• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* crypto/bio/bss_bio.c  -*- Mode: C; c-file-style: "eay" -*- */
2 /* ====================================================================
3  * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    openssl-core@openssl.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55 
56 /* Special method for a BIO where the other endpoint is also a BIO
57  * of this kind, handled by the same thread (i.e. the "peer" is actually
58  * ourselves, wearing a different hat).
59  * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces
60  * for which no specific BIO method is available.
61  * See ssl/ssltest.c for some hints on how this can be used. */
62 
63 /* BIO_DEBUG implies BIO_PAIR_DEBUG */
64 #ifdef BIO_DEBUG
65 # ifndef BIO_PAIR_DEBUG
66 #  define BIO_PAIR_DEBUG
67 # endif
68 #endif
69 
70 /* disable assert() unless BIO_PAIR_DEBUG has been defined */
71 #ifndef BIO_PAIR_DEBUG
72 # ifndef NDEBUG
73 #  define NDEBUG
74 # endif
75 #endif
76 
77 #include <assert.h>
78 #include <limits.h>
79 #include <stdlib.h>
80 #include <string.h>
81 
82 #include <openssl/bio.h>
83 #include <openssl/err.h>
84 #include <openssl/crypto.h>
85 
86 #include "e_os.h"
87 
88 /* VxWorks defines SSIZE_MAX with an empty value causing compile errors */
89 #if defined(OPENSSL_SYS_VXWORKS)
90 # undef SSIZE_MAX
91 #endif
92 #ifndef SSIZE_MAX
93 # define SSIZE_MAX INT_MAX
94 #endif
95 
96 static int bio_new(BIO *bio);
97 static int bio_free(BIO *bio);
98 static int bio_read(BIO *bio, char *buf, int size);
99 static int bio_write(BIO *bio, const char *buf, int num);
100 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr);
101 static int bio_puts(BIO *bio, const char *str);
102 
103 static int bio_make_pair(BIO *bio1, BIO *bio2);
104 static void bio_destroy_pair(BIO *bio);
105 
106 static BIO_METHOD methods_biop =
107 {
108 	BIO_TYPE_BIO,
109 	"BIO pair",
110 	bio_write,
111 	bio_read,
112 	bio_puts,
113 	NULL /* no bio_gets */,
114 	bio_ctrl,
115 	bio_new,
116 	bio_free,
117 	NULL /* no bio_callback_ctrl */
118 };
119 
BIO_s_bio(void)120 BIO_METHOD *BIO_s_bio(void)
121 	{
122 	return &methods_biop;
123 	}
124 
125 struct bio_bio_st
126 {
127 	BIO *peer;     /* NULL if buf == NULL.
128 	                * If peer != NULL, then peer->ptr is also a bio_bio_st,
129 	                * and its "peer" member points back to us.
130 	                * peer != NULL iff init != 0 in the BIO. */
131 
132 	/* This is for what we write (i.e. reading uses peer's struct): */
133 	int closed;     /* valid iff peer != NULL */
134 	size_t len;     /* valid iff buf != NULL; 0 if peer == NULL */
135 	size_t offset;  /* valid iff buf != NULL; 0 if len == 0 */
136 	size_t size;
137 	char *buf;      /* "size" elements (if != NULL) */
138 
139 	size_t request; /* valid iff peer != NULL; 0 if len != 0,
140 	                 * otherwise set by peer to number of bytes
141 	                 * it (unsuccessfully) tried to read,
142 	                 * never more than buffer space (size-len) warrants. */
143 };
144 
bio_new(BIO * bio)145 static int bio_new(BIO *bio)
146 	{
147 	struct bio_bio_st *b;
148 
149 	b = OPENSSL_malloc(sizeof *b);
150 	if (b == NULL)
151 		return 0;
152 
153 	b->peer = NULL;
154 	b->size = 17*1024; /* enough for one TLS record (just a default) */
155 	b->buf = NULL;
156 
157 	bio->ptr = b;
158 	return 1;
159 	}
160 
161 
bio_free(BIO * bio)162 static int bio_free(BIO *bio)
163 	{
164 	struct bio_bio_st *b;
165 
