Eet Data Serialization using A Ciphers

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Eet Data Serialization using A Ciphers
Eet » Eet Data Serialization

Most of the Eet Data Serialization have alternative versions that accounts for ciphers to protect their content. More...

## Functions
EAPI void * | eet_data_read_cipher (Eet_File *ef, Eet_Data_Descriptor *edd, const char *name, const char *cipher_key)
| Read a data structure from an eet file and decodes it using a cipher. More...
EAPI void * | eet_data_read_cipher_buffer (Eet_File *ef, Eet_Data_Descriptor *edd, const char *name, const char *cipher_key, char *buffer, int buffer_size)
| Read a data structure from an eet file and decodes it into a buffer using a cipher,. More...
EAPI void * | eet_data_xattr_cipher_get (const char *filename, const char *attribute, Eet_Data_Descriptor *edd, const char *cipher_key)
| Read a data structure from an eet extended attribute and decodes it using a cipher. More...
EAPI int | eet_data_write_cipher (Eet_File *ef, Eet_Data_Descriptor *edd, const char *name, const char *cipher_key, const void *data, int compress)
| Write a data structure from memory and store in an eet file using a cipher. More...
EAPI Eina_Bool | eet_data_xattr_cipher_set (const char *filename, const char *attribute, Eet_Data_Descriptor *edd, const char *cipher_key, const void *data, Eina_Xattr_Flags flags)
| Write a data structure from memory and store in an eet extended attribute using a cipher. More...
EAPI int | eet_data_text_dump_cipher (const void *data_in, const char *cipher_key, int size_in, Eet_Dump_Callback dumpfunc, void *dumpdata)
| Dump an eet encoded data structure into ascii text using a cipher. More...
EAPI void * | eet_data_text_undump_cipher (const char *text, const char *cipher_key, int textlen, int *size_ret)
| Take an ascii encoding from eet_data_text_dump() and re-encode in binary using a cipher. More...
EAPI int | eet_data_dump_cipher (Eet_File *ef, const char *name, const char *cipher_key, Eet_Dump_Callback dumpfunc, void *dumpdata)
| Dump an eet encoded data structure from an eet file into ascii text using a cipher. More...
EAPI int | eet_data_undump_cipher (Eet_File *ef, const char *name, const char *cipher_key, const char *text, int textlen, int compress)
| Take an ascii encoding from eet_data_dump() and re-encode in binary using a cipher. More...
EAPI void * | eet_data_descriptor_decode_cipher (Eet_Data_Descriptor *edd, const void *data_in, const char *cipher_key, int size_in)
| Decode a data structure from an arbitrary location in memory using a cipher. More...
EAPI void * | eet_data_descriptor_encode_cipher (Eet_Data_Descriptor *edd, const void *data_in, const char *cipher_key, int *size_ret)
| Encode a data struct to memory and return that encoded data using a cipher. More...

## Detailed Description

Most of the Eet Data Serialization have alternative versions that accounts for ciphers to protect their content.

See also
  Cipher, Identity and Protection Mechanisms

## Function Documentation

EAPI void* eet_data_read_cipher | ( | Eet_File * | ef,
|  | Eet_Data_Descriptor * | edd,
|  | const char * | name,
|  | const char * | cipher_key
| ) |  |

Read a data structure from an eet file and decodes it using a cipher.

Parameters

  ef | The eet file handle to read from.
  edd | The data descriptor handle to use when decoding.
  name | The key the data is stored under in the eet file.
  cipher_key | The key to use as cipher.

Returns
  A pointer to the decoded data structure.

This function decodes a data structure stored in an eet file, returning a pointer to it if it decoded successfully, or NULL on failure. This can save a programmer dozens of hours of work in writing configuration file parsing and writing code, as eet does all that work for the program and presents a program-friendly data structure, just as the programmer likes. Eet can handle members being added or deleted from the data in storage and safely zero-fills unfilled members if they were not found in the data. It checks sizes and headers whenever it reads data, allowing the programmer to not worry about corrupt data.

