mirror of
https://github.com/jtesta/ssh-audit.git
synced 2024-06-30 19:24:46 +02:00
Refactor ssh connection within class for future improvements.
This commit is contained in:
Andris Raugulis
parent
8442dfac0e
commit
06992d7da6
133
ssh-audit.py
133
ssh-audit.py
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@ -27,8 +27,6 @@ from __future__ import print_function
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import os, io, sys, socket, struct
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SSH_BANNER = 'SSH-2.0-OpenSSH_7.2'
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SOCK_CONN_TIMEOUT = 3.0
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SOCK_READ_TIMEOUT = 5.0
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def usage():
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p = os.path.basename(sys.argv[0])
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@ -95,6 +93,7 @@ class Kex(object):
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class ReadBuf(object):
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def __init__(self, data = None):
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super(ReadBuf, self).__init__()
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self._buf = io.BytesIO(data) if data else io.BytesIO()
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self._len = len(data) if data else 0
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@ -118,19 +117,69 @@ class ReadBuf(object):
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list_size = self.read_int()
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return self.read(list_size).decode().split(',')
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class SockBuf(ReadBuf):
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def __init__(self, s):
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super(SockBuf, self).__init__()
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self.__sock = s
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class SSH(object):
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MSG_KEXINIT = 20
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MSG_NEWKEYS = 21
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MSG_KEXDH_INIT = 30
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MSG_KEXDH_REPLY = 32
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def recv(self, size = 2048):
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data = self.__sock.recv(size)
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pos = self._buf.tell()
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self._buf.seek(0, 2)
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self._buf.write(data)
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self._len += len(data)
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self._buf.seek(pos, 0)
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class Socket(ReadBuf):
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def __init__(self, host, port, cto = 3.0, rto = 5.0):
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super(SSH.Socket, self).__init__()
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try:
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self.__sock = socket.create_connection((host, port), cto)
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self.__sock.settimeout(rto)
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except Exception as e:
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out.fail('[fail] {}'.format(e))
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sys.exit(1)
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def __enter__(self):
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return self
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def recv(self, size = 2048):
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data = self.__sock.recv(size)
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pos = self._buf.tell()
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self._buf.seek(0, 2)
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self._buf.write(data)
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self._len += len(data)
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self._buf.seek(pos, 0)
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def send(self, data):
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self.__sock.send(data)
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def read_packet(self):
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block_size = 8
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if self.unread_len < block_size:
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self.recv()
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header = self.read(block_size)
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packet_size = struct.unpack('>I', header[:4])[0]
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rest = header[4:]
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lrest = len(rest)
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padding = ord(rest[0:1])
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packet_type = ord(rest[1:2])
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if (packet_size - lrest) % block_size != 0:
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out.fail('[exception] invalid ssh packet (block size)')
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sys.exit(1)
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rlen = packet_size - lrest
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if self.unread_len < rlen:
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self.recv()
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buf = self.read(rlen)
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packet = rest[2:] + buf[0:packet_size - lrest]
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payload = packet[0:packet_size - padding]
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return packet_type, payload
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def __del__(self):
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self.__cleanup()
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def __exit__(self, ex_type, ex_value, tb):
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self.__cleanup()
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def __cleanup(self):
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try:
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self.__sock.shutdown(socket.SHUT_RDWR)
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self.__sock.close()
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except:
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pass
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def get_ssh_ver(versions):
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tv = []
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@ -309,26 +358,6 @@ def process_kex(kex):
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process_algorithms('mac', kex.server.mac, maxlen)
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out.sep()
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def read_ssh_packet(sbuf):
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block_size = 8
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if sbuf.unread_len < block_size:
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sbuf.recv()
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header = sbuf.read(block_size)
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packet_size = struct.unpack('>I', header[:4])[0]
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rest = header[4:]
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lrest = len(rest)
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padding = ord(rest[0:1])
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packet_type = ord(rest[1:2])
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if (packet_size - lrest) % block_size != 0:
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out.fail('[exception] invalid ssh packet (block size)')
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sys.exit(1)
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rlen = packet_size - lrest
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if sbuf.unread_len < rlen:
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sbuf.recv()
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buf = sbuf.read(rlen)
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packet = rest[2:] + buf[0:packet_size - lrest]
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payload = packet[0:packet_size - padding]
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return packet_type, payload
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def parse_int(v):
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try:
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@ -355,30 +384,20 @@ def parse_args():
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def main():
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host, port = parse_args()
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s = None
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try:
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s = socket.create_connection((host, port), SOCK_CONN_TIMEOUT)
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s.settimeout(SOCK_READ_TIMEOUT)
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sbuf = SockBuf(s)
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s.send(SSH_BANNER.encode() + b'\r\n')
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sbuf.recv()
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banner = sbuf.read_line()
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out.head('# general')
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out.good('[info] banner: ' + banner)
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if banner.startswith('SSH-1.99-'):
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out.fail('[fail] protocol SSH1 enabled')
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packet_type, payload = read_ssh_packet(sbuf)
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if packet_type != 20:
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out.fail('[exception] did not receive MSG_KEXINIT (20), instead received unknown message ({0})'.format(packet_type))
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sys.exit(1)
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kex = Kex.parse(payload)
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process_kex(kex)
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except Exception as e:
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out.fail('[fail] {}'.format(e))
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s = SSH.Socket(host, port)
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s.send(SSH_BANNER.encode() + b'\r\n')
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s.recv()
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banner = s.read_line()
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out.head('# general')
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out.good('[info] banner: ' + banner)
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if banner.startswith('SSH-1.99-'):
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out.fail('[fail] protocol SSH1 enabled')
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packet_type, payload = s.read_packet()
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if packet_type != SSH.MSG_KEXINIT:
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out.fail('[exception] did not receive MSG_KEXINIT (20), instead received unknown message ({0})'.format(packet_type))
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sys.exit(1)
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finally:
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if s:
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s.close()
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kex = Kex.parse(payload)
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process_kex(kex)
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if __name__ == '__main__':
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out = Output()
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