ocsp_ht.c revision bdfb8ad83da0647e9b9a32792598e8ce7ba3ef4d 
1/* ocsp_ht.c */
2/* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 <openssl/asn1.h>
60#include <stdio.h>
61#include <stdlib.h>
62#include <ctype.h>
63#include <string.h>
64#include <openssl/ocsp.h>
65#include <openssl/err.h>
66#include <openssl/buffer.h>
67#ifdef OPENSSL_SYS_SUNOS
68#define strtoul (unsigned long)strtol
69#endif /* OPENSSL_SYS_SUNOS */
70
71/* Stateful OCSP request code, supporting non-blocking I/O */
72
73/* Opaque OCSP request status structure */
74
75struct ocsp_req_ctx_st {
76	int state;		/* Current I/O state */
77	unsigned char *iobuf;	/* Line buffer */
78	int iobuflen;		/* Line buffer length */
79	BIO *io;		/* BIO to perform I/O with */
80	BIO *mem;		/* Memory BIO response is built into */
81	unsigned long asn1_len;	/* ASN1 length of response */
82	};
83
84#define OCSP_MAX_REQUEST_LENGTH	(100 * 1024)
85#define OCSP_MAX_LINE_LEN	4096;
86
87/* OCSP states */
88
89/* If set no reading should be performed */
90#define OHS_NOREAD		0x1000
91/* Error condition */
92#define OHS_ERROR		(0 | OHS_NOREAD)
93/* First line being read */
94#define OHS_FIRSTLINE		1
95/* MIME headers being read */
96#define OHS_HEADERS		2
97/* OCSP initial header (tag + length) being read */
98#define OHS_ASN1_HEADER		3
99/* OCSP content octets being read */
100#define OHS_ASN1_CONTENT	4
101/* Request being sent */
102#define OHS_ASN1_WRITE		(6 | OHS_NOREAD)
103/* Request being flushed */
104#define OHS_ASN1_FLUSH		(7 | OHS_NOREAD)
105/* Completed */
106#define OHS_DONE		(8 | OHS_NOREAD)
107
108
109static int parse_http_line1(char *line);
110
111void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
112	{
113	if (rctx->mem)
114		BIO_free(rctx->mem);
115	if (rctx->iobuf)
116		OPENSSL_free(rctx->iobuf);
117	OPENSSL_free(rctx);
118	}
119
120OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
121								int maxline)
122	{
123	static char post_hdr[] = "POST %s HTTP/1.0\r\n"
124	"Content-Type: application/ocsp-request\r\n"
125	"Content-Length: %d\r\n\r\n";
126
127	OCSP_REQ_CTX *rctx;
128	rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
129	rctx->state = OHS_FIRSTLINE;
130	rctx->mem = BIO_new(BIO_s_mem());
131	rctx->io = io;
132	if (maxline > 0)
133		rctx->iobuflen = maxline;
134	else
135		rctx->iobuflen = OCSP_MAX_LINE_LEN;
136	rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
137	if (!path)
138		path = "/";
139
140        if (BIO_printf(rctx->mem, post_hdr, path,
141				i2d_OCSP_REQUEST(req, NULL)) <= 0)
142		{
143		rctx->state = OHS_ERROR;
144		return 0;
145		}
146        if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0)
147		{
148		rctx->state = OHS_ERROR;
149		return 0;
150		}
151	rctx->state = OHS_ASN1_WRITE;
152	rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
153
154	return rctx;
155	}
156
157/* Parse the HTTP response. This will look like this:
158 * "HTTP/1.0 200 OK". We need to obtain the numeric code and
159 * (optional) informational message.
160 */
161
162static int parse_http_line1(char *line)
163	{
164	int retcode;
165	char *p, *q, *r;
166	/* Skip to first white space (passed protocol info) */
167
168	for(p = line; *p && !isspace((unsigned char)*p); p++)
169		continue;
170	if(!*p)
171		{
172		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
173					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
174		return 0;
175		}
176
177	/* Skip past white space to start of response code */
178	while(*p && isspace((unsigned char)*p))
179		p++;
180
181	if(!*p)
182		{
183		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
184					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
185		return 0;
186		}
187
188	/* Find end of response code: first whitespace after start of code */
189	for(q = p; *q && !isspace((unsigned char)*q); q++)
190		continue;
191
192	if(!*q)
193		{
194		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
195					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
196		return 0;
197		}
198
199	/* Set end of response code and start of message */
200	*q++ = 0;
201
202	/* Attempt to parse numeric code */
203	retcode = strtoul(p, &r, 10);
204
205	if(*r)
206		return 0;
207
208	/* Skip over any leading white space in message */
209	while(*q && isspace((unsigned char)*q))
210		q++;
211
212	if(*q)
213		{
214		/* Finally zap any trailing white space in message (include
215		 * CRLF) */
216
217		/* We know q has a non white space character so this is OK */
218		for(r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
219			*r = 0;
220		}
221	if(retcode != 200)
222		{
223		OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
224		if(!*q)
225			ERR_add_error_data(2, "Code=", p);
226		else
227			ERR_add_error_data(4, "Code=", p, ",Reason=", q);
228		return 0;
229		}
230
231
232	return 1;
233
234	}
235
236int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
237	{
238	int i, n;
239	const unsigned char *p;
240	next_io:
241	if (!(rctx->state & OHS_NOREAD))
242		{
243		n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
244
245		if (n <= 0)
246			{
247			if (BIO_should_retry(rctx->io))
248				return -1;
249			return 0;
250			}
251
252		/* Write data to memory BIO */
253
254		if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
255			return 0;
256		}
257
258	switch(rctx->state)
259		{
260
261		case OHS_ASN1_WRITE:
262		n = BIO_get_mem_data(rctx->mem, &p);
263
264		i = BIO_write(rctx->io,
265			p + (n - rctx->asn1_len), rctx->asn1_len);
266
267		if (i <= 0)
268			{
269			if (BIO_should_retry(rctx->io))
270				return -1;
271			rctx->state = OHS_ERROR;
272			return 0;
273			}
274
275		rctx->asn1_len -= i;
276
277		if (rctx->asn1_len > 0)
278			goto next_io;
279
280		rctx->state = OHS_ASN1_FLUSH;
281
282		(void)BIO_reset(rctx->mem);
283
284		case OHS_ASN1_FLUSH:
285
286		i = BIO_flush(rctx->io);
287
288		if (i > 0)
289			{
290			rctx->state = OHS_FIRSTLINE;
291			goto next_io;
292			}
293
294		if (BIO_should_retry(rctx->io))
295			return -1;
296
297		rctx->state = OHS_ERROR;
298		return 0;
299
300		case OHS_ERROR:
301		return 0;
302
303		case OHS_FIRSTLINE:
304		case OHS_HEADERS:
305
306		/* Attempt to read a line in */
307
308		next_line:
309		/* Due to &%^*$" memory BIO behaviour with BIO_gets we
310		 * have to check there's a complete line in there before
311		 * calling BIO_gets or we'll just get a partial read.
