# Copyright (C) 2011  Jeff Forcier <jeff@bitprophet.org>
#
# This file is part of ssh.
#
# 'ssh' is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# 'ssh' is distrubuted in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with 'ssh'; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.

"""
Some unit tests for the key exchange protocols.
"""

from binascii import hexlify
import unittest
import ssh.util
from ssh.kex_group1 import KexGroup1
from ssh.kex_gex import KexGex
from ssh import Message


class FakeRng (object):
    def read(self, n):
        return chr(0xcc) * n


class FakeKey (object):
    def __str__(self):
        return 'fake-key'
    def sign_ssh_data(self, rng, 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):
    rng = FakeRng()
    local_version = 'SSH-2.0-ssh_1.0'
    remote_version = 'SSH-2.0-lame'
    local_kex_init = 'local-kex-init'
    remote_kex_init = 'remote-kex-init'

    def _send_message(self, m):
        self._message = m
    def _expect_packet(self, *t):
        self._expect = t
    def _set_K_H(self, K, H):
        self._K = K
        self._H = H
    def _verify_key(self, host_key, sig):
        self._verify = (host_key, sig)
    def _activate_outbound(self):
        self._activated = True
    def _log(self, level, s):
        pass
    def get_server_key(self):
        return FakeKey()
    def _get_modulus_pack(self):
        return FakeModulusPack()


class KexTest (unittest.TestCase):

    K = 14730343317708716439807310032871972459448364195094179797249681733965528989482751523943515690110179031004049109375612685505881911274101441415545039654102474376472240501616988799699744135291070488314748284283496055223852115360852283821334858541043710301057312858051901453919067023103730011648890038847384890504L

    def setUp(self):
        pass

    def tearDown(self):
        pass

    def test_1_group1_client(self):
        transport = FakeTransport()
        transport.server_mode = False
        kex = KexGroup1(transport)
        kex.start_kex()
        x = '1E000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.kex_group1._MSG_KEXDH_REPLY,), transport._expect)

        # fake "reply"
        msg = Message()
        msg.add_string('fake-host-key')
        msg.add_mpint(69)
        msg.add_string('fake-sig')
        msg.rewind()
        kex.parse_next(ssh.kex_group1._MSG_KEXDH_REPLY, msg)
        H = '00EA521556297D544B4D98745424593B1E6D59E1'
        self.assertEquals(self.K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        self.assertEquals(('fake-host-key', 'fake-sig'), transport._verify)
        self.assert_(transport._activated)

    def test_2_group1_server(self):
        transport = FakeTransport()
        transport.server_mode = True
        kex = KexGroup1(transport)
        kex.start_kex()
        self.assertEquals((ssh.kex_group1._MSG_KEXDH_INIT,), transport._expect)

        msg = Message()
        msg.add_mpint(69)
        msg.rewind()
        kex.parse_next(ssh.kex_group1._MSG_KEXDH_INIT, msg)
        H = 'D38CD8117B01531F518D7AE79BB9B0B6FA79B593'
        x = '1F0000000866616B652D6B6579000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D40000000866616B652D736967'
        self.assertEquals(self.K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assert_(transport._activated)

    def test_3_gex_client(self):
        transport = FakeTransport()
        transport.server_mode = False
        kex = KexGex(transport)
        kex.start_kex()
        x = '22000004000000080000002000'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.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(ssh.kex_gex._MSG_KEXDH_GEX_GROUP, msg)
        x = '20000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.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(ssh.kex_gex._MSG_KEXDH_GEX_REPLY, msg)
        H = '4D756503562803AF1F61D76C7943331B00AF5023'
        self.assertEquals(self.K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        self.assertEquals(('fake-host-key', 'fake-sig'), transport._verify)
        self.assert_(transport._activated)

    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, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.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(ssh.kex_gex._MSG_KEXDH_GEX_GROUP, msg)
        x = '20000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D4'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.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(ssh.kex_gex._MSG_KEXDH_GEX_REPLY, msg)
        H = 'F1234C57E0946943B3757806BCEB8DC0C95B8D4B'
        self.assertEquals(self.K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        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((ssh.kex_gex._MSG_KEXDH_GEX_REQUEST, ssh.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD), transport._expect)

        msg = Message()
        msg.add_int(1024)
        msg.add_int(2048)
        msg.add_int(4096)
        msg.rewind()
        kex.parse_next(ssh.kex_gex._MSG_KEXDH_GEX_REQUEST, msg)
        x = '1F0000008100FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF0000000102'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.kex_gex._MSG_KEXDH_GEX_INIT,), transport._expect)

        msg = Message()
        msg.add_mpint(12345)
        msg.rewind()
        kex.parse_next(ssh.kex_gex._MSG_KEXDH_GEX_INIT, msg)
        K = 67592995013596137876033460028393339951879041140378510871612128162185209509220726296697886624612526735888348020498716482757677848959420073720160491114319163078862905400020959196386947926388406687288901564192071077389283980347784184487280885335302632305026248574716290537036069329724382811853044654824945750581L
        H = 'C4EF42E2AAA44B6C3545AE0E940DEF177B59D349'
        x = '210000000866616B652D6B6579000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D40000000866616B652D736967'
        self.assertEquals(K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        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((ssh.kex_gex._MSG_KEXDH_GEX_REQUEST, ssh.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD), transport._expect)

        msg = Message()
        msg.add_int(2048)
        msg.rewind()
        kex.parse_next(ssh.kex_gex._MSG_KEXDH_GEX_REQUEST_OLD, msg)
        x = '1F0000008100FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF0000000102'
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assertEquals((ssh.kex_gex._MSG_KEXDH_GEX_INIT,), transport._expect)

        msg = Message()
        msg.add_mpint(12345)
        msg.rewind()
        kex.parse_next(ssh.kex_gex._MSG_KEXDH_GEX_INIT, msg)
        K = 67592995013596137876033460028393339951879041140378510871612128162185209509220726296697886624612526735888348020498716482757677848959420073720160491114319163078862905400020959196386947926388406687288901564192071077389283980347784184487280885335302632305026248574716290537036069329724382811853044654824945750581L
        H = '75A12FD284C6536BA768307579DBE6F9B5087BC6'
        x = '210000000866616B652D6B6579000000807E2DDB1743F3487D6545F04F1C8476092FB912B013626AB5BCEB764257D88BBA64243B9F348DF7B41B8C814A995E00299913503456983FFB9178D3CD79EB6D55522418A8ABF65375872E55938AB99A84A0B5FC8A1ECC66A7C3766E7E0F80B7CE2C9225FC2DD683F4764244B72963BBB383F529DCF0C5D17740B8A2ADBE9208D40000000866616B652D736967'
        self.assertEquals(K, transport._K)
        self.assertEquals(H, hexlify(transport._H).upper())
        self.assertEquals(x, hexlify(str(transport._message)).upper())
        self.assert_(transport._activated)