166 	if (bio == NULL)
167 		return 0;
168 	b = bio->ptr;
169 
170 	assert(b != NULL);
171 
172 	if (b->peer)
173 		bio_destroy_pair(bio);
174 
175 	if (b->buf != NULL)
176 		{
177 		OPENSSL_free(b->buf);
178 		}
179 
180 	OPENSSL_free(b);
181 
182 	return 1;
183 	}
184 
185 
186 
bio_read(BIO * bio,char * buf,int size_)187 static int bio_read(BIO *bio, char *buf, int size_)
188 	{
189 	size_t size = size_;
190 	size_t rest;
191 	struct bio_bio_st *b, *peer_b;
192 
193 	BIO_clear_retry_flags(bio);
194 
195 	if (!bio->init)
196 		return 0;
197 
198 	b = bio->ptr;
199 	assert(b != NULL);
200 	assert(b->peer != NULL);
201 	peer_b = b->peer->ptr;
202 	assert(peer_b != NULL);
203 	assert(peer_b->buf != NULL);
204 
205 	peer_b->request = 0; /* will be set in "retry_read" situation */
206 
207 	if (buf == NULL || size == 0)
208 		return 0;
209 
210 	if (peer_b->len == 0)
211 		{
212 		if (peer_b->closed)
213 			return 0; /* writer has closed, and no data is left */
214 		else
215 			{
216 			BIO_set_retry_read(bio); /* buffer is empty */
217 			if (size <= peer_b->size)
218 				peer_b->request = size;
219 			else
220 				/* don't ask for more than the peer can
221 				 * deliver in one write */
222 				peer_b->request = peer_b->size;
223 			return -1;
224 			}
225 		}
226 
227 	/* we can read */
228 	if (peer_b->len < size)
229 		size = peer_b->len;
230 
231 	/* now read "size" bytes */
232 
233 	rest = size;
234 
235 	assert(rest > 0);
236 	do /* one or two iterations */
237 		{
238 		size_t chunk;
239 
240 		assert(rest <= peer_b->len);
241 		if (peer_b->offset + rest <= peer_b->size)
242 			chunk = rest;
243 		else
244 			/* wrap around ring buffer */
245 			chunk = peer_b->size - peer_b->offset;
246 		assert(peer_b->offset + chunk <= peer_b->size);
247 
248 		memcpy(buf, peer_b->buf + peer_b->offset, chunk);
249 
250 		peer_b->len -= chunk;
251 		if (peer_b->len)
252 			{
253 			peer_b->offset += chunk;
254 			assert(peer_b->offset <= peer_b->size);
255 			if (peer_b->offset == peer_b->size)
256 				peer_b->offset = 0;
257 			buf += chunk;
258 			}
259 		else
260 			{
261 			/* buffer now empty, no need to advance "buf" */
262 			assert(chunk == rest);
263 			peer_b->offset = 0;
264 			}
265 		rest -= chunk;
266 		}
267 	while (rest);
268 
269 	return size;
270 	}
271 
272 /* non-copying interface: provide pointer to available data in buffer
273  *    bio_nread0:  return number of available bytes
274  *    bio_nread:   also advance index
275  * (example usage:  bio_nread0(), read from buffer, bio_nread()
276  *  or just         bio_nread(), read from buffer)
277  */
278 /* WARNING: The non-copying interface is largely untested as of yet
279  * and may contain bugs. */
bio_nread0(BIO * bio,char ** buf)280 static ossl_ssize_t bio_nread0(BIO *bio, char **buf)
281 	{
282 	struct bio_bio_st *b, *peer_b;
283 	ossl_ssize_t num;
284 
285 	BIO_clear_retry_flags(bio);
286 
287 	if (!bio->init)
288 		return 0;
289 
290 	b = bio->ptr;
291 	assert(b != NULL);
292 	assert(b->peer != NULL);
293 	peer_b = b->peer->ptr;
294 	assert(peer_b != NULL);
295 	assert(peer_b->buf != NULL);
296 
297 	peer_b->request = 0;
298 
299 	if (peer_b->len == 0)
300 		{
301 		char dummy;
302 
303 		/* avoid code duplication -- nothing available for reading */
304 		return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
305 		}
306 
307 	num = peer_b->len;
308 	if (peer_b->size < peer_b->offset + num)
309 		/* no ring buffer wrap-around for non-copying interface */
