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
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
|
/*
* Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5_locl.h"
#include "send_to_kdc_plugin.h"
struct send_to_kdc {
krb5_send_to_kdc_func func;
void *data;
};
/*
* send the data in `req' on the socket `fd' (which is datagram iff udp)
* waiting `tmout' for a reply and returning the reply in `rep'.
* iff limit read up to this many bytes
* returns 0 and data in `rep' if succesful, otherwise -1
*/
static int
recv_loop (int fd,
time_t tmout,
int udp,
size_t limit,
krb5_data *rep)
{
fd_set fdset;
struct timeval timeout;
int ret;
int nbytes;
if (fd >= FD_SETSIZE) {
return -1;
}
krb5_data_zero(rep);
do {
FD_ZERO(&fdset);
FD_SET(fd, &fdset);
timeout.tv_sec = tmout;
timeout.tv_usec = 0;
ret = select (fd + 1, &fdset, NULL, NULL, &timeout);
if (ret < 0) {
if (errno == EINTR)
continue;
return -1;
} else if (ret == 0) {
return 0;
} else {
void *tmp;
if (ioctl (fd, FIONREAD, &nbytes) < 0) {
krb5_data_free (rep);
return -1;
}
if(nbytes <= 0)
return 0;
if (limit)
nbytes = min(nbytes, limit - rep->length);
tmp = realloc (rep->data, rep->length + nbytes);
if (tmp == NULL) {
krb5_data_free (rep);
return -1;
}
rep->data = tmp;
ret = recv (fd, (char*)tmp + rep->length, nbytes, 0);
if (ret < 0) {
krb5_data_free (rep);
return -1;
}
rep->length += ret;
}
} while(!udp && (limit == 0 || rep->length < limit));
return 0;
}
/*
* Send kerberos requests and receive a reply on a udp or any other kind
* of a datagram socket. See `recv_loop'.
*/
static int
send_and_recv_udp(int fd,
time_t tmout,
const krb5_data *req,
krb5_data *rep)
{
if (send (fd, req->data, req->length, 0) < 0)
return -1;
return recv_loop(fd, tmout, 1, 0, rep);
}
/*
* `send_and_recv' for a TCP (or any other stream) socket.
* Since there are no record limits on a stream socket the protocol here
* is to prepend the request with 4 bytes of its length and the reply
* is similarly encoded.
*/
static int
send_and_recv_tcp(int fd,
time_t tmout,
const krb5_data *req,
krb5_data *rep)
{
unsigned char len[4];
unsigned long rep_len;
krb5_data len_data;
_krb5_put_int(len, req->length, 4);
if(net_write(fd, len, sizeof(len)) < 0)
return -1;
if(net_write(fd, req->data, req->length) < 0)
return -1;
if (recv_loop (fd, tmout, 0, 4, &len_data) < 0)
return -1;
if (len_data.length != 4) {
krb5_data_free (&len_data);
return -1;
}
_krb5_get_int(len_data.data, &rep_len, 4);
krb5_data_free (&len_data);
if (recv_loop (fd, tmout, 0, rep_len, rep) < 0)
return -1;
if(rep->length != rep_len) {
krb5_data_free (rep);
return -1;
}
return 0;
}
int
_krb5_send_and_recv_tcp(int fd,
time_t tmout,
const krb5_data *req,
krb5_data *rep)
{
return send_and_recv_tcp(fd, tmout, req, rep);
}
/*
* `send_and_recv' tailored for the HTTP protocol.
