = self._eventloop
         server_socket = self._server_socket
-        eventloop.add(server_socket, event.MODE_IN)
+        self._eventloop.add(server_socket, eventloop.MODE_IN)
         is_local = self._is_local
         while True:
-            r = eventloop.poll()
-            # TODO
+            events = self._eventloop.poll()
+            for sock, event in events:
+                if sock == self._server_socket:
+                    self._handle_server()
+                else:
+                    self._handle_client(sock)
 
     def start(self):
         addrs = socket.getaddrinfo(self._listen_addr, self._listen_port, 0,
@@ -115,4 +168,6 @@ class UDPRelay(object):
         server_socket.setblocking(False)
         self._server_socket = server_socket
 
-        threading.Thread(target=self._run).start()
+        t = threading.Thread(target=self._run)
+        t.setDaemon(True)
+        t.start()