/src/libewf/libewf/libewf_deflate.c

Source
/*
 * Deflate (zlib) (un)compression functions
 *
 * Copyright (C) 2006-2026, Joachim Metz <joachim.metz@gmail.com>
 *
 * Refer to AUTHORS for acknowledgements.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <byte_stream.h>
#include <memory.h>
#include <types.h>

#include "libewf_bit_stream.h"
#include "libewf_deflate.h"
#include "libewf_huffman_tree.h"
#include "libewf_libcerror.h"
#include "libewf_libcnotify.h"

const uint8_t libewf_deflate_code_sizes_sequence[ 19 ]  = {
  16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2,
        14, 1, 15 };

const uint16_t libewf_deflate_literal_codes_base[ 29 ] = {
  3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
  35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258 };

const uint16_t libewf_deflate_literal_codes_number_of_extra_bits[ 29 ] = {
  0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
  3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0 };

const uint16_t libewf_deflate_distance_codes_base[ 30 ] = {
  1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
  257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193,
  12289, 16385, 24577 };

const uint16_t libewf_deflate_distance_codes_number_of_extra_bits[ 30 ] = {
  0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
  7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13 };

/* Initializes the dynamic Huffman trees
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_build_dynamic_huffman_trees(
     libewf_bit_stream_t *bit_stream,
     libewf_huffman_tree_t *literals_tree,
     libewf_huffman_tree_t *distances_tree,
     libcerror_error_t **error )
{
  uint8_t code_size_array[ 316 ];

  libewf_huffman_tree_t *codes_tree = NULL;
  static char *function             = "libewf_deflate_build_dynamic_huffman_trees";
  uint32_t code_size                = 0;
  uint32_t code_size_index          = 0;
  uint32_t code_size_sequence       = 0;
  uint32_t number_of_code_sizes     = 0;
  uint32_t number_of_distance_codes = 0;
  uint32_t number_of_literal_codes  = 0;
  uint32_t times_to_repeat          = 0;
  uint16_t symbol                   = 0;

  if( libewf_bit_stream_get_value(
       bit_stream,
       14,
       &number_of_code_sizes,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_GET_FAILED,
     "%s: unable to retrieve value from bit stream.",
     function );

    goto on_error;
  }
  number_of_literal_codes  = number_of_code_sizes & 0x0000001fUL;
  number_of_code_sizes   >>= 5;
  number_of_distance_codes = number_of_code_sizes & 0x0000001fUL;
  number_of_code_sizes   >>= 5;

  number_of_literal_codes += 257;

  if( number_of_literal_codes > 286 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid number of literal codes value out of bounds.",
     function );

    goto on_error;
  }
  number_of_distance_codes += 1;

  if( number_of_distance_codes > 30 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
     "%s: invalid number of distance codes value out of bounds.",
     function );

    goto on_error;
  }
  number_of_code_sizes += 4;

  for( code_size_index = 0;
       code_size_index < number_of_code_sizes;
       code_size_index++ )
  {
    if( libewf_bit_stream_get_value(
         bit_stream,
         3,
         &code_size,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_GET_FAILED,
       "%s: unable to retrieve value from bit stream.",
       function );

      goto on_error;
    }
    code_size_sequence = libewf_deflate_code_sizes_sequence[ code_size_index ];

    code_size_array[ code_size_sequence ] = (uint8_t) code_size;
  }
  while( code_size_index < 19 )
  {
    code_size_sequence = libewf_deflate_code_sizes_sequence[ code_size_index++ ];

    code_size_array[ code_size_sequence ] = 0;
  }
  if( libewf_huffman_tree_initialize(
       &codes_tree,
       19,
       15,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build codes tree.",
     function );

    goto on_error;
  }
  if( libewf_huffman_tree_build(
       codes_tree,
       code_size_array,
       19,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build codes tree.",
     function );

    goto on_error;
  }
  number_of_code_sizes = number_of_literal_codes + number_of_distance_codes;

  code_size_index = 0;

  while( code_size_index < number_of_code_sizes )
  {
    if( libewf_huffman_tree_get_symbol_from_bit_stream(
         codes_tree,
         bit_stream,
         &symbol,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_GET_FAILED,
       "%s: unable to retrieve literal value from bit stream.",
       function );

      goto on_error;
    }
    if( symbol < 16 )
    {
      code_size_array[ code_size_index++ ] = (uint8_t) symbol;

      continue;
    }
    code_size = 0;

    if( symbol == 16 )
    {
      if( code_size_index == 0 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
         LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
         "%s: invalid code size index value out of bounds.",
         function );

        goto on_error;
      }
      code_size = (uint32_t) code_size_array[ code_size_index - 1 ];