*/
static int
send_and_recv_http(int fd,
time_t tmout,
const char *prefix,
const krb5_data *req,
krb5_data *rep)
{
char *request;
char *str;
int ret;
int len = base64_encode(req->data, req->length, &str);
if(len < 0)
return -1;
asprintf(&request, "GET %s%s HTTP/1.0\r\n\r\n", prefix, str);
free(str);
if (request == NULL)
return -1;
ret = net_write (fd, request, strlen(request));
free (request);
if (ret < 0)
return ret;
ret = recv_loop(fd, tmout, 0, 0, rep);
if(ret)
return ret;
{
unsigned long rep_len;
char *s, *p;
s = realloc(rep->data, rep->length + 1);
if (s == NULL) {
krb5_data_free (rep);
return -1;
}
s[rep->length] = 0;
p = strstr(s, "\r\n\r\n");
if(p == NULL) {
krb5_data_zero(rep);
free(s);
return -1;
}
p += 4;
rep->data = s;
rep->length -= p - s;
if(rep->length < 4) { /* remove length */
krb5_data_zero(rep);
free(s);
return -1;
}
rep->length -= 4;
_krb5_get_int(p, &rep_len, 4);
if (rep_len != rep->length) {
krb5_data_zero(rep);
free(s);
return -1;
}
memmove(rep->data, p + 4, rep->length);
}
return 0;
}
static int
init_port(const char *s, int fallback)
{
if (s) {
int tmp;
sscanf (s, "%d", &tmp);
return htons(tmp);
} else
return fallback;
}
/*
* Return 0 if succesful, otherwise 1
*/
static int
send_via_proxy (krb5_context context,
const krb5_krbhst_info *hi,
const krb5_data *send_data,
krb5_data *receive)
{
char *proxy2 = strdup(context->http_proxy);
char *proxy = proxy2;
char *prefix;
char *colon;
struct addrinfo hints;
struct addrinfo *ai, *a;
int ret;
int s = -1;
char portstr[NI_MAXSERV];
if (proxy == NULL)
return ENOMEM;
if (strncmp (proxy, "http://", 7) == 0)
proxy += 7;
colon = strchr(proxy, ':');
if(colon != NULL)
*colon++ = '\0';
memset (&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
snprintf (portstr, sizeof(portstr), "%d",
ntohs(init_port (colon, htons(80))));
ret = getaddrinfo (proxy, portstr, &hints, &ai);
free (proxy2);
if (ret)
return krb5_eai_to_heim_errno(ret, errno);
for (a = ai; a != NULL; a = a->ai_next) {
s = socket (a->ai_family, a->ai_socktype, a->ai_protocol | SOCK_CLOEXEC);
if (s < 0)
continue;
rk_cloexec(s);
if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
close (s);
continue;
}
break;
}
if (a == NULL) {
freeaddrinfo (ai);
return 1;
}
freeaddrinfo (ai);
asprintf(&prefix, "http://%s/", hi->hostname);
if(prefix == NULL) {
close(s);
return 1;
}
ret = send_and_recv_http(s, context->kdc_timeout,
prefix, send_data, receive);
close (s);
free(prefix);
if(ret == 0 && receive->length != 0)
return 0;
return 1;
}
static krb5_error_code
send_via_plugin(krb5_context context,
krb5_krbhst_info *hi,
time_t timeout,
const krb5_data *send_data,
krb5_data *receive)
{
struct krb5_plugin *list = NULL, *e;
krb5_error_code ret;
ret = _krb5_plugin_find(context, PLUGIN_TYPE_DATA, KRB5_PLUGIN_SEND_TO_KDC, &list);
if(ret != 0 || list == NULL)
return KRB5_PLUGIN_NO_HANDLE;
for (e = list; e != NULL; e = _krb5_plugin_get_next(e)) {
krb5plugin_send_to_kdc_ftable *service;
void *ctx;
service = _krb5_plugin_get_symbol(e);
if (service->minor_version != 0)
continue;
(*service->init)(context, &ctx);
ret = (*service->send_to_kdc)(context, ctx, hi,
timeout, send_data, receive);
(*service->fini)(ctx);
if (ret == 0)
break;
if (ret != KRB5_PLUGIN_NO_HANDLE) {
krb5_set_error_message(context, ret,
N_("Plugin send_to_kdc failed to "
"lookup with error: %d", ""), ret);
break;
}
}
_krb5_plugin_free(list);
return KRB5_PLUGIN_NO_HANDLE;
}
/*
* Send the data `send' to one host from `handle` and get back the reply
* in `receive'.
