xref: /openbsd/lib/libssl/bio_ssl.c (revision f6aab3d8)
1 /* $OpenBSD: bio_ssl.c,v 1.40 2023/07/19 13:34:33 tb Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <errno.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 
64 #include <openssl/bio.h>
65 #include <openssl/crypto.h>
66 #include <openssl/err.h>
67 #include <openssl/ssl.h>
68 
69 #include "bio_local.h"
70 #include "ssl_local.h"
71 
72 static int ssl_write(BIO *h, const char *buf, int num);
73 static int ssl_read(BIO *h, char *buf, int size);
74 static int ssl_puts(BIO *h, const char *str);
75 static long ssl_ctrl(BIO *h, int cmd, long arg1, void *arg2);
76 static int ssl_new(BIO *h);
77 static int ssl_free(BIO *data);
78 static long ssl_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
79 typedef struct bio_ssl_st {
80 	SSL *ssl; /* The ssl handle :-) */
81 	/* re-negotiate every time the total number of bytes is this size */
82 	int num_renegotiates;
83 	unsigned long renegotiate_count;
84 	unsigned long byte_count;
85 	unsigned long renegotiate_timeout;
86 	time_t last_time;
87 } BIO_SSL;
88 
89 static const BIO_METHOD methods_sslp = {
90 	.type = BIO_TYPE_SSL,
91 	.name = "ssl",
92 	.bwrite = ssl_write,
93 	.bread = ssl_read,
94 	.bputs = ssl_puts,
95 	.ctrl = ssl_ctrl,
96 	.create = ssl_new,
97 	.destroy = ssl_free,
98 	.callback_ctrl = ssl_callback_ctrl,
99 };
100 
101 const BIO_METHOD *
102 BIO_f_ssl(void)
103 {
104 	return (&methods_sslp);
105 }
106 LSSL_ALIAS(BIO_f_ssl);
107 
108 static int
109 ssl_new(BIO *bi)
110 {
111 	BIO_SSL *bs;
112 
113 	bs = calloc(1, sizeof(BIO_SSL));
114 	if (bs == NULL) {
115 		SSLerrorx(ERR_R_MALLOC_FAILURE);
116 		return (0);
117 	}
118 	bi->init = 0;
119 	bi->ptr = (char *)bs;
120 	bi->flags = 0;
121 	return (1);
122 }
123 LSSL_ALIAS(BIO_f_ssl);
124 
125 static int
126 ssl_free(BIO *a)
127 {
128 	BIO_SSL *bs;
129 
130 	if (a == NULL)
131 		return (0);
132 	bs = (BIO_SSL *)a->ptr;
133 	if (bs->ssl != NULL)
134 		SSL_shutdown(bs->ssl);
135 	if (a->shutdown) {
136 		if (a->init && (bs->ssl != NULL))
137 			SSL_free(bs->ssl);
138 		a->init = 0;
139 		a->flags = 0;
140 	}
141 	free(a->ptr);
142 	return (1);
143 }
144 
145 static int
146 ssl_read(BIO *b, char *out, int outl)
147 {
148 	int ret = 1;
149 	BIO_SSL *sb;
150 	SSL *ssl;
151 	int retry_reason = 0;
152 	int r = 0;
153 
154 	if (out == NULL)
155 		return (0);
156 	sb = (BIO_SSL *)b->ptr;
157 	ssl = sb->ssl;
158 
159 	BIO_clear_retry_flags(b);
160 
161 	ret = SSL_read(ssl, out, outl);
162 
163 	switch (SSL_get_error(ssl, ret)) {
164 	case SSL_ERROR_NONE:
165 		if (ret <= 0)
166 			break;
167 		if (sb->renegotiate_count > 0) {
168 			sb->byte_count += ret;
169 			if (sb->byte_count > sb->renegotiate_count) {
170 				sb->byte_count = 0;
171 				sb->num_renegotiates++;
172 				SSL_renegotiate(ssl);
