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
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
|
/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/init_ctx.c */
/*
* Copyright 1994,1999,2000, 2002, 2003, 2007, 2008, 2009 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.
*/
/*
* Copyright (C) 1998 by the FundsXpress, INC.
*
* 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 FundsXpress. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. FundsXpress makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include "k5-int.h"
#include "int-proto.h"
#include "os-proto.h"
#include <ctype.h>
#include "brand.c"
#include "../krb5_libinit.h"
static krb5_enctype default_enctype_list[] = {
ENCTYPE_AES256_CTS_HMAC_SHA1_96, ENCTYPE_AES128_CTS_HMAC_SHA1_96,
ENCTYPE_AES256_CTS_HMAC_SHA384_192, ENCTYPE_AES128_CTS_HMAC_SHA256_128,
ENCTYPE_DES3_CBC_SHA1,
ENCTYPE_ARCFOUR_HMAC,
ENCTYPE_CAMELLIA128_CTS_CMAC, ENCTYPE_CAMELLIA256_CTS_CMAC,
0
};
#if (defined(_WIN32))
extern krb5_error_code krb5_vercheck();
extern void krb5_win_ccdll_load(krb5_context context);
#endif
#define DEFAULT_CLOCKSKEW 300 /* 5 min */
static krb5_error_code
get_integer(krb5_context ctx, const char *name, int def_val, int *int_out)
{
krb5_error_code retval;
retval = profile_get_integer(ctx->profile, KRB5_CONF_LIBDEFAULTS,
name, NULL, def_val, int_out);
if (retval)
TRACE_PROFILE_ERR(ctx, name, KRB5_CONF_LIBDEFAULTS, retval);
return retval;
}
static krb5_error_code
get_boolean(krb5_context ctx, const char *name, int def_val, int *boolean_out)
{
krb5_error_code retval;
retval = profile_get_boolean(ctx->profile, KRB5_CONF_LIBDEFAULTS,
name, NULL, def_val, boolean_out);
if (retval)
TRACE_PROFILE_ERR(ctx, name, KRB5_CONF_LIBDEFAULTS, retval);
return retval;
}
static krb5_error_code
get_tristate(krb5_context ctx, const char *name, const char *third_option,
int third_option_val, int def_val, int *val_out)
{
krb5_error_code retval;
char *str;
int match;
retval = profile_get_boolean(ctx->profile, KRB5_CONF_LIBDEFAULTS, name,
NULL, def_val, val_out);
if (retval != PROF_BAD_BOOLEAN)
return retval;
retval = profile_get_string(ctx->profile, KRB5_CONF_LIBDEFAULTS, name,
NULL, NULL, &str);
if (retval)
return retval;
match = (strcasecmp(third_option, str) == 0);
free(str);
if (!match)
return EINVAL;
*val_out = third_option_val;
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_init_context(krb5_context *context)
{
/*
* This is rather silly, but should improve our chances of
* retaining the krb5_brand array in the final linked library,
* better than a static variable that's unreferenced after
* optimization, or even a non-static symbol that's not exported
* from the library nor referenced from anywhere else in the
* library.
*
* If someday we grow an API to actually return the string, we can
* get rid of this silliness.
*/
int my_zero = (krb5_brand[0] == 0);
return krb5_init_context_profile(NULL, my_zero, context);
}
krb5_error_code KRB5_CALLCONV
krb5_init_secure_context(krb5_context *context)
{
return krb5_init_context_profile(NULL, KRB5_INIT_CONTEXT_SECURE, context);
}
krb5_error_code
krb5int_init_context_kdc(krb5_context *context)
{
return krb5_init_context_profile(NULL, KRB5_INIT_CONTEXT_KDC, context);
}
krb5_error_code KRB5_CALLCONV
krb5_init_context_profile(profile_t profile, krb5_flags flags,
krb5_context *context_out)
{
krb5_context ctx = 0;
krb5_error_code retval;
int tmp;
char *plugin_dir = NULL;
/* Verify some assumptions. If the assumptions hold and the
compiler is optimizing, this should result in no code being
executed. If we're guessing "unsigned long long" instead
of using uint64_t, the possibility does exist that we're
wrong. */
{
uint64_t i64;
assert(sizeof(i64) == 8);
i64 = 0, i64--, i64 >>= 62;
assert(i64 == 3);
i64 = 1, i64 <<= 31, i64 <<= 31, i64 <<= 1;
assert(i64 != 0);
i64 <<= 1;
assert(i64 == 0);
}
retval = krb5int_initialize_library();
if (retval)
return retval;
#if (defined(_WIN32))
/*
* Load the krbcc32.dll if necessary. We do this here so that
* we know to use API: later on during initialization.
* The context being NULL is ok.
