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
|
/*
SSSD
Secrets Responder
Copyright (C) Simo Sorce <ssorce@redhat.com> 2016
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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "util/util.h"
#include "responder/common/responder.h"
#include "responder/secrets/secsrv.h"
#include "confdb/confdb.h"
#include <http_parser.h>
#define SEC_REQUEST_MAX_SIZE 65536
#define SEC_PACKET_MAX_RECV_SIZE 8192
struct sec_kvp {
char *name;
char *value;
};
struct sec_data {
char *data;
size_t length;
};
struct sec_proto_ctx {
http_parser_settings callbacks;
http_parser parser;
};
struct sec_req_ctx {
struct cli_ctx *cctx;
bool complete;
size_t total_size;
char *request_url;
struct sec_kvp *headers;
int num_headers;
struct sec_data body;
struct sec_data reply;
};
/* ##### Request Handling ##### */
static int error_403_reply(TALLOC_CTX *mem_ctx,
struct sec_data *reply)
{
reply->data = talloc_asprintf(mem_ctx,
"HTTP/1.1 403 Forbidden\r\n"
"Content-Length: 0\r\n"
"\r\n"
"<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
"<html>\r\n<head>\r\n<title>403 Forbidden</title></head>\r\n"
"<body>\r\n<h1>Forbidden</h1>\r\n"
"<p>You don't have permission to access the requested "
"resource.</p>\r\n<hr>\r\n</body>");
if (!reply->data) return ENOMEM;
reply->length = strlen(reply->data);
return EOK;
}
struct sec_http_request_state {
struct tevent_context *ev;
struct sec_req_ctx *secreq;
};
static struct tevent_req *sec_http_request_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct sec_req_ctx *secreq)
{
struct tevent_req *req;
struct sec_http_request_state *state;
int ret;
req = tevent_req_create(mem_ctx, &state, struct sec_http_request_state);
if (!req) return NULL;
state->ev = ev;
state->secreq = secreq;
/* Take it form here */
/* For now, always return an error */
ret = error_403_reply(state, &state->secreq->reply);
if (ret != EOK) goto done;
done:
if (ret != EOK) {
tevent_req_error(req, ret);
} else {
tevent_req_done(req);
}
return tevent_req_post(req, state->ev);
}
static int sec_http_request_recv(struct tevent_req *req)
{
TEVENT_REQ_RETURN_ON_ERROR(req);
return EOK;
}
/* --- */
static void
sec_http_request_done(struct tevent_req *req)
{
struct cli_ctx *cctx = tevent_req_callback_data(req, struct cli_ctx);
int ret;
ret = sec_http_request_recv(req);
if (ret != EOK) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to find reply, aborting client!\n");
talloc_free(cctx);
return;
}
/* Turn writable on so we can write back the reply */
TEVENT_FD_WRITEABLE(cctx->cfde);
}
static void sec_cmd_execute(struct cli_ctx *cctx)
{
struct sec_req_ctx *secreq;
struct tevent_req *req;
secreq = talloc_get_type(cctx->state_ctx, struct sec_req_ctx);
req = sec_http_request_send(secreq, cctx->ev, secreq);
if (!req) {
DEBUG(SSSDBG_CRIT_FAILURE,
"Failed to schedule secret retrieval\n.");
talloc_free(cctx);
return;
}
tevent_req_set_callback(req, sec_http_request_done, cctx);
}
/* ##### HTTP Parsing Callbacks ##### */
static void sec_append_string(TALLOC_CTX *memctx, char **dest,
const char *src, size_t len)
{
if (*dest) {
*dest = talloc_strndup_append_buffer(*dest, src, len);
} else {
*dest = talloc_strndup(memctx, src, len);
}
}
static bool sec_too_much_data(struct sec_req_ctx *req, size_t length)
{
req->total_size += length;
if (req->total_size > SEC_REQUEST_MAX_SIZE) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Request too big, aborting client!\n");