310 		num = peer_b->size - peer_b->offset;
311 	assert(num > 0);
312 
313 	if (buf != NULL)
314 		*buf = peer_b->buf + peer_b->offset;
315 	return num;
316 	}
317 
bio_nread(BIO * bio,char ** buf,size_t num_)318 static ossl_ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
319 	{
320 	struct bio_bio_st *b, *peer_b;
321 	ossl_ssize_t num, available;
322 
323 	if (num_ > SSIZE_MAX)
324 		num = SSIZE_MAX;
325 	else
326 		num = (ossl_ssize_t)num_;
327 
328 	available = bio_nread0(bio, buf);
329 	if (num > available)
330 		num = available;
331 	if (num <= 0)
332 		return num;
333 
334 	b = bio->ptr;
335 	peer_b = b->peer->ptr;
336 
337 	peer_b->len -= num;
338 	if (peer_b->len)
339 		{
340 		peer_b->offset += num;
341 		assert(peer_b->offset <= peer_b->size);
342 		if (peer_b->offset == peer_b->size)
343 			peer_b->offset = 0;
344 		}
345 	else
346 		peer_b->offset = 0;
347 
348 	return num;
349 	}
350 
351 
bio_write(BIO * bio,const char * buf,int num_)352 static int bio_write(BIO *bio, const char *buf, int num_)
353 	{
354 	size_t num = num_;
355 	size_t rest;
356 	struct bio_bio_st *b;
357 
358 	BIO_clear_retry_flags(bio);
359 
360 	if (!bio->init || buf == NULL || num == 0)
361 		return 0;
362 
363 	b = bio->ptr;
364 	assert(b != NULL);
365 	assert(b->peer != NULL);
366 	assert(b->buf != NULL);
367 
368 	b->request = 0;
369 	if (b->closed)
370 		{
371 		/* we already closed */
372 		BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
373 		return -1;
374 		}
375 
376 	assert(b->len <= b->size);
377 
378 	if (b->len == b->size)
379 		{
380 		BIO_set_retry_write(bio); /* buffer is full */
381 		return -1;
382 		}
383 
384 	/* we can write */
385 	if (num > b->size - b->len)
386 		num = b->size - b->len;
387 
388 	/* now write "num" bytes */
389 
390 	rest = num;
391 
392 	assert(rest > 0);
393 	do /* one or two iterations */
394 		{
395 		size_t write_offset;
396 		size_t chunk;
397 
398 		assert(b->len + rest <= b->size);
399 
400 		write_offset = b->offset + b->len;
401 		if (write_offset >= b->size)
402 			write_offset -= b->size;
403 		/* b->buf[write_offset] is the first byte we can write to. */
404 
405 		if (write_offset + rest <= b->size)
406 			chunk = rest;
407 		else
408 			/* wrap around ring buffer */
409 			chunk = b->size - write_offset;
410 
411 		memcpy(b->buf + write_offset, buf, chunk);
412 
413 		b->len += chunk;
414 
415 		assert(b->len <= b->size);
416 
417 		rest -= chunk;
418 		buf += chunk;
419 		}
420 	while (rest);
421 
422 	return num;
423 	}
424 
425 /* non-copying interface: provide pointer to region to write to
426  *   bio_nwrite0:  check how much space is available
427  *   bio_nwrite:   also increase length
428  * (example usage:  bio_nwrite0(), write to buffer, bio_nwrite()
429  *  or just         bio_nwrite(), write to buffer)
430  */
bio_nwrite0(BIO * bio,char ** buf)431 static ossl_ssize_t bio_nwrite0(BIO *bio, char **buf)
432 	{
433 	struct bio_bio_st *b;
434 	size_t num;
435 	size_t write_offset;
436 
437 	BIO_clear_retry_flags(bio);
438 
439 	if (!bio->init)
440 		return 0;
441 
442 	b = bio->ptr;
443 	assert(b != NULL);
444 	assert(b->peer != NULL);
445 	assert(b->buf != NULL);
446 
447 	b->request = 0;
448 	if (b->closed)
449 		{
450 		BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
451 		return -1;
452 		}
453 
454 	assert(b->len <= b->size);
455 
456 	if (b->len == b->size)
457 		{
458 		BIO_set_retry_write(bio);
459 		return -1;
460 		}
461 
462 	num = b->size - b->len;
