def test_implementation_refers_to_public_algo_lists(self):
t = Transport(
sock=Mock(),
disabled_algorithms={
"ciphers": ["aes128-cbc"],
"macs": ["hmac-md5"],
"keys": ["ssh-dss"],
"kex": ["diffie-hellman-group14-sha256"],
"compression": ["zlib"],
},
)
# Enable compression cuz otherwise disabling one option for it makes no
# sense...
t.use_compression(True)
# Effectively a random spot check, but kex init touches most/all of the
# algorithm lists so it's a good spot.
t._send_message = Mock()
t._send_kex_init()
# Cribbed from Transport._parse_kex_init, which didn't feel worth
# refactoring given all the vars involved :(
m = t._send_message.call_args[0][0]
m.rewind()
m.get_byte() # the msg type
m.get_bytes(16) # cookie, discarded
kexen = m.get_list()
server_keys = m.get_list()
ciphers = m.get_list()
m.get_list()
macs = m.get_list()
m.get_list()
compressions = m.get_list()
# OK, now we can actually check that our disabled algos were not
# included (as this message includes the full lists)
assert "aes128-cbc" not in ciphers
assert "hmac-md5" not in macs
assert "ssh-dss" not in server_keys
assert "diffie-hellman-group14-sha256" not in kexen
assert "zlib" not in compressions
def do_ssh_paramiko_connect_to(sock, host, port, username, password, proxy_command, remote_xpra, socket_dir, display_as_args, target):
from paramiko import SSHException, Transport, Agent, RSAKey, PasswordRequiredException
from paramiko.hostkeys import HostKeys
transport = Transport(sock)
transport.use_compression(False)
log("SSH transport %s", transport)
try:
transport.start_client()
except SSHException as e:
log("start_client()", exc_info=True)
raise InitException("SSH negotiation failed: %s" % e)
host_key = transport.get_remote_server_key()
assert host_key, "no remote server key"
log("remote_server_key=%s", keymd5(host_key))
if VERIFY_HOSTKEY:
host_keys = HostKeys()
host_keys_filename = None
KNOWN_HOSTS = get_ssh_known_hosts_files()
for known_hosts in KNOWN_HOSTS:
host_keys.clear()
try:
path = os.path.expanduser(known_hosts)
if os.path.exists(path):
host_keys.load(path)
log("HostKeys.load(%s) successful", path)
host_keys_filename = path
break
except IOError:
log("HostKeys.load(%s)", known_hosts, exc_info=True)
log("host keys=%s", host_keys)
keys = host_keys.lookup(host)
known_host_key = (keys or {}).get(host_key.get_name())
def keyname():
return host_key.get_name().replace("ssh-", "")
if host_key==known_host_key:
assert host_key
log("%s host key '%s' OK for host '%s'", keyname(), keymd5(host_key), host)
else:
if known_host_key:
log.warn("Warning: SSH server key mismatch")
qinfo = [
"WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!",
"IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!",
"Someone could be eavesdropping on you right now (man-in-the-middle attack)!",
"It is also possible that a host key has just been changed.",
"The fingerprint for the %s key sent by the remote host is" % keyname(),
keymd5(host_key),
]
if VERIFY_STRICT:
log.warn("Host key verification failed.")
#TODO: show alert with no option to accept key
qinfo += [
"Please contact your system administrator.",
"Add correct host key in %s to get rid of this message.",
"Offending %s key in %s" % (keyname(), host_keys_filename),
"ECDSA host key for %s has changed and you have requested strict checking." % keyname(),
]
sys.stderr.write(os.linesep.join(qinfo))
transport.close()
raise InitExit(EXIT_SSH_KEY_FAILURE, "SSH Host key has changed")
if not confirm_key(qinfo):
transport.close()
raise InitExit(EXIT_SSH_KEY_FAILURE, "SSH Host key has changed")
else:
assert (not keys) or (host_key.get_name() not in keys)
if not keys:
log.warn("Warning: unknown SSH host")
else:
log.warn("Warning: unknown %s SSH host key", keyname())
qinfo = [
"The authenticity of host '%s' can't be established." % (host,),
"%s key fingerprint is" % keyname(),
keymd5(host_key),
]
if not confirm_key(qinfo):
transport.close()
raise InitExit(EXIT_SSH_KEY_FAILURE, "Unknown SSH host '%s'" % host)
if ADD_KEY:
try:
if not host_keys_filename:
#the first one is the default,
#ie: ~/.ssh/known_hosts on posix
host_keys_filename = os.path.expanduser(KNOWN_HOSTS[0])
log("adding %s key for host '%s' to '%s'", keyname(), host, host_keys_filename)
if not os.path.exists(host_keys_filename):
keys_dir = os.path.dirname(host_keys_filename)
if not os.path.exists(keys_dir):
log("creating keys directory '%s'", keys_dir)
os.mkdir(keys_dir, 0o700)
elif not os.path.isdir(keys_dir):
log.warn("Warning: '%s' is not a directory")
log.warn(" key not saved")
if os.path.exists(keys_dir) and os.path.isdir(keys_dir):
log("creating known host file '%s'", host_keys_filename)
with umask_context(0o133):
with open(host_keys_filename, 'a+'):
pass
host_keys.add(host, host_key.get_name(), host_key)
host_keys.save(host_keys_filename)