*/
krb5_win_ccdll_load(ctx);
/*
* krb5_vercheck() is defined in win_glue.c, and this is
* where we handle the timebomb and version server checks.
*/
retval = krb5_vercheck();
if (retval)
return retval;
#endif
*context_out = NULL;
ctx = calloc(1, sizeof(struct _krb5_context));
if (!ctx)
return ENOMEM;
ctx->magic = KV5M_CONTEXT;
ctx->profile_secure = (flags & KRB5_INIT_CONTEXT_SECURE) != 0;
retval = k5_os_init_context(ctx, profile, flags);
if (retval)
goto cleanup;
ctx->trace_callback = NULL;
#ifndef DISABLE_TRACING
if (!ctx->profile_secure)
k5_init_trace(ctx);
#endif
retval = get_boolean(ctx, KRB5_CONF_ALLOW_WEAK_CRYPTO, 0, &tmp);
if (retval)
goto cleanup;
ctx->allow_weak_crypto = tmp;
retval = get_boolean(ctx, KRB5_CONF_ALLOW_DES3, 0, &tmp);
if (retval)
goto cleanup;
ctx->allow_des3 = tmp;
retval = get_boolean(ctx, KRB5_CONF_ALLOW_RC4, 0, &tmp);
if (retval)
goto cleanup;
ctx->allow_rc4 = tmp;
retval = get_boolean(ctx, KRB5_CONF_IGNORE_ACCEPTOR_HOSTNAME, 0, &tmp);
if (retval)
goto cleanup;
ctx->ignore_acceptor_hostname = tmp;
retval = get_boolean(ctx, KRB5_CONF_ENFORCE_OK_AS_DELEGATE, 0, &tmp);
if (retval)
goto cleanup;
ctx->enforce_ok_as_delegate = tmp;
retval = get_tristate(ctx, KRB5_CONF_DNS_CANONICALIZE_HOSTNAME, "fallback",
CANONHOST_FALLBACK, 1, &tmp);
if (retval)
goto cleanup;
ctx->dns_canonicalize_hostname = tmp;
ctx->default_realm = 0;
get_integer(ctx, KRB5_CONF_CLOCKSKEW, DEFAULT_CLOCKSKEW, &tmp);
ctx->clockskew = tmp;
get_integer(ctx, KRB5_CONF_KDC_DEFAULT_OPTIONS, KDC_OPT_RENEWABLE_OK,
&tmp);
ctx->kdc_default_options = tmp;
#define DEFAULT_KDC_TIMESYNC 1
get_integer(ctx, KRB5_CONF_KDC_TIMESYNC, DEFAULT_KDC_TIMESYNC, &tmp);
ctx->library_options = tmp ? KRB5_LIBOPT_SYNC_KDCTIME : 0;
retval = profile_get_string(ctx->profile, KRB5_CONF_LIBDEFAULTS,
KRB5_CONF_PLUGIN_BASE_DIR, 0,
DEFAULT_PLUGIN_BASE_DIR, &plugin_dir);
if (!retval)
retval = k5_expand_path_tokens(ctx, plugin_dir, &ctx->plugin_base_dir);
if (retval) {
TRACE_PROFILE_ERR(ctx, KRB5_CONF_PLUGIN_BASE_DIR,
KRB5_CONF_LIBDEFAULTS, retval);
goto cleanup;
}
/*
* We use a default file credentials cache of 3. See
* lib/krb5/krb/ccache/file/fcc.h for a description of the
* credentials cache types.
*
* Note: DCE 1.0.3a only supports a cache type of 1
* DCE 1.1 supports a cache type of 2.
*/
#define DEFAULT_CCACHE_TYPE 4
get_integer(ctx, KRB5_CONF_CCACHE_TYPE, DEFAULT_CCACHE_TYPE, &tmp);
ctx->fcc_default_format = tmp + 0x0500;
ctx->prompt_types = 0;
ctx->use_conf_ktypes = 0;
ctx->udp_pref_limit = -1;
/* It's OK if this fails */
(void)profile_get_string(ctx->profile, KRB5_CONF_LIBDEFAULTS,
KRB5_CONF_ERR_FMT, NULL, NULL, &ctx->err_fmt);
*context_out = ctx;
ctx = NULL;
cleanup:
profile_release_string(plugin_dir);
krb5_free_context(ctx);
return retval;
}
void KRB5_CALLCONV
krb5_free_context(krb5_context ctx)
{
if (ctx == NULL)
return;
k5_os_free_context(ctx);
free(ctx->tgs_etypes);
ctx->tgs_etypes = NULL;
free(ctx->default_realm);
ctx->default_realm = 0;
krb5_clear_error_message(ctx);
free(ctx->err_fmt);
#ifndef DISABLE_TRACING
if (ctx->trace_callback)
ctx->trace_callback(ctx, NULL, ctx->trace_callback_data);
#endif
k5_ccselect_free_context(ctx);
k5_hostrealm_free_context(ctx);
k5_localauth_free_context(ctx);
k5_plugin_free_context(ctx);
free(ctx->plugin_base_dir);
free(ctx->tls);
ctx->magic = 0;
free(ctx);
}
/*
* Set the desired default ktypes, making sure they are valid.
