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      1 /* ocsp_ht.c */
      2 /* Written by Dr Stephen N Henson (steve (at) 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 (at) 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 (at) cryptsoft.com).  This product includes software written by Tim
     55  * Hudson (tjh (at) 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 
     76 struct 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 
    110 static int parse_http_line1(char *line);
    111 
    112 void 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 
    121 int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
    122 	{
    123 	static const char req_hdr[] =
    124 	"Content-Type: application/ocsp-request\r\n"
    125 	"Content-Length: %d\r\n\r\n";
    126         if (BIO_printf(rctx->mem, req_hdr, i2d_OCSP_REQUEST(req, NULL)) <= 0)
    127 		return 0;
    128         if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0)
    129 		return 0;
    130 	rctx->state = OHS_ASN1_WRITE;
    131 	rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
    132 	return 1;
    133 	}
    134 
    135 int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
    136 		const char *name, const char *value)
    137 	{
    138 	if (!name)
    139 		return 0;
    140 	if (BIO_puts(rctx->mem, name) <= 0)
    141 		return 0;
    142 	if (value)
    143 		{
    144 		if (BIO_write(rctx->mem, ": ", 2) != 2)
    145 			return 0;
    146 		if (BIO_puts(rctx->mem, value) <= 0)
    147 			return 0;
    148 		}
    149 	if (BIO_write(rctx->mem, "\r\n", 2) != 2)
    150 		return 0;
    151 	return 1;
    152 	}
    153 
    154 OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
    155 								int maxline)
    156 	{
    157 	static const char post_hdr[] = "POST %s HTTP/1.0\r\n";
    158 
    159 	OCSP_REQ_CTX *rctx;
    160 	rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
    161 	if (!rctx)
    162 		return NULL;
    163 	rctx->state = OHS_ERROR;
    164 	rctx->mem = BIO_new(BIO_s_mem());
    165 	rctx->io = io;
    166 	rctx->asn1_len = 0;
    167 	if (maxline > 0)
    168 		rctx->iobuflen = maxline;
    169 	else
    170 		rctx->iobuflen = OCSP_MAX_LINE_LEN;
    171 	rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
    172 	if (!rctx->mem || !rctx->iobuf)
    173 		goto err;
    174 	if (!path)
    175 		path = "/";
    176 
    177         if (BIO_printf(rctx->mem, post_hdr, path) <= 0)
    178 		goto err;
    179 
    180 	if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
    181 		goto err;
    182 
    183 	return rctx;
    184 	err:
    185 	OCSP_REQ_CTX_free(rctx);
    186 	return NULL;
    187 	}
    188 
    189 /* Parse the HTTP response. This will look like this:
    190  * "HTTP/1.0 200 OK". We need to obtain the numeric code and
    191  * (optional) informational message.
    192  */
    193 
    194 static int parse_http_line1(char *line)
    195 	{
    196 	int retcode;
    197 	char *p, *q, *r;
    198 	/* Skip to first white space (passed protocol info) */
    199 
    200 	for(p = line; *p && !isspace((unsigned char)*p); p++)
    201 		continue;
    202 	if(!*p)
    203 		{
    204 		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
    205 					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
    206 		return 0;
    207 		}
    208 
    209 	/* Skip past white space to start of response code */
    210 	while(*p && isspace((unsigned char)*p))
    211 		p++;
