From d12515f84b32b3157fa99ac3c3a7a7318f9626ba Mon Sep 17 00:00:00 2001 From: Thomas Kriechbaumer Date: Thu, 18 Aug 2016 17:31:43 +0200 Subject: websockets: refactor implementation and add tests --- netlib/websockets/masker.py | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 netlib/websockets/masker.py (limited to 'netlib/websockets/masker.py') diff --git a/netlib/websockets/masker.py b/netlib/websockets/masker.py new file mode 100644 index 00000000..bd39ed6a --- /dev/null +++ b/netlib/websockets/masker.py @@ -0,0 +1,33 @@ +from __future__ import absolute_import + +import six + + +class Masker(object): + """ + Data sent from the server must be masked to prevent malicious clients + from sending data over the wire in predictable patterns. + + Servers do not have to mask data they send to the client. + https://tools.ietf.org/html/rfc6455#section-5.3 + """ + + def __init__(self, key): + self.key = key + self.offset = 0 + + def mask(self, offset, data): + result = bytearray(data) + for i in range(len(data)): + if six.PY2: + result[i] ^= ord(self.key[offset % 4]) + else: + result[i] ^= self.key[offset % 4] + offset += 1 + result = bytes(result) + return result + + def __call__(self, data): + ret = self.mask(self.offset, data) + self.offset += len(ret) + return ret -- cgit v1.2.3