173 				r = 1;
174 			}
175 		}
176 		if ((sb->renegotiate_timeout > 0) && (!r)) {
177 			time_t tm;
178 
179 			tm = time(NULL);
180 			if (tm > sb->last_time + sb->renegotiate_timeout) {
181 				sb->last_time = tm;
182 				sb->num_renegotiates++;
183 				SSL_renegotiate(ssl);
184 			}
185 		}
186 
187 		break;
188 	case SSL_ERROR_WANT_READ:
189 		BIO_set_retry_read(b);
190 		break;
191 	case SSL_ERROR_WANT_WRITE:
192 		BIO_set_retry_write(b);
193 		break;
194 	case SSL_ERROR_WANT_X509_LOOKUP:
195 		BIO_set_retry_special(b);
196 		retry_reason = BIO_RR_SSL_X509_LOOKUP;
197 		break;
198 	case SSL_ERROR_WANT_ACCEPT:
199 		BIO_set_retry_special(b);
200 		retry_reason = BIO_RR_ACCEPT;
201 		break;
202 	case SSL_ERROR_WANT_CONNECT:
203 		BIO_set_retry_special(b);
204 		retry_reason = BIO_RR_CONNECT;
205 		break;
206 	case SSL_ERROR_SYSCALL:
207 	case SSL_ERROR_SSL:
208 	case SSL_ERROR_ZERO_RETURN:
209 	default:
210 		break;
211 	}
212 
213 	b->retry_reason = retry_reason;
214 	return (ret);
215 }
216 
217 static int
218 ssl_write(BIO *b, const char *out, int outl)
219 {
220 	int ret, r = 0;
221 	int retry_reason = 0;
222 	SSL *ssl;
223 	BIO_SSL *bs;
224 
225 	if (out == NULL)
226 		return (0);
227 	bs = (BIO_SSL *)b->ptr;
228 	ssl = bs->ssl;
229 
230 	BIO_clear_retry_flags(b);
231 
232 /*	ret=SSL_do_handshake(ssl);
233 	if (ret > 0) */
234 		ret = SSL_write(ssl, out, outl);
235 
236 	switch (SSL_get_error(ssl, ret)) {
237 	case SSL_ERROR_NONE:
238 		if (ret <= 0)
239 			break;
240 		if (bs->renegotiate_count > 0) {
241 			bs->byte_count += ret;
242 			if (bs->byte_count > bs->renegotiate_count) {
243 				bs->byte_count = 0;
244 				bs->num_renegotiates++;
245 				SSL_renegotiate(ssl);
246 				r = 1;
247 			}
248 		}
249 		if ((bs->renegotiate_timeout > 0) && (!r)) {
250 			time_t tm;
251 
252 			tm = time(NULL);
253 			if (tm > bs->last_time + bs->renegotiate_timeout) {
254 				bs->last_time = tm;
255 				bs->num_renegotiates++;
256 				SSL_renegotiate(ssl);
257 			}
258 		}
259 		break;
260 	case SSL_ERROR_WANT_WRITE:
261 		BIO_set_retry_write(b);
262 		break;
263 	case SSL_ERROR_WANT_READ:
264 		BIO_set_retry_read(b);
265 		break;
266 	case SSL_ERROR_WANT_X509_LOOKUP:
267 		BIO_set_retry_special(b);
268 		retry_reason = BIO_RR_SSL_X509_LOOKUP;
269 		break;
270 	case SSL_ERROR_WANT_CONNECT:
271 		BIO_set_retry_special(b);
272 		retry_reason = BIO_RR_CONNECT;
273 	case SSL_ERROR_SYSCALL:
274 	case SSL_ERROR_SSL:
275 	default:
276 		break;
277 	}
278 
279 	b->retry_reason = retry_reason;
280 	return (ret);
281 }
282 
283 static long
284 ssl_ctrl(BIO *b, int cmd, long num, void *ptr)
285 {
286 	SSL **sslp, *ssl;
287 	BIO_SSL *bs;
288 	BIO *dbio, *bio;
289 	long ret = 1;
290 
291 	bs = (BIO_SSL *)b->ptr;
292 	ssl = bs->ssl;
293 	if ((ssl == NULL)  && (cmd != BIO_C_SET_SSL))