      if( libewf_bit_stream_get_value(
           bit_stream,
           2,
           &times_to_repeat,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve value from bit stream.",
         function );

        goto on_error;
      }
      times_to_repeat += 3;
    }
    else if( symbol == 17 )
    {
      if( libewf_bit_stream_get_value(
           bit_stream,
           3,
           &times_to_repeat,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve value from bit stream.",
         function );

        goto on_error;
      }
      times_to_repeat += 3;
    }
    else if( symbol == 18 )
    {
      if( libewf_bit_stream_get_value(
           bit_stream,
           7,
           &times_to_repeat,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve value from bit stream.",
         function );

        goto on_error;
      }
      times_to_repeat += 11;
    }
    else
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
       LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
       "%s: invalid code value value out of bounds.",
       function );

      goto on_error;
    }
    if( ( code_size_index + times_to_repeat ) > number_of_code_sizes )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
       LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
       "%s: invalid times to repeat value out of bounds.",
       function );

      goto on_error;
    }
    while( times_to_repeat > 0 )
    {
      code_size_array[ code_size_index++ ] = (uint8_t) code_size;

      times_to_repeat--;
    }
  }
  if( code_size_array[ 256 ] == 0 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,
     "%s: end-of-block code value missing in literal codes array.",
     function );

    goto on_error;
  }
  if( libewf_huffman_tree_free(
       &codes_tree,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
     "%s: unable to free codes tree.",
     function );

    goto on_error;
  }
  if( libewf_huffman_tree_build(
       literals_tree,
       code_size_array,
       number_of_literal_codes,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build literals tree.",
     function );

    goto on_error;
  }
  if( libewf_huffman_tree_build(
       distances_tree,
       &( code_size_array[ number_of_literal_codes ] ),
       number_of_distance_codes,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build distances tree.",
     function );

    goto on_error;
  }
  return( 1 );

on_error:
  if( codes_tree != NULL )
  {
    libewf_huffman_tree_free(
     &codes_tree,
     NULL );
  }
  return( -1 );
}

/* Initializes the fixed Huffman trees
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_build_fixed_huffman_trees(
     libewf_huffman_tree_t *literals_tree,
     libewf_huffman_tree_t *distances_tree,
     libcerror_error_t **error )
{
  uint8_t code_size_array[ 318 ];

  static char *function = "libewf_deflate_build_fixed_huffman_trees";
  uint16_t symbol       = 0;

  for( symbol = 0;
       symbol < 318;
       symbol++ )
  {
    if( symbol < 144 )
    {
      code_size_array[ symbol ] = 8;
    }
    else if( symbol < 256 )
    {
      code_size_array[ symbol ] = 9;
    }
    else if( symbol < 280 )
    {
      code_size_array[ symbol ] = 7;
    }
    else if( symbol < 288 )
    {
      code_size_array[ symbol ] = 8;
    }
    else
    {
      code_size_array[ symbol ] = 5;
    }
  }
  if( libewf_huffman_tree_build(
       literals_tree,
       code_size_array,
       288,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build literals tree.",
     function );

    return( -1 );
  }
  if( libewf_huffman_tree_build(
       distances_tree,
       &( code_size_array[ 288 ] ),
       30,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to build distances tree.",
     function );

    return( -1 );
  }
  return( 1 );
}

/* Decodes a Huffman compressed block
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_decode_huffman(
     libewf_bit_stream_t *bit_stream,
     libewf_huffman_tree_t *literals_tree,
     libewf_huffman_tree_t *distances_tree,
     uint8_t *uncompressed_data,
     size_t uncompressed_data_size,
     size_t *uncompressed_data_offset,
     libcerror_error_t **error )
{
  static char *function         = "libewf_deflate_decode_huffman";
  size_t data_offset            = 0;
  uint32_t extra_bits           = 0;
  uint16_t compression_offset   = 0;
  uint16_t compression_size     = 0;
  uint16_t number_of_extra_bits = 0;
  uint16_t symbol               = 0;

  if( uncompressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data.",
     function );

    return( -1 );
  }
  if( uncompressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid uncompressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( uncompressed_data_offset == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data offset.",
     function );

    return( -1 );
  }
  data_offset = *uncompressed_data_offset;

  do
  {
    if( libewf_huffman_tree_get_symbol_from_bit_stream(
         literals_tree,
         bit_stream,
         &symbol,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_GET_FAILED,
       "%s: unable to retrieve literal value from bit stream.",
       function );

      return( -1 );
    }
    if( symbol < 256 )
    {
      if( data_offset >= uncompressed_data_size )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
         LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
         "%s: invalid uncompressed data value too small.",
         function );

