ocsp_ht.c revision 279265 
1/* ocsp_ht.c */
2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2006.
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#include <stdio.h>
60#include <stdlib.h>
61#include <ctype.h>
62#include <string.h>
63#include "e_os.h"
64#include <openssl/asn1.h>
65#include <openssl/ocsp.h>
66#include <openssl/err.h>
67#include <openssl/buffer.h>
68#ifdef OPENSSL_SYS_SUNOS
69#define strtoul (unsigned long)strtol
70#endif /* OPENSSL_SYS_SUNOS */
71
72/* Stateful OCSP request code, supporting non-blocking I/O */
73
74/* Opaque OCSP request status structure */
75
76struct ocsp_req_ctx_st {
77	int state;		/* Current I/O state */
78	unsigned char *iobuf;	/* Line buffer */
79	int iobuflen;		/* Line buffer length */
80	BIO *io;		/* BIO to perform I/O with */
81	BIO *mem;		/* Memory BIO response is built into */
82	unsigned long asn1_len;	/* ASN1 length of response */
83	};
84
85#define OCSP_MAX_REQUEST_LENGTH	(100 * 1024)
86#define OCSP_MAX_LINE_LEN	4096;
87
88/* OCSP states */
89
90/* If set no reading should be performed */
91#define OHS_NOREAD		0x1000
92/* Error condition */
93#define OHS_ERROR		(0 | OHS_NOREAD)
94/* First line being read */
95#define OHS_FIRSTLINE		1
96/* MIME headers being read */
97#define OHS_HEADERS		2
98/* OCSP initial header (tag + length) being read */
99#define OHS_ASN1_HEADER		3
100/* OCSP content octets being read */
101#define OHS_ASN1_CONTENT	4
102/* Request being sent */
103#define OHS_ASN1_WRITE		(6 | OHS_NOREAD)
104/* Request being flushed */
105#define OHS_ASN1_FLUSH		(7 | OHS_NOREAD)
106/* Completed */
107#define OHS_DONE		(8 | OHS_NOREAD)
108
109
110static int parse_http_line1(char *line);
111
112void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
113	{
114	if (rctx->mem)
115		BIO_free(rctx->mem);
116	if (rctx->iobuf)
117		OPENSSL_free(rctx->iobuf);
118	OPENSSL_free(rctx);
119	}
120
121OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
122								int maxline)
123	{
124	static char post_hdr[] = "POST %s HTTP/1.0\r\n"
125	"Content-Type: application/ocsp-request\r\n"
126	"Content-Length: %d\r\n\r\n";
127
128	OCSP_REQ_CTX *rctx;
129	rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
130	rctx->state = OHS_FIRSTLINE;
131	rctx->mem = BIO_new(BIO_s_mem());
132	rctx->io = io;
133	if (maxline > 0)
134		rctx->iobuflen = maxline;
135	else
136		rctx->iobuflen = OCSP_MAX_LINE_LEN;
137	rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
138	if (!path)
139		path = "/";
140
141        if (BIO_printf(rctx->mem, post_hdr, path,
142				i2d_OCSP_REQUEST(req, NULL)) <= 0)
143		{
144		rctx->state = OHS_ERROR;
145		return 0;
146		}
147        if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0)
148		{
149		rctx->state = OHS_ERROR;
150		return 0;
151		}
152	rctx->state = OHS_ASN1_WRITE;
153	rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
154
155	return rctx;
156	}
157
158/* Parse the HTTP response. This will look like this:
159 * "HTTP/1.0 200 OK". We need to obtain the numeric code and
160 * (optional) informational message.
161 */
162
163static int parse_http_line1(char *line)
164	{
165	int retcode;
166	char *p, *q, *r;
167	/* Skip to first white space (passed protocol info) */
168
169	for(p = line; *p && !isspace((unsigned char)*p); p++)
170		continue;
171	if(!*p)
172		{
173		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
174					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
175		return 0;
176		}
177
178	/* Skip past white space to start of response code */
179	while(*p && isspace((unsigned char)*p))
180		p++;
181
182	if(!*p)
183		{
184		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
185					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
186		return 0;
187		}
188
189	/* Find end of response code: first whitespace after start of code */
190	for(q = p; *q && !isspace((unsigned char)*q); q++)
191		continue;
192
193	if(!*q)
194		{
195		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
196					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
197		return 0;
198		}
199
200	/* Set end of response code and start of message */
201	*q++ = 0;
202
203	/* Attempt to parse numeric code */
204	retcode = strtoul(p, &r, 10);
205
206	if(*r)
207		return 0;
208
209	/* Skip over any leading white space in message */
210	while(*q && isspace((unsigned char)*q))
211		q++;
212
213	if(*q)
214		{
215		/* Finally zap any trailing white space in message (include
216		 * CRLF) */
217
218		/* We know q has a non white space character so this is OK */
219		for(r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
220			*r = 0;
221		}
222	if(retcode != 200)
223		{
224		OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
225		if(!*q)
226			ERR_add_error_data(2, "Code=", p);
227		else
228			ERR_add_error_data(4, "Code=", p, ",Reason=", q);
229		return 0;
230		}
231
232
233	return 1;
234
235	}
236
237int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
238	{
239	int i, n;
240	const unsigned char *p;
241	next_io:
242	if (!(rctx->state & OHS_NOREAD))
243		{
244		n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
245
246		if (n <= 0)
247			{
248			if (BIO_should_retry(rctx->io))
249				return -1;
250			return 0;
251			}
252
253		/* Write data to memory BIO */
254
255		if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
256			return 0;
257		}
258
259	switch(rctx->state)
260		{
261
262		case OHS_ASN1_WRITE:
263		n = BIO_get_mem_data(rctx->mem, &p);
264
265		i = BIO_write(rctx->io,
266			p + (n - rctx->asn1_len), rctx->asn1_len);
267
268		if (i <= 0)
269			{
270			if (BIO_should_retry(rctx->io))
271				return -1;
272			rctx->state = OHS_ERROR;
273			return 0;
274			}
275
276		rctx->asn1_len -= i;
277
278		if (rctx->asn1_len > 0)
279			goto next_io;
280
281		rctx->state = OHS_ASN1_FLUSH;
282
283		(void)BIO_reset(rctx->mem);
284
285		case OHS_ASN1_FLUSH:
286
287		i = BIO_flush(rctx->io);
288
289		if (i > 0)
290			{
291			rctx->state = OHS_FIRSTLINE;
292			goto next_io;
293			}
294
295		if (BIO_should_retry(rctx->io))
296			return -1;
297
298		rctx->state = OHS_ERROR;
299		return 0;
300
301		case OHS_ERROR:
302		return 0;
303
304		case OHS_FIRSTLINE:
305		case OHS_HEADERS:
306
307		/* Attempt to read a line in */
308
309		next_line:
310		/* Due to &%^*$" memory BIO behaviour with BIO_gets we
311		 * have to check there's a complete line in there before
312		 * calling BIO_gets or we'll just get a partial read.
