Disk ARchive  2.6.1
Full featured and portable backup and archiving tool
tronconneuse.hpp
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1 /*********************************************************************/
2 // dar - disk archive - a backup/restoration program
3 // Copyright (C) 2002-2019 Denis Corbin
4 //
5 // This program is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU General Public License
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9 //
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13 // GNU General Public License for more details.
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17 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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19 // to contact the author : http://dar.linux.free.fr/email.html
20 /*********************************************************************/
21 
27 
28 #ifndef TRONCONNEUSE_HPP
29 #define TRONCONNEUSE_HPP
30 
31 #include "../my_config.h"
32 #include <string>
33 
34 #include "infinint.hpp"
35 #include "generic_file.hpp"
36 #include "archive_version.hpp"
37 
38 namespace libdar
39 {
40 
43 
44 
46 
58  class tronconneuse : public generic_file
59  {
60  public:
62 
70  tronconneuse(U_32 block_size, generic_file & encrypted_side, bool no_initial_shift, const archive_version & reading_ver);
71 
73  tronconneuse(const tronconneuse & ref) : generic_file(ref) { copy_from(ref); };
74 
76  tronconneuse(tronconneuse && ref) noexcept: generic_file(std::move(ref)) { nullifyptr(); move_from(std::move(ref)); };
77 
79  tronconneuse & operator = (const tronconneuse & ref);
80 
82  tronconneuse & operator = (tronconneuse && ref) noexcept { generic_file::operator = (std::move(ref)); move_from(std::move(ref)); return *this; };
83 
85  virtual ~tronconneuse() override { detruit(); }; // must not write pure virtual method from here, directly or not
86 
88  virtual bool skippable(skippability direction, const infinint & amount) override;
90  virtual bool skip(const infinint & pos) override;
92  virtual bool skip_to_eof() override;
94  virtual bool skip_relative(S_I x) override;
96  virtual infinint get_position() const override { if(is_terminated()) throw SRC_BUG; return current_position; };
97 
99 
104  void write_end_of_file() { if(is_terminated()) throw SRC_BUG; flush(); weof = true; };
105 
106 
108 
109  void set_initial_shift(const infinint & x) { initial_shift = x; };
110 
114  void set_callback_trailing_clear_data(infinint (*call_back)(generic_file & below, const archive_version & reading_ver)) { trailing_clear_data = call_back; };
115 
117  U_32 get_clear_block_size() const { return clear_block_size; };
118 
119  private:
120 
122 
124  virtual void inherited_read_ahead(const infinint & amount) override;
125 
127  virtual U_I inherited_read(char *a, U_I size) override;
128 
130 
132  virtual void inherited_write(const char *a, U_I size) override;
133 
135  virtual void inherited_sync_write() override { flush(); };
136 
138  virtual void inherited_flush_read() override { buf_byte_data = 0; };
139 
141  virtual void inherited_terminate() override {};
142 
143  protected:
145 
151  virtual U_32 encrypted_block_size_for(U_32 clear_block_size) = 0;
152 
154 
161  virtual U_32 clear_block_allocated_size_for(U_32 clear_block_size) = 0;
162 
164 
173  virtual U_32 encrypt_data(const infinint & block_num,
174  const char *clear_buf, const U_32 clear_size, const U_32 clear_allocated,
175  char *crypt_buf, U_32 crypt_size) = 0;
176 
178 
185  virtual U_32 decrypt_data(const infinint & block_num,
186  const char *crypt_buf, const U_32 crypt_size,
187  char *clear_buf, U_32 clear_size) = 0;
188 
189  protected:
190  const archive_version & get_reading_version() const { return reading_ver; };
191 
192 
193  private:
195  //
198  U_32 buf_size;
199  char *buf;
200  //
205  //
209  //
213  char *extra_buf;
214  //
215  bool weof;
216  bool reof;
219 
220 
221  void nullifyptr() noexcept;
222  void detruit() noexcept;
223  void copy_from(const tronconneuse & ref);
224  void move_from(tronconneuse && ref) noexcept;
225  U_32 fill_buf();
226  void flush();
227  void init_buf();
228 
229 
231 
237  void position_clear2crypt(const infinint & pos,
238  infinint & file_buf_start,
239  infinint & clear_buf_start,
240  infinint & pos_in_buf,
241  infinint & block_num);
242 
245  void position_crypt2clear(const infinint & pos, infinint & clear_pos);
246 
249 
253  void remove_trailing_clear_data_from_encrypted_buf(const infinint & crypt_offset);
254 
255  };
256 
258 
259 } // end of namespace
260 
261 #endif
infinint buf_offset
offset of the first byte in buf
virtual void inherited_flush_read() override
this protected inherited method is now private for inherited classes of tronconneuse ...