463 	write_offset = b->offset + b->len;
464 	if (write_offset >= b->size)
465 		write_offset -= b->size;
466 	if (write_offset + num > b->size)
467 		/* no ring buffer wrap-around for non-copying interface
468 		 * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
469 		 * BIO_nwrite may have to be called twice) */
470 		num = b->size - write_offset;
471 
472 	if (buf != NULL)
473 		*buf = b->buf + write_offset;
474 	assert(write_offset + num <= b->size);
475 
476 	return num;
477 	}
478 
bio_nwrite(BIO * bio,char ** buf,size_t num_)479 static ossl_ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
480 	{
481 	struct bio_bio_st *b;
482 	ossl_ssize_t num, space;
483 
484 	if (num_ > SSIZE_MAX)
485 		num = SSIZE_MAX;
486 	else
487 		num = (ossl_ssize_t)num_;
488 
489 	space = bio_nwrite0(bio, buf);
490 	if (num > space)
491 		num = space;
492 	if (num <= 0)
493 		return num;
494 	b = bio->ptr;
495 	assert(b != NULL);
496 	b->len += num;
497 	assert(b->len <= b->size);
498 
499 	return num;
500 	}
501 
502 
bio_ctrl(BIO * bio,int cmd,long num,void * ptr)503 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
504 	{
505 	long ret;
506 	struct bio_bio_st *b = bio->ptr;
507 
508 	assert(b != NULL);
509 
510 	switch (cmd)
511 		{
512 	/* specific CTRL codes */
513 
514 	case BIO_C_SET_WRITE_BUF_SIZE:
515 		if (b->peer)
516 			{
517 			BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
518 			ret = 0;
519 			}
520 		else if (num == 0)
521 			{
522 			BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
523 			ret = 0;
524 			}
525 		else
526 			{
527 			size_t new_size = num;
528 
529 			if (b->size != new_size)
530 				{
531 				if (b->buf)
532 					{
533 					OPENSSL_free(b->buf);
534 					b->buf = NULL;
535 					}
536 				b->size = new_size;
537 				}
538 			ret = 1;
539 			}
540 		break;
541 
542 	case BIO_C_GET_WRITE_BUF_SIZE:
543 		ret = (long) b->size;
544 		break;
545 
546 	case BIO_C_MAKE_BIO_PAIR:
547 		{
548 		BIO *other_bio = ptr;
549 
550 		if (bio_make_pair(bio, other_bio))
551 			ret = 1;
552 		else
553 			ret = 0;
554 		}
555 		break;
556 
557 	case BIO_C_DESTROY_BIO_PAIR:
558 		/* Affects both BIOs in the pair -- call just once!
559 		 * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
560 		bio_destroy_pair(bio);
561 		ret = 1;
562 		break;
563 
564 	case BIO_C_GET_WRITE_GUARANTEE:
565 		/* How many bytes can the caller feed to the next write
566 		 * without having to keep any? */
567 		if (b->peer == NULL || b->closed)
568 			ret = 0;
569 		else
570 			ret = (long) b->size - b->len;
571 		break;
572 
573 	case BIO_C_GET_READ_REQUEST:
574 		/* If the peer unsuccessfully tried to read, how many bytes
575 		 * were requested?  (As with BIO_CTRL_PENDING, that number
576 		 * can usually be treated as boolean.) */
577 		ret = (long) b->request;
578 		break;
579 
580 	case BIO_C_RESET_READ_REQUEST:
581 		/* Reset request.  (Can be useful after read attempts
582 		 * at the other side that are meant to be non-blocking,
583 		 * e.g. when probing SSL_read to see if any data is
584 		 * available.) */
585 		b->request = 0;
586 		ret = 1;
587 		break;
588 
589 	case BIO_C_SHUTDOWN_WR:
590 		/* similar to shutdown(..., SHUT_WR) */
591 		b->closed = 1;
592 		ret = 1;
593 		break;
594 
595 	case BIO_C_NREAD0:
596 		/* prepare for non-copying read */
597 		ret = (long) bio_nread0(bio, ptr);
598 		break;
599 
600 	case BIO_C_NREAD:
601 		/* non-copying read */
602 		ret = (long) bio_nread(bio, ptr, (size_t) num);