294 		return (0);
295 	switch (cmd) {
296 	case BIO_CTRL_RESET:
297 		SSL_shutdown(ssl);
298 
299 		if (ssl->handshake_func == ssl->method->ssl_connect)
300 			SSL_set_connect_state(ssl);
301 		else if (ssl->handshake_func == ssl->method->ssl_accept)
302 			SSL_set_accept_state(ssl);
303 
304 		SSL_clear(ssl);
305 
306 		if (b->next_bio != NULL)
307 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
308 		else if (ssl->rbio != NULL)
309 			ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
310 		else
311 			ret = 1;
312 		break;
313 	case BIO_CTRL_INFO:
314 		ret = 0;
315 		break;
316 	case BIO_C_SSL_MODE:
317 		if (num) /* client mode */
318 			SSL_set_connect_state(ssl);
319 		else
320 			SSL_set_accept_state(ssl);
321 		break;
322 	case BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT:
323 		ret = bs->renegotiate_timeout;
324 		if (num < 60)
325 			num = 5;
326 		bs->renegotiate_timeout = (unsigned long)num;
327 		bs->last_time = time(NULL);
328 		break;
329 	case BIO_C_SET_SSL_RENEGOTIATE_BYTES:
330 		ret = bs->renegotiate_count;
331 		if ((long)num >=512)
332 			bs->renegotiate_count = (unsigned long)num;
333 		break;
334 	case BIO_C_GET_SSL_NUM_RENEGOTIATES:
335 		ret = bs->num_renegotiates;
336 		break;
337 	case BIO_C_SET_SSL:
338 		if (ssl != NULL) {
339 			ssl_free(b);
340 			if (!ssl_new(b))
341 				return 0;
342 		}
343 		b->shutdown = (int)num;
344 		ssl = (SSL *)ptr;
345 		((BIO_SSL *)b->ptr)->ssl = ssl;
346 		bio = SSL_get_rbio(ssl);
347 		if (bio != NULL) {
348 			if (b->next_bio != NULL)
349 				BIO_push(bio, b->next_bio);
350 			b->next_bio = bio;
351 			CRYPTO_add(&bio->references, 1, CRYPTO_LOCK_BIO);
352 		}
353 		b->init = 1;
354 		break;
355 	case BIO_C_GET_SSL:
356 		if (ptr != NULL) {
357 			sslp = (SSL **)ptr;
358 			*sslp = ssl;
359 		} else
360 			ret = 0;
361 		break;
362 	case BIO_CTRL_GET_CLOSE:
363 		ret = b->shutdown;
364 		break;
365 	case BIO_CTRL_SET_CLOSE:
366 		b->shutdown = (int)num;
367 		break;
368 	case BIO_CTRL_WPENDING:
369 		ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
370 		break;
371 	case BIO_CTRL_PENDING:
372 		ret = SSL_pending(ssl);
373 		if (ret == 0)
374 			ret = BIO_pending(ssl->rbio);
375 		break;
376 	case BIO_CTRL_FLUSH:
377 		BIO_clear_retry_flags(b);
378 		ret = BIO_ctrl(ssl->wbio, cmd, num, ptr);
379 		BIO_copy_next_retry(b);
380 		break;
381 	case BIO_CTRL_PUSH:
382 		if ((b->next_bio != NULL) && (b->next_bio != ssl->rbio)) {
383 			SSL_set_bio(ssl, b->next_bio, b->next_bio);
384 			CRYPTO_add(&b->next_bio->references, 1,
385 			    CRYPTO_LOCK_BIO);
386 		}
387 		break;
388 	case BIO_CTRL_POP:
389 		/* Only detach if we are the BIO explicitly being popped */
390 		if (b == ptr) {
391 			/* Shouldn't happen in practice because the
392 			 * rbio and wbio are the same when pushed.