*/
krb5_error_code KRB5_CALLCONV
krb5_set_default_tgs_enctypes(krb5_context context, const krb5_enctype *etypes)
{
krb5_error_code code;
krb5_enctype *list;
size_t src, dst;
if (etypes) {
/* Empty list passed in. */
if (etypes[0] == 0)
return EINVAL;
code = k5_copy_etypes(etypes, &list);
if (code)
return code;
/* Filter list in place to exclude invalid and (optionally) weak
* enctypes. */
for (src = dst = 0; list[src]; src++) {
if (!krb5_c_valid_enctype(list[src]))
continue;
if (!context->allow_weak_crypto
&& krb5int_c_weak_enctype(list[src]))
continue;
list[dst++] = list[src];
}
list[dst] = 0; /* Zero-terminate. */
if (dst == 0) {
free(list);
return KRB5_CONFIG_ETYPE_NOSUPP;
}
} else {
list = NULL;
}
free(context->tgs_etypes);
context->tgs_etypes = list;
return 0;
}
/* Old name for above function. This is not a public API, but Samba (as of
* 2021-02-12) uses this name if it finds it in the library. */
krb5_error_code
krb5_set_default_tgs_ktypes(krb5_context context, const krb5_enctype *etypes);
krb5_error_code
krb5_set_default_tgs_ktypes(krb5_context context, const krb5_enctype *etypes)
{
return krb5_set_default_tgs_enctypes(context, etypes);
}
/*
* Add etype to, or remove etype from, the zero-terminated list *list_ptr,
* reallocating if the list size changes. Filter out weak enctypes if
* allow_weak is false. If memory allocation fails, set *list_ptr to NULL and
* do nothing for subsequent operations.
*/
static void
mod_list(krb5_enctype etype, krb5_boolean add, krb5_boolean allow_weak,
krb5_enctype **list_ptr)
{
size_t i;
krb5_enctype *list = *list_ptr;
/* Stop now if a previous allocation failed or the enctype is filtered. */
if (list == NULL || (!allow_weak && krb5int_c_weak_enctype(etype)))
return;
if (add) {
/* Count entries; do nothing if etype is a duplicate. */
for (i = 0; list[i] != 0; i++) {
if (list[i] == etype)
return;
}
/* Make room for the new entry and add it. */
list = realloc(list, (i + 2) * sizeof(krb5_enctype));
if (list != NULL) {
list[i] = etype;
list[i + 1] = 0;
}
} else {
/* Look for etype in the list. */
for (i = 0; list[i] != 0; i++) {
if (list[i] != etype)
continue;
/* Perform removal. */
for (; list[i + 1] != 0; i++)
list[i] = list[i + 1];
list[i] = 0;
list = realloc(list, (i + 1) * sizeof(krb5_enctype));
break;
}
}
/* Update *list_ptr, freeing the old value if realloc failed. */
if (list == NULL)
free(*list_ptr);
*list_ptr = list;
}
/*
* Set *result to a zero-terminated list of enctypes resulting from
* parsing profstr. profstr may be modified during parsing.
