Disk ARchive  2.6.8
Full featured and portable backup and archiving tool
secu_string.hpp
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2 // dar - disk archive - a backup/restoration program
3 // Copyright (C) 2002-2020 Denis Corbin
4 //
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21 
31 
32 #ifndef SECU_STRING_HPP
33 #define SECU_STRING_HPP
34 
35 #include "../my_config.h"
36 
37 #include <string>
38 #include "integers.hpp"
39 #include "erreurs.hpp"
40 
41 namespace libdar
42 {
43 
46 
48 
56 
58  {
59  public:
61 
66  static bool is_string_secured();
67 
69 
72  secu_string(U_I storage_size = 0) { init(storage_size); };
73 
75 
77  secu_string(const char *ptr, U_I size) { init(size); append_at(0, ptr, size); };
78 
80  secu_string(const secu_string & ref) { copy_from(ref); };
81 
83  secu_string(secu_string && ref) noexcept { nullifyptr(); move_from(std::move(ref)); };
84 
86  secu_string & operator = (const secu_string & ref) { clean_and_destroy(); copy_from(ref); return *this; };
87 
89  secu_string & operator = (secu_string && ref) noexcept { move_from(std::move(ref)); return *this; };
90 
92  ~secu_string() noexcept(false) { clean_and_destroy(); };
93 
94 
95  bool operator != (const std::string & ref) const { return ! (*this == ref); };
96  bool operator != (const secu_string & ref) const { return ! (*this == ref); };
97  bool operator == (const std::string &ref) const { return compare_with(ref.c_str(),(U_I)(ref.size())); };
98  bool operator == (const secu_string &ref) const { return compare_with(ref.mem, *(ref.string_size)); };
99 
100 
102 
108  void set(int fd, U_I size);
109 
111 
119  void append_at(U_I offset, const char *ptr, U_I size);
120 
122  void append_at(U_I offset, int fd, U_I size);
123 
125  void append(const char *ptr, U_I size) { append_at(*string_size, ptr, size); };
126 
128  void append(int fd, U_I size) { append_at(*string_size, fd, size); };
129 
133  void reduce_string_size_to(U_I pos);
134 
136  void clear() { *string_size = 0; };
137 
139 
141  void resize(U_I size) { clean_and_destroy(); init(size); };
142 
144 
146  void randomize(U_I size);
147 
149 
152  const char*c_str() const { return mem == nullptr ? throw SRC_BUG : mem; };
153 
155  char * get_array() { return mem == nullptr ? throw SRC_BUG : mem; };
156 
158 
160  char & operator[] (U_I index);
161  char operator[](U_I index) const { return (const_cast<secu_string *>(this))->operator[](index); };
162 
164  U_I get_size() const { if(string_size == nullptr) throw SRC_BUG; return *string_size; }; // returns the size of the string
165 
167  bool empty() const { if(string_size == nullptr) throw SRC_BUG; return *string_size == 0; };
168 
170  U_I get_allocated_size() const { return *allocated_size - 1; };
171 
172  private:
173  U_I *allocated_size;
174  char *mem;
175  U_I *string_size;
176 
177  void nullifyptr() noexcept { allocated_size = string_size = nullptr; mem = nullptr; };
178  void init(U_I size); //< to be used at creation time or after clean_and_destroy() only
179  void copy_from(const secu_string & ref); //< to be used at creation time or after clean_and_destroy() only
180  void move_from(secu_string && ref) noexcept { std::swap(allocated_size, ref.allocated_size); std::swap(mem, ref.mem); std::swap(string_size, ref.string_size); };
181  bool compare_with(const char *ptr, U_I size) const; // return true if given sequence is the same as the one stored in "this"
182  void clean_and_destroy();
183  };
184 
186 
187 } // end of namespace
188 
189 #endif
libdar::secu_string::randomize
void randomize(U_I size)
set the string to randomize string of given size
libdar::secu_string::append
void append(const char *ptr, U_I size)
append some data at the end of the string
Definition: secu_string.hpp:125
libdar::secu_string::get_allocated_size
U_I get_allocated_size() const
get the size of the allocated secure space
Definition: secu_string.hpp:170
libdar::secu_string::empty
bool empty() const
tell whether string is empty
Definition: secu_string.hpp:167
integers.hpp
are defined here basic integer types that tend to be portable
libdar::secu_string::c_str
const char * c_str() const
get access to the secure string
Definition: secu_string.hpp:152
libdar::secu_string::append
void append(int fd, U_I size)
append some data at the end of the string
Definition: secu_string.hpp:128
libdar::secu_string::reduce_string_size_to
void reduce_string_size_to(U_I pos)
libdar::secu_string::operator=
secu_string & operator=(const secu_string &ref)
the assignment operator
Definition: secu_string.hpp:86
libdar::secu_string::secu_string
secu_string(const secu_string &ref)
the copy constructor
Definition: secu_string.hpp:80
erreurs.hpp
contains all the excetion class thrown by libdar
libdar::secu_string::get_size
U_I get_size() const
get the size of the string
Definition: secu_string.hpp:164
libdar::secu_string::operator[]
char & operator[](U_I index)
get access to the secure string by index
libdar::secu_string::set
void set(int fd, U_I size)
fill the object with data
libdar::secu_string::resize
void resize(U_I size)
clear and resize the string to the defined allocated size
Definition: secu_string.hpp:141
libdar::secu_string::is_string_secured
static bool is_string_secured()
to know if secure memory is available
libdar::secu_string::clear
void clear()
clear the string (set to an empty string)
Definition: secu_string.hpp:136
libdar::secu_string::secu_string
secu_string(U_I storage_size=0)
constructor 1
Definition: secu_string.hpp:72
libdar::secu_string::~secu_string
~secu_string() noexcept(false)
the destructor (set memory to zero before releasing it)
Definition: secu_string.hpp:92
libdar::secu_string
class secu_string
Definition: secu_string.hpp:57
libdar::secu_string::append_at
void append_at(U_I offset, const char *ptr, U_I size)
append some data to the string at a given offset
libdar::secu_string::secu_string
secu_string(const char *ptr, U_I size)
constructor 2
Definition: secu_string.hpp:77
libdar::secu_string::get_array
char * get_array()
non constant flavor of direct secure memory access
Definition: secu_string.hpp:155
libdar::secu_string::secu_string
secu_string(secu_string &&ref) noexcept
the move constructor
Definition: secu_string.hpp:83
libdar
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:46