1 /* $OpenBSD: bf_buff.c,v 1.25 2018/05/01 13:29:09 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 <string.h>
62 
63 #include <openssl/bio.h>
64 #include <openssl/err.h>
65 
66 static int buffer_write(BIO *h, const char *buf, int num);
67 static int buffer_read(BIO *h, char *buf, int size);
68 static int buffer_puts(BIO *h, const char *str);
69 static int buffer_gets(BIO *h, char *str, int size);
70 static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
71 static int buffer_new(BIO *h);
72 static int buffer_free(BIO *data);
73 static long buffer_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
74 #define DEFAULT_BUFFER_SIZE	4096
75 
76 static const BIO_METHOD methods_buffer = {
77 	.type = BIO_TYPE_BUFFER,
78 	.name = "buffer",
79 	.bwrite = buffer_write,
80 	.bread = buffer_read,
81 	.bputs = buffer_puts,
82 	.bgets = buffer_gets,
83 	.ctrl = buffer_ctrl,
84 	.create = buffer_new,
85 	.destroy = buffer_free,
86 	.callback_ctrl = buffer_callback_ctrl
87 };
88 
89 const BIO_METHOD *
90 BIO_f_buffer(void)
91 {
92 	return (&methods_buffer);
93 }
94 
95 static int
96 buffer_new(BIO *bi)
97 {
98 	BIO_F_BUFFER_CTX *ctx;
99 
100 	ctx = malloc(sizeof(BIO_F_BUFFER_CTX));
101 	if (ctx == NULL)
102 		return (0);
103 	ctx->ibuf = malloc(DEFAULT_BUFFER_SIZE);
104 	if (ctx->ibuf == NULL) {
105 		free(ctx);
106 		return (0);
107 	}
108 	ctx->obuf = malloc(DEFAULT_BUFFER_SIZE);
109 	if (ctx->obuf == NULL) {
110 		free(ctx->ibuf);
111 		free(ctx);
112 		return (0);
113 	}
114 	ctx->ibuf_size = DEFAULT_BUFFER_SIZE;
115 	ctx->obuf_size = DEFAULT_BUFFER_SIZE;
116 	ctx->ibuf_len = 0;
117 	ctx->ibuf_off = 0;
118 	ctx->obuf_len = 0;
119 	ctx->obuf_off = 0;
120 
121 	bi->init = 1;
122 	bi->ptr = (char *)ctx;
123 	bi->flags = 0;
124 	return (1);
125 }
126 
127 static int
128 buffer_free(BIO *a)
129 {
130 	BIO_F_BUFFER_CTX *b;
131 
132 	if (a == NULL)
133 		return (0);
134 	b = (BIO_F_BUFFER_CTX *)a->ptr;
135 	free(b->ibuf);
136 	free(b->obuf);
137 	free(a->ptr);
138 	a->ptr = NULL;
139 	a->init = 0;
140 	a->flags = 0;
141 	return (1);
142 }
143 
144 static int
145 buffer_read(BIO *b, char *out, int outl)
146 {
147 	int i, num = 0;
148 	BIO_F_BUFFER_CTX *ctx;
149 
150 	if (out == NULL)
151 		return (0);
152 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
153 
154 	if ((ctx == NULL) || (b->next_bio == NULL))
155 		return (0);
156 	num = 0;
157 	BIO_clear_retry_flags(b);
158 
159 start:
160 	i = ctx->ibuf_len;
161 	/* If there is stuff left over, grab it */
162 	if (i != 0) {
163 		if (i > outl)
164 			i = outl;
165 		memcpy(out, &(ctx->ibuf[ctx->ibuf_off]), i);
166 		ctx->ibuf_off += i;
167 		ctx->ibuf_len -= i;
168 		num += i;
169 		if (outl == i)
170 			return (num);
171 		outl -= i;
172 		out += i;
173 	}
174 
175 	/* We may have done a partial read. try to do more.
176 	 * We have nothing in the buffer.
177 	 * If we get an error and have read some data, just return it
178 	 * and let them retry to get the error again.
