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     if (!rctx)
 140         return;
 141     BIO_free(rctx->mem);
 142     if (rctx->iobuf)
 143         OPENSSL_free(rctx->iobuf);
 144     OPENSSL_free(rctx);
 145 }
 146
 147 BIO *OCSP_REQ_CTX_get0_mem_bio(OCSP_REQ_CTX *rctx)
 148 {
 149     return rctx->mem;
 150 }
 151
 152 void OCSP_set_max_response_length(OCSP_REQ_CTX *rctx, unsigned long len)
 153 {
 154     if (len == 0)
 155         rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
 156     else
 157         rctx->max_resp_len = len;
 158 }
 159
 160 int OCSP_REQ_CTX_i2d(OCSP_REQ_CTX *rctx, const ASN1_ITEM *it, ASN1_VALUE *val)
 161 {
 162     static const char req_hdr[] =
 163         "Content-Type: application/ocsp-request\r\n"
 164         "Content-Length: %d\r\n\r\n";
 165     int reqlen = ASN1_item_i2d(val, NULL, it);
 166     if (BIO_printf(rctx->mem, req_hdr, reqlen) <= 0)
 167         return 0;
 168     if (ASN1_item_i2d_bio(it, rctx->mem, val) <= 0)
 169         return 0;
 170     rctx->state = OHS_ASN1_WRITE_INIT;
 171     return 1;
 172 }
 173
 174 int OCSP_REQ_CTX_nbio_d2i(OCSP_REQ_CTX *rctx,
 175                           ASN1_VALUE **pval, const ASN1_ITEM *it)
 176 {
 177     int rv, len;
 178     const unsigned char *p;
 179
 180     rv = OCSP_REQ_CTX_nbio(rctx);
 181     if (rv != 1)
 182         return rv;
 183
 184     len = BIO_get_mem_data(rctx->mem, &p);
 185     *pval = ASN1_item_d2i(NULL, &p, len, it);
 186     if (*pval == NULL) {
 187         rctx->state = OHS_ERROR;
 188         return 0;
 189     }
 190     return 1;
 191 }
 192
 193 int OCSP_REQ_CTX_http(OCSP_REQ_CTX *rctx, const char *op, const char *path)
 194 {
 195     static const char http_hdr[] = "%s %s HTTP/1.0\r\n";
 196
 197     if (!path)
 198         path = "/";
 199
 200     if (BIO_printf(rctx->mem, http_hdr, op, path) <= 0)
 201         return 0;
 202     rctx->state = OHS_HTTP_HEADER;
 203     return 1;
 204 }
 205
 206 int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
 207 {
 208     return OCSP_REQ_CTX_i2d(rctx, ASN1_ITEM_rptr(OCSP_REQUEST),
 209                             (ASN1_VALUE *)req);
 210 }
 211
 212 int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
 213                              const char *name, const char *value)
 214 {
 215     if (!name)
 216         return 0;
 217     if (BIO_puts(rctx->mem, name) <= 0)
 218         return 0;
 219     if (value) {
 220         if (BIO_write(rctx->mem, ": ", 2) != 2)
 221             return 0;
 222         if (BIO_puts(rctx->mem, value) <= 0)
 223             return 0;
 224     }
 225     if (BIO_write(rctx->mem, "\r\n", 2) != 2)
 226         return 0;
 227     rctx->state = OHS_HTTP_HEADER;
 228     return 1;
 229 }
 230
 231 OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, const char *path, OCSP_REQUEST *req,
 232                                int maxline)
 233 {
 234
 235     OCSP_REQ_CTX *rctx = NULL;
 236     rctx = OCSP_REQ_CTX_new(io, maxline);
 237     if (!rctx)
 238         return NULL;
 239
 240     if (!OCSP_REQ_CTX_http(rctx, "POST", path))
 241         goto err;
 242
 243     if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
 244         goto err;
 245
 246     return rctx;
 247
 248  err:
 249     OCSP_REQ_CTX_free(rctx);
 250     return NULL;
 251 }
 252
 253 /*
 254  * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
 255  * need to obtain the numeric code and (optional) informational message.
