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source: mod_gnutls/src/gnutls_io.c @ b1f7f11

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Last change on this file since b1f7f11 was b1f7f11, checked in by Paul Querna <chip@…>, 18 years ago
hey hey, this is working code!
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1	/* ====================================================================
2	* Copyright 2004 Paul Querna
3	*
4	* Licensed under the Apache License, Version 2.0 (the "License");
5	* you may not use this file except in compliance with the License.
6	* You may obtain a copy of the License at
7	*
8	* http://www.apache.org/licenses/LICENSE-2.0
9	*
10	* Unless required by applicable law or agreed to in writing, software
11	* distributed under the License is distributed on an "AS IS" BASIS,
12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13	* See the License for the specific language governing permissions and
14	* limitations under the License.
15	*
16	*/
17
18	#include "mod_gnutls.h"
19
20	/**
21	* Describe how the GnuTLS Filter system works here
22	* - Basicly the same as what mod_ssl does with OpenSSL.
23	*
24	*/
25
26	#define HTTP_ON_HTTPS_PORT \
27	"GET /" CRLF
28
29	#define HTTP_ON_HTTPS_PORT_BUCKET(alloc) \
30	apr_bucket_immortal_create(HTTP_ON_HTTPS_PORT, \
31	sizeof(HTTP_ON_HTTPS_PORT) - 1, \
32	alloc)
33
34	static apr_status_t gnutls_io_filter_error(ap_filter_t * f,
35	apr_bucket_brigade * bb,
36	apr_status_t status)
37	{
38	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
39	apr_bucket *bucket;
40
41	switch (status) {
42	case HTTP_BAD_REQUEST:
43	/* log the situation */
44	ap_log_error(APLOG_MARK, APLOG_INFO, 0,
45	f->c->base_server,
46	"GnuTLS handshake failed: HTTP spoken on HTTPS port; "
47	"trying to send HTML error page");
48
49	ctxt->status = -1;
50
51	/* fake the request line */
52	bucket = HTTP_ON_HTTPS_PORT_BUCKET(f->c->bucket_alloc);
53	break;
54
55	default:
56	return status;
57	}
58
59	APR_BRIGADE_INSERT_TAIL(bb, bucket);
60	bucket = apr_bucket_eos_create(f->c->bucket_alloc);
61	APR_BRIGADE_INSERT_TAIL(bb, bucket);
62
63	return APR_SUCCESS;
64	}
65
66	static int char_buffer_read(mod_gnutls_char_buffer_t * buffer, char *in,
67	int inl)
68	{
69	if (!buffer->length) {
70	return 0;
71	}
72
73	if (buffer->length > inl) {
74	/* we have have enough to fill the caller's buffer */
75	memcpy(in, buffer->value, inl);
76	buffer->value += inl;
77	buffer->length -= inl;
78	}
79	else {
80	/* swallow remainder of the buffer */
81	memcpy(in, buffer->value, buffer->length);
82	inl = buffer->length;
83	buffer->value = NULL;
84	buffer->length = 0;
85	}
86
87	return inl;
88	}
89
90	static int char_buffer_write(mod_gnutls_char_buffer_t * buffer, char *in,
91	int inl)
92	{
93	buffer->value = in;
94	buffer->length = inl;
95	return inl;
96	}
97
98	/**
99	* From mod_ssl / ssl_engine_io.c
100	* This function will read from a brigade and discard the read buckets as it
101	* proceeds. It will read at most *len bytes.
102	*/
103	static apr_status_t brigade_consume(apr_bucket_brigade * bb,
104	apr_read_type_e block,
105	char c, apr_size_t len)
106	{
107	apr_size_t actual = 0;
108	apr_status_t status = APR_SUCCESS;
109
110	while (!APR_BRIGADE_EMPTY(bb)) {
111	apr_bucket *b = APR_BRIGADE_FIRST(bb);
112	const char *str;
113	apr_size_t str_len;
114	apr_size_t consume;
115
116	/* Justin points out this is an http-ism that might
117	* not fit if brigade_consume is added to APR. Perhaps
118	* apr_bucket_read(eos_bucket) should return APR_EOF?
119	* Then this becomes mainline instead of a one-off.
120	*/
121	if (APR_BUCKET_IS_EOS(b)) {
122	status = APR_EOF;
123	break;
124	}
125
126	/* The reason I'm not offering brigade_consume yet
127	* across to apr-util is that the following call
128	* illustrates how borked that API really is. For
129	* this sort of case (caller provided buffer) it
130	* would be much more trivial for apr_bucket_consume
131	* to do all the work that follows, based on the
132	* particular characteristics of the bucket we are
133	* consuming here.
