kc3-lang/harfbuzz/test/fuzzing/hb-subset-fuzzer.cc

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• Hash : b65bad18
  Author :
  Date : 2019-07-11T14:31:55
  

  [fuzz] Don't fail when blob is empty
  
  And enable more tests able to trig the issue.

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• test/fuzzing/hb-subset-fuzzer.cc

• #include "hb-fuzzer.hh"
  
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>
  #include <assert.h>
  
  #include "hb-subset.h"
  
  static void
  trySubset (hb_face_t *face,
  	   const hb_codepoint_t text[],
  	   int text_length,
  	   bool drop_hints,
  	   bool drop_layout,
  	   bool retain_gids)
  {
    hb_subset_input_t *input = hb_subset_input_create_or_fail ();
    hb_subset_input_set_drop_hints (input, drop_hints);
    hb_subset_input_set_retain_gids (input, retain_gids);
    hb_set_t *codepoints = hb_subset_input_unicode_set (input);
  
    if (!drop_layout)
    {
      hb_set_del (hb_subset_input_drop_tables_set (input), HB_TAG ('G', 'S', 'U', 'B'));
      hb_set_del (hb_subset_input_drop_tables_set (input), HB_TAG ('G', 'P', 'O', 'S'));
      hb_set_del (hb_subset_input_drop_tables_set (input), HB_TAG ('G', 'D', 'E', 'F'));
    }
  
    for (int i = 0; i < text_length; i++)
    {
      hb_set_add (codepoints, text[i]);
    }
  
    hb_face_t *result = hb_subset (face, input);
    {
      hb_blob_t *blob = hb_face_reference_blob (result);
      unsigned int length;
      const char *data = hb_blob_get_data (blob, &length);
  
      // Something not optimizable just to access all the blob data
      unsigned int bytes_count = 0;
      for (unsigned int i = 0; i < length; ++i)
        if (data[i]) ++bytes_count;
      assert (bytes_count || !length);
  
      hb_blob_destroy (blob);
    }
    hb_face_destroy (result);
  
    hb_subset_input_destroy (input);
  }
  
  static void
  trySubset (hb_face_t *face,
  	   const hb_codepoint_t text[],
  	   int text_length,
  	   const uint8_t flags[1])
  {
    bool drop_hints =  flags[0] & (1 << 0);
    bool drop_layout = flags[0] & (1 << 1);
    bool retain_gids = flags[0] & (1 << 2);
    trySubset (face, text, text_length,
  	     drop_hints, drop_layout, retain_gids);
  }
  
  extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
  {
    hb_blob_t *blob = hb_blob_create ((const char *)data, size,
  				    HB_MEMORY_MODE_READONLY, nullptr, nullptr);
    hb_face_t *face = hb_face_create (blob, 0);
  
    /* Just test this API here quickly. */
    hb_set_t *output = hb_set_create();
    hb_face_collect_unicodes (face, output);
    hb_set_destroy (output);
  
    uint8_t flags[1] = {0};
    const hb_codepoint_t text[] =
        {
  	'A', 'B', 'C', 'D', 'E', 'X', 'Y', 'Z', '1', '2',
  	'3', '@', '_', '%', '&', ')', '*', '$', '!'
        };
  
    trySubset (face, text, sizeof (text) / sizeof (hb_codepoint_t), flags);
  
    hb_codepoint_t text_from_data[16];
    if (size > sizeof(text_from_data) + sizeof(flags)) {
      memcpy (text_from_data,
  	    data + size - sizeof(text_from_data),
  	    sizeof(text_from_data));
  
      memcpy (flags,
  	    data + size - sizeof(text_from_data) - sizeof(flags),
  	    sizeof(flags));
      unsigned int text_size = sizeof (text_from_data) / sizeof (hb_codepoint_t);
  
      trySubset (face, text_from_data, text_size, flags);
    }
  
    hb_face_destroy (face);
    hb_blob_destroy (blob);
  
    return 0;
  }
  

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