parent
91d5b7131d
commit
4f4205568a
@ -0,0 +1,312 @@
|
||||
#!/usr/bin/python
|
||||
# -*- coding: utf-8 -*-
|
||||
|
||||
import bitarray
|
||||
import random
|
||||
import re
|
||||
import urllib
|
||||
from HTMLParser import HTMLParser
|
||||
|
||||
class PHelper():
|
||||
""" Packaging Helper baseclass """
|
||||
@staticmethod
|
||||
def intToBits(n, length):
|
||||
""" Convert the number n to a bitarray of length. """
|
||||
i = 0
|
||||
c = 1
|
||||
ret = [False] * length
|
||||
while i < length:
|
||||
ret[length-(i+1)] = (n & c) > 0
|
||||
i += 1
|
||||
c <<= 1
|
||||
return ret
|
||||
|
||||
@staticmethod
|
||||
def bitsToInt(bits):
|
||||
ret = 0
|
||||
for i in bits:
|
||||
ret = (ret << 1) | (i and 1 or 0)
|
||||
return ret
|
||||
|
||||
@staticmethod
|
||||
def toBin(val, leading):
|
||||
""" Binary formatter for python versions without str.format() """
|
||||
x = bin(val).replace("0b", "")
|
||||
return "0" * (leading-len(x)) + x
|
||||
|
||||
@staticmethod
|
||||
def encode(data):
|
||||
""" Encode data, return list of messages (max. 140 chars long) """
|
||||
raise NotImplementedError("You need to implement this method when subclassing.")
|
||||
|
||||
@staticmethod
|
||||
def decode(packet):
|
||||
""" Decode packet, return tuple(isFragmented boolean), packetLength int, packetId int, data (byte)string) """
|
||||
raise NotImplementedError("You need to implement this method when subclassing.")
|
||||
|
||||
|
||||
class UPHelper(PHelper):
|
||||
""" The Unicode Packaging Helper
|
||||
|
||||
Twitter supports 140 chars, while a char can be a unicode
|
||||
character. For a unicode character there are 2^20 possibilities.
|
||||
For the sake of lazyness we put two bytes in each character, using
|
||||
only 2^16. The remaining 4 bits can be used for metadata or whatever.
|
||||
|
||||
The header in the metadata is as following:
|
||||
<fragment bit (1 if packet is a fragment, 0 if last in row)>
|
||||
<9 bits length of payload>
|
||||
<32 bit random paket id greater than 0>"""
|
||||
|
||||
|
||||
@staticmethod
|
||||
def encode(data):
|
||||
""" Generate list of packets with a header from data. """
|
||||
packetId = random.randint(1, 2**32)
|
||||
fragments = []
|
||||
while len(data) >= 280:
|
||||
newData = data[0:280]
|
||||
if newData[-1] == '\x00' and newData[-2] == '\x00' and len(newData) == 280:
|
||||
fragments.append(data[0:278])
|
||||
data = data[278:]
|
||||
else:
|
||||
fragments.append(newData)
|
||||
data = data[280:]
|
||||
if len(data) > 0:
|
||||
fragments.append(data)
|
||||
|
||||
# convert to twitter message
|
||||
for y in range(len(fragments)):
|
||||
fragment = fragments[y]
|
||||
lenX = len(fragment)
|
||||
# pad packet if it is not long enouth / not aligned
|
||||
if len(fragment) < 2*11:
|
||||
fragment = fragment + "-" * (2*11-len(fragment))
|
||||
if len(fragment) % 2 == 1:
|
||||
fragment += "-"
|
||||
|
||||
# write header (bits: 1 fragment, 9 length, 32 id)
|
||||
header = bitarray.bitarray(1)
|
||||
# write fragment-bit
|
||||
header[0] = not (y+1 == len(fragments))
|
||||
# append packet length
|
||||
header.extend(UPHelper.intToBits(lenX, 9))
|
||||
# add packet id
|
||||
header.extend(UPHelper.intToBits(packetId, 32))
|
||||
# padding to complete last 4 bytes
|
||||
header.extend([False, False])
|
||||
|
||||
i = 0
|
||||
h = 0
|
||||
ret = ""
|
||||
while i+1 < len(fragment):
|
||||
val = ord(fragment[i]) << 8 | ord(fragment[i+1])
|
||||
if h < 11:
|
||||
val |= UPHelper.bitsToInt(header[h*4:(h+1)*4]) << 16
|
||||
h += 1
|
||||
# hack for (0x2026, 0x202f)
|
||||
if val > 0x2026 and val < 0x202f:
|
||||
val = val | (1<<16)
|
||||
ret += unichr(val)
|
||||
i += 2
|
||||
|
||||
# if the last characters are multiple \x00-bytes, twitter eats them!
|
||||
# we already took care so there is space at the end for an extra dot
|
||||
if ret[-1] == '\x00':
|
||||
ret = ret + "."
|
||||
fragments[y] = ret
|
||||
return fragments
|
||||
|
||||
@staticmethod
|
||||
def reassembleBrokenChars(packet):
|
||||
""" Reassemble broken characters back to unicode.