134	*/
135	status = apr_bucket_read(b, &str, &str_len, block);
136
137	if (status != APR_SUCCESS) {
138	if (APR_STATUS_IS_EOF(status)) {
139	/* This stream bucket was consumed */
140	apr_bucket_delete(b);
141	continue;
142	}
143	break;
144	}
145
146	if (str_len > 0) {
147	/* Do not block once some data has been consumed */
148	block = APR_NONBLOCK_READ;
149
150	/* Assure we don't overflow. */
151	consume = (str_len + actual > len) ? len - actual : str_len;
152
153	memcpy(c, str, consume);
154
155	c += consume;
156	actual += consume;
157
158	if (consume >= b->length) {
159	/* This physical bucket was consumed */
160	apr_bucket_delete(b);
161	}
162	else {
163	/* Only part of this physical bucket was consumed */
164	b->start += consume;
165	b->length -= consume;
166	}
167	}
168	else if (b->length == 0) {
169	apr_bucket_delete(b);
170	}
171
172	/* This could probably be actual == *len, but be safe from stray
173	* photons. */
174	if (actual >= *len) {
175	break;
176	}
177	}
178
179	*len = actual;
180	return status;
181	}
182
183
184	static apr_status_t gnutls_io_input_read(mod_gnutls_handle_t * ctxt,
185	char buf, apr_size_t len)
186	{
187	apr_size_t wanted = *len;
188	apr_size_t bytes = 0;
189	int rc;
190
191	*len = 0;
192
193	/* If we have something leftover from last time, try that first. */
194	if ((bytes = char_buffer_read(&ctxt->input_cbuf, buf, wanted))) {
195	*len = bytes;
196	if (ctxt->input_mode == AP_MODE_SPECULATIVE) {
197	/* We want to rollback this read. */
198	if (ctxt->input_cbuf.length > 0) {
199	ctxt->input_cbuf.value -= bytes;
200	ctxt->input_cbuf.length += bytes;
201	}
202	else {
203	char_buffer_write(&ctxt->input_cbuf, buf, (int) bytes);
204	}
205	return APR_SUCCESS;
206	}
207	/* This could probably be *len == wanted, but be safe from stray
208	* photons.
209	*/
210	if (*len >= wanted) {
211	return APR_SUCCESS;
212	}
213	if (ctxt->input_mode == AP_MODE_GETLINE) {
214	if (memchr(buf, APR_ASCII_LF, *len)) {
215	return APR_SUCCESS;
216	}
217	}
218	else {
219	/* Down to a nonblock pattern as we have some data already
220	*/
221	ctxt->input_block = APR_NONBLOCK_READ;
222	}
223	}
224
225	while (1) {
226
227	rc = gnutls_record_recv(ctxt->session, buf + bytes, wanted - bytes);
228
229	if (rc > 0) {
230	*len += rc;
231	if (ctxt->input_mode == AP_MODE_SPECULATIVE) {
232	/* We want to rollback this read. */
233	char_buffer_write(&ctxt->input_cbuf, buf, rc);
234	}
235	return ctxt->input_rc;
236	}
237	else if (rc == 0) {
238	/* If EAGAIN, we will loop given a blocking read,
239	* otherwise consider ourselves at EOF.
240	*/
241	if (APR_STATUS_IS_EAGAIN(ctxt->input_rc)
242	\|\| APR_STATUS_IS_EINTR(ctxt->input_rc)) {
243	/* Already read something, return APR_SUCCESS instead.
244	* On win32 in particular, but perhaps on other kernels,
245	* a blocking call isn't 'always' blocking.
246	*/
247	if (*len > 0) {
248	ctxt->input_rc = APR_SUCCESS;
249	break;
250	}
251	if (ctxt->input_block == APR_NONBLOCK_READ) {
252	break;
253	}
254	}
255	else {
256	if (*len > 0) {
257	ctxt->input_rc = APR_SUCCESS;
258	}
259	else {
260	ctxt->input_rc = APR_EOF;
261	}
262	break;
263	}
264	}
265	else { /* (rc < 0) */
266
267	if (rc == GNUTLS_E_REHANDSHAKE) {
268	/* A client has asked for a new Hankshake. Currently, we don't do it */
269	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->input_rc,
270	ctxt->c->base_server,
271	"GnuTLS: Error reading data. Client Requested a New Handshake."