179 	 * copy direct to parent address space */
180 	if (outl > ctx->ibuf_size) {
181 		for (;;) {
182 			i = BIO_read(b->next_bio, out, outl);
183 			if (i <= 0) {
184 				BIO_copy_next_retry(b);
185 				if (i < 0)
186 					return ((num > 0) ? num : i);
187 				if (i == 0)
188 					return (num);
189 			}
190 			num += i;
191 			if (outl == i)
192 				return (num);
193 			out += i;
194 			outl -= i;
195 		}
196 	}
197 	/* else */
198 
199 	/* we are going to be doing some buffering */
200 	i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
201 	if (i <= 0) {
202 		BIO_copy_next_retry(b);
203 		if (i < 0)
204 			return ((num > 0) ? num : i);
205 		if (i == 0)
206 			return (num);
207 	}
208 	ctx->ibuf_off = 0;
209 	ctx->ibuf_len = i;
210 
211 	/* Lets re-read using ourselves :-) */
212 	goto start;
213 }
214 
215 static int
216 buffer_write(BIO *b, const char *in, int inl)
217 {
218 	int i, num = 0;
219 	BIO_F_BUFFER_CTX *ctx;
220 
221 	if ((in == NULL) || (inl <= 0))
222 		return (0);
223 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
224 	if ((ctx == NULL) || (b->next_bio == NULL))
225 		return (0);
226 
227 	BIO_clear_retry_flags(b);
228 start:
229 	i = ctx->obuf_size - (ctx->obuf_len + ctx->obuf_off);
230 	/* add to buffer and return */
231 	if (i >= inl) {
232 		memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, inl);
233 		ctx->obuf_len += inl;
234 		return (num + inl);
235 	}
236 	/* else */
237 	/* stuff already in buffer, so add to it first, then flush */
238 	if (ctx->obuf_len != 0) {
239 		if (i > 0) /* lets fill it up if we can */
240 		{
241 			memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, i);
242 			in += i;
243 			inl -= i;
244 			num += i;
245 			ctx->obuf_len += i;
246 		}
247 		/* we now have a full buffer needing flushing */
248 		for (;;) {
249 			i = BIO_write(b->next_bio, &(ctx->obuf[ctx->obuf_off]),
250 			    ctx->obuf_len);
251 			if (i <= 0) {
252 				BIO_copy_next_retry(b);
253 
254 				if (i < 0)
255 					return ((num > 0) ? num : i);
256 				if (i == 0)
257 					return (num);
258 			}
259 			ctx->obuf_off += i;
260 			ctx->obuf_len -= i;
261 			if (ctx->obuf_len == 0)
262 				break;
263 		}
264 	}
265 	/* we only get here if the buffer has been flushed and we
266 	 * still have stuff to write */
267 	ctx->obuf_off = 0;
268 
269 	/* we now have inl bytes to write */
270 	while (inl >= ctx->obuf_size) {
271 		i = BIO_write(b->next_bio, in, inl);
272 		if (i <= 0) {
273 			BIO_copy_next_retry(b);
274 			if (i < 0)
275 				return ((num > 0) ? num : i);
276 			if (i == 0)
277 				return (num);
278 		}
279 		num += i;
280 		in += i;
281 		inl -= i;
282 		if (inl == 0)
283 			return (num);
284 	}
285 
286 	/* copy the rest into the buffer since we have only a small
287 	 * amount left */
288 	goto start;
289 }
290 
291 static long
292 buffer_ctrl(BIO *b, int cmd, long num, void *ptr)
293 {
294 	BIO *dbio;
295 	BIO_F_BUFFER_CTX *ctx;
296 	long ret = 1;
297 	char *p1, *p2;
298 	int r, i, *ip;
299 	int ibs, obs;
300 
301 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
302 
303 	switch (cmd) {
304 	case BIO_CTRL_RESET:
305 		ctx->ibuf_off = 0;
306 		ctx->ibuf_len = 0;
307 		ctx->obuf_off = 0;
308 		ctx->obuf_len = 0;
309 		if (b->next_bio == NULL)
310 			return (0);
311 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
312 		break;
313 	case BIO_CTRL_INFO:
314 		ret = (long)ctx->obuf_len;
315 		break;
316 	case BIO_C_GET_BUFF_NUM_LINES:
317 		ret = 0;
318 		p1 = ctx->ibuf;
319 		for (i = 0; i < ctx->ibuf_len; i++) {
320 			if (p1[ctx->ibuf_off + i] == '\n')
321 				ret++;
322 		}
323 		break;
324 	case BIO_CTRL_WPENDING:
325 		ret = (long)ctx->obuf_len;
326 		if (ret == 0) {
327 			if (b->next_bio == NULL)
328 				return (0);
329 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
330 		}
331 		break;
332 	case BIO_CTRL_PENDING:
333 		ret = (long)ctx->ibuf_len;
334 		if (ret == 0) {
335 			if (b->next_bio == NULL)
336 				return (0);
337 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
338 		}
339 		break;
340 	case BIO_C_SET_BUFF_READ_DATA:
341 		if (num > ctx->ibuf_size) {
342 			p1 = malloc(num);
343 			if (p1 == NULL)