        return( -1 );
      }
      uncompressed_data[ data_offset++ ] = (uint8_t) symbol;
    }
    else if( ( symbol > 256 )
          && ( symbol < 286 ) )
    {
      symbol -= 257;

      number_of_extra_bits = libewf_deflate_literal_codes_number_of_extra_bits[ symbol ];

      if( libewf_bit_stream_get_value(
           bit_stream,
           (uint8_t) number_of_extra_bits,
           &extra_bits,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve literal extra value from bit stream.",
         function );

        return( -1 );
      }
      compression_size = libewf_deflate_literal_codes_base[ symbol ] + (uint16_t) extra_bits;

      if( libewf_huffman_tree_get_symbol_from_bit_stream(
           distances_tree,
           bit_stream,
           &symbol,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve distance value from bit stream.",
         function );

        return( -1 );
      }
      number_of_extra_bits = libewf_deflate_distance_codes_number_of_extra_bits[ symbol ];

      if( libewf_bit_stream_get_value(
           bit_stream,
           (uint8_t) number_of_extra_bits,
           &extra_bits,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve distance extra value from bit stream.",
         function );

        return( -1 );
      }
      compression_offset = libewf_deflate_distance_codes_base[ symbol ] + (uint16_t) extra_bits;

      if( compression_offset > data_offset )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
         "%s: invalid compression offset value out of bounds.",
         function );

        return( -1 );
      }
      if( ( data_offset + compression_size ) > uncompressed_data_size )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
         LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
         "%s: invalid uncompressed data value too small.",
         function );

        return( -1 );
      }
      while( compression_size > 0 )
      {
        uncompressed_data[ data_offset ] = uncompressed_data[ data_offset - compression_offset ];

        data_offset++;
        compression_size--;
      }
    }
    else if( symbol != 256 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_GET_FAILED,
       "%s: invalid code value: %" PRIu16 ".",
       function,
       symbol );

      return( -1 );
    }
  }
  while( symbol != 256 );

  *uncompressed_data_offset = data_offset;

  return( 1 );
}

/* Calculates the little-endian Adler-32 of a buffer
 * It uses the initial value to calculate a new Adler-32
 * Returns 1 if successful or -1 on error
 */
int libewf_deflate_calculate_adler32(
     uint32_t *checksum_value,
     const uint8_t *data,
     size_t data_size,
     uint32_t initial_value,
     libcerror_error_t **error )
{
  static char *function = "libewf_deflate_calculate_adler32";
  size_t data_offset    = 0;
  uint32_t lower_word   = 0;
  uint32_t upper_word   = 0;
  uint32_t value_32bit  = 0;
  int block_index       = 0;

  if( checksum_value == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid checksum value.",
     function );

    return( -1 );
  }
  if( data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid data.",
     function );

    return( -1 );
  }
  if( data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid data size value exceeds maximum.",
     function );

    return( -1 );
  }
  lower_word = initial_value & 0xffff;
  upper_word = ( initial_value >> 16 ) & 0xffff;

  while( data_size >= 0x15b0 )
  {
    /* The modulo calculation is needed per 5552 (0x15b0) bytes
     * 5552 / 16 = 347
     */
    for( block_index = 0;
         block_index < 347;
         block_index++ )
    {
      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;
    }
    /* Optimized equivalent of:
     * lower_word %= 0xfff1
     */
    value_32bit = lower_word >> 16;
    lower_word &= 0x0000ffffUL;
    lower_word += ( value_32bit << 4 ) - value_32bit;

    if( lower_word > 65521 )
    {
      value_32bit = lower_word >> 16;
      lower_word &= 0x0000ffffUL;
      lower_word += ( value_32bit << 4 ) - value_32bit;
    }
    if( lower_word >= 65521 )
    {
      lower_word -= 65521;
    }
    /* Optimized equivalent of:
     * upper_word %= 0xfff1
     */
    value_32bit = upper_word >> 16;
    upper_word &= 0x0000ffffUL;
    upper_word += ( value_32bit << 4 ) - value_32bit;

    if( upper_word > 65521 )
    {
      value_32bit = upper_word >> 16;
      upper_word &= 0x0000ffffUL;
      upper_word += ( value_32bit << 4 ) - value_32bit;
    }
    if( upper_word >= 65521 )
    {
      upper_word -= 65521;
    }
    data_size -= 0x15b0;
  }
  if( data_size > 0 )
  {
    while( data_size > 16 )
    {
      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      data_size -= 16;
    }
    while( data_size > 0 )
    {
      lower_word += data[ data_offset++ ];
      upper_word += lower_word;