272	" (%d) '%s'", rc, gnutls_strerror(rc));
273	}
274	else {
275	/* Some Other Error. Report it. Die. */
276	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->input_rc,
277	ctxt->c->base_server,
278	"GnuTLS: Error reading data. (%d) '%s'", rc,
279	gnutls_strerror(rc));
280	}
281
282	if (ctxt->input_rc == APR_SUCCESS) {
283	ctxt->input_rc = APR_EGENERAL;
284	}
285	break;
286	}
287	}
288	return ctxt->input_rc;
289	}
290
291	static apr_status_t gnutls_io_input_getline(mod_gnutls_handle_t * ctxt,
292	char buf, apr_size_t len)
293	{
294	const char *pos = NULL;
295	apr_status_t status;
296	apr_size_t tmplen = len, buflen = len, offset = 0;
297
298	*len = 0;
299
300	while (tmplen > 0) {
301	status = gnutls_io_input_read(ctxt, buf + offset, &tmplen);
302
303	if (status != APR_SUCCESS) {
304	return status;
305	}
306
307	*len += tmplen;
308
309	if ((pos = memchr(buf, APR_ASCII_LF, *len))) {
310	break;
311	}
312
313	offset += tmplen;
314	tmplen = buflen - offset;
315	}
316
317	if (pos) {
318	char *value;
319	int length;
320	apr_size_t bytes = pos - buf;
321
322	bytes += 1;
323	value = buf + bytes;
324	length = *len - bytes;
325
326	char_buffer_write(&ctxt->input_cbuf, value, length);
327
328	*len = bytes;
329	}
330
331	return APR_SUCCESS;
332	}
333
334
335	#define GNUTLS_HANDSHAKE_ATTEMPTS 10
336
337	static void gnutls_do_handshake(mod_gnutls_handle_t * ctxt)
338	{
339	int i, ret;
340
341	if (ctxt->status != 0)
342	return;
343	#if 0
344
345	for (i = GNUTLS_HANDSHAKE_ATTEMPTS; i > 0; i--) {
346	ret = gnutls_handshake(ctxt->session);
347	if (ret == GNUTLS_E_INTERRUPTED \|\| ret == GNUTLS_E_AGAIN) {
348	continue;
349	}
350
351	if (ret < 0) {
352	if (ret == GNUTLS_E_WARNING_ALERT_RECEIVED
353	\|\| ret == GNUTLS_E_FATAL_ALERT_RECEIVED) {
354	ret = gnutls_alert_get(ctxt->session);
355	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
356	"GnuTLS: Hanshake Alert (%d) '%s'.\n", ret,
357	gnutls_alert_get_name(ret));
358	}
359
360	gnutls_deinit(ctxt->session);
361	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
362	"GnuTLS: Handshake Failed (%d) '%s'", ret,
363	gnutls_strerror(ret));
364	ctxt->status = -1;
365	return;
366	}
367	else {
368	ctxt->status = 1;
369	return; /* all done with the handshake */
370	}
371	}
372	ctxt->status = -1;
373	return;
374	#else
375	ret = gnutls_handshake(ctxt->session);
376	if (ret < 0) {
377	if (ret == GNUTLS_E_WARNING_ALERT_RECEIVED
378	\|\| ret == GNUTLS_E_FATAL_ALERT_RECEIVED) {
379	ret = gnutls_alert_get(ctxt->session);
380	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
381	"GnuTLS: Hanshake Alert (%d) '%s'.\n", ret,
382	gnutls_alert_get_name(ret));
383	}
384
385	gnutls_deinit(ctxt->session);
386	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
387	"GnuTLS: Handshake Failed (%d) '%s'", ret,
388	gnutls_strerror(ret));
389	ctxt->status = -1;
390	return;
391	}
392	else {
393	ctxt->status = 1;
394	return; /* all done with the handshake */
395	}
396
397	#endif
398	}
399
400
401	apr_status_t mod_gnutls_filter_input(ap_filter_t * f,
402	apr_bucket_brigade * bb,
403	ap_input_mode_t mode,
404	apr_read_type_e block,
405	apr_off_t readbytes)
406	{
407	apr_status_t status = APR_SUCCESS;
408	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
