crypto/ocsp/ocsp_ht.c

   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
  70 /* Stateful OCSP request code, supporting non-blocking I/O */
  71
  72 /* Opaque OCSP request status structure */
  73
  74 struct ocsp_req_ctx_st {
  75     int state;                  /* Current I/O state */
  76     unsigned char *iobuf;       /* Line buffer */
  77     int iobuflen;               /* Line buffer length */
  78     BIO *io;                    /* BIO to perform I/O with */
  79     BIO *mem;                   /* Memory BIO response is built into */
  80     unsigned long asn1_len;     /* ASN1 length of response */
  81     unsigned long max_resp_len; /* Maximum length of response */
  82 };
  83
  84 #define OCSP_MAX_RESP_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 /* First call: ready to start I/O */
 102 #define OHS_ASN1_WRITE_INIT     (5 | OHS_NOREAD)
 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 /* Headers set, no final \r\n included */
 110 #define OHS_HTTP_HEADER         (9 | OHS_NOREAD)
 111
 112 static int parse_http_line1(char *line);
 113
 114 OCSP_REQ_CTX *OCSP_REQ_CTX_new(BIO *io, int maxline)
 115 {
 116     OCSP_REQ_CTX *rctx;
 117     rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
 118     if (!rctx)
 119         return NULL;
 120     rctx->state = OHS_ERROR;
 121     rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
 122     rctx->mem = BIO_new(BIO_s_mem());
 123     rctx->io = io;
 124     rctx->asn1_len = 0;
 125     if (maxline > 0)
 126         rctx->iobuflen = maxline;
 127     else
 128         rctx->iobuflen = OCSP_MAX_LINE_LEN;
 129     rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
 130     if (!rctx->iobuf || !rctx->mem) {
 131         OCSP_REQ_CTX_free(rctx);
 132         return NULL;
 133     }
 134     return rctx;
 135 }
 136
 137 void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
 138 {
 139     BIO_free(rctx->mem);
 140     if (rctx->iobuf)
 141         OPENSSL_free(rctx->iobuf);
 142     OPENSSL_free(rctx);
 143 }
 144
 145 BIO *OCSP_REQ_CTX_get0_mem_bio(OCSP_REQ_CTX *rctx)
 146 {
 147     return rctx->mem;
 148 }
 149
 150 void OCSP_set_max_response_length(OCSP_REQ_CTX *rctx, unsigned long len)
 151 {
 152     if (len == 0)
 153         rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
 154     else
 155         rctx->max_resp_len = len;
 156 }
 157
 158 int OCSP_REQ_CTX_i2d(OCSP_REQ_CTX *rctx, const ASN1_ITEM *it, ASN1_VALUE *val)
 159 {
 160     static const char req_hdr[] =
 161         "Content-Type: application/ocsp-request\r\n"
 162         "Content-Length: %d\r\n\r\n";
 163     int reqlen = ASN1_item_i2d(val, NULL, it);
 164     if (BIO_printf(rctx->mem, req_hdr, reqlen) <= 0)
 165         return 0;
 166     if (ASN1_item_i2d_bio(it, rctx->mem, val) <= 0)
 167         return 0;
 168     rctx->state = OHS_ASN1_WRITE_INIT;
 169     return 1;
 170 }
 171
 172 int OCSP_REQ_CTX_nbio_d2i(OCSP_REQ_CTX *rctx,
 173                           ASN1_VALUE **pval, const ASN1_ITEM *it)
 174 {
 175     int rv, len;
 176     const unsigned char *p;
 177
 178     rv = OCSP_REQ_CTX_nbio(rctx);
 179     if (rv != 1)
 180         return rv;
 181
 182     len = BIO_get_mem_data(rctx->mem, &p);
 183     *pval = ASN1_item_d2i(NULL, &p, len, it);
 184     if (*pval == NULL) {
 185         rctx->state = OHS_ERROR;
 186         return 0;
 187     }
 188     return 1;
 189 }
 190
 191 int OCSP_REQ_CTX_http(OCSP_REQ_CTX *rctx, const char *op, const char *path)
 192 {
 193     static const char http_hdr[] = "%s %s HTTP/1.0\r\n";
 194
 195     if (!path)
 196         path = "/";
 197
 198     if (BIO_printf(rctx->mem, http_hdr, op, path) <= 0)
 199         return 0;
 200     rctx->state = OHS_HTTP_HEADER;
 201     return 1;
 202 }
 203
 204 int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
 205 {
 206     return OCSP_REQ_CTX_i2d(rctx, ASN1_ITEM_rptr(OCSP_REQUEST),
 207                             (ASN1_VALUE *)req);
 208 }
 209
 210 int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
 211                              const char *name, const char *value)
 212 {
 213     if (!name)
 214         return 0;
 215     if (BIO_puts(rctx->mem, name) <= 0)
 216         return 0;
 217     if (value) {
 218         if (BIO_write(rctx->mem, ": ", 2) != 2)
 219             return 0;
 220         if (BIO_puts(rctx->mem, value) <= 0)
 221             return 0;
 222     }
 223     if (BIO_write(rctx->mem, "\r\n", 2) != 2)
 224         return 0;
 225     rctx->state = OHS_HTTP_HEADER;
 226     return 1;
 227 }
 228
 229 OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, const char *path, OCSP_REQUEST *req,
 230                                int maxline)
 231 {
 232
 233     OCSP_REQ_CTX *rctx = NULL;
 234     rctx = OCSP_REQ_CTX_new(io, maxline);
 235     if (!rctx)
 236         return NULL;
 237
 238     if (!OCSP_REQ_CTX_http(rctx, "POST", path))
 239         goto err;
 240
 241     if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
 242         goto err;
 243
 244     return rctx;
 245
 246  err:
 247     OCSP_REQ_CTX_free(rctx);
 248     return NULL;
 249 }
 250
 251 /*
 252  * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
 253  * need to obtain the numeric code and (optional) informational message.
