Пример #1
0
/** Construct and return a tor_zlib_state_t object using <b>method</b>.  If
 * <b>compress</b>, it's for compression; otherwise it's for
 * decompression. */
tor_zlib_state_t *
tor_zlib_new(int compress, compress_method_t method)
{
  tor_zlib_state_t *out;

  if (method == GZIP_METHOD && !is_gzip_supported()) {
    /* Old zlib version don't support gzip in inflateInit2 */
    log_warn(LD_BUG, "Gzip not supported with zlib %s", ZLIB_VERSION);
    return NULL;
 }

 out = tor_malloc_zero(sizeof(tor_zlib_state_t));
 out->stream.zalloc = Z_NULL;
 out->stream.zfree = Z_NULL;
 out->stream.opaque = NULL;
 out->compress = compress;
 if (compress) {
   if (deflateInit2(&out->stream, Z_BEST_COMPRESSION, Z_DEFLATED,
                    method_bits(method), 8, Z_DEFAULT_STRATEGY) != Z_OK)
     goto err;
 } else {
   if (inflateInit2(&out->stream, method_bits(method)) != Z_OK)
     goto err;
 }
 return out;

 err:
 tor_free(out);
 return NULL;
}
Пример #2
0
/** Construct and return a tor_zlib_state_t object using <b>method</b>.  If
 * <b>compress</b>, it's for compression; otherwise it's for
 * decompression. */
tor_zlib_state_t *
tor_zlib_new(int compress, compress_method_t method,
             zlib_compression_level_t compression_level)
{
  tor_zlib_state_t *out;
  int bits, memlevel;

  if (method == GZIP_METHOD && !is_gzip_supported()) {
    /* Old zlib version don't support gzip in inflateInit2 */
    log_warn(LD_BUG, "Gzip not supported with zlib %s", ZLIB_VERSION);
    return NULL;
 }

 if (! compress) {
   /* use this setting for decompression, since we might have the
    * max number of window bits */
   compression_level = HIGH_COMPRESSION;
 }

 out = tor_malloc_zero(sizeof(tor_zlib_state_t));
 out->stream.zalloc = Z_NULL;
 out->stream.zfree = Z_NULL;
 out->stream.opaque = NULL;
 out->compress = compress;
 bits = method_bits(method, compression_level);
 memlevel = get_memlevel(compression_level);
 if (compress) {
   if (deflateInit2(&out->stream, Z_BEST_COMPRESSION, Z_DEFLATED,
                    bits, memlevel,
                    Z_DEFAULT_STRATEGY) != Z_OK)
     goto err;
 } else {
   if (inflateInit2(&out->stream, bits) != Z_OK)
     goto err;
 }
 out->allocation = tor_zlib_state_size_precalc(!compress, bits, memlevel);

 total_zlib_allocation += out->allocation;

 return out;

 err:
 tor_free(out);
 return NULL;
}
Пример #3
0
/** Given zero or more zlib-compressed or gzip-compressed strings of
 * total length
 * <b>in_len</b> bytes at <b>in</b>, uncompress them into a newly allocated
 * buffer, using the method described in <b>method</b>.  Store the uncompressed
 * string in *<b>out</b>, and its length in *<b>out_len</b>.  Return 0 on
 * success, -1 on failure.
 *
 * If <b>complete_only</b> is true, we consider a truncated input as a
 * failure; otherwise we decompress as much as we can.  Warn about truncated
 * or corrupt inputs at <b>protocol_warn_level</b>.
 */
int
tor_gzip_uncompress(char **out, size_t *out_len,
                    const char *in, size_t in_len,
                    compress_method_t method,
                    int complete_only,
                    int protocol_warn_level)
{
  struct z_stream_s *stream = NULL;
  size_t out_size, old_size;
  off_t offset;
  int r;

  tor_assert(out);
  tor_assert(out_len);
  tor_assert(in);
  tor_assert(in_len < UINT_MAX);

  if (method == GZIP_METHOD && !is_gzip_supported()) {
    /* Old zlib version don't support gzip in inflateInit2 */
    log_warn(LD_BUG, "Gzip not supported with zlib %s", ZLIB_VERSION);
    return -1;
  }