      data_size--;
    }
    /* Optimized equivalent of:
     * lower_word %= 0xfff1
     */
    value_32bit = lower_word >> 16;
    lower_word &= 0x0000ffffUL;
    lower_word += ( value_32bit << 4 ) - value_32bit;

    if( lower_word > 65521 )
    {
      value_32bit = lower_word >> 16;
      lower_word &= 0x0000ffffUL;
      lower_word += ( value_32bit << 4 ) - value_32bit;
    }
    if( lower_word >= 65521 )
    {
      lower_word -= 65521;
    }
    /* Optimized equivalent of:
     * upper_word %= 0xfff1
     */
    value_32bit = upper_word >> 16;
    upper_word &= 0x0000ffffUL;
    upper_word += ( value_32bit << 4 ) - value_32bit;

    if( upper_word > 65521 )
    {
      value_32bit = upper_word >> 16;
      upper_word &= 0x0000ffffUL;
      upper_word += ( value_32bit << 4 ) - value_32bit;
    }
    if( upper_word >= 65521 )
    {
      upper_word -= 65521;
    }
  }
  *checksum_value = ( upper_word << 16 ) | lower_word;

  return( 1 );
}

/* Reads the compressed data header
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_read_data_header(
     const uint8_t *compressed_data,
     size_t compressed_data_size,
     size_t *compressed_data_offset,
     libcerror_error_t **error )
{
  static char *function                 = "libewf_deflate_read_data_header";
  size_t safe_offset                    = 0;
  uint32_t compression_window_size      = 0;
  uint8_t flags                         = 0;
  uint8_t compression_data              = 0;
  uint8_t compression_information       = 0;
  uint8_t compression_method            = 0;
  uint8_t compression_window_bits       = 0;

#if defined( HAVE_DEBUG_OUTPUT )
  uint32_t preset_dictionary_identifier = 0;
#endif

  if( compressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid compressed data.",
     function );

    return( -1 );
  }
  if( compressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid compressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( compressed_data_offset == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid compressed data offset.",
     function );

    return( -1 );
  }
  safe_offset = *compressed_data_offset;

  if( ( compressed_data_size < 2 )
   || ( safe_offset > ( compressed_data_size - 2 ) ) )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
     "%s: invalid compressed data value too small.",
     function );

    return( -1 );
  }
  compression_data = compressed_data[ safe_offset++ ];
  flags            = compressed_data[ safe_offset++ ];

  compression_method      = compression_data & 0x0f;
  compression_information = compression_data >> 4;

/* TODO validate check bits */
  if( ( flags & 0x20 ) != 0 )
  {
    if( ( compressed_data_size < 6 )
     || ( safe_offset > ( compressed_data_size - 6 ) ) )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
       LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
       "%s: invalid compressed data value too small.",
       function );

      return( -1 );
    }
#if defined( HAVE_DEBUG_OUTPUT )
    byte_stream_copy_to_uint32_big_endian(
     &( compressed_data[ 2 ] ),
     preset_dictionary_identifier );
#endif
    safe_offset += 4;
  }
  if( compression_method != 8 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,
     "%s: unsupported compression method: %" PRIu8 ".",
     function,
     compression_method );

    return( -1 );
  }
  compression_window_bits = (uint8_t) compression_information + 8;
  compression_window_size = (uint32_t) 1UL << compression_window_bits;

  if( compression_window_size > 32768 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,
     "%s: unsupported compression window size: %" PRIu32 ".",
     function,
     compression_window_size );

    return( -1 );
  }
  *compressed_data_offset += safe_offset;

  return( 1 );
}

/* Reads the header of a block of compressed data
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_read_block_header(
     libewf_bit_stream_t *bit_stream,
     uint8_t *block_type,
     uint8_t *last_block_flag,
     libcerror_error_t **error )
{
  static char *function = "libewf_deflate_read_block_header";
  uint32_t value_32bit  = 0;

  if( block_type == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid block type.",
     function );

    return( -1 );
  }
  if( last_block_flag == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid last block flag.",
     function );

    return( -1 );
  }
  if( libewf_bit_stream_get_value(
       bit_stream,
       3,
       &value_32bit,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_GET_FAILED,
     "%s: unable to retrieve value from bit stream.",
     function );

    return( -1 );
  }
  *last_block_flag = (uint8_t) ( value_32bit & 0x00000001UL );
  value_32bit    >>= 1;
  *block_type      = (uint8_t) value_32bit;

