text: /* ocsp_ht.c */
  /*
   * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   * 2006.
   */
  /* ====================================================================
   * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    licensing@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <ctype.h>
  #include <string.h>
  #include "e_os.h"
  #include <openssl/asn1.h>
  #include <openssl/ocsp.h>
  #include <openssl/err.h>
  #include <openssl/buffer.h>
  #ifdef OPENSSL_SYS_SUNOS
  # define strtoul (unsigned long)strtol
  #endif                          /* OPENSSL_SYS_SUNOS */
  
  /* Stateful OCSP request code, supporting non-blocking I/O */
  
  /* Opaque OCSP request status structure */
  
  struct ocsp_req_ctx_st {
      int state;                  /* Current I/O state */
      unsigned char *iobuf;       /* Line buffer */
      int iobuflen;               /* Line buffer length */
      BIO *io;                    /* BIO to perform I/O with */
      BIO *mem;                   /* Memory BIO response is built into */
      unsigned long asn1_len;     /* ASN1 length of response */
      unsigned long max_resp_len; /* Maximum length of response */
  };
  
  #define OCSP_MAX_RESP_LENGTH    (100 * 1024)
  #define OCSP_MAX_LINE_LEN       4096;
  
  /* OCSP states */
  
  /* If set no reading should be performed */
  #define OHS_NOREAD              0x1000
  /* Error condition */
  #define OHS_ERROR               (0 | OHS_NOREAD)
  /* First line being read */
  #define OHS_FIRSTLINE           1
  /* MIME headers being read */
  #define OHS_HEADERS             2
  /* OCSP initial header (tag + length) being read */
  #define OHS_ASN1_HEADER         3
  /* OCSP content octets being read */
  #define OHS_ASN1_CONTENT        4
  /* First call: ready to start I/O */
  #define OHS_ASN1_WRITE_INIT     (5 | OHS_NOREAD)
  /* Request being sent */
  #define OHS_ASN1_WRITE          (6 | OHS_NOREAD)
  /* Request being flushed */
  #define OHS_ASN1_FLUSH          (7 | OHS_NOREAD)
  /* Completed */
  #define OHS_DONE                (8 | OHS_NOREAD)
  /* Headers set, no final \r\n included */
  #define OHS_HTTP_HEADER         (9 | OHS_NOREAD)
  
  static int parse_http_line1(char *line);
  
  OCSP_REQ_CTX *OCSP_REQ_CTX_new(BIO *io, int maxline)
  {
      OCSP_REQ_CTX *rctx;
      rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
      if (!rctx)
          return NULL;
      rctx->state = OHS_ERROR;
      rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
      rctx->mem = BIO_new(BIO_s_mem());
      rctx->io = io;
      rctx->asn1_len = 0;
      if (maxline > 0)
          rctx->iobuflen = maxline;
      else
          rctx->iobuflen = OCSP_MAX_LINE_LEN;
      rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
      if (!rctx->iobuf || !rctx->mem) {
          OCSP_REQ_CTX_free(rctx);
          return NULL;
      }
      return rctx;
  }
  
  void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
  {
      if (rctx->mem)
          BIO_free(rctx->mem);
      if (rctx->iobuf)
          OPENSSL_free(rctx->iobuf);
      OPENSSL_free(rctx);
  }
  
  BIO *OCSP_REQ_CTX_get0_mem_bio(OCSP_REQ_CTX *rctx)
  {
      return rctx->mem;
  }
  
  void OCSP_set_max_response_length(OCSP_REQ_CTX *rctx, unsigned long len)
  {
      if (len == 0)
          rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
      else
          rctx->max_resp_len = len;
  }
  
  int OCSP_REQ_CTX_i2d(OCSP_REQ_CTX *rctx, const ASN1_ITEM *it, ASN1_VALUE *val)
  {
      static const char req_hdr[] =
          "Content-Type: application/ocsp-request\r\n"
          "Content-Length: %d\r\n\r\n";
      int reqlen = ASN1_item_i2d(val, NULL, it);
      if (BIO_printf(rctx->mem, req_hdr, reqlen) <= 0)
          return 0;
      if (ASN1_item_i2d_bio(it, rctx->mem, val) <= 0)
          return 0;
      rctx->state = OHS_ASN1_WRITE_INIT;
      return 1;
  }
  
  int OCSP_REQ_CTX_nbio_d2i(OCSP_REQ_CTX *rctx,
                            ASN1_VALUE **pval, const ASN1_ITEM *it)
  {
      int rv, len;
      const unsigned char *p;
  
      rv = OCSP_REQ_CTX_nbio(rctx);
      if (rv != 1)
          return rv;
  
