xref: /openbsd/lib/libcrypto/asn1/bio_asn1.c (revision 274d7c50) 
1 /* $OpenBSD: bio_asn1.c,v 1.13 2018/05/01 13:29:09 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project.
4  */
5 /* ====================================================================
6  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 /* Experimental ASN1 BIO. When written through the data is converted
60  * to an ASN1 string type: default is OCTET STRING. Additional functions
61  * can be provided to add prefix and suffix data.
62  */
63 
64 #include <stdlib.h>
65 #include <string.h>
66 
67 #include <openssl/bio.h>
68 #include <openssl/asn1.h>
69 
70 /* Must be large enough for biggest tag+length */
71 #define DEFAULT_ASN1_BUF_SIZE 20
72 
73 typedef enum {
74 	ASN1_STATE_START,
75 	ASN1_STATE_PRE_COPY,
76 	ASN1_STATE_HEADER,
77 	ASN1_STATE_HEADER_COPY,
78 	ASN1_STATE_DATA_COPY,
79 	ASN1_STATE_POST_COPY,
80 	ASN1_STATE_DONE
81 } asn1_bio_state_t;
82 
83 typedef struct BIO_ASN1_EX_FUNCS_st {
84 	asn1_ps_func	*ex_func;
85 	asn1_ps_func	*ex_free_func;
86 } BIO_ASN1_EX_FUNCS;
87 
88 typedef struct BIO_ASN1_BUF_CTX_t {
89 	/* Internal state */
90 	asn1_bio_state_t state;
91 	/* Internal buffer */
92 	unsigned char *buf;
93 	/* Size of buffer */
94 	int bufsize;
95 	/* Current position in buffer */
96 	int bufpos;
97 	/* Current buffer length */
98 	int buflen;
99 	/* Amount of data to copy */
100 	int copylen;
101 	/* Class and tag to use */
102 	int asn1_class, asn1_tag;
103 	asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;
104 	/* Extra buffer for prefix and suffix data */
105 	unsigned char *ex_buf;
106 	int ex_len;
107 	int ex_pos;
108 	void *ex_arg;
109 } BIO_ASN1_BUF_CTX;
110 
111 
112 static int asn1_bio_write(BIO *h, const char *buf, int num);
113 static int asn1_bio_read(BIO *h, char *buf, int size);
114 static int asn1_bio_puts(BIO *h, const char *str);
115 static int asn1_bio_gets(BIO *h, char *str, int size);
116 static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);
117 static int asn1_bio_new(BIO *h);
118 static int asn1_bio_free(BIO *data);
119 static long asn1_bio_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
120 
121 static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
122 static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
123     asn1_ps_func *cleanup, asn1_bio_state_t next);
124 static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
125     asn1_ps_func *setup, asn1_bio_state_t ex_state,
126     asn1_bio_state_t other_state);
127 
128 static const BIO_METHOD methods_asn1 = {
129 	.type = BIO_TYPE_ASN1,
130 	.name = "asn1",
131 	.bwrite = asn1_bio_write,
132 	.bread = asn1_bio_read,
133 	.bputs = asn1_bio_puts,
134 	.bgets = asn1_bio_gets,
135 	.ctrl = asn1_bio_ctrl,
136 	.create = asn1_bio_new,
137 	.destroy = asn1_bio_free,
138 	.callback_ctrl = asn1_bio_callback_ctrl
139 };
140 
141 const BIO_METHOD *
142 BIO_f_asn1(void)
143 {
144 	return (&methods_asn1);
145 }
146 
147 static int
148 asn1_bio_new(BIO *b)
149 {
150 	BIO_ASN1_BUF_CTX *ctx;
151 	ctx = malloc(sizeof(BIO_ASN1_BUF_CTX));
152 	if (!ctx)
153 		return 0;
154 	if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
155 		free(ctx);
156 		return 0;
157 	}
158 	b->init = 1;
159 	b->ptr = (char *)ctx;
160 	b->flags = 0;
161 	return 1;
162 }
163 
164 static int
165 asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
166 {
167 	ctx->buf = malloc(size);
168 	if (!ctx->buf)
169 		return 0;
170 	ctx->bufsize = size;
171 	ctx->bufpos = 0;
172 	ctx->buflen = 0;
173 	ctx->copylen = 0;
174 	ctx->asn1_class = V_ASN1_UNIVERSAL;
175 	ctx->asn1_tag = V_ASN1_OCTET_STRING;
176 	ctx->ex_buf = NULL;
177 	ctx->ex_pos = 0;
178 	ctx->ex_len = 0;
179 	ctx->state = ASN1_STATE_START;