bool check_current_position()
return true if a there is a byte of information at the given offset
void set_initial_shift(const infinint &x)
this method to modify the initial shift. This overrides the constructor "no_initial_shift" of the con...
virtual infinint get_position() const override
inherited from generic_file
virtual void inherited_write(const char *a, U_I size) override
inherited from generic_file
virtual bool skip_relative(S_I x) override
inherited from generic_file
void set_callback_trailing_clear_data(infinint(*call_back)(generic_file &below, const archive_version &reading_ver))
void position_crypt2clear(const infinint &pos, infinint &clear_pos)
virtual void inherited_terminate() override
this protected inherited method is now private for inherited classes of tronconneuse ...
this is a partial implementation of the generic_file interface to cypher/decypher data block by block...
virtual U_32 encrypt_data(const infinint &block_num, const char *clear_buf, const U_32 clear_size, const U_32 clear_allocated, char *crypt_buf, U_32 crypt_size)=0
this method encrypts the clear data given
class generic_file is defined here as well as class fichierthe generic_file interface is widely used ...
virtual void inherited_read_ahead(const infinint &amount) override
inherited from generic_file
bool weof
whether write_end_of_file() has been called
U_32 clear_block_size
max amount of data that will be encrypted at once (must stay less than buf_size)
virtual ~tronconneuse() override
destructor
U_32 get_clear_block_size() const
returns the block size give to constructor
tronconneuse(tronconneuse &&ref) noexcept
move constructor
infinint initial_shift
the initial_shift first bytes of the underlying file are not encrypted
U_32 buf_byte_data
number of byte of information in buf (buf_byte_data <= buf_size)
void write_end_of_file()
in write_only mode indicate that end of file is reached
infinint block_num
block number we next read or write
char * buf
decrypted data (or data to encrypt)
infinint current_position
position of the next character to read or write from the upper layer perspective, offset zero is the ...
generic_file * encrypted
generic_file where is put / get the encrypted data
virtual U_I inherited_read(char *a, U_I size) override
this protected inherited method is now private for inherited classes of tronconneuse ...
generic_file & operator=(const generic_file &ref)
assignment operator
virtual U_32 clear_block_allocated_size_for(U_32 clear_block_size)=0
it may be necessary by the inherited class have few more bytes allocated after the clear data given f...
U_32 extra_buf_size
allocated size of extra_buf
virtual U_32 encrypted_block_size_for(U_32 clear_block_size)=0
defines the size necessary to encrypt a given amount of clear data
infinint extra_buf_offset
offset of the first byte of extra_buf
archive_version reading_ver
archive format we currently read
virtual U_32 decrypt_data(const infinint &block_num, const char *crypt_buf, const U_32 crypt_size, char *clear_buf, U_32 clear_size)=0
this method decyphers data
generic_file(gf_mode m)
main constructor
void remove_trailing_clear_data_from_encrypted_buf(const infinint &crypt_offset)
bool is_terminated() const
tronconneuse & operator=(const tronconneuse &ref)
assignment operator
tronconneuse(U_32 block_size, generic_file &encrypted_side, bool no_initial_shift, const archive_version &reading_ver)
This is the constructor.
switch module to limitint (32 ou 64 bits integers) or infinint
void position_clear2crypt(const infinint &pos, infinint &file_buf_start, infinint &clear_buf_start, infinint &pos_in_buf, infinint &block_num)
convert clear position to corresponding position in the encrypted data
this is the interface class from which all other data transfer classes inherit
U_32 encrypted_buf_size
allocated size of encrypted_buf
virtual bool skip_to_eof() override
inherited from generic_file
U_32 fill_buf()
returns the position (of the next read op) inside the buffer and fill the buffer with clear data ...
U_32 buf_size
size of allocated memory for clear data in buf
class archive_version that rules which archive format to follow
infinint(* trailing_clear_data)(generic_file &below, const archive_version &reading_ver)
callback function that gives the amount of clear data found at the end of the given file ...
void init_buf()
initialize if necessary the various buffers that relies on inherited method values ...
the arbitrary large positive integer class
virtual bool skippable(skippability direction, const infinint &amount) override
inherited from generic_file
class archive_version manages the version of the archive format
U_32 extra_buf_data
amount of byte of information in extra_buf
bool reof
whether we reached eof while reading
char * extra_buf
additional read encrypted that follow what is in encrypted_buf used to check for clear data after enc...
tronconneuse(const tronconneuse &ref)
copy constructor
U_32 encrypted_buf_data
amount of byte of information in encrypted_buf
void flush()
flush any pending data (write mode only) to encrypted device
virtual bool skip(const infinint &pos) override
inherited from generic_file
char * encrypted_buf
buffer of encrypted data (read or to write)
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:46
virtual void inherited_sync_write() override
this protected inherited method is now private for inherited classes of tronconneuse ...