 256  */
 257
 258 static int parse_http_line1(char *line)
 259 {
 260     int retcode;
 261     char *p, *q, *r;
 262     /* Skip to first white space (passed protocol info) */
 263
 264     for (p = line; *p && !isspace((unsigned char)*p); p++)
 265         continue;
 266     if (!*p) {
 267         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 268         return 0;
 269     }
 270
 271     /* Skip past white space to start of response code */
 272     while (*p && isspace((unsigned char)*p))
 273         p++;
 274
 275     if (!*p) {
 276         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 277         return 0;
 278     }
 279
 280     /* Find end of response code: first whitespace after start of code */
 281     for (q = p; *q && !isspace((unsigned char)*q); q++)
 282         continue;
 283
 284     if (!*q) {
 285         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
 286         return 0;
 287     }
 288
 289     /* Set end of response code and start of message */
 290     *q++ = 0;
 291
 292     /* Attempt to parse numeric code */
 293     retcode = strtoul(p, &r, 10);
 294
 295     if (*r)
 296         return 0;
 297
 298     /* Skip over any leading white space in message */
 299     while (*q && isspace((unsigned char)*q))
 300         q++;
 301
 302     if (*q) {
 303         /*
 304          * Finally zap any trailing white space in message (include CRLF)
 305          */
 306
 307         /* We know q has a non white space character so this is OK */
 308         for (r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
 309             *r = 0;
 310     }
 311     if (retcode != 200) {
 312         OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
 313         if (!*q)
 314             ERR_add_error_data(2, "Code=", p);
 315         else
 316             ERR_add_error_data(4, "Code=", p, ",Reason=", q);
 317         return 0;
 318     }
 319
 320     return 1;
 321
 322 }
 323
 324 int OCSP_REQ_CTX_nbio(OCSP_REQ_CTX *rctx)
 325 {
 326     int i, n;
 327     const unsigned char *p;
 328  next_io:
 329     if (!(rctx->state & OHS_NOREAD)) {
 330         n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
 331
 332         if (n <= 0) {
 333             if (BIO_should_retry(rctx->io))
 334                 return -1;
 335             return 0;
 336         }
 337
 338         /* Write data to memory BIO */
 339
 340         if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
 341             return 0;
 342     }
 343
 344     switch (rctx->state) {
 345     case OHS_HTTP_HEADER:
 346         /* Last operation was adding headers: need a final \r\n */
 347         if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
 348             rctx->state = OHS_ERROR;
 349             return 0;
 350         }
 351         rctx->state = OHS_ASN1_WRITE_INIT;
 352
 353     case OHS_ASN1_WRITE_INIT:
 354         rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
 355         rctx->state = OHS_ASN1_WRITE;
 356
 357     case OHS_ASN1_WRITE:
 358         n = BIO_get_mem_data(rctx->mem, &p);
 359
 360         i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
 361
 362         if (i <= 0) {
 363             if (BIO_should_retry(rctx->io))
 364                 return -1;
 365             rctx->state = OHS_ERROR;
 366             return 0;
 367         }
 368
 369         rctx->asn1_len -= i;
 370
 371         if (rctx->asn1_len > 0)
 372             goto next_io;
 373
 374         rctx->state = OHS_ASN1_FLUSH;
 375
 376         (void)BIO_reset(rctx->mem);
 377
 378     case OHS_ASN1_FLUSH:
 379
 380         i = BIO_flush(rctx->io);
 381
 382         if (i > 0) {
 383             rctx->state = OHS_FIRSTLINE;
 384             goto next_io;
 385         }
 386
 387         if (BIO_should_retry(rctx->io))
 388             return -1;
 389
 390         rctx->state = OHS_ERROR;
 391         return 0;
 392
 393     case OHS_ERROR:
 394         return 0;
 395
 396     case OHS_FIRSTLINE:
 397     case OHS_HEADERS:
 398
 399         /* Attempt to read a line in */
 400
 401  next_line:
 402         /*
 403          * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
 404          * there's a complete line in there before calling BIO_gets or we'll
 405          * just get a partial read.