|
||||
|
||||
Twitter breaks some characters (currently known range is 0xd800 - 0xdfff)
|
||||
into r"\XXX\XXX\XXX", X being octal numbers. These are actually strings,
|
||||
so one unicodechar from the range gets broken up to 12 chars.
|
||||
|
||||
Note that through this packets containing the following byte sequence will
|
||||
get mangled:
|
||||
00 5c 00 XX 00 XX 00 XX 00 5c 00 XX 00 XX 00 XX 00 5c 00 XX 00 XX 00 XX
|
||||
while XX is a number from ord('0') to ord('9')
|
||||
|
||||
Also _some_ of these are again converted into other chars.
|
||||
\ud800\udc00 gets converted to \U00010000, so we need to guess-convert
|
||||
these back. """
|
||||
origPacket = packet
|
||||
brokenChars = re.findall(r"(\\([0-9]{3})\\([0-9]{3})\\([0-9]{3}))", packet)
|
||||
for broken in brokenChars:
|
||||
#print "broken", broken, repr("".join(map(lambda x: chr(int(x, 8)), broken[1:])))
|
||||
newChar = "".join(map(lambda x: chr(int(x, 8)), broken[1:])).decode("utf-8")
|
||||
packet = packet.replace(broken[0], newChar)
|
||||
|
||||
# this is guesswork-derivation, its derived from these lines
|
||||
# they represent our input and twitters output
|
||||
# guesswork++: for the header, this is plausible, afterwards not.
|
||||
# u"\ud900\udc00 \uda00\udcFF \udb00\uddFF"
|
||||
# u'\U00050000 \U000900ff \U000d01ff"
|
||||
# u"\ud800\udc00 \ud800\udcFF \ud800\uddFF \ud800\ude00 \ud800\udeff \ud800\udf00 \ud800\udfff"
|
||||
# u'\U00010000 \U000100ff \U000101ff \U00010200 \U000102ff \U00010300 \U000103ff'
|
||||
# u"\ud800\udc00 \ud801\udc00 \ud802\udc00 \ud803\udc00 \ud804\udc00 \ud805\udc00\ud806\udc00 \ud807\udc00 \ud808\udc00 \ud809\udc00 \ud80a\udc00 \ud80b\udc00 \ud80c\udc00 \ud80d\udc00 \ud80e\udc00 \ud80f\udc00 \ud810\udc00 \ud811\udc00 \ud812\udc00 \ud813\udc00"
|
||||
# u'\U00010000 \U00010400 \U00010800 \U00010c00 \U00011000 \U00011400\U00011800 \U00011c00 \U00012000 \U00012400 \U00012800 \U00012c00 \U00013000 \U00013400 \U00013800 \U00013c00 \U00014000 \U00014400 \U00014800 \U00014c00'
|
||||
|
||||
|
||||
for c in origPacket[11:]:
|
||||
o = ord(c)
|
||||
# (0x2027, 0x202f) are not displayed properly
|
||||
if o > 0x12027 and o < 0x1202f:
|
||||
packet.replace(c, unichr(o & (0xFFFF)))
|
||||
elif o > 65535:
|
||||
# -.-
|
||||
a = unichr(0xd800 + ((o >> 10) - 64))
|
||||
b = unichr(0xdc00 + (o & 1023))
|
||||
packet = packet.replace(c, a+b)
|
||||
return packet
|
||||
|
||||
@staticmethod
|
||||
def decode(packet):
|
||||
""" Decodes an unicodestring (packet) back to header + data
|
||||
|
||||
Returns: tupel(isFragmented, packetLen, packetId, data) """
|
||||
|
||||
packet = UPHelper.reassembleBrokenChars(packet)
|
||||
|
||||
if len(packet) < 11:
|
||||
raise ValueError("This is not a valid packet, header is too short (should be at least 11, is %d)" % len(packet))
|
||||
header = bitarray.bitarray()
|
||||
for i in range(11):
|
||||
# format with binary is not understood by older python versions
|
||||
#header.extend("{:04b}".format(ord(packet[i]) >> 16))
|
||||
header.extend(UPHelper.toBin((ord(packet[i]) >> 16), 4))
|
||||
isFragmented = header[0]
|
||||
|
||||
packetLen = UPHelper.bitsToInt(header[1:10])
|
||||
packetId = UPHelper.bitsToInt(header[10:])
|
||||
if packetId == 0:
|
||||
raise ValueError("Packet id cannot be 0")
|
||||
|
||||
rawData = map(lambda x: ord(x) & 0xFFFF, packet)
|
||||
data = []
|
||||
for p in rawData:
|
||||
data.append(chr((p >> 8) & 255))
|
||||
data.append(chr(p & 255))
|
||||
data = "".join(data[:packetLen])
|
||||
return (isFragmented, packetLen, packetId, data)
|
||||
|
||||
class DPHelper(PHelper):
|
||||
""" The Dump Packaging Helper
|
||||
|
||||
As twitters unicodehandling is quiet random, this is an
|
||||
attempt to a more reliable en-/decoding. It uses
|
||||
the first char for an unicode header, the remaining 138
|
||||
chars are used for the networkpacket in plain.
