1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
# Copyright (C) 2011 by the Massachusetts Institute of Technology.
# All rights reserved.
#
# Export of this software from the United States of America may
# require a specific license from the United States Government.
# It is the responsibility of any person or organization contemplating
# export to obtain such a license before exporting.
#
# WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
# distribute this software and its documentation for any purpose and
# without fee is hereby granted, provided that the above copyright
# notice appear in all copies and that both that copyright notice and
# this permission notice appear in supporting documentation, and that
# the name of M.I.T. not be used in advertising or publicity pertaining
# to distribution of the software without specific, written prior
# permission. Furthermore if you modify this software you must label
# your software as modified software and not distribute it in such a
# fashion that it might be confused with the original M.I.T. software.
# M.I.T. makes no representations about the suitability of
# this software for any purpose. It is provided "as is" without express
# or implied warranty.
from k5test import *
def test_kvno(r, princ, test, env=None):
r.run([kvno, princ], env=env, expected_msg=princ)
def stop(*realms):
for r in realms:
r.stop()
# Verify that the princs appear as the service principals in the klist
# output for the realm r, in order.
def check_klist(r, princs):
out = r.run([klist])
count = 0
seen_header = False
for l in out.split('\n'):
if l.startswith('Valid starting'):
seen_header = True
continue
if not seen_header or l == '':
continue
if count >= len(princs):
fail('too many entries in klist output')
svcprinc = l.split()[4]
if svcprinc != princs[count]:
fail('saw service princ %s in klist output, expected %s' %
(svcprinc, princs[count]))
count += 1
if count != len(princs):
fail('not enough entries in klist output')
def tgt(r1, r2):
return 'krbtgt/%s@%s' % (r1.realm, r2.realm)
# Basic two-realm test with cross TGTs in both directions.
mark('two realms')
r1, r2 = cross_realms(2)
test_kvno(r1, r2.host_princ, 'basic r1->r2')
check_klist(r1, (tgt(r1, r1), tgt(r2, r1), r2.host_princ))
test_kvno(r2, r1.host_princ, 'basic r2->r1')
check_klist(r2, (tgt(r2, r2), tgt(r1, r2), r1.host_princ))
stop(r1, r2)
# Test the KDC domain walk for hierarchically arranged realms. The
# client in A.X will ask for a cross TGT to B.X, but A.X's KDC only
# has a TGT for the intermediate realm X, so it will return that
# instead. The client will use that to get a TGT for B.X.
mark('hierarchical realms')
r1, r2, r3 = cross_realms(3, xtgts=((0,1), (1,2)),
args=({'realm': 'A.X'}, {'realm': 'X'},
{'realm': 'B.X'}))
test_kvno(r1, r3.host_princ, 'KDC domain walk')
check_klist(r1, (tgt(r1, r1), r3.host_princ))
stop(r1, r2, r3)
# Test client capaths. The client in A will ask for a cross TGT to D,
# but A's KDC won't have it and won't know an intermediate to return.
# The client will walk its A->D capaths to get TGTs for B, then C,
# then D. The KDCs for C and D need capaths settings to avoid failing
# transited checks, including a capaths for A->C.
mark('client capaths')
capaths = {'capaths': {'A': {'D': ['B', 'C'], 'C': 'B'}}}
r1, r2, r3, r4 = cross_realms(4, xtgts=((0,1), (1,2), (2,3)),
args=({'realm': 'A'},
{'realm': 'B'},
{'realm': 'C', 'krb5_conf': capaths},
{'realm': 'D', 'krb5_conf': capaths}))
r1client = r1.special_env('client', False, krb5_conf=capaths)
test_kvno(r1, r4.host_princ, 'client capaths', r1client)
check_klist(r1, (tgt(r1, r1), tgt(r2, r1), tgt(r3, r2), tgt(r4, r3),
r4.host_princ))
stop(r1, r2, r3, r4)