#if defined( HAVE_DEBUG_OUTPUT )
  if( libcnotify_verbose != 0 )
  {
    libcnotify_printf(
     "%s: block header last block flag\t\t\t: %" PRIu8 "\n",
     function,
     *last_block_flag );

    libcnotify_printf(
     "%s: block header block type\t\t\t: %" PRIu8 " (",
     function,
     *block_type );

    switch( *block_type )
    {
      case LIBEWF_DEFLATE_BLOCK_TYPE_UNCOMPRESSED:
        libcnotify_printf(
         "Uncompressed" );
        break;

      case LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_FIXED:
        libcnotify_printf(
         "Fixed Huffman" );
        break;

      case LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_DYNAMIC:
        libcnotify_printf(
         "Dynamic Huffman" );
        break;

      case LIBEWF_DEFLATE_BLOCK_TYPE_RESERVED:
      default:
        libcnotify_printf(
         "Reserved" );
        break;
    }
    libcnotify_printf(
     ")\n" );

    libcnotify_printf(
     "\n" );
  }
#endif /* defined( HAVE_DEBUG_OUTPUT ) */

  return( 1 );
}

/* Reads a block of compressed data
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_read_block(
     libewf_bit_stream_t *bit_stream,
     uint8_t block_type,
     libewf_huffman_tree_t *fixed_huffman_literals_tree,
     libewf_huffman_tree_t *fixed_huffman_distances_tree,
     uint8_t *uncompressed_data,
     size_t uncompressed_data_size,
     size_t *uncompressed_data_offset,
     libcerror_error_t **error )
{
  libewf_huffman_tree_t *dynamic_huffman_distances_tree = NULL;
  libewf_huffman_tree_t *dynamic_huffman_literals_tree  = NULL;
  static char *function                                 = "libewf_deflate_read_block";
  size_t safe_uncompressed_data_offset                  = 0;
  uint32_t block_size                                   = 0;
  uint32_t block_size_copy                              = 0;
  uint32_t value_32bit                                  = 0;
  uint8_t skip_bits                                     = 0;

  if( bit_stream == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid bit stream.",
     function );

    return( -1 );
  }
  if( uncompressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data.",
     function );

    return( -1 );
  }
  if( uncompressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid uncompressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( uncompressed_data_offset == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data.",
     function );

    return( -1 );
  }
  safe_uncompressed_data_offset = *uncompressed_data_offset;

  switch( block_type )
  {
    case LIBEWF_DEFLATE_BLOCK_TYPE_UNCOMPRESSED:
      /* Ignore the bits in the buffer upto the next byte
       */
      skip_bits = bit_stream->bit_buffer_size & 0x07;

      if( skip_bits > 0 )
      {
        if( libewf_bit_stream_get_value(
             bit_stream,
             skip_bits,
             &value_32bit,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_GET_FAILED,
           "%s: unable to retrieve value from bit stream.",
           function );

          goto on_error;
        }
      }
      if( libewf_bit_stream_get_value(
           bit_stream,
           32,
           &block_size,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to retrieve value from bit stream.",
         function );

        goto on_error;
      }
      block_size_copy = ( block_size >> 16 ) ^ 0x0000ffffUL;
      block_size     &= 0x0000ffffUL;

      if( block_size != block_size_copy )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_INPUT,
         LIBCERROR_INPUT_ERROR_VALUE_MISMATCH,
         "%s: mismatch in block size ( %" PRIu32 " != %" PRIu32 " ).",
         function,
         block_size,
         block_size_copy );

        goto on_error;
      }
      if( block_size == 0 )
      {
        break;
      }
      if( (size_t) block_size > ( bit_stream->byte_stream_size - bit_stream->byte_stream_offset ) )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
         LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
         "%s: invalid compressed data value too small.",
         function );

        goto on_error;
      }
      if( (size_t) block_size > ( uncompressed_data_size - safe_uncompressed_data_offset ) )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
         LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
         "%s: invalid uncompressed data value too small.",
         function );

        goto on_error;
      }
      if( memory_copy(
           &( uncompressed_data[ safe_uncompressed_data_offset ] ),
           &( bit_stream->byte_stream[ bit_stream->byte_stream_offset ] ),
           (size_t) block_size ) == NULL )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_MEMORY,
         LIBCERROR_MEMORY_ERROR_COPY_FAILED,
         "%s: unable to initialize lz buffer.",
         function );

        goto on_error;
      }
      bit_stream->byte_stream_offset += block_size;
      safe_uncompressed_data_offset  += block_size;

