ocsp_ht.c revision 296465 
1/* ocsp_ht.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2006.
5 */
6/* ====================================================================
7 * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <stdio.h>
61#include <stdlib.h>
62#include <ctype.h>
63#include <string.h>
64#include "e_os.h"
65#include <openssl/asn1.h>
66#include <openssl/ocsp.h>
67#include <openssl/err.h>
68#include <openssl/buffer.h>
69#ifdef OPENSSL_SYS_SUNOS
70# define strtoul (unsigned long)strtol
71#endif                          /* OPENSSL_SYS_SUNOS */
72
73/* Stateful OCSP request code, supporting non-blocking I/O */
74
75/* Opaque OCSP request status structure */
76
77struct ocsp_req_ctx_st {
78    int state;                  /* Current I/O state */
79    unsigned char *iobuf;       /* Line buffer */
80    int iobuflen;               /* Line buffer length */
81    BIO *io;                    /* BIO to perform I/O with */
82    BIO *mem;                   /* Memory BIO response is built into */
83    unsigned long asn1_len;     /* ASN1 length of response */
84};
85
86#define OCSP_MAX_REQUEST_LENGTH (100 * 1024)
87#define OCSP_MAX_LINE_LEN       4096;
88
89/* OCSP states */
90
91/* If set no reading should be performed */
92#define OHS_NOREAD              0x1000
93/* Error condition */
94#define OHS_ERROR               (0 | OHS_NOREAD)
95/* First line being read */
96#define OHS_FIRSTLINE           1
97/* MIME headers being read */
98#define OHS_HEADERS             2
99/* OCSP initial header (tag + length) being read */
100#define OHS_ASN1_HEADER         3
101/* OCSP content octets being read */
102#define OHS_ASN1_CONTENT        4
103/* Request being sent */
104#define OHS_ASN1_WRITE          (6 | OHS_NOREAD)
105/* Request being flushed */
106#define OHS_ASN1_FLUSH          (7 | OHS_NOREAD)
107/* Completed */
108#define OHS_DONE                (8 | OHS_NOREAD)
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        rctx->state = OHS_ERROR;
144        return 0;
145    }
146    if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0) {
147        rctx->state = OHS_ERROR;
148        return 0;
149    }
150    rctx->state = OHS_ASN1_WRITE;
151    rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
152
153    return rctx;
154}
155
156/*
157 * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
158 * need to obtain the numeric code and (optional) informational message.
159 */
160
161static int parse_http_line1(char *line)
162{
163    int retcode;
164    char *p, *q, *r;
165    /* Skip to first white space (passed protocol info) */
166
167    for (p = line; *p && !isspace((unsigned char)*p); p++)
168        continue;
169    if (!*p) {
170        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
171        return 0;
172    }
173
174    /* Skip past white space to start of response code */
175    while (*p && isspace((unsigned char)*p))
176        p++;
177
178    if (!*p) {
179        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
180        return 0;
181    }
182
183    /* Find end of response code: first whitespace after start of code */
184    for (q = p; *q && !isspace((unsigned char)*q); q++)
185        continue;
186
187    if (!*q) {
188        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
189        return 0;
190    }
191
192    /* Set end of response code and start of message */
193    *q++ = 0;
194
195    /* Attempt to parse numeric code */
196    retcode = strtoul(p, &r, 10);
197
198    if (*r)
199        return 0;
200
201    /* Skip over any leading white space in message */
202    while (*q && isspace((unsigned char)*q))
203        q++;
204
205    if (*q) {
206        /*
207         * Finally zap any trailing white space in message (include CRLF)
208         */
209
210        /* We know q has a non white space character so this is OK */
211        for (r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
212            *r = 0;
213    }
214    if (retcode != 200) {
215        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
216        if (!*q)
217            ERR_add_error_data(2, "Code=", p);
218        else
219            ERR_add_error_data(4, "Code=", p, ",Reason=", q);
220        return 0;
221    }
222
223    return 1;
224
225}
226
227int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
228{
229    int i, n;
230    const unsigned char *p;
231 next_io:
232    if (!(rctx->state & OHS_NOREAD)) {
233        n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
234
235        if (n <= 0) {
236            if (BIO_should_retry(rctx->io))
237                return -1;
238            return 0;
239        }
240
241        /* Write data to memory BIO */
242
243        if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
244            return 0;
245    }
246
247    switch (rctx->state) {
248
249    case OHS_ASN1_WRITE:
250        n = BIO_get_mem_data(rctx->mem, &p);
251
252        i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
253
254        if (i <= 0) {
255            if (BIO_should_retry(rctx->io))
256                return -1;
257            rctx->state = OHS_ERROR;
258            return 0;
259        }
260
261        rctx->asn1_len -= i;
262
263        if (rctx->asn1_len > 0)
264            goto next_io;
265
266        rctx->state = OHS_ASN1_FLUSH;
267
268        (void)BIO_reset(rctx->mem);
269
270    case OHS_ASN1_FLUSH:
271
272        i = BIO_flush(rctx->io);
273
274        if (i > 0) {
275            rctx->state = OHS_FIRSTLINE;
276            goto next_io;
277        }
278
279        if (BIO_should_retry(rctx->io))
280            return -1;
281
282        rctx->state = OHS_ERROR;
283        return 0;
284
285    case OHS_ERROR:
286        return 0;
287
288    case OHS_FIRSTLINE:
289    case OHS_HEADERS:
290
291        /* Attempt to read a line in */
292
293 next_line:
294        /*
295         * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
296         * there's a complete line in there before calling BIO_gets or we'll
297         * just get a partial read.
