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Disk ARchive
2.6.8
Full featured and portable backup and archiving tool
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this is a partial implementation of the generic_file interface to cypher/decypher data block by block. More...
#include <tronconneuse.hpp>
Inherits libdar::generic_file.
Inherited by libdar::crypto_sym.
Public Member Functions | |
tronconneuse (U_32 block_size, generic_file &encrypted_side, bool no_initial_shift, const archive_version &reading_ver) | |
This is the constructor. More... | |
tronconneuse (const tronconneuse &ref) | |
copy constructor | |
tronconneuse (tronconneuse &&ref) noexcept | |
move constructor | |
tronconneuse & | operator= (const tronconneuse &ref) |
assignment operator | |
tronconneuse & | operator= (tronconneuse &&ref) noexcept |
move operator | |
virtual | ~tronconneuse () override |
destructor | |
virtual bool | skippable (skippability direction, const infinint &amount) override |
inherited from generic_file | |
virtual bool | skip (const infinint &pos) override |
inherited from generic_file | |
virtual bool | skip_to_eof () override |
inherited from generic_file | |
virtual bool | skip_relative (S_I x) override |
inherited from generic_file | |
virtual infinint | get_position () const override |
inherited from generic_file | |
void | write_end_of_file () |
in write_only mode indicate that end of file is reached More... | |
void | set_initial_shift (const infinint &x) |
this method to modify the initial shift. This overrides the constructor "no_initial_shift" of the constructor | |
void | set_callback_trailing_clear_data (infinint(*call_back)(generic_file &below, const archive_version &reading_ver)) |
U_32 | get_clear_block_size () const |
returns the block size give to constructor | |
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generic_file (gf_mode m) | |
main constructor | |
generic_file (const generic_file &ref) | |
copy constructor | |
generic_file (generic_file &&ref) noexcept | |
move constructor | |
generic_file & | operator= (const generic_file &ref) |
assignment operator | |
generic_file & | operator= (generic_file &&ref) noexcept |
move operator | |
~generic_file () noexcept(false) | |
virtual destructor, More... | |
void | terminate () |
destructor-like call, except that it is allowed to throw exceptions | |
bool | operator== (generic_file &ref) |
bool | operator!= (generic_file &ref) |
gf_mode | get_mode () const |
retreive the openning mode for this object | |
void | read_ahead (const infinint &amount) |
void | ignore_read_ahead (bool mode) |
virtual U_I | read (char *a, U_I size) override |
read data from the generic_file inherited from proto_generic_file | |
virtual void | write (const char *a, U_I size) override |
write data to the generic_file inherited from proto_generic_file | |
void | write (const std::string &arg) |
write a string to the generic_file More... | |
S_I | read_back (char &a) |
skip back one char, read on char and skip back one char | |
S_I | read_forward (char &a) |
read one char | |
virtual void | copy_to (generic_file &ref) |
copy all data from current position to the object in argument | |
virtual void | copy_to (generic_file &ref, const infinint &crc_size, crc *&value) |
copy all data from the current position to the object in argument and computes a CRC value of the transmitted data More... | |
U_32 | copy_to (generic_file &ref, U_32 size) |
small copy (up to 4GB) with CRC calculation | |
infinint | copy_to (generic_file &ref, infinint size) |
copy the given amount to the object in argument | |
bool | diff (generic_file &f, const infinint &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value) |
compares the contents with the object in argument More... | |
bool | diff (generic_file &f, const infinint &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value, infinint &err_offset) |
void | reset_crc (const infinint &width) |
reset CRC on read or writen data More... | |
bool | crc_status () const |
to known whether CRC calculation is activated or not | |
crc * | get_crc () |
get CRC of the transfered date since last reset More... | |
void | sync_write () |
write any pending data | |
void | flush_read () |
be ready to read at current position, reseting all pending data for reading, cached and in compression engine for example | |
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proto_generic_file (const proto_generic_file &ref)=default | |
copy constructor | |
proto_generic_file (proto_generic_file &&ref) noexcept=default | |
move constructor | |
proto_generic_file & | operator= (const proto_generic_file &ref)=default |
assignment operator | |
proto_generic_file & | operator= (proto_generic_file &&ref) noexcept=default |
move operator | |
virtual | ~proto_generic_file () noexcept(false) |
virtual destructor More... | |
Protected Member Functions | |
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 More... | |
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 for encryption More... | |
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 More... | |
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 More... | |
const archive_version & | get_reading_version () const |
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void | set_mode (gf_mode x) |
bool | is_terminated () const |
Private Member Functions | |
virtual void | inherited_read_ahead (const infinint &amount) override |
inherited from generic_file More... | |
virtual U_I | inherited_read (char *a, U_I size) override |
this protected inherited method is now private for inherited classes of tronconneuse | |
virtual void | inherited_write (const char *a, U_I size) override |
inherited from generic_file More... | |
virtual void | inherited_sync_write () override |
this protected inherited method is now private for inherited classes of tronconneuse | |
virtual void | inherited_flush_read () override |
this protected inherited method is now private for inherited classes of tronconneuse | |
virtual void | inherited_terminate () override |
this protected inherited method is now private for inherited classes of tronconneuse | |
void | nullifyptr () noexcept |
void | detruit () noexcept |
void | copy_from (const tronconneuse &ref) |
void | move_from (tronconneuse &&ref) noexcept |
U_32 | fill_buf () |
returns the position (of the next read op) inside the buffer and fill the buffer with clear data | |
void | flush () |
flush any pending data (write mode only) to encrypted device | |
void | init_buf () |
initialize if necessary the various buffers that relies on inherited method values | |
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 More... | |
void | position_crypt2clear (const infinint &pos, infinint &clear_pos) |
bool | check_current_position () |
return true if a there is a byte of information at the given offset | |
void | remove_trailing_clear_data_from_encrypted_buf (const infinint &crypt_offset) |
