forked from msktutil/msktutil
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathmsktkrb5.cpp
430 lines (362 loc) · 16 KB
/
msktkrb5.cpp
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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
/*
*----------------------------------------------------------------------------
*
* msktkrb5.cpp
*
* (C) 2004-2006 Dan Perry ([email protected])
* (C) 2006 Brian Elliott Finley ([email protected])
* (C) 2009-2010 Doug Engert ([email protected])
* (C) 2010 James Y Knight ([email protected])
* (C) 2010-2013 Ken Dreyer <ktdreyer at ktdreyer.com>
* (C) 2012-2017 Mark Proehl <mark at mproehl.net>
* (C) 2012-2017 Olaf Flebbe <of at oflebbe.de>
* (C) 2013-2017 Daniel Kobras <d.kobras at science-computing.de>
*
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*-----------------------------------------------------------------------------
*/
#include "msktutil.h"
#include <cctype>
#include <algorithm>
void get_default_keytab(msktutil_flags *flags)
{
char keytab_name[MAX_KEYTAB_NAME_LEN];
if (flags->keytab_file.empty()) {
/* Only set the field to a default if it's empty */
krb5_error_code ret = krb5_kt_default_name(g_context,
keytab_name,
MAX_KEYTAB_NAME_LEN);
if (ret) {
throw KRB5Exception("krb5_kt_default_name (get_default_keytab)",
ret);
}
flags->keytab_readname = std::string(keytab_name);
#ifdef HEIMDAL
ret = krb5_kt_default_modify_name(g_context,
keytab_name,
MAX_KEYTAB_NAME_LEN);
if (ret) {
throw KRB5Exception("krb5_kt_default_modify_name "
"(get_default_keytab)",
ret);
}
flags->keytab_writename = std::string(keytab_name);
if (!strncmp(keytab_name, "FILE:", 5)) {
/* Ignore opening FILE: part */
flags->keytab_file = std::string(keytab_name + 5);
} else {
/* untyped or unsupported--just try to use it as
* a filename for now */
flags->keytab_file = std::string(keytab_name);
}
#else
if (!strncmp(keytab_name, "FILE:", 5)) {
/* Ignore opening FILE: part */
flags->keytab_writename = "WRFILE:" + std::string(keytab_name + 5);
} else if (!strncmp(keytab_name, "WRFILE:", 7)) {
/* Already includes the opening WRFILE: part */
flags->keytab_writename = std::string(keytab_name);
} else {
/* No prefix to the keytab path */
flags->keytab_writename = "WRFILE:" + std::string(keytab_name);
}
/* Ignore opening WRFILE: part */
flags->keytab_file = flags->keytab_writename.substr(7);
#endif
VERBOSE("Obtaining the default keytab name: %s",
flags->keytab_readname.c_str());
} else {
flags->keytab_writename = "WRFILE:" + flags->keytab_file;
flags->keytab_readname = "FILE:" + flags->keytab_file;
}
}
/* Salt creation -- see windows-salt.txt */
std::string get_salt(msktutil_flags *flags)
{
std::string salt;
if (flags->use_service_account) {
if (flags->userPrincipalName.empty()) {
salt = sform("%s%s",
flags->realm_name.c_str(),
flags->sAMAccountName.c_str());
} else {
std::string upnsalt = flags->userPrincipalName;
upnsalt.erase(std::remove(upnsalt.begin(),
upnsalt.end(),
'/'),
upnsalt.end());
salt = sform("%s%s",
flags->realm_name.c_str(),
upnsalt.c_str());
}
} else {
std::string lower_accountname = flags->sAMAccountName_nodollar;
for(std::string::iterator it = lower_accountname.begin();
it != lower_accountname.end(); ++it) {
*it = std::tolower(*it);
}
salt = sform("%shost%s.%s",
flags->realm_name.c_str(),
lower_accountname.c_str(),
flags->lower_realm_name.c_str());
}
VERBOSE("Using salt: %s", salt.c_str());
return(salt);
}
int flush_keytab(msktutil_flags *flags)
{
VERBOSE("Flushing the keytab");
KRB5Keytab keytab(flags->keytab_writename);
std::vector<KRB5KeytabEntry> keytab_entries;
/* Extract a vector of keytab entries */
for (KRB5Keytab::cursor cursor(keytab); cursor.next(); ) {
keytab_entries.push_back(cursor);
}
for (std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin(); it != keytab_entries.end(); it++) {
KRB5Principal principal(it->principal());
std::string principal_name(principal.name());
size_t first_chr = principal_name.find('/') + 1;
size_t last_chr = principal_name.rfind('@');
std::string host = principal_name.substr(first_chr,
last_chr - first_chr);
if (host != flags->hostname) {