180 	return 1;
181 }
182 
183 static int
184 asn1_bio_free(BIO *b)
185 {
186 	BIO_ASN1_BUF_CTX *ctx;
187 
188 	ctx = (BIO_ASN1_BUF_CTX *) b->ptr;
189 	if (ctx == NULL)
190 		return 0;
191 	free(ctx->buf);
192 	free(ctx);
193 	b->init = 0;
194 	b->ptr = NULL;
195 	b->flags = 0;
196 	return 1;
197 }
198 
199 static int
200 asn1_bio_write(BIO *b, const char *in , int inl)
201 {
202 	BIO_ASN1_BUF_CTX *ctx;
203 	int wrmax, wrlen, ret, buflen;
204 	unsigned char *p;
205 
206 	if (!in || (inl < 0) || (b->next_bio == NULL))
207 		return 0;
208 	ctx = (BIO_ASN1_BUF_CTX *) b->ptr;
209 	if (ctx == NULL)
210 		return 0;
211 
212 	wrlen = 0;
213 	ret = -1;
214 
215 	for (;;) {
216 		switch (ctx->state) {
217 
218 			/* Setup prefix data, call it */
219 		case ASN1_STATE_START:
220 			if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
221 				    ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
222 				return 0;
223 			break;
224 
225 			/* Copy any pre data first */
226 		case ASN1_STATE_PRE_COPY:
227 			ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
228 			    ASN1_STATE_HEADER);
229 			if (ret <= 0)
230 				goto done;
231 			break;
232 
233 		case ASN1_STATE_HEADER:
234 			buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
235 			if (buflen <= 0 || buflen > ctx->bufsize)
236 				return -1;
237 			ctx->buflen = buflen;
238 			p = ctx->buf;
239 			ASN1_put_object(&p, 0, inl,
240 			    ctx->asn1_tag, ctx->asn1_class);
241 			ctx->copylen = inl;
242 			ctx->state = ASN1_STATE_HEADER_COPY;
243 			break;
244 
245 		case ASN1_STATE_HEADER_COPY:
246 			ret = BIO_write(b->next_bio,
247 			    ctx->buf + ctx->bufpos, ctx->buflen);
248 			if (ret <= 0)
249 				goto done;
250 
251 			ctx->buflen -= ret;
252 			if (ctx->buflen)
253 				ctx->bufpos += ret;
254 			else {
255 				ctx->bufpos = 0;
256 				ctx->state = ASN1_STATE_DATA_COPY;
257 			}
258 			break;
259 
260 		case ASN1_STATE_DATA_COPY:
261 
262 			if (inl > ctx->copylen)
263 				wrmax = ctx->copylen;
264 			else
265 				wrmax = inl;
266 			ret = BIO_write(b->next_bio, in, wrmax);
267 			if (ret <= 0)
268 				break;
269 			wrlen += ret;
270 			ctx->copylen -= ret;
271 			in += ret;
272 			inl -= ret;
273 
274 			if (ctx->copylen == 0)
275 				ctx->state = ASN1_STATE_HEADER;
276 			if (inl == 0)
277 				goto done;
278 			break;
279 
280 		default:
281 			BIO_clear_retry_flags(b);
282 			return 0;
283 		}
284 
285 	}
286 
287 done:
288 	BIO_clear_retry_flags(b);
289 	BIO_copy_next_retry(b);
290 
291 	return (wrlen > 0) ? wrlen : ret;
292 }
293 
294 static int
295 asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx, asn1_ps_func *cleanup,
296     asn1_bio_state_t next)
297 {
298 	int ret;
299 
300 	if (ctx->ex_len <= 0)
301 		return 1;
302 	for (;;) {
303 		ret = BIO_write(b->next_bio, ctx->ex_buf + ctx->ex_pos,
304 		    ctx->ex_len);
305 		if (ret <= 0)
306 			break;
307 		ctx->ex_len -= ret;
308 		if (ctx->ex_len > 0)
309 			ctx->ex_pos += ret;
310 		else {
311 			if (cleanup)
312 				cleanup(b, &ctx->ex_buf, &ctx->ex_len,
313 				    &ctx->ex_arg);
314 			ctx->state = next;
315 			ctx->ex_pos = 0;
316 			break;
317 		}
318 	}
319 	return ret;
320 }
321 
322 static int
323 asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx, asn1_ps_func *setup,
324     asn1_bio_state_t ex_state, asn1_bio_state_t other_state)
325 {
326 	if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
327 		BIO_clear_retry_flags(b);
328 		return 0;
329 	}
330 	if (ctx->ex_len > 0)
331 		ctx->state = ex_state;
332 	else
333 		ctx->state = other_state;
334 	return 1;
335 }
336 
337 static int
338 asn1_bio_read(BIO *b, char *in , int inl)
339 {
340 	if (!b->next_bio)
341 		return 0;
342 	return BIO_read(b->next_bio, in , inl);