Private Attributes | |
infinint | initial_shift |
the initial_shift first bytes of the underlying file are not encrypted | |
infinint | buf_offset |
offset of the first byte in buf | |
U_32 | buf_byte_data |
number of byte of information in buf (buf_byte_data <= buf_size) | |
U_32 | buf_size |
size of allocated memory for clear data in buf | |
char * | buf |
decrypted data (or data to encrypt) | |
U_32 | clear_block_size |
max amount of data that will be encrypted at once (must stay less than buf_size) | |
infinint | current_position |
position of the next character to read or write from the upper layer perspective, offset zero is the first encrypted byte, thus the first byte after initial_shift | |
infinint | block_num |
block number we next read or write | |
generic_file * | encrypted |
generic_file where is put / get the encrypted data | |
U_32 | encrypted_buf_size |
allocated size of encrypted_buf | |
U_32 | encrypted_buf_data |
amount of byte of information in encrypted_buf | |
char * | encrypted_buf |
buffer of encrypted data (read or to write) | |
infinint | extra_buf_offset |
offset of the first byte of extra_buf | |
U_32 | extra_buf_size |
allocated size of extra_buf | |
U_32 | extra_buf_data |
amount of byte of information in extra_buf | |
char * | extra_buf |
additional read encrypted that follow what is in encrypted_buf used to check for clear data after encrypted data | |
bool | weof |
whether write_end_of_file() has been called | |
bool | reof |
whether we reached eof while reading | |
archive_version | reading_ver |
archive format we currently read | |
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 | |
Additional Inherited Members | |
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enum | skippability { skip_backward, skip_forward } |
this is a partial implementation of the generic_file interface to cypher/decypher data block by block.
This class is a pure virtual one, as several calls have to be defined by inherited classes
tronconneuse is either read_only or write_only, read_write is not allowed. The openning mode is defined by encrypted_side's mode. In write_only no skip() is allowed, writing is sequential from the beginning of the file to the end (like writing to a pipe). In read_only all skip() functions are available.
Definition at line 58 of file tronconneuse.hpp.
libdar::tronconneuse::tronconneuse | ( | U_32 | block_size, |
generic_file & | encrypted_side, | ||
bool | no_initial_shift, | ||
const archive_version & | reading_ver | ||
) |
This is the constructor.
[in] | block_size | is the size of block encryption (the size of clear data encrypted toghether). |
[in] | encrypted_side | where encrypted data are read from or written to. |
[in] | no_initial_shift | assume that no unencrypted data is located at the begining of the underlying file, else this is the position of the encrypted_side at the time of this call that is used as initial_shift |
[in] | reading_ver | version of the archive format |
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protectedpure virtual |
it may be necessary by the inherited class have few more bytes allocated after the clear data given for encryption
[in] | clear_block_size | is the size in byte of the clear data that will be asked to encrypt. |
Implemented in libdar::crypto_sym.
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protectedpure virtual |
this method decyphers data
[in] | block_num | block number of the data to decrypt. |
[in] | crypt_buf | pointer to the first byte of encrypted data. |
[in] | crypt_size | size of encrypted data to decrypt. |
[in,out] | clear_buf | pointer where to put clear data. |
[in] | clear_size | allocated size of clear_buf. |
Implemented in libdar::crypto_sym.
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protectedpure virtual |
this method encrypts the clear data given
block_num | is the number of the block to which correspond the given data, This is an informational field for inherited classes. | |
[in] | clear_buf | points to the first byte of clear data to encrypt. |
[in] | clear_size | is the length in byte of data to encrypt. |
[in] | clear_allocated | is the size of the allocated memory (modifiable bytes) in clear_buf: clear_block_allocated_size_for(clear_size) |
[in,out] | crypt_buf | is the area where to put corresponding encrypted data. |
[in] | crypt_size | is the allocated memory size for crypt_buf: encrypted_block_size_for(clear_size) |
Implemented in libdar::crypto_sym.
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protectedpure virtual |
defines the size necessary to encrypt a given amount of clear data
[in] | clear_block_size | is the size of the clear block to encrypt. |
Implemented in libdar::crypto_sym.
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overrideprivatevirtual |
inherited from generic_file
this protected inherited method is now private for inherited classes of tronconneuse
Implements libdar::generic_file.
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overrideprivatevirtual |
inherited from generic_file
this protected inherited method is now private for inherited classes of tronconneuse
Implements libdar::generic_file.
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private |
convert clear position to corresponding position in the encrypted data
[in] | pos | is the position in the clear data |
[out] | file_buf_start | is the position of the beginning of the crypted block where can be found the data |
[out] | clear_buf_start | is the position of the beginning of the corresponding clear block |
[out] | pos_in_buf | is the position in the clear block of the 'pos' offset |
[out] | block_num | is the block number we have our requested position inside |
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private |
gives the position of the next character of clear data that corresponds to the encrypted data which index is pos
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private |
remove clear data at the end of the encrypted_buf
[in] | crypt_offset | is the offset of the first byte of encrypted_buf not considering initial_shift bytes before the begining of the encrypted data |
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inline |
let the caller give a callback function that given a generic_file with cyphered data, is able to return the offset of the first clear byte located after all the cyphered data, this callback function is used (if defined by the following method), when reaching End of File.
Definition at line 114 of file tronconneuse.hpp.
References trailing_clear_data.
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inline |
in write_only mode indicate that end of file is reached
this call must be called in write mode to purge the internal cache before deleting the object (else some data may be lost) no further write call is allowed
Definition at line 104 of file tronconneuse.hpp.
References libdar::generic_file::is_terminated().