Disk ARchive  2.6.8
Full featured and portable backup and archiving tool
scrambler.hpp
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2 // dar - disk archive - a backup/restoration program
3 // Copyright (C) 2002-2020 Denis Corbin
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21 
25 
26 #ifndef SCRAMBLER_HPP
27 #define SCRAMBLER_HPP
28 
29 #include "../my_config.h"
30 #include <string>
31 #include "infinint.hpp"
32 #include "generic_file.hpp"
33 #include "erreurs.hpp"
34 #include "secu_string.hpp"
35 
36 namespace libdar
37 {
38 
41 
42 
44 
45  class scrambler : public generic_file
46  {
47  public:
48  scrambler(const secu_string & pass, generic_file & hidden_side);
49  scrambler(const scrambler & ref) = delete;
50  scrambler(scrambler && ref) noexcept = delete;
51  scrambler & operator = (const scrambler & ref) = delete;
52  scrambler & operator = (scrambler && ref) noexcept = delete;
53  ~scrambler() { if(buffer != nullptr) delete [] buffer; };
54 
55 
56  virtual bool skippable(skippability direction, const infinint & amount) override { return ref->skippable(direction, amount); };
57  virtual bool skip(const infinint & pos) override { if(ref == nullptr) throw SRC_BUG; return ref->skip(pos); };
58  virtual bool skip_to_eof() override { if(ref==nullptr) throw SRC_BUG; return ref->skip_to_eof(); };
59  virtual bool skip_relative(S_I x) override { if(ref == nullptr) throw SRC_BUG; return ref->skip_relative(x); };
60  virtual infinint get_position() const override { if(ref == nullptr) throw SRC_BUG; return ref->get_position(); };
61 
62  protected:
63  virtual void inherited_read_ahead(const infinint & amount) override { ref->read_ahead(amount); };
64  virtual U_I inherited_read(char *a, U_I size) override;
65  virtual void inherited_write(const char *a, U_I size) override;
66  virtual void inherited_sync_write() override {}; // nothing to do
67  virtual void inherited_flush_read() override {}; // nothing to do
68  virtual void inherited_terminate() override {}; // nothing to do
69 
70  private:
71  secu_string key;
72  U_I len;
73  generic_file *ref;
74  unsigned char *buffer;
75  U_I buf_size;
76  };
77 
79 
80 } // end of namespace
81 
82 #endif
libdar::scrambler::inherited_read
virtual U_I inherited_read(char *a, U_I size) override
implementation of read() operation
libdar::scrambler
scrambler is a very weak encryption scheme
Definition: scrambler.hpp:45
infinint.hpp
switch module to limitint (32 ou 64 bits integers) or infinint
libdar::infinint
the arbitrary large positive integer class
Definition: real_infinint.hpp:61
libdar::scrambler::skip
virtual bool skip(const infinint &pos) override
skip at the absolute position
Definition: scrambler.hpp:57
libdar::scrambler::skip_relative
virtual bool skip_relative(S_I x) override
skip relatively to the current position
Definition: scrambler.hpp:59
libdar::scrambler::inherited_sync_write
virtual void inherited_sync_write() override
write down any pending data
Definition: scrambler.hpp:66
libdar::scrambler::skippable
virtual bool skippable(skippability direction, const infinint &amount) override
whether the implementation is able to skip
Definition: scrambler.hpp:56
generic_file.hpp
class generic_file is defined here as well as class fichier
erreurs.hpp
contains all the excetion class thrown by libdar
libdar::scrambler::inherited_terminate
virtual void inherited_terminate() override
destructor-like call, except that it is allowed to throw exceptions
Definition: scrambler.hpp:68
libdar::scrambler::inherited_write
virtual void inherited_write(const char *a, U_I size) override
implementation of the write() operation
secu_string.hpp
this file contains the definition of secu_string class, a std::string like class but allocated in sec...
libdar::generic_file::read_ahead
void read_ahead(const infinint &amount)
libdar::generic_file
this is the interface class from which all other data transfer classes inherit
Definition: generic_file.hpp:76
libdar::secu_string
class secu_string
Definition: secu_string.hpp:57
libdar::scrambler::inherited_flush_read
virtual void inherited_flush_read() override
reset internal engine, flush caches in order to read the data at current position
Definition: scrambler.hpp:67
libdar::scrambler::inherited_read_ahead
virtual void inherited_read_ahead(const infinint &amount) override
tells the object that several calls to read() will follow to probably obtain at least the given amoun...
Definition: scrambler.hpp:63
libdar::scrambler::get_position
virtual infinint get_position() const override
get the current read/write position
Definition: scrambler.hpp:60
libdar
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:46
libdar::scrambler::skip_to_eof
virtual bool skip_to_eof() override
skip to the end of file
Definition: scrambler.hpp:58