rnc.h

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/* This file is part of LibT2FS.
 *
 * LibT2FS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LibT2FS 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 General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef H_T2FS_RNC
#define H_T2FS_RNC
 
#include <stdint.h>
 
#define RNC_SIGN 0x524E43 // RNC
#define RNC_HEADER_SIZE 0x12
 
typedef enum e_RNCStatus {
  RNC_OK           =  0, // success
  RNC_ERR_INPUT    =  4, // input crc mismatch
  RNC_ERR_CRC      =  5, // crc mismatch
  RNC_ERR_HEADER   =  6, // invalid RNC header
  RNC_ERR_NEED_KEY = 10, // decryption key needed
  RNC_ERR_EOMEM    = 16  // out of mem
} RNCStatus;
 
 
#pragma pack(push, 1)
typedef struct s_rncHuftable {
  uint32_t l1; // +0
  uint16_t l2; // +4
  uint32_t l3; // +6
  uint16_t bit_depth; // +A
} t_rncHuftable;
#pragma pack(pop)
 
 
typedef struct s_rnc {
  // user input
  uint16_t enc_key;
  uint8_t *input; // user given, do not free
  uint32_t input_size;
 
  // read from input buffer
  uint32_t method;
  uint32_t decompressed_size;
  uint32_t compressed_size;
  uint16_t unpacked_crc;
  uint16_t packed_crc;
  uint32_t leeway;
  uint32_t chunks_count;
 
  // inner
  uint32_t processed_size;
  uint16_t bit_count;
  uint16_t match_count;
  uint16_t match_offset;
  uint32_t bit_buffer;
 
  uint32_t unpacked_size;
  uint32_t rnc_data_size;
  uint16_t unpacked_crc_real;
 
  uint8_t *mem1; // allocated to heap, do free
  uint8_t *pack_block_start; // pointer to allocated heap, do not free
 
  uint8_t *decoded; // allocated to heap, do free
  uint8_t *window; // pointer to allocated heap, do not free
 
  size_t read_start_offset;
 
  // we allocate this on rnc_decompress_buf(), do only free on error,
  // else user is responsible..
  uint8_t *output;
  size_t input_offset, output_offset;
 
  t_rncHuftable raw_table[16];
  t_rncHuftable pos_table[16];
  t_rncHuftable len_table[16];
 
  // header reading endianess handling
  uint32_t (*read_dword)(uint8_t *, size_t *);
  uint16_t (*read_word)(uint8_t *, size_t *);
} t_rnc;
 
 
RNCStatus
rnc_init(t_rnc *rnc);
 
 
void
rnc_free(t_rnc *rnc);
 
 
void
rnc_set_be(t_rnc *rnc);
 
 
RNCStatus
rnc_decompress_buf(t_rnc *rnc,
                   uint8_t *const input, const size_t input_size,
                   uint8_t **outbuf, size_t *outbufSize);
 
#endif