  *out = NULL;

  stream = tor_malloc_zero(sizeof(struct z_stream_s));
  stream->zalloc = Z_NULL;
  stream->zfree = Z_NULL;
  stream->opaque = NULL;
  stream->next_in = (unsigned char*) in;
  stream->avail_in = (unsigned int)in_len;

  if (inflateInit2(stream,
                   method_bits(method, HIGH_COMPRESSION)) != Z_OK) {
    log_warn(LD_GENERAL, "Error from inflateInit2: %s",
             stream->msg?stream->msg:"<no message>");
    goto err;
  }

  out_size = in_len * 2;  /* guess 50% compression. */
  if (out_size < 1024) out_size = 1024;
  if (out_size >= SIZE_T_CEILING || out_size > UINT_MAX)
    goto err;

  *out = tor_malloc(out_size);
  stream->next_out = (unsigned char*)*out;
  stream->avail_out = (unsigned int)out_size;

  while (1) {
    switch (inflate(stream, complete_only ? Z_FINISH : Z_SYNC_FLUSH))
      {
      case Z_STREAM_END:
        if (stream->avail_in == 0)
          goto done;
        /* There may be more compressed data here. */
        if ((r = inflateEnd(stream)) != Z_OK) {
          log_warn(LD_BUG, "Error freeing gzip structures");
          goto err;
        }
        if (inflateInit2(stream,
                         method_bits(method,HIGH_COMPRESSION)) != Z_OK) {
          log_warn(LD_GENERAL, "Error from second inflateInit2: %s",
                   stream->msg?stream->msg:"<no message>");
          goto err;
        }
        break;
      case Z_OK:
        if (!complete_only && stream->avail_in == 0)
          goto done;
        /* In case zlib doesn't work as I think.... */
        if (stream->avail_out >= stream->avail_in+16)
          break;
      case Z_BUF_ERROR:
        if (stream->avail_out > 0) {
          log_fn(protocol_warn_level, LD_PROTOCOL,
                 "possible truncated or corrupt zlib data");
          goto err;
        }
        offset = stream->next_out - (unsigned char*)*out;
        old_size = out_size;
        out_size *= 2;
        if (out_size < old_size) {
          log_warn(LD_GENERAL, "Size overflow in uncompression.");
          goto err;
        }
        if (is_compression_bomb(in_len, out_size)) {
          log_warn(LD_GENERAL, "Input looks like a possible zlib bomb; "
                   "not proceeding.");
          goto err;
        }
        if (out_size >= SIZE_T_CEILING) {
          log_warn(LD_BUG, "Hit SIZE_T_CEILING limit while uncompressing.");
          goto err;
        }
        *out = tor_realloc(*out, out_size);
        stream->next_out = (unsigned char*)(*out + offset);
        if (out_size - offset > UINT_MAX) {
          log_warn(LD_BUG,  "Ran over unsigned int limit of zlib while "
                   "uncompressing.");
          goto err;
        }
        stream->avail_out = (unsigned int)(out_size - offset);
        break;
      default:
        log_warn(LD_GENERAL, "Gzip decompression returned an error: %s",
                 stream->msg ? stream->msg : "<no message>");
        goto err;
      }
  }
 done:
  *out_len = stream->next_out - (unsigned char*)*out;
  r = inflateEnd(stream);
  tor_free(stream);
  if (r != Z_OK) {
    log_warn(LD_BUG, "Error freeing gzip structures");
    goto err;
  }

