ssh-audit/src/ssh_audit/utils.py

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"""
The MIT License (MIT)
Copyright (C) 2017-2020 Joe Testa (jtesta@positronsecurity.com)
Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
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.
"""
import ipaddress
import re
import sys
# pylint: disable=unused-import
from typing import Dict, List, Set, Sequence, Tuple, Iterable # noqa: F401
from typing import Callable, Optional, Union, Any # noqa: F401
class Utils:
@classmethod
def _type_err(cls, v: Any, target: str) -> TypeError:
return TypeError('cannot convert {} to {}'.format(type(v), target))
@classmethod
def to_bytes(cls, v: Union[bytes, str], enc: str = 'utf-8') -> bytes:
if isinstance(v, bytes):
return v
elif isinstance(v, str):
return v.encode(enc)
raise cls._type_err(v, 'bytes')
@classmethod
def to_text(cls, v: Union[str, bytes], enc: str = 'utf-8') -> str:
if isinstance(v, str):
return v
elif isinstance(v, bytes):
return v.decode(enc)
raise cls._type_err(v, 'unicode text')
@classmethod
def _is_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127) -> bool:
r = False
if isinstance(v, str):
for c in v:
i = cls.ctoi(c)
if not char_filter(i):
return r
r = True
return r
@classmethod
def _to_ascii(cls, v: str, char_filter: Callable[[int], bool] = lambda x: x <= 127, errors: str = 'replace') -> str:
if isinstance(v, str):
r = bytearray()
for c in v:
i = cls.ctoi(c)
if char_filter(i):
r.append(i)
else:
if errors == 'ignore':
continue
r.append(63)
return cls.to_text(r.decode('ascii'))
raise cls._type_err(v, 'ascii')
@classmethod
def is_ascii(cls, v: str) -> bool:
return cls._is_ascii(v)
@classmethod
def to_ascii(cls, v: str, errors: str = 'replace') -> str:
return cls._to_ascii(v, errors=errors)
@classmethod
def is_print_ascii(cls, v: str) -> bool:
return cls._is_ascii(v, lambda x: 126 >= x >= 32)
@classmethod
def to_print_ascii(cls, v: str, errors: str = 'replace') -> str:
return cls._to_ascii(v, lambda x: 126 >= x >= 32, errors)
@classmethod
def unique_seq(cls, seq: Sequence[Any]) -> Sequence[Any]:
seen = set() # type: Set[Any]
def _seen_add(x: Any) -> bool:
seen.add(x)
return False
if isinstance(seq, tuple):
return tuple(x for x in seq if x not in seen and not _seen_add(x))
else:
return [x for x in seq if x not in seen and not _seen_add(x)]
@classmethod
def ctoi(cls, c: Union[str, int]) -> int:
if isinstance(c, str):
return ord(c[0])
else:
return c
@staticmethod
def parse_int(v: Any) -> int:
try:
return int(v)
except Exception: # pylint: disable=bare-except
return 0
@staticmethod
def parse_float(v: Any) -> float:
try:
return float(v)
except Exception: # pylint: disable=bare-except
return -1.0
@staticmethod
def parse_host_and_port(host_and_port: str) -> Tuple[str, int]:
'''Parses a string into a tuple of its host and port. The port is 0 if not specified.'''
host = host_and_port
port = 0
mx = re.match(r'^\[([^\]]+)\](?::(\d+))?$', host_and_port)
if mx is not None:
host = mx.group(1)
port_str = mx.group(2)
if port_str is not None:
port = int(port_str)
else:
s = host_and_port.split(':')
if len(s) == 2:
host = s[0]
if len(s[1]) > 0:
port = int(s[1])
return host, port
@staticmethod
def is_ipv6_address(address: str) -> bool:
'''Returns True if address is an IPv6 address, otherwise False.'''
is_ipv6 = True
try:
ipaddress.IPv6Address(address)
except ipaddress.AddressValueError:
is_ipv6 = False
return is_ipv6
@staticmethod
def is_windows() -> bool:
return sys.platform in ['win32', 'cygwin']