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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.
"""
from typing import Dict, List
from typing import Union
from ssh_audit.outputbuffer import OutputBuffer
from ssh_audit.readbuf import ReadBuf
from ssh_audit.ssh2_kexparty import SSH2_KexParty
from ssh_audit.writebuf import WriteBuf
class SSH2_Kex:
def __init__(self, outputbuffer: 'OutputBuffer', cookie: bytes, kex_algs: List[str], key_algs: List[str], cli: 'SSH2_KexParty', srv: 'SSH2_KexParty', follows: bool, unused: int = 0) -> None: # pylint: disable=too-many-arguments
self.__outputbuffer = outputbuffer
self.__cookie = cookie
self.__kex_algs = kex_algs
self.__key_algs = key_algs
self.__client = cli
self.__server = srv
self.__follows = follows
self.__unused = unused
self.__dh_modulus_sizes: Dict[str, int] = {}
self.__host_keys: Dict[str, Dict[str, Union[bytes, str, int]]] = {}
@property
def cookie(self) -> bytes:
return self.__cookie
@property
def kex_algorithms(self) -> List[str]:
return self.__kex_algs
@property
def key_algorithms(self) -> List[str]:
return self.__key_algs
# client_to_server
@property
def client(self) -> 'SSH2_KexParty':
return self.__client
# server_to_client
@property
def server(self) -> 'SSH2_KexParty':
return self.__server
@property
def follows(self) -> bool:
return self.__follows
@property
def unused(self) -> int:
return self.__unused
def set_dh_modulus_size(self, gex_alg: str, modulus_size: int) -> None:
self.__dh_modulus_sizes[gex_alg] = modulus_size
def dh_modulus_sizes(self) -> Dict[str, int]:
return self.__dh_modulus_sizes
def set_host_key(self, key_type: str, raw_hostkey_bytes: bytes, hostkey_size: int, ca_key_type: str, ca_key_size: int) -> None:
if key_type not in self.__host_keys:
self.__host_keys[key_type] = {'raw_hostkey_bytes': raw_hostkey_bytes, 'hostkey_size': hostkey_size, 'ca_key_type': ca_key_type, 'ca_key_size': ca_key_size}
else: # A host key may only have one CA signature...
self.__outputbuffer.d("WARNING: called SSH2_Kex.set_host_key() multiple times with the same host key type (%s)! Existing info: %r, %r, %r; Duplicate (ignored) info: %r, %r, %r" % (key_type, self.__host_keys[key_type]['hostkey_size'], self.__host_keys[key_type]['ca_key_type'], self.__host_keys[key_type]['ca_key_size'], hostkey_size, ca_key_type, ca_key_size))
def host_keys(self) -> Dict[str, Dict[str, Union[bytes, str, int]]]:
return self.__host_keys
def write(self, wbuf: 'WriteBuf') -> None:
wbuf.write(self.cookie)
wbuf.write_list(self.kex_algorithms)
wbuf.write_list(self.key_algorithms)
wbuf.write_list(self.client.encryption)
wbuf.write_list(self.server.encryption)
wbuf.write_list(self.client.mac)
wbuf.write_list(self.server.mac)
wbuf.write_list(self.client.compression)
wbuf.write_list(self.server.compression)
wbuf.write_list(self.client.languages)
wbuf.write_list(self.server.languages)
wbuf.write_bool(self.follows)
wbuf.write_int(self.__unused)
@property
def payload(self) -> bytes:
wbuf = WriteBuf()
self.write(wbuf)
return wbuf.write_flush()
@classmethod
def parse(cls, outputbuffer: 'OutputBuffer', payload: bytes) -> 'SSH2_Kex':
buf = ReadBuf(payload)
cookie = buf.read(16)
kex_algs = buf.read_list()
key_algs = buf.read_list()
cli_enc = buf.read_list()
srv_enc = buf.read_list()
cli_mac = buf.read_list()
srv_mac = buf.read_list()
cli_compression = buf.read_list()
srv_compression = buf.read_list()
cli_languages = buf.read_list()
srv_languages = buf.read_list()
follows = buf.read_bool()
unused = buf.read_int()
cli = SSH2_KexParty(cli_enc, cli_mac, cli_compression, cli_languages)
srv = SSH2_KexParty(srv_enc, srv_mac, srv_compression, srv_languages)
kex = cls(outputbuffer, cookie, kex_algs, key_algs, cli, srv, follows, unused)
return kex
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