343 }
344 
345 static int
346 asn1_bio_puts(BIO *b, const char *str)
347 {
348 	return asn1_bio_write(b, str, strlen(str));
349 }
350 
351 static int
352 asn1_bio_gets(BIO *b, char *str, int size)
353 {
354 	if (!b->next_bio)
355 		return 0;
356 	return BIO_gets(b->next_bio, str , size);
357 }
358 
359 static long
360 asn1_bio_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
361 {
362 	if (b->next_bio == NULL)
363 		return (0);
364 	return BIO_callback_ctrl(b->next_bio, cmd, fp);
365 }
366 
367 static long
368 asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)
369 {
370 	BIO_ASN1_BUF_CTX *ctx;
371 	BIO_ASN1_EX_FUNCS *ex_func;
372 	long ret = 1;
373 
374 	ctx = (BIO_ASN1_BUF_CTX *) b->ptr;
375 	if (ctx == NULL)
376 		return 0;
377 	switch (cmd) {
378 
379 	case BIO_C_SET_PREFIX:
380 		ex_func = arg2;
381 		ctx->prefix = ex_func->ex_func;
382 		ctx->prefix_free = ex_func->ex_free_func;
383 		break;
384 
385 	case BIO_C_GET_PREFIX:
386 		ex_func = arg2;
387 		ex_func->ex_func = ctx->prefix;
388 		ex_func->ex_free_func = ctx->prefix_free;
389 		break;
390 
391 	case BIO_C_SET_SUFFIX:
392 		ex_func = arg2;
393 		ctx->suffix = ex_func->ex_func;
394 		ctx->suffix_free = ex_func->ex_free_func;
395 		break;
396 
397 	case BIO_C_GET_SUFFIX:
398 		ex_func = arg2;
399 		ex_func->ex_func = ctx->suffix;
400 		ex_func->ex_free_func = ctx->suffix_free;
401 		break;
402 
403 	case BIO_C_SET_EX_ARG:
404 		ctx->ex_arg = arg2;
405 		break;
406 
407 	case BIO_C_GET_EX_ARG:
408 		*(void **)arg2 = ctx->ex_arg;
409 		break;
410 
411 	case BIO_CTRL_FLUSH:
412 		if (!b->next_bio)
413 			return 0;
414 
415 		/* Call post function if possible */
416 		if (ctx->state == ASN1_STATE_HEADER) {
417 			if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
418 			    ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
419 				return 0;
420 		}
421 
422 		if (ctx->state == ASN1_STATE_POST_COPY) {
423 			ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
424 			    ASN1_STATE_DONE);
425 			if (ret <= 0)
426 				return ret;
427 		}
428 
429 		if (ctx->state == ASN1_STATE_DONE)
430 			return BIO_ctrl(b->next_bio, cmd, arg1, arg2);
431 		else {
432 			BIO_clear_retry_flags(b);
433 			return 0;
434 		}
435 		break;
436 
437 
438 	default:
439 		if (!b->next_bio)
440 			return 0;
441 		return BIO_ctrl(b->next_bio, cmd, arg1, arg2);
442 
443 	}
444 
445 	return ret;
446 }
447 
448 static int
449 asn1_bio_set_ex(BIO *b, int cmd, asn1_ps_func *ex_func, asn1_ps_func
450     *ex_free_func)
451 {
452 	BIO_ASN1_EX_FUNCS extmp;
453 
454 	extmp.ex_func = ex_func;
455 	extmp.ex_free_func = ex_free_func;
456 	return BIO_ctrl(b, cmd, 0, &extmp);
457 }
458 
459 static int
460 asn1_bio_get_ex(BIO *b, int cmd, asn1_ps_func **ex_func,
461     asn1_ps_func **ex_free_func)
462 {
463 	BIO_ASN1_EX_FUNCS extmp;
464 	int ret;
465 
466 	ret = BIO_ctrl(b, cmd, 0, &extmp);
467 	if (ret > 0) {
468 		*ex_func = extmp.ex_func;
469 		*ex_free_func = extmp.ex_free_func;
470 	}
471 	return ret;
472 }
473 
474 int
475 BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix, asn1_ps_func *prefix_free)
476 {
477 	return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
478 }
479 
480 int
481 BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix, asn1_ps_func **pprefix_free)
482 {
483 	return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
484 }
485 
486 int
487 BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix, asn1_ps_func *suffix_free)
488 {
489 	return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
490 }
491 
492 int
493 BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix, asn1_ps_func **psuffix_free)
494 {
495 	return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
496 }
497