LibCapy - feistelCipher

Feistel ciphering class.

Macros:

Definition of the round function parent class. Round functions passed to CapyFeistelCipher methods must inherits this class. It has a dummy 'run' method for test purpose (which simply xor its input with the key). The inheriting class should replace it with its own round function in its constructor. The 'run' method is called by CapyFeistelCipher at each round with arguments: key: a null terminated string, the key to be used by the round function block: the block of data to which apply the round function sizeData: the size in byte of the block of data output: the adress in memory where to write the output of the round function (must be already allocated and have same size as 'block')

Enumerations:

Operation modes of the Feistel network

Typedefs:

Typedef for the keys

Typedef for the list of keys

Round function parent class

Type of the counter for CTR mode

Struct CapyFeistelCipher :

Struct CapyFeistelCipher's properties:

Operation mode

Initialisation vector

Counter for CTR mode

Struct CapyFeistelCipher's methods:

Destructor

Cipher function

Input argument(s):

roundFun: the round function used to cipher
keys: the keys used to cipher, a list of null terminated strings
data: the data to cipher

Output and side effect(s):

Return a newly allocated array of 'sizeData' bytes containing the ciphered data. Exceptions: May raise CapyExc_MallocFailed

Decipher function

Input argument(s):

roundFun: the round function used to decipher
keys: the keys used to decipher, a list of null terminated strings
data: the data to decipher

Output and side effect(s):

Return a newly allocated array of 'sizeData' bytes containing the deciphered data. Exceptions: May raise CapyExc_MallocFailed

Set the initialisation vector for CBC and CTR mode

Input argument(s):

initVector, the initialisation vector Exceptions: May raise CapyExc_MallocFailed

Functions:

Create a CapyFeistelRoundFun

Output and side effect(s):

Return a CapyFeistelRoundFun

Create a CapyFeistelCipher

Input argument(s):

opMode: operation mode

Output and side effect(s):

Return a CapyFeistelCipher

Exception(s):

May raise CapyExc_MallocFailed, CapyExc_UndefinedExecution.

Allocate memory for a new CapyFeistelCipher and create it

Input argument(s):

opMode: operation mode

Output and side effect(s):

Return a CapyFeistelCipher

Exception(s):

May raise CapyExc_MallocFailed, CapyExc_UndefinedExecution.

Free the memory used by a CapyFeistelCipher* and reset '*that' to NULL

Input argument(s):

that: a pointer to the CapyFeistelCipher to free

2021-11-08
in LibCapy,
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