409	apr_size_t len = sizeof(ctxt->input_buffer);
410
411	if (f->c->aborted) {
412	apr_bucket *bucket = apr_bucket_eos_create(f->c->bucket_alloc);
413	APR_BRIGADE_INSERT_TAIL(bb, bucket);
414	return APR_ECONNABORTED;
415	}
416
417	if (ctxt->status == 0) {
418	gnutls_do_handshake(ctxt);
419	}
420
421	if (ctxt->status < 0) {
422	// return ap_get_brigade(f->next, bb, mode, block, readbytes);
423	}
424
425	/* XXX: we don't currently support anything other than these modes. */
426	if (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE &&
427	mode != AP_MODE_SPECULATIVE && mode != AP_MODE_INIT) {
428	return APR_ENOTIMPL;
429	}
430
431	ctxt->input_mode = mode;
432	ctxt->input_block = block;
433
434	if (ctxt->input_mode == AP_MODE_READBYTES \|\|
435	ctxt->input_mode == AP_MODE_SPECULATIVE) {
436	/* Err. This is bad. readbytes can be a 64bit int! len.. is NOT */
437	if (readbytes < len) {
438	len = (apr_size_t) readbytes;
439	}
440	status = gnutls_io_input_read(ctxt, ctxt->input_buffer, &len);
441	}
442	else if (ctxt->input_mode == AP_MODE_GETLINE) {
443	status = gnutls_io_input_getline(ctxt, ctxt->input_buffer, &len);
444	}
445	else {
446	/* We have no idea what you are talking about, so return an error. */
447	return APR_ENOTIMPL;
448	}
449
450	if (status != APR_SUCCESS) {
451	return gnutls_io_filter_error(f, bb, status);
452	}
453
454	/* Create a transient bucket out of the decrypted data. */
455	if (len > 0) {
456	apr_bucket *bucket =
457	apr_bucket_transient_create(ctxt->input_buffer, len,
458	f->c->bucket_alloc);
459	APR_BRIGADE_INSERT_TAIL(bb, bucket);
460	}
461
462	return status;
463	}
464
465	apr_status_t mod_gnutls_filter_output(ap_filter_t * f,
466	apr_bucket_brigade * bb)
467	{
468	int ret;
469	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
470	apr_status_t status = APR_SUCCESS;
471	apr_read_type_e rblock = APR_NONBLOCK_READ;
472
473	if (f->c->aborted) {
474	apr_brigade_cleanup(bb);
475	return APR_ECONNABORTED;
476	}
477
478	if (ctxt->status == 0) {
479	gnutls_do_handshake(ctxt);
480	}
481
482	if (ctxt->status < 0) {
483	return ap_pass_brigade(f->next, bb);
484	}
485
486	while (!APR_BRIGADE_EMPTY(bb)) {
487	apr_bucket *bucket = APR_BRIGADE_FIRST(bb);
488	if (APR_BUCKET_IS_EOS(bucket) \|\| APR_BUCKET_IS_FLUSH(bucket)) {
489	/ TODO: GnuTLS doesn't have a special flush method? /
490	if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) {
491	return status;
492	}
493	break;
494	}
495	else if (AP_BUCKET_IS_EOC(bucket)) {
496	gnutls_bye(ctxt->session, GNUTLS_SHUT_WR);
497
498	if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) {
499	return status;
500	}
501	break;
502	}
503	else {
504	/* filter output */
505	const char *data;
506	apr_size_t len;
507
508	status = apr_bucket_read(bucket, &data, &len, rblock);
509
510	if (APR_STATUS_IS_EAGAIN(status)) {
511	rblock = APR_BLOCK_READ;
512	continue; /* and try again with a blocking read. */
513	}
514
515	rblock = APR_NONBLOCK_READ;
516
517	if (!APR_STATUS_IS_EOF(status) && (status != APR_SUCCESS)) {
518	break;
519	}
520
521	ret = gnutls_record_send(ctxt->session, data, len);
522
523	if (ret < 0) {
524	/* error sending output */
525	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->output_rc,
526	ctxt->c->base_server,
527	"GnuTLS: Error writing data."