    212 
    213 	if(!*p)
    214 		{
    215 		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
    216 					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
    217 		return 0;
    218 		}
    219 
    220 	/* Find end of response code: first whitespace after start of code */
    221 	for(q = p; *q && !isspace((unsigned char)*q); q++)
    222 		continue;
    223 
    224 	if(!*q)
    225 		{
    226 		OCSPerr(OCSP_F_PARSE_HTTP_LINE1,
    227 					OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
    228 		return 0;
    229 		}
    230 
    231 	/* Set end of response code and start of message */
    232 	*q++ = 0;
    233 
    234 	/* Attempt to parse numeric code */
    235 	retcode = strtoul(p, &r, 10);
    236 
    237 	if(*r)
    238 		return 0;
    239 
    240 	/* Skip over any leading white space in message */
    241 	while(*q && isspace((unsigned char)*q))
    242 		q++;
    243 
    244 	if(*q)
    245 		{
    246 		/* Finally zap any trailing white space in message (include
    247 		 * CRLF) */
    248 
    249 		/* We know q has a non white space character so this is OK */
    250 		for(r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
    251 			*r = 0;
    252 		}
    253 	if(retcode != 200)
    254 		{
    255 		OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
    256 		if(!*q)
    257 			ERR_add_error_data(2, "Code=", p);
    258 		else
    259 			ERR_add_error_data(4, "Code=", p, ",Reason=", q);
    260 		return 0;
    261 		}
    262 
    263 
    264 	return 1;
    265 
    266 	}
    267 
    268 int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
    269 	{
    270 	int i, n;
    271 	const unsigned char *p;
    272 	next_io:
    273 	if (!(rctx->state & OHS_NOREAD))
    274 		{
    275 		n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
    276 
    277 		if (n <= 0)
    278 			{
    279 			if (BIO_should_retry(rctx->io))
    280 				return -1;
    281 			return 0;
    282 			}
    283 
    284 		/* Write data to memory BIO */
    285 
    286 		if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
    287 			return 0;
    288 		}
    289 
    290 	switch(rctx->state)
    291 		{
    292 
    293 		case OHS_ASN1_WRITE:
    294 		n = BIO_get_mem_data(rctx->mem, &p);
    295 
    296 		i = BIO_write(rctx->io,
    297 			p + (n - rctx->asn1_len), rctx->asn1_len);
    298 
    299 		if (i <= 0)
    300 			{
    301 			if (BIO_should_retry(rctx->io))
    302 				return -1;
    303 			rctx->state = OHS_ERROR;
    304 			return 0;
    305 			}
    306 
    307 		rctx->asn1_len -= i;
    308 
    309 		if (rctx->asn1_len > 0)
    310 			goto next_io;
    311 
    312 		rctx->state = OHS_ASN1_FLUSH;
    313 
    314 		(void)BIO_reset(rctx->mem);
    315 
    316 		case OHS_ASN1_FLUSH:
    317 
    318 		i = BIO_flush(rctx->io);
    319 
    320 		if (i > 0)
    321 			{
    322 			rctx->state = OHS_FIRSTLINE;
    323 			goto next_io;
    324 			}
    325 
    326 		if (BIO_should_retry(rctx->io))
    327 			return -1;
    328 
    329 		rctx->state = OHS_ERROR;
    330 		return 0;
    331 
    332 		case OHS_ERROR:
    333 		return 0;
    334 
    335 		case OHS_FIRSTLINE:
    336 		case OHS_HEADERS:
    337 
    338 		/* Attempt to read a line in */
    339 
    340 		next_line:
    341 		/* Due to &%^*$" memory BIO behaviour with BIO_gets we
    342 		 * have to check there's a complete line in there before
    343 		 * calling BIO_gets or we'll just get a partial read.
