def decode(self, in_stream, out_stream):
bs = BitStream()
dq = deque()
at_least_three = False
for word in self.words_from_file(in_stream):
if not word or word not in self.word_dict:
continue
#print >> sys.stderr, 'word:"', word, '"'
dq.append(self.word_dict[word])
if at_least_three or len(dq) == 3:
bs.append(pack(self.int_type, dq.popleft()))
at_least_three = True
if bs.len > self.bit_buffer:
cut = 0
for byte in bs.cut(self.bit_buffer):
cut += 1
byte.tofile(out_stream)
del bs[:cut * self.bit_buffer]
# dq has to have exactly 2 elements here, the last is the bit length of the first, unless it's 0
#print >> sys.stderr, 'dq:', dq
extra_bits = dq.pop()
bs.append(pack('uint:' + str(extra_bits), dq.popleft()))
bs.tofile(out_stream)
def decode(self, in_stream, out_stream):
bs = BitStream()
dq = deque()
at_least_three = False
for word in self.words_from_file(in_stream):
if not word or word not in self.word_dict:
continue
#print >> sys.stderr, 'word:"', word, '"'
dq.append(self.word_dict[word])
if at_least_three or len(dq) == 3:
bs.append(pack(self.int_type, dq.popleft()))
at_least_three = True
if bs.len > self.bit_buffer:
cut = 0
for byte in bs.cut(self.bit_buffer):
cut += 1
byte.tofile(out_stream)
del bs[:cut * self.bit_buffer]
# dq has to have exactly 2 elements here, the last is the bit length of the first, unless it's 0
#print >> sys.stderr, 'dq:', dq
extra_bits = dq.pop()
bs.append(pack('uint:' + str(extra_bits), dq.popleft()))
bs.tofile(out_stream)
def find_mapping(infile, outfile):
stream = BitStream()
with open(infile) as f:
byte = f.read(1)
while byte:
if byte == '\x01':
stream.append('0b1')
else:
stream.append('0b0')
byte = f.read(1)
iteration = 0
for mapping in bitmappings:
stream.pos = 0
tmpstream = BitStream()
for pie in stream.cut(2):
index = pie.read('uint:2')
tmpstream.append( BitArray(uint=mapping[index], length=2) )
# look for the start of the flag in the stream of bits
pos = tmpstream.find(ZULU)
if len(pos) > 0:
# print("Found the bytes we are looking for on iteration {}".format(iteration))
# print("pos = {}".format(pos))
tmpstream <<= pos[0] % 8
data = tmpstream.tobytes()
# print(data)
with open(outfile, 'wb') as fh:
fh.write(data)
break
else:
# print("Did not find the header")
iteration += 1
