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[project @ robey@lag.net-20060723235649-5f757e44908ffb31] 

attempt to implement support for kex-gex 'old' packet type, which is apparently used by putty (this would only affect paramiko in server mode)
This commit is contained in:
Robey Pointer 2006-07-23 16:56:49 -07:00
parent c925c41437
commit 787b0b461d
2 changed files with 110 additions and 17 deletions
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39
paramiko/kex_gex.py
View File

@ -31,7 +31,8 @@ from paramiko.message import Message
from paramiko.ssh_exception import SSHException
_MSG_KEXDH_GEX_GROUP, _MSG_KEXDH_GEX_INIT, _MSG_KEXDH_GEX_REPLY, _MSG_KEXDH_GEX_REQUEST = range(31, 35)
_MSG_KEXDH_GEX_REQUEST_OLD, _MSG_KEXDH_GEX_GROUP, _MSG_KEXDH_GEX_INIT, \
_MSG_KEXDH_GEX_REPLY, _MSG_KEXDH_GEX_REQUEST = range(30, 35)
class KexGex (object):
@ -49,15 +50,21 @@ class KexGex (object):
self.x = None
self.e = None
self.f = None
self.old_style = False
def start_kex(self):
def start_kex(self, _test_old_style=False):
if self.transport.server_mode:
self.transport._expect_packet(_MSG_KEXDH_GEX_REQUEST)
self.transport._expect_packet(_MSG_KEXDH_GEX_REQUEST, _MSG_KEXDH_GEX_REQUEST_OLD)
return
# request a bit range: we accept (min_bits) to (max_bits), but prefer
# (preferred_bits). according to the spec, we shouldn't pull the
# minimum up above 1024.
m = Message()
if _test_old_style:
# only used for unit tests: we shouldn't ever send this
m.add_byte(chr(_MSG_KEXDH_GEX_REQUEST_OLD))
m.add_int(self.preferred_bits)
else:
m.add_byte(chr(_MSG_KEXDH_GEX_REQUEST))
m.add_int(self.min_bits)
m.add_int(self.preferred_bits)
@ -74,6 +81,8 @@ class KexGex (object):
return self._parse_kexdh_gex_init(m)
elif ptype == _MSG_KEXDH_GEX_REPLY:
return self._parse_kexdh_gex_reply(m)
elif ptype == _MSG_KEXDH_GEX_REQUEST_OLD:
return self._parse_kexdh_gex_request_old(m)
raise SSHException('KexGex asked to handle packet type %d' % ptype)
@ -132,6 +141,28 @@ class KexGex (object):
self.transport._send_message(m)
self.transport._expect_packet(_MSG_KEXDH_GEX_INIT)
def _parse_kexdh_gex_request_old(self, m):
# same as above, but without min_bits or max_bits (used by older clients like putty)
self.preferred_bits = m.get_int()
# smoosh the user's preferred size into our own limits
if self.preferred_bits > self.max_bits:
self.preferred_bits = self.max_bits
if self.preferred_bits < self.min_bits:
self.preferred_bits = self.min_bits
# generate prime
pack = self.transport._get_modulus_pack()
if pack is None:
raise SSHException('Can\'t do server-side gex with no modulus pack')
self.transport._log(DEBUG, 'Picking p (~ %d bits)' % (self.preferred_bits,))
self.g, self.p = pack.get_modulus(self.min_bits, self.preferred_bits, self.max_bits)
m = Message()
m.add_byte(chr(_MSG_KEXDH_GEX_GROUP))
m.add_mpint(self.p)
m.add_mpint(self.g)
self.transport._send_message(m)
self.transport._expect_packet(_MSG_KEXDH_GEX_INIT)
self.old_style = True
def _parse_kexdh_gex_group(self, m):
self.p = m.get_mpint()
self.g = m.get_mpint()
@ -162,8 +193,10 @@ class KexGex (object):
hm.add(self.transport.remote_version, self.transport.local_version,
self.transport.remote_kex_init, self.transport.local_kex_init,
key)
if not self.old_style:
hm.add_int(self.min_bits)
hm.add_int(self.preferred_bits)
if not self.old_style:
hm.add_int(self.max_bits)
hm.add_mpint(self.p)
hm.add_mpint(self.g)