393 			 */
394 			if (ssl->rbio != ssl->wbio)
395 				BIO_free_all(ssl->wbio);
396 			if (b->next_bio != NULL)
397 				CRYPTO_add(&b->next_bio->references, -1, CRYPTO_LOCK_BIO);
398 			ssl->wbio = NULL;
399 			ssl->rbio = NULL;
400 		}
401 		break;
402 	case BIO_C_DO_STATE_MACHINE:
403 		BIO_clear_retry_flags(b);
404 
405 		b->retry_reason = 0;
406 		ret = (int)SSL_do_handshake(ssl);
407 
408 		switch (SSL_get_error(ssl, (int)ret)) {
409 		case SSL_ERROR_WANT_READ:
410 			BIO_set_flags(b,
411 			    BIO_FLAGS_READ|BIO_FLAGS_SHOULD_RETRY);
412 			break;
413 		case SSL_ERROR_WANT_WRITE:
414 			BIO_set_flags(b,
415 			    BIO_FLAGS_WRITE|BIO_FLAGS_SHOULD_RETRY);
416 			break;
417 		case SSL_ERROR_WANT_CONNECT:
418 			BIO_set_flags(b,
419 			    BIO_FLAGS_IO_SPECIAL|BIO_FLAGS_SHOULD_RETRY);
420 			b->retry_reason = b->next_bio->retry_reason;
421 			break;
422 		default:
423 			break;
424 		}
425 		break;
426 	case BIO_CTRL_DUP:
427 		dbio = (BIO *)ptr;
428 		if (((BIO_SSL *)dbio->ptr)->ssl != NULL)
429 			SSL_free(((BIO_SSL *)dbio->ptr)->ssl);
430 		((BIO_SSL *)dbio->ptr)->ssl = SSL_dup(ssl);
431 		((BIO_SSL *)dbio->ptr)->renegotiate_count =
432 		    ((BIO_SSL *)b->ptr)->renegotiate_count;
433 		((BIO_SSL *)dbio->ptr)->byte_count =
434 		    ((BIO_SSL *)b->ptr)->byte_count;
435 		((BIO_SSL *)dbio->ptr)->renegotiate_timeout =
436 		    ((BIO_SSL *)b->ptr)->renegotiate_timeout;
437 		((BIO_SSL *)dbio->ptr)->last_time =
438 		    ((BIO_SSL *)b->ptr)->last_time;
439 		ret = (((BIO_SSL *)dbio->ptr)->ssl != NULL);
440 		break;
441 	case BIO_C_GET_FD:
442 		ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
443 		break;
444 	case BIO_CTRL_SET_CALLBACK:
445 		{
446 			ret = 0;
447 		}
448 		break;
449 	case BIO_CTRL_GET_CALLBACK:
450 		{
451 			void (**fptr)(const SSL *xssl, int type, int val);
452 
453 			fptr = (void (**)(const SSL *xssl, int type, int val))
454 			    ptr;
455 			*fptr = SSL_get_info_callback(ssl);
456 		}
457 		break;
458 	default:
459 		ret = BIO_ctrl(ssl->rbio, cmd, num, ptr);
460 		break;
461 	}
462 	return (ret);
463 }
464 
465 static long
466 ssl_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
467 {
468 	SSL *ssl;
469 	BIO_SSL *bs;
470 	long ret = 1;
471 
472 	bs = (BIO_SSL *)b->ptr;
473 	ssl = bs->ssl;
474 	switch (cmd) {
475 	case BIO_CTRL_SET_CALLBACK:
476 		{
477 		/* FIXME: setting this via a completely different prototype
478 		   seems like a crap idea */
479 			SSL_set_info_callback(ssl,