      len = BIO_get_mem_data(rctx->mem, &p);
      *pval = ASN1_item_d2i(NULL, &p, len, it);
      if (*pval == NULL) {
          rctx->state = OHS_ERROR;
          return 0;
      }
      return 1;
  }
  
  int OCSP_REQ_CTX_http(OCSP_REQ_CTX *rctx, const char *op, const char *path)
  {
      static const char http_hdr[] = "%s %s HTTP/1.0\r\n";
  
      if (!path)
          path = "/";
  
      if (BIO_printf(rctx->mem, http_hdr, op, path) <= 0)
          return 0;
      rctx->state = OHS_HTTP_HEADER;
      return 1;
  }
  
  int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
  {
      return OCSP_REQ_CTX_i2d(rctx, ASN1_ITEM_rptr(OCSP_REQUEST),
                              (ASN1_VALUE *)req);
  }
  
  int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
                               const char *name, const char *value)
  {
      if (!name)
          return 0;
      if (BIO_puts(rctx->mem, name) <= 0)
          return 0;
      if (value) {
          if (BIO_write(rctx->mem, ": ", 2) != 2)
              return 0;
          if (BIO_puts(rctx->mem, value) <= 0)
              return 0;
      }
      if (BIO_write(rctx->mem, "\r\n", 2) != 2)
          return 0;
      rctx->state = OHS_HTTP_HEADER;
      return 1;
  }
  
  OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, const char *path, OCSP_REQUEST *req,
                                 int maxline)
  {
  
      OCSP_REQ_CTX *rctx = NULL;
      rctx = OCSP_REQ_CTX_new(io, maxline);
      if (!rctx)
          return NULL;
  
      if (!OCSP_REQ_CTX_http(rctx, "POST", path))
          goto err;
  
      if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
          goto err;
  
      return rctx;
  
   err:
      OCSP_REQ_CTX_free(rctx);
      return NULL;
  }
  
  /*
   * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
   * need to obtain the numeric code and (optional) informational message.
   */
  
  static int parse_http_line1(char *line)
  {
      int retcode;
      char *p, *q, *r;
      /* Skip to first white space (passed protocol info) */
  
      for (p = line; *p && !isspace((unsigned char)*p); p++)
          continue;
      if (!*p) {
          OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
          return 0;
      }
  
      /* Skip past white space to start of response code */
      while (*p && isspace((unsigned char)*p))
          p++;
  
      if (!*p) {
          OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
          return 0;
      }
  
      /* Find end of response code: first whitespace after start of code */
      for (q = p; *q && !isspace((unsigned char)*q); q++)
          continue;
  
      if (!*q) {
          OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
          return 0;
      }
  
      /* Set end of response code and start of message */
      *q++ = 0;
  
      /* Attempt to parse numeric code */
      retcode = strtoul(p, &r, 10);
  
      if (*r)
          return 0;
  
      /* Skip over any leading white space in message */
      while (*q && isspace((unsigned char)*q))
          q++;
  
      if (*q) {
          /*
           * Finally zap any trailing white space in message (include CRLF)
           */
  
          /* We know q has a non white space character so this is OK */
          for (r = q + strlen(q) - 1; isspace((unsigned char)*r); r--)
              *r = 0;
      }
      if (retcode != 200) {
          OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
          if (!*q)
              ERR_add_error_data(2, "Code=", p);
          else
              ERR_add_error_data(4, "Code=", p, ",Reason=", q);
          return 0;
      }
  
      return 1;
  
  }
  
  int OCSP_REQ_CTX_nbio(OCSP_REQ_CTX *rctx)
  {
      int i, n;
      const unsigned char *p;
   next_io:
      if (!(rctx->state & OHS_NOREAD)) {
          n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
  
          if (n <= 0) {
              if (BIO_should_retry(rctx->io))
                  return -1;
              return 0;
          }
  
          /* Write data to memory BIO */
  
          if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
              return 0;
      }
  
      switch (rctx->state) {
      case OHS_HTTP_HEADER:
          /* Last operation was adding headers: need a final \r\n */
          if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
              rctx->state = OHS_ERROR;
              return 0;
          }
          rctx->state = OHS_ASN1_WRITE_INIT;
  
      case OHS_ASN1_WRITE_INIT:
          rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
          rctx->state = OHS_ASN1_WRITE;
  
      case OHS_ASN1_WRITE:
          n = BIO_get_mem_data(rctx->mem, &p);
  
          i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
  
          if (i <= 0) {
              if (BIO_should_retry(rctx->io))
                  return -1;
              rctx->state = OHS_ERROR;
              return 0;
          }
  
          rctx->asn1_len -= i;
  
          if (rctx->asn1_len > 0)
              goto next_io;
  
          rctx->state = OHS_ASN1_FLUSH;
  