Once a data structure has been described by the programmer with the fields they wish to save or load, storing or retrieving a data structure from an eet file, or from a chunk of memory is as simple as a single function call.

See also
  eet_data_read()

Since
  1.0.0

References eet_dictionary_get(), eet_read_cipher(), and eet_read_direct().

Referenced by eet_data_read().

EAPI void* eet_data_read_cipher_buffer | ( | Eet_File * | ef,
|  | Eet_Data_Descriptor * | edd,
|  | const char * | name,
|  | const char * | cipher_key,
|  | char * | buffer,
|  | int | buffer_size
| ) |  |

Read a data structure from an eet file and decodes it into a buffer using a cipher,.

Parameters

  ef | The eet file handle to read from.
  edd | The data descriptor handle to use when decoding.
  name | The key the data is stored under in the eet file.
  cipher_key | The key to use as cipher.
  buffer | Buffer.
  buffer_size | The buffer size.

Returns
  A pointer to buffer if successful and NULL on error.

This function decodes a data structure stored in an eet file, returning a pointer to it if it decoded successfully, or NULL on failure. This can save a programmer dozens of hours of work in writing configuration file parsing and writing code, as eet does all that work for the program and presents a program-friendly data structure, just as the programmer likes. Eet can handle members being added or deleted from the data in storage and safely zero-fills unfilled members if they were not found in the data. It checks sizes and headers whenever it reads data, allowing the programmer to not worry about corrupt data.

Once a data structure has been described by the programmer with the fields they wish to save or load, storing or retrieving a data structure from an eet file, or from a chunk of memory is as simple as a single function call.

See also
  eet_data_read_cipher()

Since
  1.10.0

References eet_dictionary_get(), eet_read_cipher(), and eet_read_direct().

EAPI void* eet_data_xattr_cipher_get | ( | const char * | filename,
|  | const char * | attribute,
|  | Eet_Data_Descriptor * | edd,
|  | const char * | cipher_key
| ) |  |

Read a data structure from an eet extended attribute and decodes it using a cipher.

Parameters

  filename | The file to extract the extended attribute from.
  attribute | The attribute to get the data from.
  edd | The data descriptor handle to use when decoding.
  cipher_key | The key to use as cipher.

Returns
  A pointer to the decoded data structure.

This function decodes a data structure stored in an eet extended attribute, returning a pointer to it if it decoded successfully, or NULL on failure. Eet can handle members being added or deleted from the data in storage and safely zero-fills unfilled members if they were not found in the data. It checks sizes and headers whenever it reads data, allowing the programmer to not worry about corrupt data.

Once a data structure has been described by the programmer with the fields they wish to save or load, storing or retrieving a data structure from an eet file, from a chunk of memory or from an extended attribute is as simple as a single function call.

Since
  1.5.0

References eet_data_descriptor_decode_cipher(), and eina_xattr_get().

EAPI int eet_data_write_cipher | ( | Eet_File * | ef,
|  | Eet_Data_Descriptor * | edd,
|  | const char * | name,
|  | const char * | cipher_key,
|  | const void * | data,
|  | int | compress
| ) |  |

Write a data structure from memory and store in an eet file using a cipher.

Parameters

  ef | The eet file handle to write to.
  edd | The data descriptor to use when encoding.
  name | The key to store the data under in the eet file.
  cipher_key | The key to use as cipher.
  data | A pointer to the data structure to save and encode.
  compress | Compression flags for storage.

Returns
  bytes written on successful write, 0 on failure.

This function is the reverse of eet_data_read_cipher(), saving a data structure to an eet file.

Since
  1.0.0

References eet_dictionary_get(), and eet_write_cipher().

Referenced by eet_data_write().

EAPI Eina_Bool eet_data_xattr_cipher_set | ( | const char * | filename,
|  | const char * | attribute,
|  | Eet_Data_Descriptor * | edd,
|  | const char * | cipher_key,
|  | const void * | data,
|  | Eina_Xattr_Flags | flags
| ) |  |

Write a data structure from memory and store in an eet extended attribute using a cipher.

