xref: /openbsd/lib/libcrypto/bio/bf_buff.c (revision acf64401)
1 /* $OpenBSD: bf_buff.c,v 1.28 2023/07/05 21:23:37 beck 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 <string.h>
62 
63 #include <openssl/bio.h>
64 #include <openssl/err.h>
65 
66 #include "bio_local.h"
67 
68 static int buffer_write(BIO *h, const char *buf, int num);
69 static int buffer_read(BIO *h, char *buf, int size);
70 static int buffer_puts(BIO *h, const char *str);
71 static int buffer_gets(BIO *h, char *str, int size);
72 static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
73 static int buffer_new(BIO *h);
74 static int buffer_free(BIO *data);
75 static long buffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
76 #define DEFAULT_BUFFER_SIZE	4096
77 
78 static const BIO_METHOD methods_buffer = {
79 	.type = BIO_TYPE_BUFFER,
80 	.name = "buffer",
81 	.bwrite = buffer_write,
82 	.bread = buffer_read,
83 	.bputs = buffer_puts,
84 	.bgets = buffer_gets,
85 	.ctrl = buffer_ctrl,
86 	.create = buffer_new,
87 	.destroy = buffer_free,
88 	.callback_ctrl = buffer_callback_ctrl
89 };
90 
91 const BIO_METHOD *
BIO_f_buffer(void)92 BIO_f_buffer(void)
93 {
94 	return (&methods_buffer);
95 }
96 LCRYPTO_ALIAS(BIO_f_buffer);
97 
98 static int
buffer_new(BIO * bi)99 buffer_new(BIO *bi)
100 {
101 	BIO_F_BUFFER_CTX *ctx;
102 
103 	ctx = malloc(sizeof(BIO_F_BUFFER_CTX));
104 	if (ctx == NULL)
105 		return (0);
106 	ctx->ibuf = malloc(DEFAULT_BUFFER_SIZE);
107 	if (ctx->ibuf == NULL) {
108 		free(ctx);
109 		return (0);
110 	}
111 	ctx->obuf = malloc(DEFAULT_BUFFER_SIZE);
112 	if (ctx->obuf == NULL) {
113 		free(ctx->ibuf);
114 		free(ctx);
115 		return (0);
116 	}
117 	ctx->ibuf_size = DEFAULT_BUFFER_SIZE;
118 	ctx->obuf_size = DEFAULT_BUFFER_SIZE;
119 	ctx->ibuf_len = 0;
120 	ctx->ibuf_off = 0;
121 	ctx->obuf_len = 0;
122 	ctx->obuf_off = 0;
123 
124 	bi->init = 1;
125 	bi->ptr = (char *)ctx;
126 	bi->flags = 0;
127 	return (1);
128 }
129 
130 static int
buffer_free(BIO * a)131 buffer_free(BIO *a)
132 {
133 	BIO_F_BUFFER_CTX *b;
134 
135 	if (a == NULL)
136 		return (0);
137 	b = (BIO_F_BUFFER_CTX *)a->ptr;
138 	free(b->ibuf);
139 	free(b->obuf);
140 	free(a->ptr);
141 	a->ptr = NULL;
142 	a->init = 0;
143 	a->flags = 0;
144 	return (1);
145 }
146 
147 static int
buffer_read(BIO * b,char * out,int outl)148 buffer_read(BIO *b, char *out, int outl)
149 {
150 	int i, num = 0;
151 	BIO_F_BUFFER_CTX *ctx;
152 
153 	if (out == NULL)
154 		return (0);
155 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
156 
157 	if ((ctx == NULL) || (b->next_bio == NULL))
158 		return (0);
159 	num = 0;
160 	BIO_clear_retry_flags(b);
161 
162 start:
163 	i = ctx->ibuf_len;
164 	/* If there is stuff left over, grab it */
165 	if (i != 0) {
166 		if (i > outl)
167 			i = outl;
168 		memcpy(out, &(ctx->ibuf[ctx->ibuf_off]), i);
169 		ctx->ibuf_off += i;
170 		ctx->ibuf_len -= i;
171 		num += i;
172 		if (outl == i)
173 			return (num);
174 		outl -= i;
175 		out += i;
176 	}
177 
178 	/* We may have done a partial read. try to do more.
179 	 * We have nothing in the buffer.
180 	 * If we get an error and have read some data, just return it
181 	 * and let them retry to get the error again.