return true;
}
return false;
}
static int sec_on_message_begin(http_parser *parser)
{
DEBUG(SSSDBG_TRACE_INTERNAL, "HTTP Message parsing begins\n");
return 0;
}
static int sec_on_url(http_parser *parser,
const char *at, size_t length)
{
struct sec_req_ctx *req =
talloc_get_type(parser->data, struct sec_req_ctx);
if (sec_too_much_data(req, length)) return -1;
sec_append_string(req, &req->request_url, at, length);
if (!req->request_url) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to store URL, aborting client!\n");
return -1;
}
return 0;
}
static int sec_on_header_field(http_parser *parser,
const char *at, size_t length)
{
struct sec_req_ctx *req =
talloc_get_type(parser->data, struct sec_req_ctx);
int n = req->num_headers;
if (sec_too_much_data(req, length)) return -1;
if (!req->headers) {
req->headers = talloc_zero_array(req, struct sec_kvp, 10);
} else if ((n % 10 == 0) &&
(req->headers[n - 1].value)) {
req->headers = talloc_realloc(req, req->headers,
struct sec_kvp, n + 10);
if (req->headers) {
memset(&req->headers[n], 0, sizeof(struct sec_kvp) * 10);
}
}
if (!req->headers) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to store headers, aborting client!\n");
return -1;
}
if (!n || req->headers[n - 1].value) {
/* new field */
n++;
}
sec_append_string(req->headers, &req->headers[n - 1].name, at, length);
if (!req->headers[n - 1].name) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to store header name, aborting client!\n");
return -1;
}
return 0;
}
static int sec_on_header_value(http_parser *parser,
const char *at, size_t length)
{
struct sec_req_ctx *req =
talloc_get_type(parser->data, struct sec_req_ctx);
int n = req->num_headers;
if (sec_too_much_data(req, length)) return -1;
if (!req->headers) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Invalid headers pointer, aborting client!\n");
return -1;
}
if (req->headers[n].name && !req->headers[n].value) {
/* we increment on new value */
n = ++req->num_headers;
}
sec_append_string(req->headers, &req->headers[n - 1].value, at, length);
if (!req->headers[n - 1].value) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to store header value, aborting client!\n");
return -1;
}
return 0;
}
static int sec_on_headers_complete(http_parser *parser)
{
/* TODO: if message has no body we should return 1 */
return 0;
}
static int sec_on_body(http_parser *parser,
const char *at, size_t length)
{
struct sec_req_ctx *req =
talloc_get_type(parser->data, struct sec_req_ctx);
if (sec_too_much_data(req, length)) return -1;
sec_append_string(req, &req->body.data, at, length);
if (!req->body.data) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to store body, aborting client!\n");
return -1;
}
req->body.length += length;
return 0;
}
static int sec_on_message_complete(http_parser *parser)
{
struct sec_req_ctx *req =
talloc_get_type(parser->data, struct sec_req_ctx);
req->complete = true;
return 0;
}
/* ##### Communications ##### */
static int sec_send_data(int fd, struct sec_data *data)
{
ssize_t len;
errno = 0;
len = send(fd, data->data, data->length, 0);
if (len == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
return EAGAIN;
} else {
return errno;
}
}
if (len == 0) {
return EIO;
}
data->length -= len;
data->data += len;
return EOK;
}
static void sec_send(struct cli_ctx *cctx)
{
struct sec_req_ctx *req;
int ret;
req = talloc_get_type(cctx->state_ctx, struct sec_req_ctx);
ret = sec_send_data(cctx->cfd, &req->reply);