continue;
}
VERBOSE("Deleting %s (kvno=%d, enctype=%d) from keytab", principal_name.c_str(), it->kvno(), it->enctype());
keytab.removeEntry(principal, it->kvno(), it->enctype());
}
return ldap_flush_principals(flags);
}
void cleanup_keytab(msktutil_flags *flags)
{
VERBOSE("Cleaning the keytab");
KRB5Keytab keytab(flags->keytab_writename);
std::vector<KRB5KeytabEntry> keytab_entries;
/* Extract a vector of keytab entries */
for (KRB5Keytab::cursor cursor(keytab); cursor.next(); ) {
keytab_entries.push_back(cursor);
}
/* cleanup all entries that match --remove-enctype */
for (std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin(); it != keytab_entries.end(); it++) {
if (it->enctype() != flags->cleanup_enctype) {
continue;
}
KRB5Principal principal(it->principal());
VERBOSE("Deleting %s with kvno=%d, enctype=%d from keytab", principal.name().c_str(), it->kvno(), it->enctype());
keytab.removeEntry(principal, it->kvno(), it->enctype());
}
/* stop further processing unless --remove-old was given */
if (flags->cleanup_days == -1) {
return;
}
/* Sort vector by timestamp in descending order */
std::sort(keytab_entries.rbegin(), keytab_entries.rend());
std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin();
/* Empty list? Nothing to do */
if (it == keytab_entries.end())
return;
/* kvno of the first (== most recent) entry */
/* FIXME this will work nicely for multiple principals derived from the
* same account/password, but what about multiple independent principals
* within the same keytab? We could run the cleanup separately for each
* principal, but then there's no way to get rid of truly obsolete
* principals. */
krb5_kvno keep_kvno = it->kvno();
time_t min_keep_timestamp = time(0) - flags->cleanup_days * 60 * 60 * 24;
for (; it != keytab_entries.end(); it++) {
if (it->timestamp() > min_keep_timestamp || it->kvno() == keep_kvno) {
continue;
}
KRB5Principal principal(it->principal());
VERBOSE("Deleting %s (kvno=%d, enctype=%d) from keytab", principal.name().c_str(), it->kvno(), it->enctype());
keytab.removeEntry(principal, it->kvno(), it->enctype());
}
}
void remove_keytab_entries(msktutil_flags *flags,
std::vector<std::string> remove_principals)
{
KRB5Keytab keytab(flags->keytab_writename);
VERBOSE("Trying to remove entries for %s from keytab", flags->sAMAccountName.c_str());
std::vector<KRB5KeytabEntry> keytab_entries;
/* Extract a vector of keytab entries */
for (KRB5Keytab::cursor cursor(keytab); cursor.next(); ) {
keytab_entries.push_back(cursor);
}
for (std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin(); it != keytab_entries.end(); it++) {
KRB5Principal principal(it->principal());
std::string principal_name(principal.name());
for (size_t i = 0; i < remove_principals.size(); ++i) {
std::string remove_principal = remove_principals[i] + "@" + flags->realm_name;
if (principal_name.compare(remove_principal) == 0) {
VERBOSE("Deleting %s (kvno=%d, enctype=%d) from keytab", principal.name().c_str(), it->kvno(), it->enctype());
keytab.removeEntry(principal, it->kvno(), it->enctype());
}
}
}
}
void add_keytab_entries(msktutil_flags *flags)
{
KRB5Keytab keytab(flags->keytab_writename);
VERBOSE("Trying to add missing entries for %s to keytab", flags->sAMAccountName.c_str());
std::vector<KRB5KeytabEntry> keytab_entries;
std::vector<KRB5KeytabEntry> sam_entries;
std::string template_principal = flags->sAMAccountName + "@" + flags->realm_name;
/* Extract a vector of keytab entries */
for (KRB5Keytab::cursor cursor(keytab); cursor.next(); ) {
keytab_entries.push_back(cursor);
if (cursor.principal().name().compare(template_principal) == 0) {
sam_entries.push_back(cursor);
}
}
for (size_t i = 0; i < flags->ad_principals.size(); ++i) {
/* We look at all keytab entries that match the account name
* and fetch their kvno, enctype and key. If an entry for the
* principal that needs to be added already exists, we do
* nothing. If not, we are adding it by using the fetched keys
* from the account name entry. Doing it this way we are able
* to add service principals without changing the account
* password.