      /* Flush the bit stream buffer
       */
      bit_stream->bit_buffer      = 0;
      bit_stream->bit_buffer_size = 0;

      break;

    case LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_FIXED:
      if( libewf_deflate_decode_huffman(
           bit_stream,
           fixed_huffman_literals_tree,
           fixed_huffman_distances_tree,
           uncompressed_data,
           uncompressed_data_size,
           &safe_uncompressed_data_offset,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to decode fixed Huffman encoded bit stream.",
         function );

        goto on_error;
      }
      break;

    case LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_DYNAMIC:
      if( libewf_huffman_tree_initialize(
           &dynamic_huffman_literals_tree,
           288,
           15,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
         "%s: unable to build dynamic literals Huffman tree.",
         function );

        goto on_error;
      }
      if( libewf_huffman_tree_initialize(
           &dynamic_huffman_distances_tree,
           30,
           15,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
         "%s: unable to build dynamic distances Huffman tree.",
         function );

        goto on_error;
      }
      if( libewf_deflate_build_dynamic_huffman_trees(
           bit_stream,
           dynamic_huffman_literals_tree,
           dynamic_huffman_distances_tree,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
         "%s: unable to build dynamic Huffman trees.",
         function );

        goto on_error;
      }
      if( libewf_deflate_decode_huffman(
           bit_stream,
           dynamic_huffman_literals_tree,
           dynamic_huffman_distances_tree,
           uncompressed_data,
           uncompressed_data_size,
           &safe_uncompressed_data_offset,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_GET_FAILED,
         "%s: unable to decode dynamic Huffman encoded bit stream.",
         function );

        goto on_error;
      }
      if( libewf_huffman_tree_free(
           &dynamic_huffman_distances_tree,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
         "%s: unable to free dynamic distances Huffman tree.",
         function );

        goto on_error;
      }
      if( libewf_huffman_tree_free(
           &dynamic_huffman_literals_tree,
           error ) != 1 )
      {
        libcerror_error_set(
         error,
         LIBCERROR_ERROR_DOMAIN_RUNTIME,
         LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
         "%s: unable to free dynamic literals Huffman tree.",
         function );

        goto on_error;
      }
      break;

    case LIBEWF_DEFLATE_BLOCK_TYPE_RESERVED:
    default:
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,
       "%s: unsupported block type.",
       function );

      goto on_error;
  }
  *uncompressed_data_offset = safe_uncompressed_data_offset;

  return( 1 );

on_error:
  if( dynamic_huffman_distances_tree != NULL )
  {
    libewf_huffman_tree_free(
     &dynamic_huffman_distances_tree,
     NULL );
  }
  if( dynamic_huffman_literals_tree != NULL )
  {
    libewf_huffman_tree_free(
     &dynamic_huffman_literals_tree,
     NULL );
  }
  return( -1 );
}

/* Decompresses data using deflate compression
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_decompress(
     const uint8_t *compressed_data,
     size_t compressed_data_size,
     uint8_t *uncompressed_data,
     size_t *uncompressed_data_size,
     libcerror_error_t **error )
{
  libewf_bit_stream_t *bit_stream                     = NULL;
  libewf_huffman_tree_t *fixed_huffman_distances_tree = NULL;
  libewf_huffman_tree_t *fixed_huffman_literals_tree  = NULL;
  static char *function                               = "libewf_deflate_decompress";
  size_t compressed_data_offset                       = 0;
  size_t safe_uncompressed_data_size                  = 0;
  size_t uncompressed_data_offset                     = 0;
  uint8_t block_type                                  = 0;
  uint8_t last_block_flag                             = 0;

  if( compressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid compressed data.",
     function );

    return( -1 );
  }
  if( compressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid compressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( uncompressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data.",
     function );

    return( -1 );
  }
  if( uncompressed_data_size == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data size.",
     function );

    return( -1 );
  }
  safe_uncompressed_data_size = *uncompressed_data_size;

  if( safe_uncompressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid uncompressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( compressed_data_offset >= compressed_data_size )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
     "%s: invalid compressed data value too small.",
     function );

    return( -1 );
  }
  if( libewf_bit_stream_initialize(
       &bit_stream,
       compressed_data,
       compressed_data_size,
       compressed_data_offset,
       LIBEWF_BIT_STREAM_STORAGE_TYPE_BYTE_BACK_TO_FRONT,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to create bit stream.",
     function );

    goto on_error;
  }
  while( bit_stream->byte_stream_offset < bit_stream->byte_stream_size )
  {
    if( libewf_deflate_read_block_header(
         bit_stream,
         &block_type,
         &last_block_flag,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_IO,
       LIBCERROR_IO_ERROR_READ_FAILED,
       "%s: unable to read compressed data block header.",
       function );

