ocsp_ht.c revision 296341 
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
121int 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
135int 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        if (BIO_write(rctx->mem, ": ", 2) != 2)
144            return 0;
145        if (BIO_puts(rctx->mem, value) <= 0)
146            return 0;
147    }
148    if (BIO_write(rctx->mem, "\r\n", 2) != 2)
149        return 0;
150    return 1;
151}
152
153OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
154                               int maxline)
155{
156    static const char post_hdr[] = "POST %s HTTP/1.0\r\n";
157
158    OCSP_REQ_CTX *rctx;
159    rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
160    if (!rctx)
161        return NULL;
162    rctx->state = OHS_ERROR;
163    rctx->mem = BIO_new(BIO_s_mem());
164    rctx->io = io;
165    rctx->asn1_len = 0;
166    if (maxline > 0)
167        rctx->iobuflen = maxline;
168    else
169        rctx->iobuflen = OCSP_MAX_LINE_LEN;
170    rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
171    if (!rctx->mem || !rctx->iobuf)
172        goto err;
173    if (!path)
174        path = "/";
175
176    if (BIO_printf(rctx->mem, post_hdr, path) <= 0)
177        goto err;
178
179    if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
180        goto err;
181
182    return rctx;
183 err:
184    OCSP_REQ_CTX_free(rctx);
185    return NULL;
186}
187
188/*
189 * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
190 * need to obtain the numeric code and (optional) informational message.
191 */
192
193static int parse_http_line1(char *line)
194{
195    int retcode;
196    char *p, *q, *r;
197    /* Skip to first white space (passed protocol info) */
198
199    for (p = line; *p && !isspace((unsigned char)*p); p++)
200        continue;
201    if (!*p) {
202        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
203        return 0;
204    }
205
206    /* Skip past white space to start of response code */
207    while (*p && isspace((unsigned char)*p))
208        p++;
209
210    if (!*p) {
211        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
212        return 0;
213    }
214
215    /* Find end of response code: first whitespace after start of code */
216    for (q = p; *q && !isspace((unsigned char)*q); q++)
217        continue;
218
219    if (!*q) {
220        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
221        return 0;
222    }
223
224    /* Set end of response code and start of message */
225    *q++ = 0;
226
227    /* Attempt to parse numeric code */
228    retcode = strtoul(p, &r, 10);
229
230    if (*r)
231        return 0;
232
233    /* Skip over any leading white space in message */
234    while (*q && isspace((unsigned char)*q))
235        q++;
236
237    if (*q) {
238        /*
239         * Finally zap any trailing white space in message (include CRLF)
240         */
241
242        /* We know q has a non white space character so this is OK */
243        for (r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
244            *r = 0;
245    }
246    if (retcode != 200) {
247        OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
248        if (!*q)
249            ERR_add_error_data(2, "Code=", p);
250        else
251            ERR_add_error_data(4, "Code=", p, ",Reason=", q);
252        return 0;
253    }
254
255    return 1;
256
257}
258
259int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
260{
261    int i, n;
262    const unsigned char *p;
263 next_io:
264    if (!(rctx->state & OHS_NOREAD)) {
265        n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
266
267        if (n <= 0) {
268            if (BIO_should_retry(rctx->io))
269                return -1;
270            return 0;
271        }
272
273        /* Write data to memory BIO */
274
275        if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
276            return 0;
277    }
278
279    switch (rctx->state) {
280
281    case OHS_ASN1_WRITE:
282        n = BIO_get_mem_data(rctx->mem, &p);
283
284        i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
285
286        if (i <= 0) {
287            if (BIO_should_retry(rctx->io))
288                return -1;
289            rctx->state = OHS_ERROR;
290            return 0;
291        }
292
293        rctx->asn1_len -= i;
294
295        if (rctx->asn1_len > 0)
296            goto next_io;
297
298        rctx->state = OHS_ASN1_FLUSH;
299
300        (void)BIO_reset(rctx->mem);
301
302    case OHS_ASN1_FLUSH:
303
304        i = BIO_flush(rctx->io);
305
306        if (i > 0) {
307            rctx->state = OHS_FIRSTLINE;
308            goto next_io;
309        }
310
311        if (BIO_should_retry(rctx->io))
312            return -1;
313
314        rctx->state = OHS_ERROR;
315        return 0;
316
317    case OHS_ERROR:
318        return 0;
319
320    case OHS_FIRSTLINE:
321    case OHS_HEADERS:
322
323        /* Attempt to read a line in */
324
325 next_line:
326        /*
327         * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
328         * there's a complete line in there before calling BIO_gets or we'll
329         * just get a partial read.