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_sendto (krb5_context context,
const krb5_data *send_data,
krb5_krbhst_handle handle,
krb5_data *receive)
{
krb5_error_code ret;
int fd;
int i;
krb5_data_zero(receive);
for (i = 0; i < context->max_retries; ++i) {
krb5_krbhst_info *hi;
while (krb5_krbhst_next(context, handle, &hi) == 0) {
struct addrinfo *ai, *a;
if (context->send_to_kdc) {
struct send_to_kdc *s = context->send_to_kdc;
ret = (*s->func)(context, s->data, hi,
context->kdc_timeout, send_data, receive);
if (ret == 0 && receive->length != 0)
goto out;
continue;
}
ret = send_via_plugin(context, hi, context->kdc_timeout,
send_data, receive);
if (ret == 0 && receive->length != 0)
goto out;
else if (ret != KRB5_PLUGIN_NO_HANDLE)
continue;
if(hi->proto == KRB5_KRBHST_HTTP && context->http_proxy) {
if (send_via_proxy (context, hi, send_data, receive) == 0) {
ret = 0;
goto out;
}
continue;
}
ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
if (ret)
continue;
for (a = ai; a != NULL; a = a->ai_next) {
fd = socket (a->ai_family, a->ai_socktype | SOCK_CLOEXEC, a->ai_protocol);
if (fd < 0)
continue;
rk_cloexec(fd);
if (connect (fd, a->ai_addr, a->ai_addrlen) < 0) {
close (fd);
continue;
}
switch (hi->proto) {
case KRB5_KRBHST_HTTP :
ret = send_and_recv_http(fd, context->kdc_timeout,
"", send_data, receive);
break;
case KRB5_KRBHST_TCP :
ret = send_and_recv_tcp (fd, context->kdc_timeout,
send_data, receive);
break;
case KRB5_KRBHST_UDP :
ret = send_and_recv_udp (fd, context->kdc_timeout,
send_data, receive);
break;
}
close (fd);
if(ret == 0 && receive->length != 0)
goto out;
}
}
krb5_krbhst_reset(context, handle);
}
krb5_clear_error_message (context);
ret = KRB5_KDC_UNREACH;
out:
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_sendto_kdc(krb5_context context,
const krb5_data *send_data,
const krb5_realm *realm,
krb5_data *receive)
{
return krb5_sendto_kdc_flags(context, send_data, realm, receive, 0);
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_sendto_kdc_flags(krb5_context context,
const krb5_data *send_data,
const krb5_realm *realm,
krb5_data *receive,
int flags)
{
krb5_error_code ret;
krb5_sendto_ctx ctx;
ret = krb5_sendto_ctx_alloc(context, &ctx);
if (ret)
return ret;
krb5_sendto_ctx_add_flags(ctx, flags);
krb5_sendto_ctx_set_func(ctx, _krb5_kdc_retry, NULL);
ret = krb5_sendto_context(context, ctx, send_data, *realm, receive);
krb5_sendto_ctx_free(context, ctx);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_set_send_to_kdc_func(krb5_context context,
krb5_send_to_kdc_func func,
void *data)
{
free(context->send_to_kdc);
if (func == NULL) {
context->send_to_kdc = NULL;
return 0;
}
context->send_to_kdc = malloc(sizeof(*context->send_to_kdc));
if (context->send_to_kdc == NULL) {
krb5_set_error_message(context, ENOMEM,
N_("malloc: out of memory", ""));
return ENOMEM;
}
context->send_to_kdc->func = func;
context->send_to_kdc->data = data;
return 0;
}
krb5_error_code KRB5_LIB_FUNCTION
_krb5_copy_send_to_kdc_func(krb5_context context, krb5_context to)
{
if (context->send_to_kdc)
return krb5_set_send_to_kdc_func(to,
context->send_to_kdc->func,