  /* NUL-terminate output. */
  if (out_size == *out_len)
    *out = tor_realloc(*out, out_size + 1);
  (*out)[*out_len] = '\0';

  return 0;
 err:
  if (stream) {
    inflateEnd(stream);
    tor_free(stream);
  }
  if (*out) {
    tor_free(*out);
  }
  return -1;
}
Пример #4
0
/** Given <b>in_len</b> bytes at <b>in</b>, compress them into a newly
 * allocated buffer, using the method described in <b>method</b>.  Store the
 * compressed string in *<b>out</b>, and its length in *<b>out_len</b>.
 * Return 0 on success, -1 on failure.
 */
int
tor_gzip_compress(char **out, size_t *out_len,
                  const char *in, size_t in_len,
                  compress_method_t method)
{
  struct z_stream_s *stream = NULL;
  size_t out_size, old_size;
  off_t offset;

  tor_assert(out);
  tor_assert(out_len);
  tor_assert(in);
  tor_assert(in_len < UINT_MAX);

  *out = NULL;

  if (method == GZIP_METHOD && !is_gzip_supported()) {
    /* Old zlib version don't support gzip in deflateInit2 */
    log_warn(LD_BUG, "Gzip not supported with zlib %s", ZLIB_VERSION);
    goto err;
  }

  stream = tor_malloc_zero(sizeof(struct z_stream_s));
  stream->zalloc = Z_NULL;
  stream->zfree = Z_NULL;
  stream->opaque = NULL;
  stream->next_in = (unsigned char*) in;
  stream->avail_in = (unsigned int)in_len;

  if (deflateInit2(stream, Z_BEST_COMPRESSION, Z_DEFLATED,
                   method_bits(method, HIGH_COMPRESSION),
                   get_memlevel(HIGH_COMPRESSION),
                   Z_DEFAULT_STRATEGY) != Z_OK) {
    log_warn(LD_GENERAL, "Error from deflateInit2: %s",
             stream->msg?stream->msg:"<no message>");
    goto err;
  }

  /* Guess 50% compression. */
  out_size = in_len / 2;
  if (out_size < 1024) out_size = 1024;
  *out = tor_malloc(out_size);
  stream->next_out = (unsigned char*)*out;
  stream->avail_out = (unsigned int)out_size;

  while (1) {
    switch (deflate(stream, Z_FINISH))
      {
      case Z_STREAM_END:
        goto done;
      case Z_OK:
        /* In case zlib doesn't work as I think .... */
        if (stream->avail_out >= stream->avail_in+16)
          break;
      case Z_BUF_ERROR:
        offset = stream->next_out - ((unsigned char*)*out);
        old_size = out_size;
        out_size *= 2;
        if (out_size < old_size) {
          log_warn(LD_GENERAL, "Size overflow in compression.");
          goto err;
        }
        *out = tor_realloc(*out, out_size);
        stream->next_out = (unsigned char*)(*out + offset);
        if (out_size - offset > UINT_MAX) {
          log_warn(LD_BUG,  "Ran over unsigned int limit of zlib while "
                   "uncompressing.");
          goto err;
        }
        stream->avail_out = (unsigned int)(out_size - offset);
        break;
      default:
        log_warn(LD_GENERAL, "Gzip compression didn't finish: %s",
                 stream->msg ? stream->msg : "<no message>");
        goto err;
      }
  }
 done:
  *out_len = stream->total_out;
#ifdef OPENBSD
  /* "Hey Rocky!  Watch me change an unsigned field to a signed field in a
   *    third-party API!"
   * "Oh, that trick will just make people do unsafe casts to the unsigned
   *    type in their cross-platform code!"
   * "Don't be foolish.  I'm _sure_ they'll have the good sense to make sure
   *    the newly unsigned field isn't negative." */
  tor_assert(stream->total_out >= 0);
#endif
  if (((size_t)stream->total_out) > out_size + 4097) {
    /* If we're wasting more than 4k, don't. */
    *out = tor_realloc(*out, stream->total_out + 1);
  }
  if (deflateEnd(stream)!=Z_OK) {
    log_warn(LD_BUG, "Error freeing gzip structures");
    goto err;
  }
  tor_free(stream);

  if (is_compression_bomb(*out_len, in_len)) {
    log_warn(LD_BUG, "We compressed something and got an insanely high "
          "compression factor; other Tors would think this was a zlib bomb.");
    goto err;
  }

  return 0;
 err:
  if (stream) {
    deflateEnd(stream);
    tor_free(stream);
  }
  tor_free(*out);
  return -1;
}