313		 */
314		n = BIO_get_mem_data(rctx->mem, &p);
315		if ((n <= 0) || !memchr(p, '\n', n))
316			{
317			if (n >= rctx->iobuflen)
318				{
319				rctx->state = OHS_ERROR;
320				return 0;
321				}
322			goto next_io;
323			}
324		n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
325
326		if (n <= 0)
327			{
328			if (BIO_should_retry(rctx->mem))
329				goto next_io;
330			rctx->state = OHS_ERROR;
331			return 0;
332			}
333
334		/* Don't allow excessive lines */
335		if (n == rctx->iobuflen)
336			{
337			rctx->state = OHS_ERROR;
338			return 0;
339			}
340
341		/* First line */
342		if (rctx->state == OHS_FIRSTLINE)
343			{
344			if (parse_http_line1((char *)rctx->iobuf))
345				{
346				rctx->state = OHS_HEADERS;
347				goto next_line;
348				}
349			else
350				{
351				rctx->state = OHS_ERROR;
352				return 0;
353				}
354			}
355		else
356			{
357			/* Look for blank line: end of headers */
358			for (p = rctx->iobuf; *p; p++)
359				{
360				if ((*p != '\r') && (*p != '\n'))
361					break;
362				}
363			if (*p)
364				goto next_line;
365
366			rctx->state = OHS_ASN1_HEADER;
367
368			}
369
370		/* Fall thru */
371
372
373		case OHS_ASN1_HEADER:
374		/* Now reading ASN1 header: can read at least 2 bytes which
375		 * is enough for ASN1 SEQUENCE header and either length field
376		 * or at least the length of the length field.
377		 */
378		n = BIO_get_mem_data(rctx->mem, &p);
379		if (n < 2)
380			goto next_io;
381
382		/* Check it is an ASN1 SEQUENCE */
383		if (*p++ != (V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED))
384			{
385			rctx->state = OHS_ERROR;
386			return 0;
387			}
388
389		/* Check out length field */
390		if (*p & 0x80)
391			{
392			/* If MSB set on initial length octet we can now
393			 * always read 6 octets: make sure we have them.
394			 */
395			if (n < 6)
396				goto next_io;
397			n = *p & 0x7F;
398			/* Not NDEF or excessive length */
399			if (!n || (n > 4))
400				{
401				rctx->state = OHS_ERROR;
402				return 0;
403				}
404			p++;
405			rctx->asn1_len = 0;
406			for (i = 0; i < n; i++)
407				{
408				rctx->asn1_len <<= 8;
409				rctx->asn1_len |= *p++;
410				}
411
412			if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH)
413				{
414				rctx->state = OHS_ERROR;
415				return 0;
416				}
417
418			rctx->asn1_len += n + 2;
419			}
420		else
421			rctx->asn1_len = *p + 2;
422
423		rctx->state = OHS_ASN1_CONTENT;
424
425		/* Fall thru */
426
427		case OHS_ASN1_CONTENT:
428		n = BIO_get_mem_data(rctx->mem, &p);
429		if (n < (int)rctx->asn1_len)
430			goto next_io;
431
432
433		*presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
434		if (*presp)
435			{
436			rctx->state = OHS_DONE;
437			return 1;
438			}
439
440		rctx->state = OHS_ERROR;
441		return 0;
442
443		break;
444
445		case OHS_DONE:
446		return 1;
447
448		}
449
450
451
452	return 0;
453
454
455	}
456
457/* Blocking OCSP request handler: now a special case of non-blocking I/O */
458
459OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, char *path, OCSP_REQUEST *req)
460	{
461	OCSP_RESPONSE *resp = NULL;
462	OCSP_REQ_CTX *ctx;
463	int rv;
464
465	ctx = OCSP_sendreq_new(b, path, req, -1);
466
467	if (!ctx)
468		return NULL;
469
470	do
471		{
472		rv = OCSP_sendreq_nbio(&resp, ctx);
473		} while ((rv == -1) && BIO_should_retry(b));
474
475	OCSP_REQ_CTX_free(ctx);
476
477	if (rv)
478		return resp;
479
480	return NULL;
481	}
482