 254  */
 255
 256 static int parse_http_line1(char *line)
 257 {
 258     int retcode;
 259     char *p, *q, *r;
 260     /* Skip to first white space (passed protocol info) */
 261
 262     for (p = line; *p && !isspace((unsigned char)*p); p++)
 263         continue;
 264     if (!*p) {
 265         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 266         return 0;
 267     }
 268
 269     /* Skip past white space to start of response code */
 270     while (*p && isspace((unsigned char)*p))
 271         p++;
 272
 273     if (!*p) {
 274         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 275         return 0;
 276     }
 277
 278     /* Find end of response code: first whitespace after start of code */
 279     for (q = p; *q && !isspace((unsigned char)*q); q++)
 280         continue;
 281
 282     if (!*q) {
 283         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 284         return 0;
 285     }
 286
 287     /* Set end of response code and start of message */
 288     *q++ = 0;
 289
 290     /* Attempt to parse numeric code */
 291     retcode = strtoul(p, &r, 10);
 292
 293     if (*r)
 294         return 0;
 295
 296     /* Skip over any leading white space in message */
 297     while (*q && isspace((unsigned char)*q))
 298         q++;
 299
 300     if (*q) {
 301         /*
 302          * Finally zap any trailing white space in message (include CRLF)
 303          */
 304
 305         /* We know q has a non white space character so this is OK */
 306         for (r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
 307             *r = 0;
 308     }
 309     if (retcode != 200) {
 310         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
 311         if (!*q)
 312             ERR_add_error_data(2, "Code=", p);
 313         else
 314             ERR_add_error_data(4, "Code=", p, ",Reason=", q);
 315         return 0;
 316     }
 317
 318     return 1;
 319
 320 }
 321
 322 int OCSP_REQ_CTX_nbio(OCSP_REQ_CTX *rctx)
 323 {
 324     int i, n;
 325     const unsigned char *p;
 326  next_io:
 327     if (!(rctx->state & OHS_NOREAD)) {
 328         n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
 329
 330         if (n <= 0) {
 331             if (BIO_should_retry(rctx->io))
 332                 return -1;
 333             return 0;
 334         }
 335
 336         /* Write data to memory BIO */
 337
 338         if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
 339             return 0;
 340     }
 341
 342     switch (rctx->state) {
 343     case OHS_HTTP_HEADER:
 344         /* Last operation was adding headers: need a final \r\n */
 345         if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
 346             rctx->state = OHS_ERROR;
 347             return 0;
 348         }
 349         rctx->state = OHS_ASN1_WRITE_INIT;
 350
 351     case OHS_ASN1_WRITE_INIT:
 352         rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
 353         rctx->state = OHS_ASN1_WRITE;
 354
 355     case OHS_ASN1_WRITE:
 356         n = BIO_get_mem_data(rctx->mem, &p);
 357
 358         i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
 359
 360         if (i <= 0) {
 361             if (BIO_should_retry(rctx->io))
 362                 return -1;
 363             rctx->state = OHS_ERROR;
 364             return 0;
 365         }
 366
 367         rctx->asn1_len -= i;
 368
 369         if (rctx->asn1_len > 0)
 370             goto next_io;
 371
 372         rctx->state = OHS_ASN1_FLUSH;
 373
 374         (void)BIO_reset(rctx->mem);
 375
 376     case OHS_ASN1_FLUSH:
 377
 378         i = BIO_flush(rctx->io);
 379
 380         if (i > 0) {
 381             rctx->state = OHS_FIRSTLINE;
 382             goto next_io;
 383         }
 384
 385         if (BIO_should_retry(rctx->io))
 386             return -1;
 387
 388         rctx->state = OHS_ERROR;
 389         return 0;
 390
 391     case OHS_ERROR:
 392         return 0;
 393
 394     case OHS_FIRSTLINE:
 395     case OHS_HEADERS:
 396
 397         /* Attempt to read a line in */
 398
 399  next_line:
 400         /*
 401          * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
 402          * there's a complete line in there before calling BIO_gets or we'll
 403          * just get a partial read.