76
tests/test_kex.py
View File

@ -35,18 +35,21 @@ class FakeRandpool (object):
def get_bytes(self, n):
return chr(0xcc) * n
class FakeKey (object):
def __str__(self):
return 'fake-key'
def sign_ssh_data(self, randpool, H):
return 'fake-sig'
class FakeModulusPack (object):
P = 0xFFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFFL
G = 2
def get_modulus(self, min, ask, max):
return self.G, self.P
class FakeTransport (object):
randpool = FakeRandpool()
local_version = 'SSH-2.0-paramiko_1.0'
@ -56,7 +59,7 @@ class FakeTransport (object):
def _send_message(self, m):
self._message = m
def _expect_packet(self, t):
def _expect_packet(self, *t):
self._expect = t
def _set_K_H(self, K, H):
self._K = K
@ -90,7 +93,7 @@ class KexTest (unittest.TestCase):
kex.start_kex()
x = '1E000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals(paramiko.kex_group1._MSG_KEXDH_REPLY, transport._expect)
self.assertEquals((paramiko.kex_group1._MSG_KEXDH_REPLY,), transport._expect)
# fake "reply"
msg = Message()
@ -110,7 +113,7 @@ class KexTest (unittest.TestCase):
transport.server_mode = True
kex = KexGroup1(transport)
kex.start_kex()
self.assertEquals(paramiko.kex_group1._MSG_KEXDH_INIT, transport._expect)
self.assertEquals((paramiko.kex_group1._MSG_KEXDH_INIT,), transport._expect)
msg = Message()
msg.add_mpint(69)
@ -130,7 +133,7 @@ class KexTest (unittest.TestCase):
kex.start_kex()
x = '22000004000000080000002000'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals(paramiko.kex_gex._MSG_KEXDH_GEX_GROUP, transport._expect)
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_GROUP,), transport._expect)
msg = Message()
msg.add_mpint(FakeModulusPack.P)
@ -139,7 +142,7 @@ class KexTest (unittest.TestCase):
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_GROUP, msg)
x = '20000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals(paramiko.kex_gex._MSG_KEXDH_GEX_REPLY, transport._expect)
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_REPLY,), transport._expect)
msg = Message()
msg.add_string('fake-host-key')
@ -153,12 +156,42 @@ class KexTest (unittest.TestCase):
self.assertEquals(('fake-host-key', 'fake-sig'), transport._verify)
self.assert_(transport._activated)
def test_4_gex_server(self):
def test_4_gex_old_client(self):
transport = FakeTransport()
transport.server_mode = False
kex = KexGex(transport)
kex.start_kex(_test_old_style=True)
x = '1E00000800'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_GROUP,), transport._expect)
msg = Message()
msg.add_mpint(FakeModulusPack.P)
msg.add_mpint(FakeModulusPack.G)
msg.rewind()
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_GROUP, msg)
x = '20000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_REPLY,), transport._expect)
msg = Message()
msg.add_string('fake-host-key')
msg.add_mpint(69)
msg.add_string('fake-sig')
msg.rewind()
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_REPLY, msg)
H = 'A265563F2FA87F1A89BF007EE90D58BE2E4A4BD0'
self.assertEquals(self.K, transport._K)
self.assertEquals(H, paramiko.util.hexify(transport._H))
self.assertEquals(('fake-host-key', 'fake-sig'), transport._verify)
self.assert_(transport._activated)
def test_5_gex_server(self):
transport = FakeTransport()
transport.server_mode = True
kex = KexGex(transport)
kex.start_kex()
self.assertEquals(paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST, transport._expect)
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST, paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD), transport._expect)
msg = Message()
msg.add_int(1024)
@ -168,7 +201,7 @@ class KexTest (unittest.TestCase):
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST, msg)
x = '1F0000008100FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF0000000102'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals(paramiko.kex_gex._MSG_KEXDH_GEX_INIT, transport._expect)
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_INIT,), transport._expect)
msg = Message()
msg.add_mpint(12345)
@ -181,3 +214,30 @@ class KexTest (unittest.TestCase):
self.assertEquals(H, paramiko.util.hexify(transport._H))
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assert_(transport._activated)
def test_6_gex_server_with_old_client(self):
transport = FakeTransport()
transport.server_mode = True
kex = KexGex(transport)
kex.start_kex()
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST, paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD), transport._expect)
msg = Message()
msg.add_int(2048)
msg.rewind()
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD, msg)
x = '1F0000008100FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF0000000102'
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assertEquals((paramiko.kex_gex._MSG_KEXDH_GEX_INIT,), transport._expect)
msg = Message()
msg.add_mpint(12345)
msg.rewind()
kex.parse_next(paramiko.kex_gex._MSG_KEXDH_GEX_INIT, msg)
K = 67592995013596137876033460028393339951879041140378510871612128162185209509220726296697886624612526735888348020498716482757677848959420073720160491114319163078862905400020959196386947926388406687288901564192071077389283980347784184487280885335302632305026248574716290537036069329724382811853044654824945750581L
H = 'B41A06B2E59043CEFC1AE16EC31F1E2D12EC455B'
x = '210000000866616B652D6B6579000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D40000000866616B652D736967'
self.assertEquals(K, transport._K)
self.assertEquals(H, paramiko.util.hexify(transport._H))
self.assertEquals(x, paramiko.util.hexify(str(transport._message)))
self.assert_(transport._activated)