      goto on_error;
    }
    if( block_type == LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_FIXED )
    {
      if( ( fixed_huffman_literals_tree == NULL )
       && ( fixed_huffman_distances_tree == NULL ) )
      {
        if( libewf_huffman_tree_initialize(
             &fixed_huffman_literals_tree,
             288,
             15,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed literals Huffman tree.",
           function );

          goto on_error;
        }
        if( libewf_huffman_tree_initialize(
             &fixed_huffman_distances_tree,
             30,
             15,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed distances Huffman tree.",
           function );

          goto on_error;
        }
        if( libewf_deflate_build_fixed_huffman_trees(
             fixed_huffman_literals_tree,
             fixed_huffman_distances_tree,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed Huffman trees.",
           function );

          goto on_error;
        }
      }
    }
    if( libewf_deflate_read_block(
         bit_stream,
         block_type,
         fixed_huffman_literals_tree,
         fixed_huffman_distances_tree,
         uncompressed_data,
         safe_uncompressed_data_size,
         &uncompressed_data_offset,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_IO,
       LIBCERROR_IO_ERROR_READ_FAILED,
       "%s: unable to read block of compressed data.",
       function );

      goto on_error;
    }
    if( last_block_flag != 0 )
    {
      break;
    }
  }
  if( fixed_huffman_distances_tree != NULL )
  {
    if( libewf_huffman_tree_free(
         &fixed_huffman_distances_tree,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
       "%s: unable to free fixed distances Huffman tree.",
       function );

      goto on_error;
    }
  }
  if( fixed_huffman_literals_tree != NULL )
  {
    if( libewf_huffman_tree_free(
         &fixed_huffman_literals_tree,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
       "%s: unable to free fixed literals Huffman tree.",
       function );

      goto on_error;
    }
  }
  if( libewf_bit_stream_free(
       &bit_stream,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
     "%s: unable to free bit stream.",
     function );

    goto on_error;
  }
  *uncompressed_data_size = uncompressed_data_offset;

  return( 1 );

on_error:
  if( fixed_huffman_distances_tree != NULL )
  {
    libewf_huffman_tree_free(
     &fixed_huffman_distances_tree,
     NULL );
  }
  if( fixed_huffman_literals_tree != NULL )
  {
    libewf_huffman_tree_free(
     &fixed_huffman_literals_tree,
     NULL );
  }
  if( bit_stream != NULL )
  {
    libewf_bit_stream_free(
     &bit_stream,
     NULL );
  }
  return( -1 );
}

/* Decompresses data using zlib compression
 * Returns 1 on success or -1 on error
 */
int libewf_deflate_decompress_zlib(
     const uint8_t *compressed_data,
     size_t compressed_data_size,
     uint8_t *uncompressed_data,
     size_t *uncompressed_data_size,
     libcerror_error_t **error )
{
  libewf_bit_stream_t *bit_stream                     = NULL;
  libewf_huffman_tree_t *fixed_huffman_distances_tree = NULL;
  libewf_huffman_tree_t *fixed_huffman_literals_tree  = NULL;
  static char *function                               = "libewf_deflate_decompress_zlib";
  size_t compressed_data_offset                       = 0;
  size_t safe_uncompressed_data_size                  = 0;
  size_t uncompressed_data_offset                     = 0;
  uint32_t calculated_checksum                        = 0;
  uint32_t stored_checksum                            = 0;
  uint8_t block_type                                  = 0;
  uint8_t last_block_flag                             = 0;

  if( compressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid compressed data.",
     function );

    return( -1 );
  }
  if( compressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid compressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( uncompressed_data == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data.",
     function );

    return( -1 );
  }
  if( uncompressed_data_size == NULL )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
     "%s: invalid uncompressed data size.",
     function );

    return( -1 );
  }
  safe_uncompressed_data_size = *uncompressed_data_size;

  if( safe_uncompressed_data_size > (size_t) SSIZE_MAX )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
     "%s: invalid uncompressed data size value exceeds maximum.",
     function );

    return( -1 );
  }
  if( libewf_deflate_read_data_header(
       compressed_data,
       compressed_data_size,
       &compressed_data_offset,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_IO,
     LIBCERROR_IO_ERROR_READ_FAILED,
     "%s: unable to read data header.",
     function );

    goto on_error;
  }
  if( compressed_data_offset >= compressed_data_size )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
     LIBCERROR_ARGUMENT_ERROR_VALUE_TOO_SMALL,
     "%s: invalid compressed data value too small.",
     function );

    goto on_error;
  }
  if( libewf_bit_stream_initialize(
       &bit_stream,
       compressed_data,
       compressed_data_size,
       compressed_data_offset,
       LIBEWF_BIT_STREAM_STORAGE_TYPE_BYTE_BACK_TO_FRONT,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
     "%s: unable to create bit stream.",
     function );