# Test KDC capaths. The KDCs for A and B have appropriate capaths
# settings to determine intermediate TGTs to return, but the client
# has no idea.
mark('kdc capaths')
capaths = {'capaths': {'A': {'D': ['B', 'C'], 'C': 'B'}, 'B': {'D': 'C'}}}
r1, r2, r3, r4 = cross_realms(4, xtgts=((0,1), (1,2), (2,3)),
args=({'realm': 'A', 'krb5_conf': capaths},
{'realm': 'B', 'krb5_conf': capaths},
{'realm': 'C', 'krb5_conf': capaths},
{'realm': 'D', 'krb5_conf': capaths}))
r1client = r1.special_env('client', False, krb5_conf={'capaths': None})
test_kvno(r1, r4.host_princ, 'KDC capaths', r1client)
check_klist(r1, (tgt(r1, r1), r4.host_princ))
stop(r1, r2, r3, r4)
# A capaths value of '.' should enforce direct cross-realm, with no
# intermediate.
mark('direct cross-realm enforcement')
capaths = {'capaths': {'A.X': {'B.X': '.'}}}
r1, r2, r3 = cross_realms(3, xtgts=((0,1), (1,2)),
args=({'realm': 'A.X', 'krb5_conf': capaths},
{'realm': 'X'}, {'realm': 'B.X'}))
r1.run([kvno, r3.host_princ], expected_code=1,
expected_msg='Server krbtgt/B.X@A.X not found in Kerberos database')
stop(r1, r2, r3)
# Test transited error. The KDC for C does not recognize B as an
# intermediate realm for A->C, so it refuses to issue a service
# ticket.
mark('transited error (three realms)')
capaths = {'capaths': {'A': {'C': 'B'}}}
r1, r2, r3 = cross_realms(3, xtgts=((0,1), (1,2)),
args=({'realm': 'A', 'krb5_conf': capaths},
{'realm': 'B'}, {'realm': 'C'}))
r1.run([kvno, r3.host_princ], expected_code=1,
expected_msg='KDC policy rejects request')
check_klist(r1, (tgt(r1, r1), tgt(r3, r2)))
stop(r1, r2, r3)
# Test server transited checking. The KDC for C recognizes B as an
# intermediate realm for A->C, but the server environment does not.
# The server should honor the ticket if the transited-policy-checked
# flag is set, but not if it isn't. (It is only possible for our KDC
# to issue a ticket without the transited-policy-checked flag with
# reject_bad_transit=false.)
mark('server transited checking')
capaths = {'capaths': {'A': {'C': 'B'}}}
noreject = {'realms': {'$realm': {'reject_bad_transit': 'false'}}}
r1, r2, r3 = cross_realms(3, xtgts=((0,1), (1,2)),
args=({'realm': 'A', 'krb5_conf': capaths},
{'realm': 'B'},
{'realm': 'C', 'krb5_conf': capaths,
'kdc_conf': noreject}))
r3server = r3.special_env('server', False, krb5_conf={'capaths': None})
# Process a ticket with the transited-policy-checked flag set.
shutil.copy(r1.ccache, r1.ccache + '.copy')
r1.run(['./gcred', 'principal', r3.host_princ])
os.rename(r1.ccache, r3.ccache)
r3.run(['./rdreq', r3.host_princ], env=r3server, expected_msg='0 success')
# Try again with the transited-policy-checked flag unset.
os.rename(r1.ccache + '.copy', r1.ccache)
r1.run(['./gcred', '-t', 'principal', r3.host_princ])
os.rename(r1.ccache, r3.ccache)
r3.run(['./rdreq', r3.host_princ], env=r3server,
expected_msg='43 Illegal cross-realm ticket')
stop(r1, r2, r3)
# Test a four-realm scenario. This test used to result in an "Illegal
# cross-realm ticket" error as the KDC for D would refuse to process
# the cross-realm ticket from C. Now that we honor the
# transited-policy-checked flag in krb5_rd_req(), it instead issues a
# policy error as in the three-realm scenario.
mark('transited error (four realms)')
capaths = {'capaths': {'A': {'D': ['B', 'C'], 'C': 'B'}, 'B': {'D': 'C'}}}
r1, r2, r3, r4 = cross_realms(4, xtgts=((0,1), (1,2), (2,3)),
args=({'realm': 'A', 'krb5_conf': capaths},
{'realm': 'B', 'krb5_conf': capaths},
{'realm': 'C', 'krb5_conf': capaths},
{'realm': 'D'}))
r1.run([kvno, r4.host_princ], expected_code=1,
expected_msg='KDC policy rejects request')
check_klist(r1, (tgt(r1, r1), tgt(r4, r3)))
stop(r1, r2, r3, r4)
success('Cross-realm tests')
|