if (ret == EAGAIN) {
/* not all data was sent, loop again */
return;
}
if (ret != EOK) {
DEBUG(SSSDBG_FATAL_FAILURE, "Failed to send data, aborting client!\n");
talloc_free(cctx);
return;
}
/* ok all sent */
TEVENT_FD_NOT_WRITEABLE(cctx->cfde);
TEVENT_FD_READABLE(cctx->cfde);
talloc_zfree(cctx->state_ctx);
return;
}
static int sec_recv_data(int fd, struct sec_data *data)
{
ssize_t len;
errno = 0;
len = recv(fd, data->data, data->length, 0);
if (len == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
return EAGAIN;
} else {
return errno;
}
}
if (len == 0) {
return ENODATA;
}
data->length = len;
return EOK;
}
static void sec_recv(struct cli_ctx *cctx)
{
struct sec_proto_ctx *prctx;
struct sec_req_ctx *req;
char buffer[SEC_PACKET_MAX_RECV_SIZE];
struct sec_data data = { buffer,
SEC_PACKET_MAX_RECV_SIZE };
size_t len;
int ret;
prctx = talloc_get_type(cctx->protocol_ctx, struct sec_proto_ctx);
req = talloc_get_type(cctx->state_ctx, struct sec_req_ctx);
if (!req) {
/* A new request comes in, setup data structures */
req = talloc_zero(cctx, struct sec_req_ctx);
if (!req) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to setup request handlers, aborting client\n");
talloc_free(cctx);
return;
}
req->cctx = cctx;
cctx->state_ctx = req;
http_parser_init(&prctx->parser, HTTP_REQUEST);
prctx->parser.data = req;
}
ret = sec_recv_data(cctx->cfd, &data);
switch (ret) {
case ENODATA:
DEBUG(SSSDBG_TRACE_ALL,
"Client closed connection.\n");
talloc_free(cctx);
return;
case EAGAIN:
DEBUG(SSSDBG_TRACE_ALL,
"Interrupted before any data could be read, retry later\n");
return;
case EOK:
/* all fine */
break;
default:
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to receive data (%d, %s), aborting client\n",
ret, sss_strerror(ret));
talloc_free(cctx);
return;
}
len = http_parser_execute(&prctx->parser, &prctx->callbacks,
data.data, data.length);
if (len != data.length) {
DEBUG(SSSDBG_FATAL_FAILURE,
"Failed to parse request, aborting client!\n");
talloc_free(cctx);
return;
}
if (!req->complete) {
return;
}
/* do not read anymore, client is done sending */
TEVENT_FD_NOT_READABLE(cctx->cfde);
sec_cmd_execute(cctx);
}
static void sec_fd_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *ptr)
{
errno_t ret;
struct cli_ctx *cctx = talloc_get_type(ptr, struct cli_ctx);
/* Always reset the idle timer on any activity */
ret = reset_idle_timer(cctx);
if (ret != EOK) {
DEBUG(SSSDBG_CRIT_FAILURE,
"Could not create idle timer for client. "
"This connection may not auto-terminate\n");
/* Non-fatal, continue */
}
if (flags & TEVENT_FD_READ) {
sec_recv(cctx);
return;
}
if (flags & TEVENT_FD_WRITE) {
sec_send(cctx);
return;
}
}
static http_parser_settings sec_callbacks = {
.on_message_begin = sec_on_message_begin,
.on_url = sec_on_url,
.on_header_field = sec_on_header_field,
.on_header_value = sec_on_header_value,
.on_headers_complete = sec_on_headers_complete,
.on_body = sec_on_body,
.on_message_complete = sec_on_message_complete
};
int sec_connection_setup(struct cli_ctx *cctx)
{
struct sec_proto_ctx *protocol_ctx;
protocol_ctx = talloc_zero(cctx, struct sec_proto_ctx);
if (!protocol_ctx) return ENOMEM;
protocol_ctx->callbacks = sec_callbacks;
cctx->protocol_ctx = protocol_ctx;
cctx->cfd_handler = sec_fd_handler;
return EOK;
}
/* Dummy, not used here but required to link to other responder files */
struct cli_protocol_version *register_cli_protocol_version(void)
{
return NULL;
}
|