context->send_to_kdc->data);
else
return krb5_set_send_to_kdc_func(to, NULL, NULL);
}
struct krb5_sendto_ctx_data {
int flags;
int type;
krb5_sendto_ctx_func func;
void *data;
};
krb5_error_code KRB5_LIB_FUNCTION
krb5_sendto_ctx_alloc(krb5_context context, krb5_sendto_ctx *ctx)
{
*ctx = calloc(1, sizeof(**ctx));
if (*ctx == NULL) {
krb5_set_error_message(context, ENOMEM,
N_("malloc: out of memory", ""));
return ENOMEM;
}
return 0;
}
void KRB5_LIB_FUNCTION
krb5_sendto_ctx_add_flags(krb5_sendto_ctx ctx, int flags)
{
ctx->flags |= flags;
}
int KRB5_LIB_FUNCTION
krb5_sendto_ctx_get_flags(krb5_sendto_ctx ctx)
{
return ctx->flags;
}
void KRB5_LIB_FUNCTION
krb5_sendto_ctx_set_type(krb5_sendto_ctx ctx, int type)
{
ctx->type = type;
}
void KRB5_LIB_FUNCTION
krb5_sendto_ctx_set_func(krb5_sendto_ctx ctx,
krb5_sendto_ctx_func func,
void *data)
{
ctx->func = func;
ctx->data = data;
}
void KRB5_LIB_FUNCTION
krb5_sendto_ctx_free(krb5_context context, krb5_sendto_ctx ctx)
{
memset(ctx, 0, sizeof(*ctx));
free(ctx);
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_sendto_context(krb5_context context,
krb5_sendto_ctx ctx,
const krb5_data *send_data,
const krb5_realm realm,
krb5_data *receive)
{
krb5_error_code ret;
krb5_krbhst_handle handle = NULL;
int type, freectx = 0;
int action;
krb5_data_zero(receive);
if (ctx == NULL) {
freectx = 1;
ret = krb5_sendto_ctx_alloc(context, &ctx);
if (ret)
return ret;
}
type = ctx->type;
if (type == 0) {
if ((ctx->flags & KRB5_KRBHST_FLAGS_MASTER) || context->use_admin_kdc)
type = KRB5_KRBHST_ADMIN;
else
type = KRB5_KRBHST_KDC;
}
if (send_data->length > context->large_msg_size)
ctx->flags |= KRB5_KRBHST_FLAGS_LARGE_MSG;
/* loop until we get back a appropriate response */
do {
action = KRB5_SENDTO_DONE;
krb5_data_free(receive);
if (handle == NULL) {
ret = krb5_krbhst_init_flags(context, realm, type,
ctx->flags, &handle);
if (ret) {
if (freectx)
krb5_sendto_ctx_free(context, ctx);
return ret;
}
}
ret = krb5_sendto(context, send_data, handle, receive);
if (ret)
break;
if (ctx->func) {
ret = (*ctx->func)(context, ctx, ctx->data, receive, &action);
if (ret)
break;
}
if (action != KRB5_SENDTO_CONTINUE) {
krb5_krbhst_free(context, handle);
handle = NULL;
}
} while (action != KRB5_SENDTO_DONE);
if (handle)
krb5_krbhst_free(context, handle);
if (ret == KRB5_KDC_UNREACH)
krb5_set_error_message(context, ret,
N_("unable to reach any KDC in realm %s", ""),
realm);
if (ret)
krb5_data_free(receive);
if (freectx)
krb5_sendto_ctx_free(context, ctx);
return ret;
}
krb5_error_code
_krb5_kdc_retry(krb5_context context, krb5_sendto_ctx ctx, void *data,
const krb5_data *reply, int *action)
{
krb5_error_code ret;
KRB_ERROR error;
if(krb5_rd_error(context, reply, &error))
return 0;
ret = krb5_error_from_rd_error(context, &error, NULL);
krb5_free_error_contents(context, &error);
switch(ret) {
case KRB5KRB_ERR_RESPONSE_TOO_BIG: {
if (krb5_sendto_ctx_get_flags(ctx) & KRB5_KRBHST_FLAGS_LARGE_MSG)
break;
krb5_sendto_ctx_add_flags(ctx, KRB5_KRBHST_FLAGS_LARGE_MSG);
*action = KRB5_SENDTO_RESTART;
break;
}
case KRB5KDC_ERR_SVC_UNAVAILABLE:
*action = KRB5_SENDTO_CONTINUE;
break;
}
return 0;
}
|