312		 */
313		n = BIO_get_mem_data(rctx->mem, &p);
314		if ((n <= 0) || !memchr(p, '\n', n))
315			{
316			if (n >= rctx->iobuflen)
317				{
318				rctx->state = OHS_ERROR;
319				return 0;
320				}
321			goto next_io;
322			}
323		n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
324
325		if (n <= 0)
326			{
327			if (BIO_should_retry(rctx->mem))
328				goto next_io;
329			rctx->state = OHS_ERROR;
330			return 0;
331			}
332
333		/* Don't allow excessive lines */
334		if (n == rctx->iobuflen)
335			{
336			rctx->state = OHS_ERROR;
337			return 0;
338			}
339
340		/* First line */
341		if (rctx->state == OHS_FIRSTLINE)
342			{
343			if (parse_http_line1((char *)rctx->iobuf))
344				{
345				rctx->state = OHS_HEADERS;
346				goto next_line;
347				}
348			else
349				{
350				rctx->state = OHS_ERROR;
351				return 0;
352				}
353			}
354		else
355			{
356			/* Look for blank line: end of headers */
357			for (p = rctx->iobuf; *p; p++)
358				{
359				if ((*p != '\r') && (*p != '\n'))
360					break;
361				}
362			if (*p)
363				goto next_line;
364
365			rctx->state = OHS_ASN1_HEADER;
366
367			}
368
369		/* Fall thru */
370
371
372		case OHS_ASN1_HEADER:
373		/* Now reading ASN1 header: can read at least 6 bytes which
374		 * is more than enough for any valid ASN1 SEQUENCE header
375		 */
376		n = BIO_get_mem_data(rctx->mem, &p);
377		if (n < 6)
378			goto next_io;
379
380		/* Check it is an ASN1 SEQUENCE */
381		if (*p++ != (V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED))
382			{
383			rctx->state = OHS_ERROR;
384			return 0;
385			}
386
387		/* Check out length field */
388		if (*p & 0x80)
389			{
390			n = *p & 0x7F;
391			/* Not NDEF or excessive length */
392			if (!n || (n > 4))
393				{
394				rctx->state = OHS_ERROR;
395				return 0;
396				}
397			p++;
398			rctx->asn1_len = 0;
399			for (i = 0; i < n; i++)
400				{
401				rctx->asn1_len <<= 8;
402				rctx->asn1_len |= *p++;
403				}
404
405			if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH)
406				{
407				rctx->state = OHS_ERROR;
408				return 0;
409				}
410
411			rctx->asn1_len += n + 2;
412			}
413		else
414			rctx->asn1_len = *p + 2;
415
416		rctx->state = OHS_ASN1_CONTENT;
417
418		/* Fall thru */
419
420		case OHS_ASN1_CONTENT:
421		n = BIO_get_mem_data(rctx->mem, &p);
422		if (n < (int)rctx->asn1_len)
423			goto next_io;
424
425
426		*presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
427		if (*presp)
428			{
429			rctx->state = OHS_DONE;
430			return 1;
431			}
432
433		rctx->state = OHS_ERROR;
434		return 0;
435
436		break;
437
438		case OHS_DONE:
439		return 1;
440
441		}
442
443
444
445	return 0;
446
447
448	}
449
450/* Blocking OCSP request handler: now a special case of non-blocking I/O */
451
452OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, char *path, OCSP_REQUEST *req)
453	{
454	OCSP_RESPONSE *resp = NULL;
455	OCSP_REQ_CTX *ctx;
456	int rv;
457
458	ctx = OCSP_sendreq_new(b, path, req, -1);
459
460	do
461		{
462		rv = OCSP_sendreq_nbio(&resp, ctx);
463		} while ((rv == -1) && BIO_should_retry(b));
464
465	OCSP_REQ_CTX_free(ctx);
466
467	if (rv)
468		return resp;
469
470	return NULL;
471	}
472