mirror of
https://github.com/evilhero/mylar
synced 2024-12-22 15:52:47 +00:00
281 lines
8.9 KiB
Python
281 lines
8.9 KiB
Python
# Copyright (C) 2011 by clueless <clueless.nospam ! mail.com>
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
# of this software and associated documentation files (the "Software"), to deal
|
|
# in the Software without restriction, including without limitation the rights
|
|
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
# copies of the Software, and to permit persons to whom the Software is
|
|
# furnished to do so, subject to the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be included in
|
|
# all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
# THE SOFTWARE.
|
|
#
|
|
# Version: 20111107
|
|
#
|
|
# Changelog
|
|
# ---------
|
|
# 2011-11-07 - Added support for Python2 (tested on 2.6)
|
|
# 2011-10-03 - Fixed: moved check for end of list at the top of the while loop
|
|
# in _decode_list (in case the list is empty) (Chris Lucas)
|
|
# - Converted dictionary keys to str
|
|
# 2011-04-24 - Changed date format to YYYY-MM-DD for versioning, bigger
|
|
# integer denotes a newer version
|
|
# - Fixed a bug that would treat False as an integral type but
|
|
# encode it using the 'False' string, attempting to encode a
|
|
# boolean now results in an error
|
|
# - Fixed a bug where an integer value of 0 in a list or
|
|
# dictionary resulted in a parse error while decoding
|
|
#
|
|
# 2011-04-03 - Original release
|
|
|
|
import sys
|
|
|
|
_py3 = sys.version_info[0] == 3
|
|
|
|
if _py3:
|
|
_VALID_STRING_TYPES = (str,)
|
|
else:
|
|
_VALID_STRING_TYPES = (str, unicode) # @UndefinedVariable
|
|
|
|
_TYPE_INT = 1
|
|
_TYPE_STRING = 2
|
|
_TYPE_LIST = 3
|
|
_TYPE_DICTIONARY = 4
|
|
_TYPE_END = 5
|
|
_TYPE_INVALID = 6
|
|
|
|
# Function to determine the type of he next value/item
|
|
# Arguments:
|
|
# char First character of the string that is to be decoded
|
|
# Return value:
|
|
# Returns an integer that describes what type the next value/item is
|
|
|
|
|
|
def _gettype(char):
|
|
if not isinstance(char, int):
|
|
char = ord(char)
|
|
if char == 0x6C: # 'l'
|
|
return _TYPE_LIST
|
|
elif char == 0x64: # 'd'
|
|
return _TYPE_DICTIONARY
|
|
elif char == 0x69: # 'i'
|
|
return _TYPE_INT
|
|
elif char == 0x65: # 'e'
|
|
return _TYPE_END
|
|
elif char >= 0x30 and char <= 0x39: # '0' '9'
|
|
return _TYPE_STRING
|
|
else:
|
|
return _TYPE_INVALID
|
|
|
|
# Function to parse a string from the bendcoded data
|
|
# Arguments:
|
|
# data bencoded data, must be guaranteed to be a string
|
|
# Return Value:
|
|
# Returns a tuple, the first member of the tuple is the parsed string
|
|
# The second member is whatever remains of the bencoded data so it can
|
|
# be used to parse the next part of the data
|
|
|
|
|
|
def _decode_string(data):
|
|
end = 1
|
|
# if py3, data[end] is going to be an int
|
|
# if py2, data[end] will be a string
|
|
if _py3:
|
|
char = 0x3A
|
|
else:
|
|
char = chr(0x3A)
|
|
|
|
while data[end] != char: # ':'
|
|
end = end + 1
|
|
strlen = int(data[:end])
|
|
return (data[end + 1:strlen + end + 1], data[strlen + end + 1:])
|
|
|
|
# Function to parse an integer from the bencoded data
|
|
# Arguments:
|
|
# data bencoded data, must be guaranteed to be an integer
|
|
# Return Value:
|
|
# Returns a tuple, the first member of the tuple is the parsed string
|
|
# The second member is whatever remains of the bencoded data so it can
|
|
# be used to parse the next part of the data
|
|
|
|
|
|
def _decode_int(data):
|
|
end = 1
|
|
# if py3, data[end] is going to be an int
|
|
# if py2, data[end] will be a string
|
|
if _py3:
|
|
char = 0x65
|
|
else:
|
|
char = chr(0x65)
|
|
|
|
while data[end] != char: # 'e'
|
|
end = end + 1
|
|
return (int(data[1:end]), data[end + 1:])
|
|
|
|
# Function to parse a bencoded list
|
|
# Arguments:
|
|
# data bencoded data, must be guaranted to be the start of a list
|
|
# Return Value:
|
|
# Returns a tuple, the first member of the tuple is the parsed list
|
|
# The second member is whatever remains of the bencoded data so it can
|
|
# be used to parse the next part of the data
|
|
|
|
|
|
def _decode_list(data):
|
|
x = []
|
|
overflow = data[1:]
|
|
while True: # Loop over the data
|
|
if _gettype(overflow[0]) == _TYPE_END: # - Break if we reach the end of the list
|
