/usr/lib/python3/dist-packages/paramiko/ber.py is in python3-paramiko 1.16.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | # 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)
raise BERException('Unknown ber encoding type %d (robey is lazy)' % 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: %s' % repr(type(x)))
@staticmethod
def encode_sequence(data):
ber = BER()
for item in data:
ber.encode(item)
return ber.asbytes()
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