    goto on_error;
  }
  while( bit_stream->byte_stream_offset < bit_stream->byte_stream_size )
  {
    if( libewf_deflate_read_block_header(
         bit_stream,
         &block_type,
         &last_block_flag,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_IO,
       LIBCERROR_IO_ERROR_READ_FAILED,
       "%s: unable to read compressed data block header.",
       function );

      goto on_error;
    }
    if( block_type == LIBEWF_DEFLATE_BLOCK_TYPE_HUFFMAN_FIXED )
    {
      if( ( fixed_huffman_literals_tree == NULL )
       && ( fixed_huffman_distances_tree == NULL ) )
      {
        if( libewf_huffman_tree_initialize(
             &fixed_huffman_literals_tree,
             288,
             15,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed literals Huffman tree.",
           function );

          goto on_error;
        }
        if( libewf_huffman_tree_initialize(
             &fixed_huffman_distances_tree,
             30,
             15,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed distances Huffman tree.",
           function );

          goto on_error;
        }
        if( libewf_deflate_build_fixed_huffman_trees(
             fixed_huffman_literals_tree,
             fixed_huffman_distances_tree,
             error ) != 1 )
        {
          libcerror_error_set(
           error,
           LIBCERROR_ERROR_DOMAIN_RUNTIME,
           LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
           "%s: unable to build fixed Huffman trees.",
           function );

          goto on_error;
        }
      }
    }
    if( libewf_deflate_read_block(
         bit_stream,
         block_type,
         fixed_huffman_literals_tree,
         fixed_huffman_distances_tree,
         uncompressed_data,
         safe_uncompressed_data_size,
         &uncompressed_data_offset,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_IO,
       LIBCERROR_IO_ERROR_READ_FAILED,
       "%s: unable to read block of compressed data.",
       function );

      goto on_error;
    }
    if( last_block_flag != 0 )
    {
      break;
    }
  }
  if( ( bit_stream->byte_stream_size - bit_stream->byte_stream_offset ) >= 4 )
  {
    while( bit_stream->bit_buffer_size >= 8 )
    {
      bit_stream->byte_stream_offset -= 1;
      bit_stream->bit_buffer_size    -= 8;
    }
    byte_stream_copy_to_uint32_big_endian(
     &( bit_stream->byte_stream[ bit_stream->byte_stream_offset ] ),
     stored_checksum );

    if( libewf_deflate_calculate_adler32(
         &calculated_checksum,
         uncompressed_data,
         uncompressed_data_offset,
         1,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_SET_FAILED,
       "%s: unable to calculate checksum.",
       function );

      goto on_error;
    }
    if( stored_checksum != calculated_checksum )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_INPUT,
       LIBCERROR_INPUT_ERROR_CHECKSUM_MISMATCH,
       "%s: checksum does not match (stored: 0x%08" PRIx32 ", calculated: 0x%08" PRIx32 ").",
       function,
       stored_checksum,
       calculated_checksum );

      goto on_error;
    }
  }
  if( fixed_huffman_distances_tree != NULL )
  {
    if( libewf_huffman_tree_free(
         &fixed_huffman_distances_tree,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
       "%s: unable to free fixed distances Huffman tree.",
       function );

      goto on_error;
    }
  }
  if( fixed_huffman_literals_tree != NULL )
  {
    if( libewf_huffman_tree_free(
         &fixed_huffman_literals_tree,
         error ) != 1 )
    {
      libcerror_error_set(
       error,
       LIBCERROR_ERROR_DOMAIN_RUNTIME,
       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
       "%s: unable to free fixed literals Huffman tree.",
       function );

      goto on_error;
    }
  }
  if( libewf_bit_stream_free(
       &bit_stream,
       error ) != 1 )
  {
    libcerror_error_set(
     error,
     LIBCERROR_ERROR_DOMAIN_RUNTIME,
     LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,
     "%s: unable to free bit stream.",
     function );

    goto on_error;
  }
  *uncompressed_data_size = uncompressed_data_offset;

  return( 1 );

on_error:
  if( fixed_huffman_distances_tree != NULL )
  {
    libewf_huffman_tree_free(
     &fixed_huffman_distances_tree,
     NULL );
  }
  if( fixed_huffman_literals_tree != NULL )
  {
    libewf_huffman_tree_free(
     &fixed_huffman_literals_tree,
     NULL );
  }
  if( bit_stream != NULL )
  {
    libewf_bit_stream_free(
     &bit_stream,
     NULL );
  }
  return( -1 );
}


Coverage Report

Created: 2026-08-31 07:43