 404          */
 405         n = BIO_get_mem_data(rctx->mem, &p);
 406         if ((n <= 0) || !memchr(p, '\n', n)) {
 407             if (n >= rctx->iobuflen) {
 408                 rctx->state = OHS_ERROR;
 409                 return 0;
 410             }
 411             goto next_io;
 412         }
 413         n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
 414
 415         if (n <= 0) {
 416             if (BIO_should_retry(rctx->mem))
 417                 goto next_io;
 418             rctx->state = OHS_ERROR;
 419             return 0;
 420         }
 421
 422         /* Don't allow excessive lines */
 423         if (n == rctx->iobuflen) {
 424             rctx->state = OHS_ERROR;
 425             return 0;
 426         }
 427
 428         /* First line */
 429         if (rctx->state == OHS_FIRSTLINE) {
 430             if (parse_http_line1((char *)rctx->iobuf)) {
 431                 rctx->state = OHS_HEADERS;
 432                 goto next_line;
 433             } else {
 434                 rctx->state = OHS_ERROR;
 435                 return 0;
 436             }
 437         } else {
 438             /* Look for blank line: end of headers */
 439             for (p = rctx->iobuf; *p; p++) {
 440                 if ((*p != '\r') && (*p != '\n'))
 441                     break;
 442             }
 443             if (*p)
 444                 goto next_line;
 445
 446             rctx->state = OHS_ASN1_HEADER;
 447
 448         }
 449
 450         /* Fall thru */
 451
 452     case OHS_ASN1_HEADER:
 453         /*
 454          * Now reading ASN1 header: can read at least 2 bytes which is enough
 455          * for ASN1 SEQUENCE header and either length field or at least the
 456          * length of the length field.
 457          */
 458         n = BIO_get_mem_data(rctx->mem, &p);
 459         if (n < 2)
 460             goto next_io;
 461
 462         /* Check it is an ASN1 SEQUENCE */
 463         if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
 464             rctx->state = OHS_ERROR;
 465             return 0;
 466         }
 467
 468         /* Check out length field */
 469         if (*p & 0x80) {
 470             /*
 471              * If MSB set on initial length octet we can now always read 6
 472              * octets: make sure we have them.
 473              */
 474             if (n < 6)
 475                 goto next_io;
 476             n = *p & 0x7F;
 477             /* Not NDEF or excessive length */
 478             if (!n || (n > 4)) {
 479                 rctx->state = OHS_ERROR;
 480                 return 0;
 481             }
 482             p++;
 483             rctx->asn1_len = 0;
 484             for (i = 0; i < n; i++) {
 485                 rctx->asn1_len <<= 8;
 486                 rctx->asn1_len |= *p++;
 487             }
 488
 489             if (rctx->asn1_len > rctx->max_resp_len) {
 490                 rctx->state = OHS_ERROR;
 491                 return 0;
 492             }
 493
 494             rctx->asn1_len += n + 2;
 495         } else
 496             rctx->asn1_len = *p + 2;
 497
 498         rctx->state = OHS_ASN1_CONTENT;
 499
 500         /* Fall thru */
 501
 502     case OHS_ASN1_CONTENT:
 503         n = BIO_get_mem_data(rctx->mem, NULL);
 504         if (n < (int)rctx->asn1_len)
 505             goto next_io;
 506
 507         rctx->state = OHS_DONE;
 508         return 1;
 509
 510     case OHS_DONE:
 511         return 1;
 512
 513     }
 514
 515     return 0;
 516
 517 }
 518
 519 int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
 520 {
 521     return OCSP_REQ_CTX_nbio_d2i(rctx,
 522                                  (ASN1_VALUE **)presp,
 523                                  ASN1_ITEM_rptr(OCSP_RESPONSE));
 524 }
 525
 526 /* Blocking OCSP request handler: now a special case of non-blocking I/O */
 527
 528 OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, const char *path, OCSP_REQUEST *req)
 529 {
 530     OCSP_RESPONSE *resp = NULL;
 531     OCSP_REQ_CTX *ctx;
 532     int rv;
 533
 534     ctx = OCSP_sendreq_new(b, path, req, -1);
 535
 536     if (!ctx)
 537         return NULL;
 538
 539     do {
 540         rv = OCSP_sendreq_nbio(&resp, ctx);
 541     } while ((rv == -1) && BIO_should_retry(b));
 542
 543     OCSP_REQ_CTX_free(ctx);
 544
 545     if (rv)
 546         return resp;
 547
 548     return NULL;
 549 }