603 		break;
604 
605 	case BIO_C_NWRITE0:
606 		/* prepare for non-copying write */
607 		ret = (long) bio_nwrite0(bio, ptr);
608 		break;
609 
610 	case BIO_C_NWRITE:
611 		/* non-copying write */
612 		ret = (long) bio_nwrite(bio, ptr, (size_t) num);
613 		break;
614 
615 
616 	/* standard CTRL codes follow */
617 
618 	case BIO_CTRL_RESET:
619 		if (b->buf != NULL)
620 			{
621 			b->len = 0;
622 			b->offset = 0;
623 			}
624 		ret = 0;
625 		break;
626 
627 	case BIO_CTRL_GET_CLOSE:
628 		ret = bio->shutdown;
629 		break;
630 
631 	case BIO_CTRL_SET_CLOSE:
632 		bio->shutdown = (int) num;
633 		ret = 1;
634 		break;
635 
636 	case BIO_CTRL_PENDING:
637 		if (b->peer != NULL)
638 			{
639 			struct bio_bio_st *peer_b = b->peer->ptr;
640 
641 			ret = (long) peer_b->len;
642 			}
643 		else
644 			ret = 0;
645 		break;
646 
647 	case BIO_CTRL_WPENDING:
648 		if (b->buf != NULL)
649 			ret = (long) b->len;
650 		else
651 			ret = 0;
652 		break;
653 
654 	case BIO_CTRL_DUP:
655 		/* See BIO_dup_chain for circumstances we have to expect. */
656 		{
657 		BIO *other_bio = ptr;
658 		struct bio_bio_st *other_b;
659 
660 		assert(other_bio != NULL);
661 		other_b = other_bio->ptr;
662 		assert(other_b != NULL);
663 
664 		assert(other_b->buf == NULL); /* other_bio is always fresh */
665 
666 		other_b->size = b->size;
667 		}
668 
669 		ret = 1;
670 		break;
671 
672 	case BIO_CTRL_FLUSH:
673 		ret = 1;
674 		break;
675 
676 	case BIO_CTRL_EOF:
677 		{
678 		BIO *other_bio = ptr;
679 
680 		if (other_bio)
681 			{
682 			struct bio_bio_st *other_b = other_bio->ptr;
683 
684 			assert(other_b != NULL);
685 			ret = other_b->len == 0 && other_b->closed;
686 			}
687 		else
688 			ret = 1;
689 		}
690 		break;
691 
692 	default:
693 		ret = 0;
694 		}
695 	return ret;
696 	}
697 
bio_puts(BIO * bio,const char * str)698 static int bio_puts(BIO *bio, const char *str)
699 	{
700 	return bio_write(bio, str, strlen(str));
701 	}
702 
703 
bio_make_pair(BIO * bio1,BIO * bio2)704 static int bio_make_pair(BIO *bio1, BIO *bio2)
705 	{
706 	struct bio_bio_st *b1, *b2;
707 
708 	assert(bio1 != NULL);
709 	assert(bio2 != NULL);
710 
711 	b1 = bio1->ptr;
712 	b2 = bio2->ptr;
713 
714 	if (b1->peer != NULL || b2->peer != NULL)
715 		{
716 		BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
717 		return 0;
718 		}
719 
720 	if (b1->buf == NULL)
721 		{
722 		b1->buf = OPENSSL_malloc(b1->size);
723 		if (b1->buf == NULL)
724 			{
725 			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
726 			return 0;
727 			}
728 		b1->len = 0;
729 		b1->offset = 0;
730 		}
731 
732 	if (b2->buf == NULL)
733 		{
734 		b2->buf = OPENSSL_malloc(b2->size);
735 		if (b2->buf == NULL)
736 			{
737 			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
738 			return 0;
739 			}
740 		b2->len = 0;
741 		b2->offset = 0;
742 		}
743 
744 	b1->peer = bio2;
745 	b1->closed = 0;
746 	b1->request = 0;
747 	b2->peer = bio1;
748 	b2->closed = 0;
749 	b2->request = 0;
750 
751 	bio1->init = 1;
752 	bio2->init = 1;
753 
754 	return 1;
755 	}
756 
bio_destroy_pair(BIO * bio)757 static void bio_destroy_pair(BIO *bio)
758 	{
759 	struct bio_bio_st *b = bio->ptr;
760 
761 	if (b != NULL)
762 		{
763 		BIO *peer_bio = b->peer;
764 
765 		if (peer_bio != NULL)
766 			{
767 			struct bio_bio_st *peer_b = peer_bio->ptr;
768 
769 			assert(peer_b != NULL);
770 			assert(peer_b->peer == bio);
771 
772 			peer_b->peer = NULL;
773 			peer_bio->init = 0;