          (void)BIO_reset(rctx->mem);
  
      case OHS_ASN1_FLUSH:
  
          i = BIO_flush(rctx->io);
  
          if (i > 0) {
              rctx->state = OHS_FIRSTLINE;
              goto next_io;
          }
  
          if (BIO_should_retry(rctx->io))
              return -1;
  
          rctx->state = OHS_ERROR;
          return 0;
  
      case OHS_ERROR:
          return 0;
  
      case OHS_FIRSTLINE:
      case OHS_HEADERS:
  
          /* Attempt to read a line in */
  
   next_line:
          /*
           * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
           * there's a complete line in there before calling BIO_gets or we'll
           * just get a partial read.
           */
          n = BIO_get_mem_data(rctx->mem, &p);
          if ((n <= 0) || !memchr(p, '\n', n)) {
              if (n >= rctx->iobuflen) {
                  rctx->state = OHS_ERROR;
                  return 0;
              }
              goto next_io;
          }
          n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
  
          if (n <= 0) {
              if (BIO_should_retry(rctx->mem))
                  goto next_io;
              rctx->state = OHS_ERROR;
              return 0;
          }
  
          /* Don't allow excessive lines */
          if (n == rctx->iobuflen) {
              rctx->state = OHS_ERROR;
              return 0;
          }
  
          /* First line */
          if (rctx->state == OHS_FIRSTLINE) {
              if (parse_http_line1((char *)rctx->iobuf)) {
                  rctx->state = OHS_HEADERS;
                  goto next_line;
              } else {
                  rctx->state = OHS_ERROR;
                  return 0;
              }
          } else {
              /* Look for blank line: end of headers */
              for (p = rctx->iobuf; *p; p++) {
                  if ((*p != '\r') && (*p != '\n'))
                      break;
              }
              if (*p)
                  goto next_line;
  
              rctx->state = OHS_ASN1_HEADER;
  
          }
  
          /* Fall thru */
  
      case OHS_ASN1_HEADER:
          /*
           * Now reading ASN1 header: can read at least 2 bytes which is enough
           * for ASN1 SEQUENCE header and either length field or at least the
           * length of the length field.
           */
          n = BIO_get_mem_data(rctx->mem, &p);
          if (n < 2)
              goto next_io;
  
          /* Check it is an ASN1 SEQUENCE */
          if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
              rctx->state = OHS_ERROR;
              return 0;
          }
  
          /* Check out length field */
          if (*p & 0x80) {
              /*
               * If MSB set on initial length octet we can now always read 6
               * octets: make sure we have them.
               */
              if (n < 6)
                  goto next_io;
              n = *p & 0x7F;
              /* Not NDEF or excessive length */
              if (!n || (n > 4)) {
                  rctx->state = OHS_ERROR;
                  return 0;
              }
              p++;
              rctx->asn1_len = 0;
              for (i = 0; i < n; i++) {
                  rctx->asn1_len <<= 8;
                  rctx->asn1_len |= *p++;
              }
  
              if (rctx->asn1_len > rctx->max_resp_len) {
                  rctx->state = OHS_ERROR;
                  return 0;
              }
  
              rctx->asn1_len += n + 2;
          } else
              rctx->asn1_len = *p + 2;
  
          rctx->state = OHS_ASN1_CONTENT;
  
          /* Fall thru */
  
      case OHS_ASN1_CONTENT:
          n = BIO_get_mem_data(rctx->mem, NULL);
          if (n < (int)rctx->asn1_len)
              goto next_io;
  
          rctx->state = OHS_DONE;
          return 1;
  
          break;
  
      case OHS_DONE:
          return 1;
  
      }
  
      return 0;
  
  }
  
  int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
  {
      return OCSP_REQ_CTX_nbio_d2i(rctx,
                                   (ASN1_VALUE **)presp,
                                   ASN1_ITEM_rptr(OCSP_RESPONSE));
  }
  
  /* Blocking OCSP request handler: now a special case of non-blocking I/O */
  
  OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, const char *path, OCSP_REQUEST *req)
  {
      OCSP_RESPONSE *resp = NULL;
      OCSP_REQ_CTX *ctx;
      int rv;
  
      ctx = OCSP_sendreq_new(b, path, req, -1);
  
      if (!ctx)
          return NULL;
  
      do {
          rv = OCSP_sendreq_nbio(&resp, ctx);
      } while ((rv == -1) && BIO_should_retry(b));
  
      OCSP_REQ_CTX_free(ctx);
  
      if (rv)
          return resp;
  
      return NULL;
  }
  