except OSError as e:
log("failed to add key to '%s'", host_keys_filename)
log.error("Error adding key to '%s'", host_keys_filename)
log.error(" %s", e)
except Exception as e:
log.error("cannot add key", exc_info=True)
def auth_agent():
agent = Agent()
agent_keys = agent.get_keys()
log("agent keys: %s", agent_keys)
if agent_keys:
for agent_key in agent_keys:
log("trying ssh-agent key '%s'", keymd5(agent_key))
try:
transport.auth_publickey(username, agent_key)
if transport.is_authenticated():
log("authenticated using agent and key '%s'", keymd5(agent_key))
break
except SSHException:
log("agent key '%s' rejected", keymd5(agent_key), exc_info=True)
if not transport.is_authenticated():
log.info("agent authentication failed, tried %i key%s", len(agent_keys), engs(agent_keys))
def auth_publickey():
log("trying public key authentication")
for keyfile in ("id_rsa", "id_dsa"):
keyfile_path = osexpand(os.path.join("~/", ".ssh", keyfile))
if not os.path.exists(keyfile_path):
log("no keyfile at '%s'", keyfile_path)
continue
key = None
try:
key = RSAKey.from_private_key_file(keyfile_path)
except PasswordRequiredException:
log("%s keyfile requires a passphrase", keyfile_path)
passphrase = input_pass("please enter the passphrase for %s:" % (keyfile_path,))
if passphrase:
try:
key = RSAKey.from_private_key_file(keyfile_path, passphrase)
except SSHException as e:
log("from_private_key_file", exc_info=True)
log.info("cannot load key from file '%s':", keyfile_path)
log.info(" %s", e)
if key:
log("auth_publickey using %s: %s", keyfile_path, keymd5(key))
try:
transport.auth_publickey(username, key)
except SSHException as e:
log("key '%s' rejected", keyfile_path, exc_info=True)
log.info("SSH authentication using key '%s' failed:", keyfile_path)
log.info(" %s", e)
else:
if transport.is_authenticated():
break
def auth_none():
log("trying none authentication")
try:
transport.auth_none(username)
except SSHException as e:
log("auth_none()", exc_info=True)
def auth_password():
log("trying password authentication")
try:
transport.auth_password(username, password)
except SSHException as e:
log("auth_password(..)", exc_info=True)
log.info("SSH password authentication failed: %s", e)
banner = transport.get_banner()
if banner:
log.info("SSH server banner:")
for x in banner.splitlines():
log.info(" %s", x)
log("starting authentication")
if not transport.is_authenticated() and NONE_AUTH:
auth_none()
if not transport.is_authenticated() and PASSWORD_AUTH and password:
auth_password()
if not transport.is_authenticated() and AGENT_AUTH:
auth_agent()
if not transport.is_authenticated() and KEY_AUTH:
auth_publickey()
if not transport.is_authenticated() and PASSWORD_AUTH and not password:
for _ in range(1+PASSWORD_RETRY):
password = input_pass("please enter the SSH password for %s@%s" % (username, host))
if not password:
break
auth_password()
if transport.is_authenticated():
break
if not transport.is_authenticated():
transport.close()
raise InitException("SSH Authentication failed")
assert len(remote_xpra)>0
log("will try to run xpra from: %s", remote_xpra)
for xpra_cmd in remote_xpra:
try:
chan = transport.open_session(window_size=None, max_packet_size=0, timeout=60)
chan.set_name("find %s" % xpra_cmd)
except SSHException as e:
log("open_session", exc_info=True)
raise InitException("failed to open SSH session: %s" % e)
cmd = "which %s" % xpra_cmd
log("exec_command('%s')", cmd)
chan.exec_command(cmd)
#poll until the command terminates:
start = monotonic_time()
while not chan.exit_status_ready():
if monotonic_time()-start>10:
chan.close()
raise InitException("SSH test command '%s' timed out" % cmd)
log("exit status is not ready yet, sleeping")
time.sleep(0.01)
r = chan.recv_exit_status()
log("exec_command('%s')=%s", cmd, r)
chan.close()
if r!=0:
continue
cmd = xpra_cmd + " " + " ".join(shellquote(x) for x in proxy_command)
if socket_dir:
cmd += " \"--socket-dir=%s\"" % socket_dir
if display_as_args:
cmd += " "
cmd += " ".join(shellquote(x) for x in display_as_args)
log("cmd(%s, %s)=%s", proxy_command, display_as_args, cmd)
#see https://github.com/paramiko/paramiko/issues/175
#WINDOW_SIZE = 2097152
log("trying to open SSH session, window-size=%i, timeout=%i", WINDOW_SIZE, TIMEOUT)
try:
chan = transport.open_session(window_size=WINDOW_SIZE, max_packet_size=0, timeout=TIMEOUT)
chan.set_name("run-xpra")
except SSHException as e:
log("open_session", exc_info=True)
raise InitException("failed to open SSH session: %s" % e)
else:
log("channel exec_command(%s)" % cmd)
chan.exec_command(cmd)
info = {
"host" : host,
"port" : port,
}
conn = SSHSocketConnection(chan, sock, target, info)
conn.timeout = SOCKET_TIMEOUT
conn.start_stderr_reader()
child = None
conn.process = (child, "ssh", cmd)
return conn
raise Exception("all SSH remote proxy commands have failed")
