added stem python library

lib/stem/response/authchallenge.py

@@ -0,0 +1,56 @@
+# Copyright 2012-2013, Damian Johnson and The Tor Project
+# See LICENSE for licensing information
+
+import binascii
+
+import stem.response
+import stem.socket
+import stem.util.str_tools
+import stem.util.tor_tools
+
+
+class AuthChallengeResponse(stem.response.ControlMessage):
+  """
+  AUTHCHALLENGE query response.
+
+  :var str server_hash: server hash provided by tor
+  :var str server_nonce: server nonce provided by tor
+  """
+
+  def _parse_message(self):
+    # Example:
+    #   250 AUTHCHALLENGE SERVERHASH=680A73C9836C4F557314EA1C4EDE54C285DB9DC89C83627401AEF9D7D27A95D5 SERVERNONCE=F8EA4B1F2C8B40EF1AF68860171605B910E3BBCABADF6FC3DB1FA064F4690E85
+
+    self.server_hash = None
+    self.server_nonce = None
+
+    if not self.is_ok():
+      raise stem.ProtocolError("AUTHCHALLENGE response didn't have an OK status:\n%s" % self)
+    elif len(self) > 1:
+      raise stem.ProtocolError("Received multiline AUTHCHALLENGE response:\n%s" % self)
+
+    line = self[0]
+
+    # sanity check that we're a AUTHCHALLENGE response
+    if not line.pop() == "AUTHCHALLENGE":
+      raise stem.ProtocolError("Message is not an AUTHCHALLENGE response (%s)" % self)
+
+    if line.is_next_mapping("SERVERHASH"):
+      value = line.pop_mapping()[1]
+
+      if not stem.util.tor_tools.is_hex_digits(value, 64):
+        raise stem.ProtocolError("SERVERHASH has an invalid value: %s" % value)
+
+      self.server_hash = binascii.a2b_hex(stem.util.str_tools._to_bytes(value))
+    else:
+      raise stem.ProtocolError("Missing SERVERHASH mapping: %s" % line)
+
+    if line.is_next_mapping("SERVERNONCE"):
+      value = line.pop_mapping()[1]
+
+      if not stem.util.tor_tools.is_hex_digits(value, 64):
+        raise stem.ProtocolError("SERVERNONCE has an invalid value: %s" % value)
+
+      self.server_nonce = binascii.a2b_hex(stem.util.str_tools._to_bytes(value))
+    else:
+      raise stem.ProtocolError("Missing SERVERNONCE mapping: %s" % line)