182 	 * copy direct to parent address space */
183 	if (outl > ctx->ibuf_size) {
184 		for (;;) {
185 			i = BIO_read(b->next_bio, out, outl);
186 			if (i <= 0) {
187 				BIO_copy_next_retry(b);
188 				if (i < 0)
189 					return ((num > 0) ? num : i);
190 				if (i == 0)
191 					return (num);
192 			}
193 			num += i;
194 			if (outl == i)
195 				return (num);
196 			out += i;
197 			outl -= i;
198 		}
199 	}
200 	/* else */
201 
202 	/* we are going to be doing some buffering */
203 	i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
204 	if (i <= 0) {
205 		BIO_copy_next_retry(b);
206 		if (i < 0)
207 			return ((num > 0) ? num : i);
208 		if (i == 0)
209 			return (num);
210 	}
211 	ctx->ibuf_off = 0;
212 	ctx->ibuf_len = i;
213 
214 	/* Lets re-read using ourselves :-) */
215 	goto start;
216 }
217 
218 static int
buffer_write(BIO * b,const char * in,int inl)219 buffer_write(BIO *b, const char *in, int inl)
220 {
221 	int i, num = 0;
222 	BIO_F_BUFFER_CTX *ctx;
223 
224 	if ((in == NULL) || (inl <= 0))
225 		return (0);
226 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
227 	if ((ctx == NULL) || (b->next_bio == NULL))
228 		return (0);
229 
230 	BIO_clear_retry_flags(b);
231 start:
232 	i = ctx->obuf_size - (ctx->obuf_len + ctx->obuf_off);
233 	/* add to buffer and return */
234 	if (i >= inl) {
235 		memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, inl);
236 		ctx->obuf_len += inl;
237 		return (num + inl);
238 	}
239 	/* else */
240 	/* stuff already in buffer, so add to it first, then flush */
241 	if (ctx->obuf_len != 0) {
242 		if (i > 0) /* lets fill it up if we can */
243 		{
244 			memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, i);
245 			in += i;
246 			inl -= i;
247 			num += i;
248 			ctx->obuf_len += i;
249 		}
250 		/* we now have a full buffer needing flushing */
251 		for (;;) {
252 			i = BIO_write(b->next_bio, &(ctx->obuf[ctx->obuf_off]),
253 			    ctx->obuf_len);
254 			if (i <= 0) {
255 				BIO_copy_next_retry(b);
256 
257 				if (i < 0)
258 					return ((num > 0) ? num : i);
259 				if (i == 0)
260 					return (num);
261 			}
262 			ctx->obuf_off += i;
263 			ctx->obuf_len -= i;
264 			if (ctx->obuf_len == 0)
265 				break;
266 		}
267 	}
268 	/* we only get here if the buffer has been flushed and we
269 	 * still have stuff to write */
270 	ctx->obuf_off = 0;
271 
272 	/* we now have inl bytes to write */
273 	while (inl >= ctx->obuf_size) {
274 		i = BIO_write(b->next_bio, in, inl);
275 		if (i <= 0) {
276 			BIO_copy_next_retry(b);
277 			if (i < 0)
278 				return ((num > 0) ? num : i);
279 			if (i == 0)
280 				return (num);
281 		}
282 		num += i;
283 		in += i;
284 		inl -= i;
285 		if (inl == 0)
286 			return (num);
287 	}
288 
289 	/* copy the rest into the buffer since we have only a small
290 	 * amount left */
291 	goto start;
292 }
293 
294 static long
buffer_ctrl(BIO * b,int cmd,long num,void * ptr)295 buffer_ctrl(BIO *b, int cmd, long num, void *ptr)
296 {
297 	BIO *dbio;
298 	BIO_F_BUFFER_CTX *ctx;
299 	long ret = 1;
300 	char *p1, *p2;
301 	int r, i, *ip;
302 	int ibs, obs;
303 
304 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
305 
306 	switch (cmd) {
307 	case BIO_CTRL_RESET:
308 		ctx->ibuf_off = 0;
309 		ctx->ibuf_len = 0;
310 		ctx->obuf_off = 0;
311 		ctx->obuf_len = 0;
312 		if (b->next_bio == NULL)
313 			return (0);
314 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
315 		break;
316 	case BIO_CTRL_INFO:
317 		ret = (long)ctx->obuf_len;
318 		break;
319 	case BIO_C_GET_BUFF_NUM_LINES:
320 		ret = 0;
321 		p1 = ctx->ibuf;
322 		for (i = 0; i < ctx->ibuf_len; i++) {
323 			if (p1[ctx->ibuf_off + i] == '\n')
324 				ret++;
325 		}
326 		break;
327 	case BIO_CTRL_WPENDING:
328 		ret = (long)ctx->obuf_len;
329 		if (ret == 0) {
330 			if (b->next_bio == NULL)
331 				return (0);
332 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
333 		}
334 		break;
335 	case BIO_CTRL_PENDING:
336 		ret = (long)ctx->ibuf_len;
337 		if (ret == 0) {
338 			if (b->next_bio == NULL)
339 				return (0);
340 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
341 		}
342 		break;
343 	case BIO_C_SET_BUFF_READ_DATA:
344 		if (num > ctx->ibuf_size) {
345 			p1 = malloc(num);
346 			if (p1 == NULL)
347 				goto malloc_error;