|
||||
|
||||
Header:
|
||||
<1 bit, True if fragment>
|
||||
<8 bit, lenght of packet>
|
||||
<11 bit, packet id [1, 2047]>
|
||||
"""
|
||||
|
||||
@staticmethod
|
||||
def textEncode(t):
|
||||
return t.replace("&", "&") \
|
||||
.replace("\r", " ")
|
||||
|
||||
@staticmethod
|
||||
def textDecode(t):
|
||||
return t.replace("<", "<") \
|
||||
.replace(">", ">") \
|
||||
.replace("
", "\r")\
|
||||
.replace("&", "&") \
|
||||
|
||||
@staticmethod
|
||||
def encode(data):
|
||||
# twitter encodes <>'s ==> we need to encode & to distinguish between < and an encoded etc.
|
||||
data = DPHelper.textEncode(data)
|
||||
packetId = random.randint(1, 2**11)
|
||||
fragments = []
|
||||
while len(data) >= 139:
|
||||
newData = data[0:139]
|
||||
if newData[-1] == '\x00' and newData[-2] == '\x00' and len(newData) == 139:
|
||||
fragments.append(data[0:138])
|
||||
data = data[138:]
|
||||
else:
|
||||
fragments.append(newData)
|
||||
data = data[139:]
|
||||
if len(data) > 0:
|
||||
fragments.append(data)
|
||||
|
||||
# convert to twitter message
|
||||
for y in range(len(fragments)):
|
||||
fragment = fragments[y]
|
||||
lenX = len(fragment)
|
||||
|
||||
# write header (bits: 1 fragment, 8 length, 11 id)
|
||||
header = bitarray.bitarray(1)
|
||||
# write fragment-bit
|
||||
header[0] = not (y+1 == len(fragments))
|
||||
# append packet length
|
||||
header.extend(DPHelper.intToBits(lenX, 8))
|
||||
# add packet id
|
||||
header.extend(DPHelper.intToBits(packetId, 11))
|
||||
ret = unichr(DPHelper.bitsToInt(header)) + "".join([unichr(ord(i)) for i in fragment])
|
||||
|
||||
# if the last characters are multiple \x00-bytes, twitter eats them!
|
||||
# we already took care so there is space at the end for an extra dot
|
||||
if ret[-1] == '\x00' and ret[-2] == '\x00':
|
||||
ret = ret + "."
|
||||
fragments[y] = ret
|
||||
return fragments
|
||||
|
||||
@staticmethod
|
||||
def decode(packet):
|
||||
""" Decodes an unicodestring (packet) back to header + data
|
||||
|
||||
Returns: tupel(isFragmented, packetLen, packetId, data) """
|
||||
|
||||
# twitter urlencodes < and > to < and ≷
|
||||
# this will of course break packets containing an actual < or >
|
||||
packet = DPHelper.textDecode(packet)
|
||||
#packet = packet.replace("<", "<").replace(">", ">").replace("&", "&")
|
||||
|
||||
if len(packet) < 2:
|
||||
raise ValueError("This is not a valid packet, header is too short (should be at least 11, is %d)" % len(packet))
|
||||
header = bitarray.bitarray(DPHelper.toBin(ord(packet[0]), 20))
|
||||
isFragmented = header[0]
|
||||
|
||||
packetLen = DPHelper.bitsToInt(header[1:9])
|
||||
packetId = DPHelper.bitsToInt(header[9:])
|
||||
if packetId == 0:
|
||||
raise ValueError("Packet id cannot be 0")
|
||||
|
||||
data = "".join(map(lambda x: chr(ord(x)), packet[1:packetLen+1]))
|
||||
return (isFragmented, packetLen, packetId, data)
|
||||
|
||||
if __name__ == '__main__':
|
||||
msg = '\x00\x00\x08\x00E\x00\x00T\x00\x00@\x00@\x01\x12\x81\n\n\n\x0b\n\n\n\n\x08\x00\xd7Gt\xd2\x00\x01[U\xf1Nl=\x08\x00\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./01234567'
|
||||
enc = DPHelper.encode(msg)
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print repr(enc)
|
||||
ret = ""
|
||||
for e in enc:
|
||||
e = DPHelper.decode(e)
|
||||
ret += e[3]
|
||||
print "broken", repr(DPHelper.encode(msg)[0])
|
||||
m = DPHelper.decode(DPHelper.encode(msg)[0])
|
||||
print repr(msg)
|
||||
print repr(ret)
|
||||
if ret == msg:
|
||||
print "success"
|
||||
else:
|
||||
print "failure"
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
|
||||
print DPHelper.decode(DPHelper.encode("X"*281)[0])
|
||||
print DPHelper.decode(DPHelper.encode("X"*281)[1])
|
||||
print DPHelper.decode(DPHelper.encode("X"*281)[2])
|
||||
print repr(DPHelper.encode("foo & < \r\r > and <")[0].replace("<", "<").replace(">", ">"))
|
||||
print DPHelper.decode(DPHelper.encode("foo & < \r\r > and <")[0].replace("<", "<").replace(">", ">"))
|
||||
|
Loading…
Reference in new issue