298         */
299        n = BIO_get_mem_data(rctx->mem, &p);
300        if ((n <= 0) || !memchr(p, '\n', n)) {
301            if (n >= rctx->iobuflen) {
302                rctx->state = OHS_ERROR;
303                return 0;
304            }
305            goto next_io;
306        }
307        n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
308
309        if (n <= 0) {
310            if (BIO_should_retry(rctx->mem))
311                goto next_io;
312            rctx->state = OHS_ERROR;
313            return 0;
314        }
315
316        /* Don't allow excessive lines */
317        if (n == rctx->iobuflen) {
318            rctx->state = OHS_ERROR;
319            return 0;
320        }
321
322        /* First line */
323        if (rctx->state == OHS_FIRSTLINE) {
324            if (parse_http_line1((char *)rctx->iobuf)) {
325                rctx->state = OHS_HEADERS;
326                goto next_line;
327            } else {
328                rctx->state = OHS_ERROR;
329                return 0;
330            }
331        } else {
332            /* Look for blank line: end of headers */
333            for (p = rctx->iobuf; *p; p++) {
334                if ((*p != '\r') && (*p != '\n'))
335                    break;
336            }
337            if (*p)
338                goto next_line;
339
340            rctx->state = OHS_ASN1_HEADER;
341
342        }
343
344        /* Fall thru */
345
346    case OHS_ASN1_HEADER:
347        /*
348         * Now reading ASN1 header: can read at least 2 bytes which is enough
349         * for ASN1 SEQUENCE header and either length field or at least the
350         * length of the length field.
351         */
352        n = BIO_get_mem_data(rctx->mem, &p);
353        if (n < 2)
354            goto next_io;
355
356        /* Check it is an ASN1 SEQUENCE */
357        if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
358            rctx->state = OHS_ERROR;
359            return 0;
360        }
361
362        /* Check out length field */
363        if (*p & 0x80) {
364            /*
365             * If MSB set on initial length octet we can now always read 6
366             * octets: make sure we have them.
367             */
368            if (n < 6)
369                goto next_io;
370            n = *p & 0x7F;
371            /* Not NDEF or excessive length */
372            if (!n || (n > 4)) {
373                rctx->state = OHS_ERROR;
374                return 0;
375            }
376            p++;
377            rctx->asn1_len = 0;
378            for (i = 0; i < n; i++) {
379                rctx->asn1_len <<= 8;
380                rctx->asn1_len |= *p++;
381            }
382
383            if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH) {
384                rctx->state = OHS_ERROR;
385                return 0;
386            }
387
388            rctx->asn1_len += n + 2;
389        } else
390            rctx->asn1_len = *p + 2;
391
392        rctx->state = OHS_ASN1_CONTENT;
393
394        /* Fall thru */
395
396    case OHS_ASN1_CONTENT:
397        n = BIO_get_mem_data(rctx->mem, &p);
398        if (n < (int)rctx->asn1_len)
399            goto next_io;
400
401        *presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
402        if (*presp) {
403            rctx->state = OHS_DONE;
404            return 1;
405        }
406
407        rctx->state = OHS_ERROR;
408        return 0;
409
410        break;
411
412    case OHS_DONE:
413        return 1;
414
415    }
416
417    return 0;
418
419}
420
421/* Blocking OCSP request handler: now a special case of non-blocking I/O */
422
423OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, char *path, OCSP_REQUEST *req)
424{
425    OCSP_RESPONSE *resp = NULL;
426    OCSP_REQ_CTX *ctx;
427    int rv;
428
429    ctx = OCSP_sendreq_new(b, path, req, -1);
430
431    if (!ctx)
432        return NULL;
433
434    do {
435        rv = OCSP_sendreq_nbio(&resp, ctx);
436    } while ((rv == -1) && BIO_should_retry(b));
437
438    OCSP_REQ_CTX_free(ctx);
439
440    if (rv)
441        return resp;
442
443    return NULL;
444}
445