|
return (x, overflow[1:]) # and return the list and overflow
|
|
|
|
value, overflow = _decode(overflow) #
|
|
if isinstance(value, bool) or overflow == '': # - if we have a parse error
|
|
return (False, False) # Die with error
|
|
else: # - Otherwise
|
|
x.append(value) # add the value to the list
|
|
|
|
|
|
# Function to parse a bencoded list
|
|
# Arguments:
|
|
# data bencoded data, must be guaranted to be the start of a list
|
|
# Return Value:
|
|
# Returns a tuple, the first member of the tuple is the parsed dictionary
|
|
# The second member is whatever remains of the bencoded data so it can
|
|
# be used to parse the next part of the data
|
|
def _decode_dict(data):
|
|
x = {}
|
|
overflow = data[1:]
|
|
while True: # Loop over the data
|
|
if _gettype(overflow[0]) != _TYPE_STRING: # - If the key is not a string
|
|
return (False, False) # Die with error
|
|
key, overflow = _decode(overflow) #
|
|
if key == False or overflow == '': # - If parse error
|
|
return (False, False) # Die with error
|
|
value, overflow = _decode(overflow) #
|
|
if isinstance(value, bool) or overflow == '': # - If parse error
|
|
print("Error parsing value")
|
|
print(value)
|
|
print(overflow)
|
|
return (False, False) # Die with error
|
|
else:
|
|
# don't use bytes for the key
|
|
key = key.decode()
|
|
x[key] = value
|
|
if _gettype(overflow[0]) == _TYPE_END:
|
|
return (x, overflow[1:])
|
|
|
|
# Arguments:
|
|
# data bencoded data in bytes format
|
|
# Return Values:
|
|
# Returns a tuple, the first member is the parsed data, could be a string,
|
|
# an integer, a list or a dictionary, or a combination of those
|
|
# The second member is the leftover of parsing, if everything parses correctly this
|
|
# should be an empty byte string
|
|
|
|
|
|
def _decode(data):
|
|
btype = _gettype(data[0])
|
|
if btype == _TYPE_INT:
|
|
return _decode_int(data)
|
|
elif btype == _TYPE_STRING:
|
|
return _decode_string(data)
|
|
elif btype == _TYPE_LIST:
|
|
return _decode_list(data)
|
|
elif btype == _TYPE_DICTIONARY:
|
|
return _decode_dict(data)
|
|
else:
|
|
return (False, False)
|
|
|
|
# Function to decode bencoded data
|
|
# Arguments:
|
|
# data bencoded data, can be str or bytes
|
|
# Return Values:
|
|
# Returns the decoded data on success, this coud be bytes, int, dict or list
|
|
# or a combinatin of those
|
|
# If an error occurs the return value is False
|
|
|
|
|
|
def decode(data):
|
|
# if isinstance(data, str):
|
|
# data = data.encode()
|
|
decoded, overflow = _decode(data)
|
|
return decoded
|
|
|
|
# Args: data as integer
|
|
# return: encoded byte string
|
|
|
|
|
|
def _encode_int(data):
|
|
return b'i' + str(data).encode() + b'e'
|
|
|
|
# Args: data as string or bytes
|
|
# Return: encoded byte string
|
|
|
|
|
|
def _encode_string(data):
|
|
return str(len(data)).encode() + b':' + data
|
|
|
|
# Args: data as list
|
|
# Return: Encoded byte string, false on error
|
|
|
|
|
|
def _encode_list(data):
|
|
elist = b'l'
|
|
for item in data:
|
|
eitem = encode(item)
|
|
if eitem == False:
|
|
return False
|
|
elist += eitem
|
|
return elist + b'e'
|
|
|
|
# Args: data as dict
|
|
# Return: encoded byte string, false on error
|
|
|
|
|
|
def _encode_dict(data):
|
|
edict = b'd'
|
|
keys = []
|
|
for key in data:
|
|
if not isinstance(key, _VALID_STRING_TYPES) and not isinstance(key, bytes):
|
|
return False
|
|
keys.append(key)
|
|
keys.sort()
|
|
for key in keys:
|
|
ekey = encode(key)
|
|
eitem = encode(data[key])
|
|
if ekey == False or eitem == False:
|
|
return False
|
|
edict += ekey + eitem
|
|
return edict + b'e'
|
|
|
|
# Function to encode a variable in bencoding
|
|
# Arguments:
|
|
# data Variable to be encoded, can be a list, dict, str, bytes, int or a combination of those
|
|
# Return Values:
|
|
# Returns the encoded data as a byte string when successful
|
|
# If an error occurs the return value is False
|
|
|
|
|
|
def encode(data):
|
|
if isinstance(data, bool):
|
|
return False
|
|
elif isinstance(data, int):
|
|
return _encode_int(data)
|
|
elif isinstance(data, bytes):
|
|
return _encode_string(data)
|
|
elif isinstance(data, _VALID_STRING_TYPES):
|
|
return _encode_string(data.encode())
|
|
elif isinstance(data, list):
|
|
return _encode_list(data)
|
|
elif isinstance(data, dict):
|
|
return _encode_dict(data)
|
|
else:
|
|
return False
|