528	" (%d) '%s'", ret, gnutls_strerror(ret));
529	if (ctxt->output_rc == APR_SUCCESS) {
530	ctxt->output_rc = APR_EGENERAL;
531	}
532	}
533	else if ((apr_size_t) ret != len) {
534	/* not all of the data was sent. */
535	/* mod_ssl basicly errors out here.. this doesn't seem right? */
536	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->output_rc,
537	ctxt->c->base_server,
538	"GnuTLS: failed to write %" APR_SSIZE_T_FMT
539	" of %" APR_SIZE_T_FMT " bytes.",
540	len - (apr_size_t) ret, len);
541	if (ctxt->output_rc == APR_SUCCESS) {
542	ctxt->output_rc = APR_EGENERAL;
543	}
544	}
545
546	apr_bucket_delete(bucket);
547
548	if (ctxt->output_rc != APR_SUCCESS) {
549	break;
550	}
551	}
552	}
553
554	return status;
555	}
556
557	ssize_t mod_gnutls_transport_read(gnutls_transport_ptr_t ptr,
558	void *buffer, size_t len)
559	{
560	mod_gnutls_handle_t *ctxt = ptr;
561	apr_status_t rc;
562	apr_size_t in = len;
563	apr_read_type_e block = ctxt->input_block;
564
565	ctxt->input_rc = APR_SUCCESS;
566
567	/* If Len = 0, we don't do anything. */
568	if (!len)
569	return 0;
570
571	if (!ctxt->input_bb) {
572	ctxt->input_rc = APR_EOF;
573	return -1;
574	}
575
576	if (APR_BRIGADE_EMPTY(ctxt->input_bb)) {
577
578	rc = ap_get_brigade(ctxt->input_filter->next, ctxt->input_bb,
579	AP_MODE_READBYTES, ctxt->input_block, in);
580
581	/* Not a problem, there was simply no data ready yet.
582	*/
583	if (APR_STATUS_IS_EAGAIN(rc) \|\| APR_STATUS_IS_EINTR(rc)
584	\|\| (rc == APR_SUCCESS && APR_BRIGADE_EMPTY(ctxt->input_bb))) {
585	return 0;
586	}
587
588	if (rc != APR_SUCCESS) {
589	/* Unexpected errors discard the brigade */
590	apr_brigade_cleanup(ctxt->input_bb);
591	ctxt->input_bb = NULL;
592	return -1;
593	}
594	}
595
596	ctxt->input_rc = brigade_consume(ctxt->input_bb, block, buffer, &len);
597
598	if (ctxt->input_rc == APR_SUCCESS) {
599	return (ssize_t) len;
600	}
601
602	if (APR_STATUS_IS_EAGAIN(ctxt->input_rc)
603	\|\| APR_STATUS_IS_EINTR(ctxt->input_rc)) {
604	return (ssize_t) len;
605	}
606
607	/* Unexpected errors and APR_EOF clean out the brigade.
608	* Subsequent calls will return APR_EOF.
609	*/
610	apr_brigade_cleanup(ctxt->input_bb);
611	ctxt->input_bb = NULL;
612
613	if (APR_STATUS_IS_EOF(ctxt->input_rc) && len) {
614	/* Provide the results of this read pass,
615	* without resetting the BIO retry_read flag
616	*/
617	return (ssize_t) len;
618	}
619
620	return -1;
621	}
622
623
624	static ssize_t write_flush(mod_gnutls_handle_t * ctxt)
625	{
626	apr_bucket *e;
627
628	if (!(ctxt->output_blen \|\| ctxt->output_length)) {
629	ctxt->output_rc = APR_SUCCESS;
630	return 1;
631	}
632
633	if (ctxt->output_blen) {
634	e = apr_bucket_transient_create(ctxt->output_buffer,
635	ctxt->output_blen,
636	ctxt->output_bb->bucket_alloc);
637	/* we filled this buffer first so add it to the
638	* head of the brigade
639	*/
640	APR_BRIGADE_INSERT_HEAD(ctxt->output_bb, e);
641	ctxt->output_blen = 0;
642	}
643
644	ctxt->output_length = 0;
645	e = apr_bucket_flush_create(ctxt->output_bb->bucket_alloc);
646	APR_BRIGADE_INSERT_TAIL(ctxt->output_bb, e);
647
648	ctxt->output_rc = ap_pass_brigade(ctxt->output_filter->next,
649	ctxt->output_bb);
650	/* create new brigade ready for next time through */
651	ctxt->output_bb =
652	apr_brigade_create(ctxt->c->pool, ctxt->c->bucket_alloc);
653	return (ctxt->output_rc == APR_SUCCESS) ? 1 : -1;
654	}
655
656	ssize_t mod_gnutls_transport_write(gnutls_transport_ptr_t ptr,
657	const void *buffer, size_t len)
658	{
659	mod_gnutls_handle_t *ctxt = ptr;
660
661	/* pass along the encrypted data
662	* need to flush since we're using SSL's malloc-ed buffer
663	* which will be overwritten once we leave here
664	*/
665	apr_bucket *bucket = apr_bucket_transient_create(buffer, len,
666	ctxt->output_bb->
667	bucket_alloc);
668
669	ctxt->output_length += len;
670	APR_BRIGADE_INSERT_TAIL(ctxt->output_bb, bucket);
671
672	if (write_flush(ctxt) < 0) {
673	return -1;
674	}
675	return len;
676	}

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