Peter Surda
e649adbe37
- helper classes for encoding/decoding messages - includes both old as well as new extended one (msgpack+zlib) - the classes are unused yet and are supposed to be for experimenting
87 lines
2.9 KiB
Python
87 lines
2.9 KiB
Python
#!/usr/bin/python2.7
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import msgpack
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import zlib
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from debug import logger
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BITMESSAGE_ENCODING_IGNORE = 0
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BITMESSAGE_ENCODING_TRIVIAL = 1
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BITMESSAGE_ENCODING_SIMPLE = 2
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BITMESSAGE.ENCODING_EXTENDED = 3
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class MsgEncode(object):
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def __init__(self, message, encoding = BITMESSAGE_ENCODING_SIMPLE):
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self.data = None
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self.encoding = encoding
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self.length = 0
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if self.encoding == BITMESSAGE_ENCODING_EXTENDED:
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self.encodeExtended(message)
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elif self.encoding == BITMESSAGE_ENCODING_SIMPLE:
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self.encodeSimple(message)
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elif self.encoding == BITMESSAGE_ENCODING_TRIVIAL:
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self.encodeTrivial(message)
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def encodeExtended(self, message):
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try:
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self.data = zlib.compress(msgpack.dumps({"": "message", "subject": message['subject'], "message": ['body']}), 9)
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except zlib.error:
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logger.error ("Error compressing message")
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raise
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except msgpack.exceptions.PackException:
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logger.error ("Error msgpacking message")
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raise
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self.length = len(self.data)
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def encodeSimple(self, message):
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self.data = 'Subject:' + message['subject'] + '\n' + 'Body:' + message['body']
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self.length = len(self.data)
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def encodeTrivial(self, message):
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self.data = message['body']
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self.length = len(self.data)
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class MsgDecode(object):
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def __init__(self, encoding, data):
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self.encoding = encoding
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if self.encoding == BITMESSAGE_ENCODING_EXTENDED:
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self.decodeExtended(data)
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elif self.encoding in [BITMESSAGE_ENCODING_SIMPLE, BITMESSAGE_ENCODING_TRIVIAL]:
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self.decodeSimple(data)
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return
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def decodeExtended(self, data):
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try:
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tmp = msgpack.loads(zlib.decompress(data))
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except zlib.error:
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logger.error ("Error decompressing message")
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raise
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except (msgpack.exceptions.UnpackException,
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msgpack.exceptions.ExtraData):
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logger.error ("Error msgunpacking message")
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raise
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try:
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if tmp[""] == "message":
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self.body = tmp["body"]
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self.subject = tmp["subject"]
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except:
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logger.error ("Malformed message")
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raise
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def decodeSimple(self, data):
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bodyPositionIndex = string.find(data, '\nBody:')
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if bodyPositionIndex > 1:
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subject = message[8:bodyPositionIndex]
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# Only save and show the first 500 characters of the subject.
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# Any more is probably an attack.
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subject = subject[:500]
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body = message[bodyPositionIndex + 6:]
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else:
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subject = ''
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body = message
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# Throw away any extra lines (headers) after the subject.
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if subject:
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subject = subject.splitlines()[0]
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self.subject = subject
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self.message = body
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