mirror of
https://github.com/thegeeklab/ansible-later.git
synced 2024-11-25 22:30:42 +00:00
139 lines
4.2 KiB
Python
139 lines
4.2 KiB
Python
# Copyright (C) 2003-2007 Robey Pointer <robeypointer@gmail.com>
|
|
#
|
|
# This file is part of paramiko.
|
|
#
|
|
# Paramiko is free software; you can redistribute it and/or modify it under the
|
|
# terms of the GNU Lesser General Public License as published by the Free
|
|
# Software Foundation; either version 2.1 of the License, or (at your option)
|
|
# any later version.
|
|
#
|
|
# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
|
|
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
|
|
# details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public License
|
|
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
|
|
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
from paramiko.common import max_byte, zero_byte
|
|
from paramiko.py3compat import b, byte_ord, byte_chr, long
|
|
|
|
import paramiko.util as util
|
|
|
|
|
|
class BERException(Exception):
|
|
pass
|
|
|
|
|
|
class BER(object):
|
|
"""
|
|
Robey's tiny little attempt at a BER decoder.
|
|
"""
|
|
|
|
def __init__(self, content=bytes()):
|
|
self.content = b(content)
|
|
self.idx = 0
|
|
|
|
def asbytes(self):
|
|
return self.content
|
|
|
|
def __str__(self):
|
|
return self.asbytes()
|
|
|
|
def __repr__(self):
|
|
return "BER('" + repr(self.content) + "')"
|
|
|
|
def decode(self):
|
|
return self.decode_next()
|
|
|
|
def decode_next(self):
|
|
if self.idx >= len(self.content):
|
|
return None
|
|
ident = byte_ord(self.content[self.idx])
|
|
self.idx += 1
|
|
if (ident & 31) == 31:
|
|
# identifier > 30
|
|
ident = 0
|
|
while self.idx < len(self.content):
|
|
t = byte_ord(self.content[self.idx])
|
|
self.idx += 1
|
|
ident = (ident << 7) | (t & 0x7f)
|
|
if not (t & 0x80):
|
|
break
|
|
if self.idx >= len(self.content):
|
|
return None
|
|
# now fetch length
|
|
size = byte_ord(self.content[self.idx])
|
|
self.idx += 1
|
|
if size & 0x80:
|
|
# more complimicated...
|
|
# FIXME: theoretically should handle indefinite-length (0x80)
|
|
t = size & 0x7f
|
|
if self.idx + t > len(self.content):
|
|
return None
|
|
size = util.inflate_long(
|
|
self.content[self.idx : self.idx + t], True
|
|
)
|
|
self.idx += t
|
|
if self.idx + size > len(self.content):
|
|
# can't fit
|
|
return None
|
|
data = self.content[self.idx : self.idx + size]
|
|
self.idx += size
|
|
# now switch on id
|
|
if ident == 0x30:
|
|
# sequence
|
|
return self.decode_sequence(data)
|
|
elif ident == 2:
|
|
# int
|
|
return util.inflate_long(data)
|
|
else:
|
|
# 1: boolean (00 false, otherwise true)
|
|
msg = "Unknown ber encoding type {:d} (robey is lazy)"
|
|
raise BERException(msg.format(ident))
|
|
|
|
@staticmethod
|
|
def decode_sequence(data):
|
|
out = []
|
|
ber = BER(data)
|
|
while True:
|
|
x = ber.decode_next()
|
|
if x is None:
|
|
break
|
|
out.append(x)
|
|
return out
|
|
|
|
def encode_tlv(self, ident, val):
|
|
# no need to support ident > 31 here
|
|
self.content += byte_chr(ident)
|
|
if len(val) > 0x7f:
|
|
lenstr = util.deflate_long(len(val))
|
|
self.content += byte_chr(0x80 + len(lenstr)) + lenstr
|
|
else:
|
|
self.content += byte_chr(len(val))
|
|
self.content += val
|
|
|
|
def encode(self, x):
|
|
if type(x) is bool:
|
|
if x:
|
|
self.encode_tlv(1, max_byte)
|
|
else:
|
|
self.encode_tlv(1, zero_byte)
|
|
elif (type(x) is int) or (type(x) is long):
|
|
self.encode_tlv(2, util.deflate_long(x))
|
|
elif type(x) is str:
|
|
self.encode_tlv(4, x)
|
|
elif (type(x) is list) or (type(x) is tuple):
|
|
self.encode_tlv(0x30, self.encode_sequence(x))
|
|
else:
|
|
raise BERException(
|
|
"Unknown type for encoding: {!r}".format(type(x))
|
|
)
|
|
|
|
@staticmethod
|
|
def encode_sequence(data):
|
|
ber = BER()
|
|
for item in data:
|
|
ber.encode(item)
|
|
return ber.asbytes()
|