*/
VERBOSE("Checking if %s needs to be added to keytab", flags->ad_principals[i].c_str());
std::string add_principal = flags->ad_principals[i] + "@" + flags->realm_name;
for (std::vector<KRB5KeytabEntry>::iterator sam = sam_entries.begin(); sam != sam_entries.end(); sam++) {
std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin();
for (; it != keytab_entries.end(); it++) {
if (sam->kvno() != it->kvno() || sam->enctype() != it->enctype()) {
continue;
}
if (add_principal.compare(KRB5Principal(it->principal()).name()) == 0) {
break;
}
}
if (it != keytab_entries.end()) {
/* Matching entry already present for this kvno and enctype */
continue;
}
VERBOSE("Adding %s (kvno=%d, enctype=%d) to keytab", add_principal.c_str(), sam->kvno(), sam->enctype());
KRB5Principal princ(add_principal);
krb5_keyblock keyblock(sam->keyblock());
keytab.addEntry(princ, sam->kvno(), keyblock);
}
}
}
void update_keytab(msktutil_flags *flags)
{
VERBOSE("Updating all entries for %s", flags->sAMAccountName.c_str());
add_principal_keytab(flags->sAMAccountName, flags);
if (!flags->use_service_account) {
add_principal_keytab(flags->sAMAccountName_uppercase, flags);
}
/* add upn */
if (!flags->userPrincipalName.empty()) {
add_principal_keytab(flags->userPrincipalName, flags);
}
for (size_t i = 0; i < flags->ad_principals.size(); ++i) {
if ((flags->userPrincipalName.empty()) ||
flags->userPrincipalName.compare(flags->ad_principals[i]) != 0) {
add_principal_keytab(flags->ad_principals[i], flags);
} else {
VERBOSE("Entries for SPN %s have already been added. Skipping ...",
flags->ad_principals[i].c_str()
);
}
}
}
static void prune_keytab(KRB5Keytab& keytab, KRB5Principal &principal, krb5_timestamp min_keep_timestamp)
{
std::vector<KRB5KeytabEntry> keytab_entries;
/* Extract a vector of keytab entries for this principal */
for (KRB5Keytab::cursor cursor(keytab); cursor.next(); ) {
if (cursor.principal().name() != principal.name())
continue;
keytab_entries.push_back(cursor);
}
/* Sort vector by timestamp in descending order */
std::sort(keytab_entries.rbegin(), keytab_entries.rend());
/* Now find the first entry older than min_keep_timestamp */
std::vector<KRB5KeytabEntry>::iterator it = keytab_entries.begin();
for (; it != keytab_entries.end(); it++) {
if (it->timestamp() < min_keep_timestamp)
break;
}
if (it == keytab_entries.end())
return;
/* Keys for this kvno may still be valid, but any older entries for
* different keys (different kvno) have definitely been stale for more
* than min_keep_timestamp, and can therefore be pruned. */
krb5_kvno keep_kvno = it->kvno();
for (; it != keytab_entries.end(); it++) {
if (it->kvno() == keep_kvno)
continue;
KRB5Principal principal(it->principal());
VERBOSE("Deleting %s (kvno=%d, enctype=%d) from keytab",
principal.name().c_str(), it->kvno(), it->enctype());
keytab.removeEntry(principal, it->kvno(), it->enctype());
}
}
void add_principal_keytab(const std::string &principal, msktutil_flags *flags)
{
std::string principal_string = "";
if (principal.find("@") != std::string::npos) {
principal_string = sform("%s", principal.c_str());
} else {
principal_string = sform("%s@%s",
principal.c_str(),
flags->realm_name.c_str());
}
VERBOSE("Adding principal to keytab: %s", principal_string.c_str());
VERBOSE("Using supportedEncryptionTypes: %d", flags->ad_supportedEncryptionTypes);
/* FIXME: Why do we use a fixed magic number instead of reusing
* flags->cleanup_days for update as well? */
krb5_timestamp min_keep_timestamp = time(NULL) - (7*24*60*60);
KRB5Principal princ(principal_string);
KRB5Keytab keytab(flags->keytab_writename);
prune_keytab(keytab, princ, min_keep_timestamp);
std::vector<int32_t> enc_types;
if (flags->ad_supportedEncryptionTypes & MS_KERB_ENCTYPE_DES_CBC_CRC) {
enc_types.push_back(ENCTYPE_DES_CBC_CRC);
}
if (flags->ad_supportedEncryptionTypes & MS_KERB_ENCTYPE_DES_CBC_MD5) {
enc_types.push_back(ENCTYPE_DES_CBC_MD5);
}
if (flags->ad_supportedEncryptionTypes & MS_KERB_ENCTYPE_RC4_HMAC_MD5) {
enc_types.push_back(ENCTYPE_ARCFOUR_HMAC);
}
#if HAVE_DECL_ENCTYPE_AES128_CTS_HMAC_SHA1_96
if (flags->ad_supportedEncryptionTypes &
MS_KERB_ENCTYPE_AES128_CTC_HMAC_SHA1_96) {
enc_types.push_back(ENCTYPE_AES128_CTS_HMAC_SHA1_96);
}
#endif
#if HAVE_DECL_ENCTYPE_AES256_CTS_HMAC_SHA1_96
if (flags->ad_supportedEncryptionTypes &
MS_KERB_ENCTYPE_AES256_CTS_HMAC_SHA1_96) {
enc_types.push_back(ENCTYPE_AES256_CTS_HMAC_SHA1_96);
}
#endif
std::string salt = get_salt(flags);
std::string password = flags->dont_change_password ?
flags->old_account_password : flags->password;
if (password.empty()) {
VERBOSE("No password available, skipping creation "
"of password-based keytab entries");
} else {
for(size_t i = 0; i < enc_types.size(); ++i) {
VERBOSE(" Adding entry of enctype 0x%x", enc_types[i]);
keytab.addEntry(princ, flags->kvno,
static_cast<krb5_enctype>(enc_types[i]),
password, salt);
}
}
}