774 			assert(peer_b->buf != NULL);
775 			peer_b->len = 0;
776 			peer_b->offset = 0;
777 
778 			b->peer = NULL;
779 			bio->init = 0;
780 			assert(b->buf != NULL);
781 			b->len = 0;
782 			b->offset = 0;
783 			}
784 		}
785 	}
786 
787 
788 /* Exported convenience functions */
BIO_new_bio_pair(BIO ** bio1_p,size_t writebuf1,BIO ** bio2_p,size_t writebuf2)789 int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
790 	BIO **bio2_p, size_t writebuf2)
791 	 {
792 	 BIO *bio1 = NULL, *bio2 = NULL;
793 	 long r;
794 	 int ret = 0;
795 
796 	 bio1 = BIO_new(BIO_s_bio());
797 	 if (bio1 == NULL)
798 		 goto err;
799 	 bio2 = BIO_new(BIO_s_bio());
800 	 if (bio2 == NULL)
801 		 goto err;
802 
803 	 if (writebuf1)
804 		 {
805 		 r = BIO_set_write_buf_size(bio1, writebuf1);
806 		 if (!r)
807 			 goto err;
808 		 }
809 	 if (writebuf2)
810 		 {
811 		 r = BIO_set_write_buf_size(bio2, writebuf2);
812 		 if (!r)
813 			 goto err;
814 		 }
815 
816 	 r = BIO_make_bio_pair(bio1, bio2);
817 	 if (!r)
818 		 goto err;
819 	 ret = 1;
820 
821  err:
822 	 if (ret == 0)
823 		 {
824 		 if (bio1)
825 			 {
826 			 BIO_free(bio1);
827 			 bio1 = NULL;
828 			 }
829 		 if (bio2)
830 			 {
831 			 BIO_free(bio2);
832 			 bio2 = NULL;
833 			 }
834 		 }
835 
836 	 *bio1_p = bio1;
837 	 *bio2_p = bio2;
838 	 return ret;
839 	 }
840 
BIO_ctrl_get_write_guarantee(BIO * bio)841 size_t BIO_ctrl_get_write_guarantee(BIO *bio)
842 	{
843 	return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
844 	}
845 
BIO_ctrl_get_read_request(BIO * bio)846 size_t BIO_ctrl_get_read_request(BIO *bio)
847 	{
848 	return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
849 	}
850 
BIO_ctrl_reset_read_request(BIO * bio)851 int BIO_ctrl_reset_read_request(BIO *bio)
852 	{
853 	return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
854 	}
855 
856 
857 /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
858  * (conceivably some other BIOs could allow non-copying reads and writes too.)
859  */
BIO_nread0(BIO * bio,char ** buf)860 int BIO_nread0(BIO *bio, char **buf)
861 	{
862 	long ret;
863 
864 	if (!bio->init)
865 		{
866 		BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
867 		return -2;
868 		}
869 
870 	ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
871 	if (ret > INT_MAX)
872 		return INT_MAX;
873 	else
874 		return (int) ret;
875 	}
876 
BIO_nread(BIO * bio,char ** buf,int num)877 int BIO_nread(BIO *bio, char **buf, int num)
878 	{
879 	int ret;
880 
881 	if (!bio->init)
882 		{
883 		BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
884 		return -2;
885 		}
886 
887 	ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
888 	if (ret > 0)
889 		bio->num_read += ret;
890 	return ret;
891 	}
892 
BIO_nwrite0(BIO * bio,char ** buf)893 int BIO_nwrite0(BIO *bio, char **buf)
894 	{
895 	long ret;
896 
897 	if (!bio->init)
898 		{
899 		BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
900 		return -2;
901 		}
902 
903 	ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
904 	if (ret > INT_MAX)
905 		return INT_MAX;
906 	else
907 		return (int) ret;
908 	}
909 
BIO_nwrite(BIO * bio,char ** buf,int num)910 int BIO_nwrite(BIO *bio, char **buf, int num)
911 	{
912 	int ret;
913 
914 	if (!bio->init)
915 		{
916 		BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
917 		return -2;
918 		}
919 
920 	ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
921 	if (ret > 0)
922 		bio->num_write += ret;
923 	return ret;
924 	}
925