*/
krb5_error_code
krb5int_parse_enctype_list(krb5_context context, const char *profkey,
char *profstr, krb5_enctype *default_list,
krb5_enctype **result)
{
char *token, *delim = " \t\r\n,", *save = NULL;
krb5_boolean sel, weak = context->allow_weak_crypto;
krb5_enctype etype, *list;
unsigned int i;
*result = NULL;
/* Set up an empty list. Allocation failure is detected at the end. */
list = malloc(sizeof(krb5_enctype));
if (list != NULL)
list[0] = 0;
/* Walk through the words in profstr. */
for (token = strtok_r(profstr, delim, &save); token;
token = strtok_r(NULL, delim, &save)) {
/* Determine if we are adding or removing enctypes. */
sel = TRUE;
if (*token == '+' || *token == '-')
sel = (*token++ == '+');
if (strcasecmp(token, "DEFAULT") == 0) {
/* Set all enctypes in the default list. */
for (i = 0; default_list[i]; i++)
mod_list(default_list[i], sel, weak, &list);
} else if (strcasecmp(token, "des3") == 0) {
mod_list(ENCTYPE_DES3_CBC_SHA1, sel, weak, &list);
} else if (strcasecmp(token, "aes") == 0) {
mod_list(ENCTYPE_AES256_CTS_HMAC_SHA1_96, sel, weak, &list);
mod_list(ENCTYPE_AES128_CTS_HMAC_SHA1_96, sel, weak, &list);
mod_list(ENCTYPE_AES256_CTS_HMAC_SHA384_192, sel, weak, &list);
mod_list(ENCTYPE_AES128_CTS_HMAC_SHA256_128, sel, weak, &list);
} else if (strcasecmp(token, "rc4") == 0) {
mod_list(ENCTYPE_ARCFOUR_HMAC, sel, weak, &list);
} else if (strcasecmp(token, "camellia") == 0) {
mod_list(ENCTYPE_CAMELLIA256_CTS_CMAC, sel, weak, &list);
mod_list(ENCTYPE_CAMELLIA128_CTS_CMAC, sel, weak, &list);
} else if (krb5_string_to_enctype(token, &etype) == 0) {
/* Set a specific enctype. */
mod_list(etype, sel, weak, &list);
} else {
TRACE_ENCTYPE_LIST_UNKNOWN(context, profkey, token);
}
}
if (list == NULL)
return ENOMEM;
if (list[0] == ENCTYPE_NULL) {
free(list);
return KRB5_CONFIG_ETYPE_NOSUPP;
}
*result = list;
return 0;
}
krb5_error_code
krb5_get_default_in_tkt_ktypes(krb5_context context, krb5_enctype **ktypes)
{
krb5_error_code ret;
char *profstr = NULL;
const char *profkey;
*ktypes = NULL;
profkey = KRB5_CONF_DEFAULT_TKT_ENCTYPES;
ret = profile_get_string(context->profile, KRB5_CONF_LIBDEFAULTS,
profkey, NULL, NULL, &profstr);
if (ret)
return ret;
if (profstr == NULL) {
profkey = KRB5_CONF_PERMITTED_ENCTYPES;
ret = profile_get_string(context->profile, KRB5_CONF_LIBDEFAULTS,
profkey, NULL, "DEFAULT", &profstr);
if (ret)
return ret;
}
ret = krb5int_parse_enctype_list(context, profkey, profstr,
default_enctype_list, ktypes);
profile_release_string(profstr);
return ret;
}
void
KRB5_CALLCONV
krb5_free_enctypes(krb5_context context, krb5_enctype *val)
{
free (val);
}
krb5_error_code KRB5_CALLCONV
krb5_get_tgs_ktypes(krb5_context context, krb5_const_principal princ,
krb5_enctype **ktypes)
{
krb5_error_code ret;
char *profstr = NULL;
const char *profkey;
*ktypes = NULL;
/* Use only profile configuration when use_conf_ktypes is set. */
if (!context->use_conf_ktypes && context->tgs_etypes != NULL)
return k5_copy_etypes(context->tgs_etypes, ktypes);
profkey = KRB5_CONF_DEFAULT_TGS_ENCTYPES;
ret = profile_get_string(context->profile, KRB5_CONF_LIBDEFAULTS,
profkey, NULL, NULL, &profstr);
if (ret)
return ret;
if (profstr == NULL) {
profkey = KRB5_CONF_PERMITTED_ENCTYPES;
ret = profile_get_string(context->profile, KRB5_CONF_LIBDEFAULTS,
profkey, NULL, "DEFAULT", &profstr);
if (ret)
return ret;
}
ret = krb5int_parse_enctype_list(context, profkey, profstr,
default_enctype_list, ktypes);
profile_release_string(profstr);
return ret;
}
krb5_error_code KRB5_CALLCONV
krb5_get_permitted_enctypes(krb5_context context, krb5_enctype **ktypes)
{
krb5_error_code ret;
char *profstr = NULL;
const char *profkey;
*ktypes = NULL;
if (context->tgs_etypes != NULL)
return k5_copy_etypes(context->tgs_etypes, ktypes);
profkey = KRB5_CONF_PERMITTED_ENCTYPES;
ret = profile_get_string(context->profile, KRB5_CONF_LIBDEFAULTS,
profkey, NULL, "DEFAULT", &profstr);
if (ret)
return ret;
ret = krb5int_parse_enctype_list(context, profkey, profstr,
default_enctype_list, ktypes);
profile_release_string(profstr);
return ret;
}
krb5_boolean
krb5_is_permitted_enctype(krb5_context context, krb5_enctype etype)
{
krb5_enctype *list;
krb5_boolean ret;
if (krb5_get_permitted_enctypes(context, &list))
return FALSE;
ret = k5_etypes_contains(list, etype);
krb5_free_enctypes(context, list);
return ret;
}
|