 406          */
 407         n = BIO_get_mem_data(rctx->mem, &p);
 408         if ((n <= 0) || !memchr(p, '\n', n)) {
 409             if (n >= rctx->iobuflen) {
 410                 rctx->state = OHS_ERROR;
 411                 return 0;
 412             }
 413             goto next_io;
 414         }
 415         n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
 416
 417         if (n <= 0) {
 418             if (BIO_should_retry(rctx->mem))
 419                 goto next_io;
 420             rctx->state = OHS_ERROR;
 421             return 0;
 422         }
 423
 424         /* Don't allow excessive lines */
 425         if (n == rctx->iobuflen) {
 426             rctx->state = OHS_ERROR;
 427             return 0;
 428         }
 429
 430         /* First line */
 431         if (rctx->state == OHS_FIRSTLINE) {
 432             if (parse_http_line1((char *)rctx->iobuf)) {
 433                 rctx->state = OHS_HEADERS;
 434                 goto next_line;
 435             } else {
 436                 rctx->state = OHS_ERROR;
 437                 return 0;
 438             }
 439         } else {
 440             /* Look for blank line: end of headers */
 441             for (p = rctx->iobuf; *p; p++) {
 442                 if ((*p != '\r') && (*p != '\n'))
 443                     break;
 444             }
 445             if (*p)
 446                 goto next_line;
 447
 448             rctx->state = OHS_ASN1_HEADER;
 449
 450         }
 451
 452         /* Fall thru */
 453
 454     case OHS_ASN1_HEADER:
 455         /*
 456          * Now reading ASN1 header: can read at least 2 bytes which is enough
 457          * for ASN1 SEQUENCE header and either length field or at least the
 458          * length of the length field.
 459          */
 460         n = BIO_get_mem_data(rctx->mem, &p);
 461         if (n < 2)
 462             goto next_io;
 463
 464         /* Check it is an ASN1 SEQUENCE */
 465         if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
 466             rctx->state = OHS_ERROR;
 467             return 0;
 468         }
 469
 470         /* Check out length field */
 471         if (*p & 0x80) {
 472             /*
 473              * If MSB set on initial length octet we can now always read 6
 474              * octets: make sure we have them.
 475              */
 476             if (n < 6)
 477                 goto next_io;
 478             n = *p & 0x7F;
 479             /* Not NDEF or excessive length */
 480             if (!n || (n > 4)) {
 481                 rctx->state = OHS_ERROR;
 482                 return 0;
 483             }
 484             p++;
 485             rctx->asn1_len = 0;
 486             for (i = 0; i < n; i++) {
 487                 rctx->asn1_len <<= 8;
 488                 rctx->asn1_len |= *p++;
 489             }
 490
 491             if (rctx->asn1_len > rctx->max_resp_len) {
 492                 rctx->state = OHS_ERROR;
 493                 return 0;
 494             }
 495
 496             rctx->asn1_len += n + 2;
 497         } else
 498             rctx->asn1_len = *p + 2;
 499
 500         rctx->state = OHS_ASN1_CONTENT;
 501
 502         /* Fall thru */
 503
 504     case OHS_ASN1_CONTENT:
 505         n = BIO_get_mem_data(rctx->mem, NULL);
 506         if (n < (int)rctx->asn1_len)
 507             goto next_io;
 508
 509         rctx->state = OHS_DONE;
 510         return 1;
 511
 512     case OHS_DONE:
 513         return 1;
 514
 515     }
 516
 517     return 0;
 518
 519 }
 520
 521 int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
 522 {
 523     return OCSP_REQ_CTX_nbio_d2i(rctx,
 524                                  (ASN1_VALUE **)presp,
 525                                  ASN1_ITEM_rptr(OCSP_RESPONSE));
 526 }
 527
 528 /* Blocking OCSP request handler: now a special case of non-blocking I/O */
 529
 530 OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, const char *path, OCSP_REQUEST *req)
 531 {
 532     OCSP_RESPONSE *resp = NULL;
 533     OCSP_REQ_CTX *ctx;
 534     int rv;
 535
 536     ctx = OCSP_sendreq_new(b, path, req, -1);
 537
 538     if (!ctx)
 539         return NULL;
 540
 541     do {
 542         rv = OCSP_sendreq_nbio(&resp, ctx);
 543     } while ((rv == -1) && BIO_should_retry(b));
 544
 545     OCSP_REQ_CTX_free(ctx);
 546
 547     if (rv)
 548         return resp;
 549
 550     return NULL;
 551 }