344 				goto malloc_error;
345 			free(ctx->ibuf);
346 			ctx->ibuf = p1;
347 		}
348 		ctx->ibuf_off = 0;
349 		ctx->ibuf_len = (int)num;
350 		memcpy(ctx->ibuf, ptr, num);
351 		ret = 1;
352 		break;
353 	case BIO_C_SET_BUFF_SIZE:
354 		if (ptr != NULL) {
355 			ip = (int *)ptr;
356 			if (*ip == 0) {
357 				ibs = (int)num;
358 				obs = ctx->obuf_size;
359 			}
360 			else /* if (*ip == 1) */
361 			{
362 				ibs = ctx->ibuf_size;
363 				obs = (int)num;
364 			}
365 		} else {
366 			ibs = (int)num;
367 			obs = (int)num;
368 		}
369 		p1 = ctx->ibuf;
370 		p2 = ctx->obuf;
371 		if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size)) {
372 			p1 = malloc(num);
373 			if (p1 == NULL)
374 				goto malloc_error;
375 		}
376 		if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size)) {
377 			p2 = malloc(num);
378 			if (p2 == NULL) {
379 				if (p1 != ctx->ibuf)
380 					free(p1);
381 				goto malloc_error;
382 			}
383 		}
384 		if (ctx->ibuf != p1) {
385 			free(ctx->ibuf);
386 			ctx->ibuf = p1;
387 			ctx->ibuf_off = 0;
388 			ctx->ibuf_len = 0;
389 			ctx->ibuf_size = ibs;
390 		}
391 		if (ctx->obuf != p2) {
392 			free(ctx->obuf);
393 			ctx->obuf = p2;
394 			ctx->obuf_off = 0;
395 			ctx->obuf_len = 0;
396 			ctx->obuf_size = obs;
397 		}
398 		break;
399 	case BIO_C_DO_STATE_MACHINE:
400 		if (b->next_bio == NULL)
401 			return (0);
402 		BIO_clear_retry_flags(b);
403 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
404 		BIO_copy_next_retry(b);
405 		break;
406 
407 	case BIO_CTRL_FLUSH:
408 		if (b->next_bio == NULL)
409 			return (0);
410 		if (ctx->obuf_len <= 0) {
411 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
412 			break;
413 		}
414 
415 		for (;;) {
416 			BIO_clear_retry_flags(b);
417 			if (ctx->obuf_len > 0) {
418 				r = BIO_write(b->next_bio,
419 				    &(ctx->obuf[ctx->obuf_off]),
420 				    ctx->obuf_len);
421 				BIO_copy_next_retry(b);
422 				if (r <= 0)
423 					return ((long)r);
424 				ctx->obuf_off += r;
425 				ctx->obuf_len -= r;
426 			} else {
427 				ctx->obuf_len = 0;
428 				ctx->obuf_off = 0;
429 				break;
430 			}
431 		}
432 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
433 		break;
434 	case BIO_CTRL_DUP:
435 		dbio = (BIO *)ptr;
436 		if (!BIO_set_read_buffer_size(dbio, ctx->ibuf_size) ||
437 		    !BIO_set_write_buffer_size(dbio, ctx->obuf_size))
438 			ret = 0;
439 		break;
440 	default:
441 		if (b->next_bio == NULL)
442 			return (0);
443 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
444 		break;
445 	}
446 	return (ret);
447 malloc_error:
448 	BIOerror(ERR_R_MALLOC_FAILURE);
449 	return (0);
450 }
451 
452 static long
453 buffer_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
454 {
455 	long ret = 1;
456 
457 	if (b->next_bio == NULL)
458 		return (0);
459 	switch (cmd) {
460 	default:
461 		ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
462 		break;
463 	}
464 	return (ret);
465 }
466 
467 static int
468 buffer_gets(BIO *b, char *buf, int size)
469 {
470 	BIO_F_BUFFER_CTX *ctx;
471 	int num = 0, i, flag;
472 	char *p;
473 
474 	ctx = (BIO_F_BUFFER_CTX *)b->ptr;
475 	size--; /* reserve space for a '\0' */
476 	BIO_clear_retry_flags(b);
477 
478 	for (;;) {
479 		if (ctx->ibuf_len > 0) {
480 			p = &(ctx->ibuf[ctx->ibuf_off]);
481 			flag = 0;
482 			for (i = 0; (i < ctx->ibuf_len) && (i < size); i++) {
483 				*(buf++) = p[i];
484 				if (p[i] == '\n') {
485 					flag = 1;
486 					i++;
487 					break;
488 				}
489 			}
490 			num += i;
491 			size -= i;
492 			ctx->ibuf_len -= i;
493 			ctx->ibuf_off += i;
494 			if (flag || size == 0) {
495 				*buf = '\0';
496 				return (num);
497 			}
498 		}
499 		else	/* read another chunk */
500 		{
501 			i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
502 			if (i <= 0) {
503 				BIO_copy_next_retry(b);
504 				*buf = '\0';
505 				if (i < 0)
506 					return ((num > 0) ? num : i);
507 				if (i == 0)
508 					return (num);
509 			}
510 			ctx->ibuf_len = i;
511 			ctx->ibuf_off = 0;
512 		}
513 	}
514 }
515 
516 static int
517 buffer_puts(BIO *b, const char *str)
518 {
519 	return (buffer_write(b, str, strlen(str)));
520 }
521