    344 		 */
    345 		n = BIO_get_mem_data(rctx->mem, &p);
    346 		if ((n <= 0) || !memchr(p, '\n', n))
    347 			{
    348 			if (n >= rctx->iobuflen)
    349 				{
    350 				rctx->state = OHS_ERROR;
    351 				return 0;
    352 				}
    353 			goto next_io;
    354 			}
    355 		n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
    356 
    357 		if (n <= 0)
    358 			{
    359 			if (BIO_should_retry(rctx->mem))
    360 				goto next_io;
    361 			rctx->state = OHS_ERROR;
    362 			return 0;
    363 			}
    364 
    365 		/* Don't allow excessive lines */
    366 		if (n == rctx->iobuflen)
    367 			{
    368 			rctx->state = OHS_ERROR;
    369 			return 0;
    370 			}
    371 
    372 		/* First line */
    373 		if (rctx->state == OHS_FIRSTLINE)
    374 			{
    375 			if (parse_http_line1((char *)rctx->iobuf))
    376 				{
    377 				rctx->state = OHS_HEADERS;
    378 				goto next_line;
    379 				}
    380 			else
    381 				{
    382 				rctx->state = OHS_ERROR;
    383 				return 0;
    384 				}
    385 			}
    386 		else
    387 			{
    388 			/* Look for blank line: end of headers */
    389 			for (p = rctx->iobuf; *p; p++)
    390 				{
    391 				if ((*p != '\r') && (*p != '\n'))
    392 					break;
    393 				}
    394 			if (*p)
    395 				goto next_line;
    396 
    397 			rctx->state = OHS_ASN1_HEADER;
    398 
    399 			}
    400 
    401 		/* Fall thru */
    402 
    403 
    404 		case OHS_ASN1_HEADER:
    405 		/* Now reading ASN1 header: can read at least 2 bytes which
    406 		 * is enough for ASN1 SEQUENCE header and either length field
    407 		 * or at least the length of the length field.
    408 		 */
    409 		n = BIO_get_mem_data(rctx->mem, &p);
    410 		if (n < 2)
    411 			goto next_io;
    412 
    413 		/* Check it is an ASN1 SEQUENCE */
    414 		if (*p++ != (V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED))
    415 			{
    416 			rctx->state = OHS_ERROR;
    417 			return 0;
    418 			}
    419 
    420 		/* Check out length field */
    421 		if (*p & 0x80)
    422 			{
    423 			/* If MSB set on initial length octet we can now
    424 			 * always read 6 octets: make sure we have them.
    425 			 */
    426 			if (n < 6)
    427 				goto next_io;
    428 			n = *p & 0x7F;
    429 			/* Not NDEF or excessive length */
    430 			if (!n || (n > 4))
    431 				{
    432 				rctx->state = OHS_ERROR;
    433 				return 0;
    434 				}
    435 			p++;
    436 			rctx->asn1_len = 0;
    437 			for (i = 0; i < n; i++)
    438 				{
    439 				rctx->asn1_len <<= 8;
    440 				rctx->asn1_len |= *p++;
    441 				}
    442 
    443 			if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH)
    444 				{
    445 				rctx->state = OHS_ERROR;
    446 				return 0;
    447 				}
    448 
    449 			rctx->asn1_len += n + 2;
    450 			}
    451 		else
    452 			rctx->asn1_len = *p + 2;
    453 
    454 		rctx->state = OHS_ASN1_CONTENT;
    455 
    456 		/* Fall thru */
    457 
    458 		case OHS_ASN1_CONTENT:
    459 		n = BIO_get_mem_data(rctx->mem, &p);
    460 		if (n < (int)rctx->asn1_len)
    461 			goto next_io;
    462 
    463 
    464 		*presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
    465 		if (*presp)
    466 			{
    467 			rctx->state = OHS_DONE;
    468 			return 1;
    469 			}
    470 
    471 		rctx->state = OHS_ERROR;
    472 		return 0;
    473 
    474 		break;
    475 
    476 		case OHS_DONE:
    477 		return 1;
    478 
    479 		}
    480 
    481 
    482 
    483 	return 0;
    484 
    485 
    486 	}
    487 
    488 /* Blocking OCSP request handler: now a special case of non-blocking I/O */
    489 
    490 OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, char *path, OCSP_REQUEST *req)
    491 	{
    492 	OCSP_RESPONSE *resp = NULL;
    493 	OCSP_REQ_CTX *ctx;
    494 	int rv;
    495 
    496 	ctx = OCSP_sendreq_new(b, path, req, -1);
    497 
    498 	if (!ctx)
    499 		return NULL;
    500 
    501 	do
    502 		{
    503 		rv = OCSP_sendreq_nbio(&resp, ctx);
    504 		} while ((rv == -1) && BIO_should_retry(b));
    505 
    506 	OCSP_REQ_CTX_free(ctx);
    507 
    508 	if (rv)
    509 		return resp;
    510 
    511 	return NULL;
    512 	}
    513