Parameters

  filename | The file to write the extended attribute to.
  attribute | The attribute to store the data to.
  edd | The data descriptor to use when encoding.
  cipher_key | The key to use as cipher.
  data | A pointer to the data structure to save and encode.
  flags | The policy to use when setting the data.

Returns
  EINA_TRUE on success, EINA_FALSE on failure.

This function is the reverse of eet_data_xattr_cipher_get(), saving a data structure to an eet extended attribute.

Since
  1.5.0

References eet_data_descriptor_encode_cipher(), EINA_FALSE, and eina_xattr_set().

EAPI int eet_data_text_dump_cipher | ( | const void * | data_in,
|  | const char * | cipher_key,
|  | int | size_in,
|  | Eet_Dump_Callback | dumpfunc,
|  | void * | dumpdata
| ) |  |

Dump an eet encoded data structure into ascii text using a cipher.

Parameters

  data_in | The pointer to the data to decode into a struct.
  cipher_key | The key to use as cipher.
  size_in | The size of the data pointed to in bytes.
  dumpfunc | The function to call passed a string when new data is converted to text
  dumpdata | The data to pass to the `dumpfunc` callback.

Returns
  1 on success, 0 on failure

This function will take a chunk of data encoded by eet_data_descriptor_encode() and convert it into human readable ascii text. It does this by calling the `dumpfunc` callback for all new text that is generated. This callback should append to any existing text buffer and will be passed the pointer `dumpdata` as a parameter as well as a string with new text to be appended.

Example:

1 void output(void *data, const char *string)
2 {
3 printf("%s", string);
4 }
5
6 void dump(const char *file)
7 {
8 FILE *f;
9 int len;
10 void *data;
11
12 f = fopen(file, "r");
13 fseek(f, 0, SEEK_END);
14 len = ftell(f);
15 rewind(f);
16 data = malloc(len);
17 fread(data, len, 1, f);
18 fclose(f);
19 eet_data_text_dump_cipher(data, cipher_key, len, output, NULL);
20 }

See also
  eet_data_text_dump()

Since
  1.0.0

References eet_node_del(), and eet_node_dump().

Referenced by eet_data_text_dump().

EAPI void* eet_data_text_undump_cipher | ( | const char * | text,
|  | const char * | cipher_key,
|  | int | textlen,
|  | int * | size_ret
| ) |  |

Take an ascii encoding from eet_data_text_dump() and re-encode in binary using a cipher.

Parameters

  text | The pointer to the string data to parse and encode.
  cipher_key | The key to use as cipher.
  textlen | The size of the string in bytes (not including 0 byte terminator).
  size_ret | This gets filled in with the encoded data blob size in bytes.

Returns
  The encoded data on success, NULL on failure.

This function will parse the string pointed to by `text` and return an encoded data lump the same way eet_data_descriptor_encode() takes an in-memory data struct and encodes into a binary blob. `text` is a normal C string.

See also
  eet_data_text_undump()

Since
  1.0.0

Referenced by eet_data_text_undump().

EAPI int eet_data_dump_cipher | ( | Eet_File * | ef,
|  | const char * | name,
|  | const char * | cipher_key,
|  | Eet_Dump_Callback | dumpfunc,
|  | void * | dumpdata
| ) |  |

Dump an eet encoded data structure from an eet file into ascii text using a cipher.

Parameters

  ef | A valid eet file handle.
  name | Name of the entry. eg: "/base/file_i_want".
  cipher_key | The key to use as cipher.
  dumpfunc | The function to call passed a string when new data is converted to text
  dumpdata | The data to pass to the `dumpfunc` callback.

Returns
  1 on success, 0 on failure

This function will take an open and valid eet file from eet_open() request the data encoded by eet_data_descriptor_encode() corresponding to the key `name` and convert it into human readable ascii text. It does this by calling the `dumpfunc` callback for all new text that is generated. This callback should append to any existing text buffer and will be passed the pointer `dumpdata` as a parameter as well as a string with new text to be appended.