330         */
331        n = BIO_get_mem_data(rctx->mem, &p);
332        if ((n <= 0) || !memchr(p, '\n', n)) {
333            if (n >= rctx->iobuflen) {
334                rctx->state = OHS_ERROR;
335                return 0;
336            }
337            goto next_io;
338        }
339        n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
340
341        if (n <= 0) {
342            if (BIO_should_retry(rctx->mem))
343                goto next_io;
344            rctx->state = OHS_ERROR;
345            return 0;
346        }
347
348        /* Don't allow excessive lines */
349        if (n == rctx->iobuflen) {
350            rctx->state = OHS_ERROR;
351            return 0;
352        }
353
354        /* First line */
355        if (rctx->state == OHS_FIRSTLINE) {
356            if (parse_http_line1((char *)rctx->iobuf)) {
357                rctx->state = OHS_HEADERS;
358                goto next_line;
359            } else {
360                rctx->state = OHS_ERROR;
361                return 0;
362            }
363        } else {
364            /* Look for blank line: end of headers */
365            for (p = rctx->iobuf; *p; p++) {
366                if ((*p != '\r') && (*p != '\n'))
367                    break;
368            }
369            if (*p)
370                goto next_line;
371
372            rctx->state = OHS_ASN1_HEADER;
373
374        }
375
376        /* Fall thru */
377
378    case OHS_ASN1_HEADER:
379        /*
380         * Now reading ASN1 header: can read at least 2 bytes which is enough
381         * for ASN1 SEQUENCE header and either length field or at least the
382         * length of the length field.
383         */
384        n = BIO_get_mem_data(rctx->mem, &p);
385        if (n < 2)
386            goto next_io;
387
388        /* Check it is an ASN1 SEQUENCE */
389        if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
390            rctx->state = OHS_ERROR;
391            return 0;
392        }
393
394        /* Check out length field */
395        if (*p & 0x80) {
396            /*
397             * If MSB set on initial length octet we can now always read 6
398             * octets: make sure we have them.
399             */
400            if (n < 6)
401                goto next_io;
402            n = *p & 0x7F;
403            /* Not NDEF or excessive length */
404            if (!n || (n > 4)) {
405                rctx->state = OHS_ERROR;
406                return 0;
407            }
408            p++;
409            rctx->asn1_len = 0;
410            for (i = 0; i < n; i++) {
411                rctx->asn1_len <<= 8;
412                rctx->asn1_len |= *p++;
413            }
414
415            if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH) {
416                rctx->state = OHS_ERROR;
417                return 0;
418            }
419
420            rctx->asn1_len += n + 2;
421        } else
422            rctx->asn1_len = *p + 2;
423
424        rctx->state = OHS_ASN1_CONTENT;
425
426        /* Fall thru */
427
428    case OHS_ASN1_CONTENT:
429        n = BIO_get_mem_data(rctx->mem, &p);
430        if (n < (int)rctx->asn1_len)
431            goto next_io;
432
433        *presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
434        if (*presp) {
435            rctx->state = OHS_DONE;
436            return 1;
437        }
438
439        rctx->state = OHS_ERROR;
440        return 0;
441
442        break;
443
444    case OHS_DONE:
445        return 1;
446
447    }
448
449    return 0;
450
451}
452
453/* Blocking OCSP request handler: now a special case of non-blocking I/O */
454
455OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, char *path, OCSP_REQUEST *req)
456{
457    OCSP_RESPONSE *resp = NULL;
458    OCSP_REQ_CTX *ctx;
459    int rv;
460
461    ctx = OCSP_sendreq_new(b, path, req, -1);
462
463    if (!ctx)
464        return NULL;
465
466    do {
467        rv = OCSP_sendreq_nbio(&resp, ctx);
468    } while ((rv == -1) && BIO_should_retry(b));
469
470    OCSP_REQ_CTX_free(ctx);
471
472    if (rv)
473        return resp;
474
475    return NULL;
476}
477