480 			    (void (*)(const SSL *, int, int))fp);
481 		}
482 		break;
483 	default:
484 		ret = BIO_callback_ctrl(ssl->rbio, cmd, fp);
485 		break;
486 	}
487 	return (ret);
488 }
489 
490 static int
491 ssl_puts(BIO *bp, const char *str)
492 {
493 	int n, ret;
494 
495 	n = strlen(str);
496 	ret = BIO_write(bp, str, n);
497 	return (ret);
498 }
499 
500 BIO *
501 BIO_new_buffer_ssl_connect(SSL_CTX *ctx)
502 {
503 	BIO *ret = NULL, *buf = NULL, *ssl = NULL;
504 
505 	if ((buf = BIO_new(BIO_f_buffer())) == NULL)
506 		goto err;
507 	if ((ssl = BIO_new_ssl_connect(ctx)) == NULL)
508 		goto err;
509 	if ((ret = BIO_push(buf, ssl)) == NULL)
510 		goto err;
511 	return (ret);
512 
513  err:
514 	BIO_free(buf);
515 	BIO_free(ssl);
516 	return (NULL);
517 }
518 LSSL_ALIAS(BIO_new_buffer_ssl_connect);
519 
520 BIO *
521 BIO_new_ssl_connect(SSL_CTX *ctx)
522 {
523 	BIO *ret = NULL, *con = NULL, *ssl = NULL;
524 
525 	if ((con = BIO_new(BIO_s_connect())) == NULL)
526 		goto err;
527 	if ((ssl = BIO_new_ssl(ctx, 1)) == NULL)
528 		goto err;
529 	if ((ret = BIO_push(ssl, con)) == NULL)
530 		goto err;
531 	return (ret);
532 
533  err:
534 	BIO_free(con);
535 	BIO_free(ssl);
536 	return (NULL);
537 }
538 LSSL_ALIAS(BIO_new_ssl_connect);
539 
540 BIO *
541 BIO_new_ssl(SSL_CTX *ctx, int client)
542 {
543 	BIO *ret;
544 	SSL *ssl;
545 
546 	if ((ret = BIO_new(BIO_f_ssl())) == NULL)
547 		goto err;
548 	if ((ssl = SSL_new(ctx)) == NULL)
549 		goto err;
550 
551 	if (client)
552 		SSL_set_connect_state(ssl);
553 	else
554 		SSL_set_accept_state(ssl);
555 
556 	BIO_set_ssl(ret, ssl, BIO_CLOSE);
557 	return (ret);
558 
559  err:
560 	BIO_free(ret);
561 	return (NULL);
562 }
563 LSSL_ALIAS(BIO_new_ssl);
564 
565 int
566 BIO_ssl_copy_session_id(BIO *t, BIO *f)
567 {
568 	t = BIO_find_type(t, BIO_TYPE_SSL);
569 	f = BIO_find_type(f, BIO_TYPE_SSL);
570 	if ((t == NULL) || (f == NULL))
571 		return (0);
572 	if ((((BIO_SSL *)t->ptr)->ssl == NULL) ||
573 	    (((BIO_SSL *)f->ptr)->ssl == NULL))
574 		return (0);
575 	if (!SSL_copy_session_id(((BIO_SSL *)t->ptr)->ssl,
576 	    ((BIO_SSL *)f->ptr)->ssl))
577 		return (0);
578 	return (1);
579 }
580 LSSL_ALIAS(BIO_ssl_copy_session_id);
581 
582 void
583 BIO_ssl_shutdown(BIO *b)
584 {
585 	SSL *s;
586 
587 	while (b != NULL) {
588 		if (b->method->type == BIO_TYPE_SSL) {
589 			s = ((BIO_SSL *)b->ptr)->ssl;
590 			SSL_shutdown(s);
591 			break;
592 		}
593 		b = b->next_bio;
594 	}
595 }
596 LSSL_ALIAS(BIO_ssl_shutdown);
597