ssh-audit/src/ssh_audit/ssh1_publickeymessage.py

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"""
The MIT License (MIT)
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.
"""
# pylint: disable=unused-import
from typing import Dict, List, Set, Sequence, Tuple, Iterable # noqa: F401
from typing import Callable, Optional, Union, Any # noqa: F401
from ssh_audit.ssh1 import SSH1
from ssh_audit.readbuf import ReadBuf
from ssh_audit.utils import Utils
from ssh_audit.writebuf import WriteBuf
class SSH1_PublicKeyMessage:
def __init__(self, cookie: bytes, skey: Tuple[int, int, int], hkey: Tuple[int, int, int], pflags: int, cmask: int, amask: int) -> None:
if len(skey) != 3:
raise ValueError('invalid server key pair: {}'.format(skey))
if len(hkey) != 3:
raise ValueError('invalid host key pair: {}'.format(hkey))
self.__cookie = cookie
self.__server_key = skey
self.__host_key = hkey
self.__protocol_flags = pflags
self.__supported_ciphers_mask = cmask
self.__supported_authentications_mask = amask
@property
def cookie(self) -> bytes:
return self.__cookie
@property
def server_key_bits(self) -> int:
return self.__server_key[0]
@property
def server_key_public_exponent(self) -> int:
return self.__server_key[1]
@property
def server_key_public_modulus(self) -> int:
return self.__server_key[2]
@property
def host_key_bits(self) -> int:
return self.__host_key[0]
@property
def host_key_public_exponent(self) -> int:
return self.__host_key[1]
@property
def host_key_public_modulus(self) -> int:
return self.__host_key[2]
@property
def host_key_fingerprint_data(self) -> bytes:
# pylint: disable=protected-access
mod = WriteBuf._create_mpint(self.host_key_public_modulus, False)
e = WriteBuf._create_mpint(self.host_key_public_exponent, False)
return mod + e
@property
def protocol_flags(self) -> int:
return self.__protocol_flags
@property
def supported_ciphers_mask(self) -> int:
return self.__supported_ciphers_mask
@property
def supported_ciphers(self) -> List[str]:
ciphers = []
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for i in range(len(SSH1.CIPHERS)): # pylint: disable=consider-using-enumerate
if self.__supported_ciphers_mask & (1 << i) != 0:
ciphers.append(Utils.to_text(SSH1.CIPHERS[i]))
return ciphers
@property
def supported_authentications_mask(self) -> int:
return self.__supported_authentications_mask
@property
def supported_authentications(self) -> List[str]:
auths = []
for i in range(1, len(SSH1.AUTHS)):
if self.__supported_authentications_mask & (1 << i) != 0:
auths.append(Utils.to_text(SSH1.AUTHS[i]))
return auths
def write(self, wbuf: 'WriteBuf') -> None:
wbuf.write(self.cookie)
wbuf.write_int(self.server_key_bits)
wbuf.write_mpint1(self.server_key_public_exponent)
wbuf.write_mpint1(self.server_key_public_modulus)
wbuf.write_int(self.host_key_bits)
wbuf.write_mpint1(self.host_key_public_exponent)
wbuf.write_mpint1(self.host_key_public_modulus)
wbuf.write_int(self.protocol_flags)
wbuf.write_int(self.supported_ciphers_mask)
wbuf.write_int(self.supported_authentications_mask)
@property
def payload(self) -> bytes:
wbuf = WriteBuf()
self.write(wbuf)
return wbuf.write_flush()
@classmethod
def parse(cls, payload: bytes) -> 'SSH1_PublicKeyMessage':
buf = ReadBuf(payload)
cookie = buf.read(8)
server_key_bits = buf.read_int()
server_key_exponent = buf.read_mpint1()
server_key_modulus = buf.read_mpint1()
skey = (server_key_bits, server_key_exponent, server_key_modulus)
host_key_bits = buf.read_int()
host_key_exponent = buf.read_mpint1()
host_key_modulus = buf.read_mpint1()
hkey = (host_key_bits, host_key_exponent, host_key_modulus)
pflags = buf.read_int()
cmask = buf.read_int()
amask = buf.read_int()
pkm = cls(cookie, skey, hkey, pflags, cmask, amask)
return pkm