348 			free(ctx->ibuf);
349 			ctx->ibuf = p1;
350 		}
351 		ctx->ibuf_off = 0;
352 		ctx->ibuf_len = (int)num;
353 		memcpy(ctx->ibuf, ptr, num);
354 		ret = 1;
355 		break;
356 	case BIO_C_SET_BUFF_SIZE:
357 		if (ptr != NULL) {
358 			ip = (int *)ptr;
359 			if (*ip == 0) {
360 				ibs = (int)num;
361 				obs = ctx->obuf_size;
362 			}
363 			else /* if (*ip == 1) */
364 			{
365 				ibs = ctx->ibuf_size;
366 				obs = (int)num;
367 			}
368 		} else {
369 			ibs = (int)num;
370 			obs = (int)num;
371 		}
372 		p1 = ctx->ibuf;
373 		p2 = ctx->obuf;
374 		if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size)) {
375 			p1 = malloc(num);
376 			if (p1 == NULL)
377 				goto malloc_error;
378 		}
379 		if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size)) {
380 			p2 = malloc(num);
381 			if (p2 == NULL) {
382 				if (p1 != ctx->ibuf)
383 					free(p1);
384 				goto malloc_error;
385 			}
386 		}
387 		if (ctx->ibuf != p1) {
388 			free(ctx->ibuf);
389 			ctx->ibuf = p1;
390 			ctx->ibuf_off = 0;
391 			ctx->ibuf_len = 0;
392 			ctx->ibuf_size = ibs;
393 		}
394 		if (ctx->obuf != p2) {
395 			free(ctx->obuf);
396 			ctx->obuf = p2;
397 			ctx->obuf_off = 0;
398 			ctx->obuf_len = 0;
399 			ctx->obuf_size = obs;
400 		}
401 		break;
402 	case BIO_C_DO_STATE_MACHINE:
403 		if (b->next_bio == NULL)
404 			return (0);
405 		BIO_clear_retry_flags(b);
406 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
407 		BIO_copy_next_retry(b);
408 		break;
409 
410 	case BIO_CTRL_FLUSH:
411 		if (b->next_bio == NULL)
412 			return (0);
413 		if (ctx->obuf_len <= 0) {
414 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
415 			break;
416 		}
417 
418 		for (;;) {
419 			BIO_clear_retry_flags(b);
420 			if (ctx->obuf_len > 0) {
421 				r = BIO_write(b->next_bio,
422 				    &(ctx->obuf[ctx->obuf_off]),
423 				    ctx->obuf_len);
424 				BIO_copy_next_retry(b);
425 				if (r <= 0)
426 					return ((long)r);
427 				ctx->obuf_off += r;
428 				ctx->obuf_len -= r;
429 			} else {
430 				ctx->obuf_len = 0;
431 				ctx->obuf_off = 0;
432 				break;
433 			}
434 		}
435 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
436 		break;
437 	case BIO_CTRL_DUP:
438 		dbio = (BIO *)ptr;
439 		if (!BIO_set_read_buffer_size(dbio, ctx->ibuf_size) ||
440 		    !BIO_set_write_buffer_size(dbio, ctx->obuf_size))
441 			ret = 0;
442 		break;
443 	default:
444 		if (b->next_bio == NULL)
445 			return (0);
446 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
447 		break;
448 	}
449 	return (ret);
450 malloc_error:
451 	BIOerror(ERR_R_MALLOC_FAILURE);
452 	return (0);
453 }
454 
455 static long
buffer_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)456 buffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
457 {
458 	long ret = 1;
459 
460 	if (b->next_bio == NULL)
461 		return (0);
462 	switch (cmd) {
463 	default:
464 		ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
465 		break;
466 	}
467 	return (ret);
468 }
469 
470 static int
buffer_gets(BIO * b,char * buf,int size)471 buffer_gets(BIO *b, char *buf, int size)
472 {
473 	BIO_F_BUFFER_CTX *ctx;
474 	int num = 0, i, flag;
475 	char *p;
476 
477 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
478 	size--; /* reserve space for a '\0' */
479 	BIO_clear_retry_flags(b);
480 
481 	for (;;) {
482 		if (ctx->ibuf_len > 0) {
483 			p = &(ctx->ibuf[ctx->ibuf_off]);
484 			flag = 0;
485 			for (i = 0; (i < ctx->ibuf_len) && (i < size); i++) {
486 				*(buf++) = p[i];
487 				if (p[i] == '\n') {
488 					flag = 1;
489 					i++;
490 					break;
491 				}
492 			}
493 			num += i;
494 			size -= i;
495 			ctx->ibuf_len -= i;
496 			ctx->ibuf_off += i;
497 			if (flag || size == 0) {
498 				*buf = '\0';
499 				return (num);
500 			}
501 		}
502 		else	/* read another chunk */
503 		{
504 			i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
505 			if (i <= 0) {
506 				BIO_copy_next_retry(b);
507 				*buf = '\0';
508 				if (i < 0)
509 					return ((num > 0) ? num : i);
510 				if (i == 0)
511 					return (num);
512 			}
513 			ctx->ibuf_len = i;
514 			ctx->ibuf_off = 0;
515 		}
516 	}
517 }
518 
519 static int
buffer_puts(BIO * b,const char * str)520 buffer_puts(BIO *b, const char *str)
521 {
522 	return (buffer_write(b, str, strlen(str)));
523 }
524