See also
  eet_data_dump()

Since
  1.0.0

References eet_dictionary_get(), eet_node_del(), eet_node_dump(), eet_read_cipher(), and eet_read_direct().

Referenced by eet_data_dump().

EAPI int eet_data_undump_cipher | ( | Eet_File * | ef,
|  | const char * | name,
|  | const char * | cipher_key,
|  | const char * | text,
|  | int | textlen,
|  | int | compress
| ) |  |

Take an ascii encoding from eet_data_dump() and re-encode in binary using a cipher.

Parameters

  ef | A valid eet file handle.
  name | Name of the entry. eg: "/base/file_i_want".
  cipher_key | The key to use as cipher.
  text | The pointer to the string data to parse and encode.
  textlen | The size of the string in bytes (not including 0 byte terminator).
  compress | Compression flags (1 == compress, 0 = don't compress).

Returns
  1 on success, 0 on failure

This function will parse the string pointed to by `text`, encode it the same way eet_data_descriptor_encode() takes an in-memory data struct and encodes into a binary blob.

The data (optionally compressed) will be in ram, pending a flush to disk (it will stay in ram till the eet file handle is closed though).

See also
  eet_data_undump()

Since
  1.0.0

References eet_dictionary_get(), and eet_write_cipher().

Referenced by eet_data_undump().

EAPI void* eet_data_descriptor_decode_cipher | ( | Eet_Data_Descriptor * | edd,
|  | const void * | data_in,
|  | const char * | cipher_key,
|  | int | size_in
| ) |  |

Decode a data structure from an arbitrary location in memory using a cipher.

Parameters

  edd | The data descriptor to use when decoding.
  data_in | The pointer to the data to decode into a struct.
  cipher_key | The key to use as cipher.
  size_in | The size of the data pointed to in bytes.

Returns
  NULL on failure, or a valid decoded struct pointer on success.

This function will decode a data structure that has been encoded using eet_data_descriptor_encode(), and return a data structure with all its elements filled out, if successful, or NULL on failure.

The data to be decoded is stored at the memory pointed to by `data_in`, and is described by the descriptor pointed to by `edd`. The data size is passed in as the value to `size_in`, ande must be greater than 0 to succeed.

This function is useful for decoding data structures delivered to the application by means other than an eet file, such as an IPC or socket connection, raw files, shared memory etc.

Please see eet_data_read() for more information.

See also
  eet_data_descriptor_decode()

Since
  1.0.0

Referenced by eet_data_descriptor_decode(), and eet_data_xattr_cipher_get().

EAPI void* eet_data_descriptor_encode_cipher | ( | Eet_Data_Descriptor * | edd,
|  | const void * | data_in,
|  | const char * | cipher_key,
|  | int * | size_ret
| ) |  |

Encode a data struct to memory and return that encoded data using a cipher.

Parameters

  edd | The data descriptor to use when encoding.
  data_in | The pointer to the struct to encode into data.
  cipher_key | The key to use as cipher.
  size_ret | pointer to the an int to be filled with the decoded size.

Returns
  NULL on failure, or a valid encoded data chunk on success.

This function takes a data structutre in memory and encodes it into a serialised chunk of data that can be decoded again by eet_data_descriptor_decode(). This is useful for being able to transmit data structures across sockets, pipes, IPC or shared file mechanisms, without having to worry about memory space, machine type, endianess etc.

The parameter `edd` must point to a valid data descriptor, and `data_in` must point to the right data structure to encode. If not, the encoding may fail.

On success a non NULL valid pointer is returned and what `size_ret` points to is set to the size of this decoded data, in bytes. When the encoded data is no longer needed, call free() on it. On failure NULL is returned and what `size_ret` points to is set to 0.

Please see eet_data_write() for more information.

See also
  eet_data_descriptor_encode()

Since
  1.0.0

Referenced by eet_connection_send(), eet_data_descriptor_encode(), and eet_data_xattr_cipher_set().