Data Encryption Standard (DES)

See Quick start guide for XMEGA DES driver.

This is a driver for the AVR XMEGA DES core instruction. It provides functions for des, 3des and CBC des encryption and decryption operations.

DES Start Setting

DES is supported by a DES instruction in the AVR XMEGA core. The 8-byte key and 8-byte data blocks must be loaded into the Register file, and then DES must be executed 16 times to encrypt/decrypt the data block.

Note

The functions for loading configurations/data/key are not protected against interrupts.

start guide

See Quick start guide for XMEGA DES driver

Modules
	Related Project(s)
	In this section you can find all the projects related to the Data Encryption Standard (DES).
	Quick Start Guide(s)
	In this section you can find a list of all Quick Start guides related to the Data Encryption Standard (DES).

Functions
void	des_3des_decrypt (uint8_t *ciphertext, uint8_t *plaintext, uint8_t *keys)
	Function that does a 3DES decryption on one 64-bit data block. More...
void	des_3des_encrypt (uint8_t *plaintext, uint8_t *ciphertext, uint8_t *keys)
	Function that does a 3DES encryption on one 64-bit data block. More...
void	des_cbc_decrypt (uint8_t *ciphertext, uint8_t *plaintext, uint8_t *keys, uint8_t *init, bool triple_DES, uint16_t block_length)
	Function that does DES Cipher Block Chaining decryption on a given number of 64-bit data block. More...
void	des_cbc_encrypt (uint8_t *plaintext, uint8_t *ciphertext, uint8_t *keys, uint8_t *init, bool triple_DES, uint16_t block_length)
	Function that does DES Cipher Block Chaining encryption on a given number of 64-bit data block. More...
void	des_decrypt (uint8_t *ciphertext, uint8_t *plaintext, uint8_t *key)
	Function that does a DES decryption on one 64-bit data block. More...
void	des_encrypt (uint8_t *plaintext, uint8_t *ciphertext, uint8_t *key)
	Function that does a DES encryption on one 64-bit data block. More...

void des_3des_decrypt	(	uint8_t *	ciphertext,
		uint8_t *	plaintext,
		uint8_t *	keys
	)

Function that does a 3DES decryption on one 64-bit data block.

Parameters

ciphertext	Pointer to the ciphertext that shall be decrypted.
plaintext	Pointer to where in memory the plaintext (answer) shall be stored.
keys	Pointer to the array of the 3 DES keys.

Referenced by main(), run_3des_decryption(), and run_3des_encryption_and_decryption_test().

void des_3des_encrypt	(	uint8_t *	plaintext,
		uint8_t *	ciphertext,
		uint8_t *	keys
	)

Function that does a 3DES encryption on one 64-bit data block.

Parameters

plaintext	Pointer to the plaintext that shall be encrypted.
ciphertext	Pointer to where in memory the ciphertext (answer) shall be stored.
keys	Pointer to the array of the 3 DES keys.

Referenced by main(), run_3des_encryption(), and run_3des_encryption_and_decryption_test().

void des_cbc_decrypt	(	uint8_t *	ciphertext,
		uint8_t *	plaintext,
		uint8_t *	keys,
		uint8_t *	init,
		bool	triple_DES,
		uint16_t	block_length
	)

Function that does DES Cipher Block Chaining decryption on a given number of 64-bit data block.

Parameters

ciphertext	Pointer to the ciphertext that shall be decrypted.
plaintext	Pointer to where in memory the plaintext (answer) shall be stored.
keys	Pointer to the array of the one or three DES keys needed.
init	Pointer to initial vector used in in CBC.
triple_DES	Bool that indicate if 3DES or DES shall be used.
block_length	Value that tells how many blocks to encrypt.

Note

The pointer to the ciphertext and plaintext must not be the same because the CBC algorithm uses previous values of the ciphertext to calculate the plaintext.

Referenced by main(), run_3des_cbc_decryption_test(), and run_des_cbc_decryption_test().

void des_cbc_encrypt	(	uint8_t *	plaintext,
		uint8_t *	ciphertext,
		uint8_t *	keys,
		uint8_t *	init,
		bool	triple_DES,
		uint16_t	block_length
	)

Function that does DES Cipher Block Chaining encryption on a given number of 64-bit data block.

Parameters

plaintext	Pointer to the plaintext that shall be encrypted.
ciphertext	Pointer to where in memory the ciphertext(answer) shall be stored.
keys	Pointer to the array of the one or three DES keys needed.
init	Pointer to initial vector used in in CBC.
triple_DES	Bool that indicate if 3DES or DES shall be used.
block_length	Value that tells how many blocks to encrypt.

Referenced by main(), run_3des_cbc_encryption_test(), and run_des_cbc_encryption_test().

void des_decrypt	(	uint8_t *	ciphertext,
		uint8_t *	plaintext,
		uint8_t *	key
	)

Function that does a DES decryption on one 64-bit data block.

Parameters

ciphertext	Pointer to the ciphertext that shall be decrypted.
plaintext	Pointer to where in memory the plaintext (answer) shall be stored.
key	Pointer to the DES key.

Referenced by main(), run_des_decryption(), and run_des_encryption_and_decryption_test().

void des_encrypt	(	uint8_t *	plaintext,
		uint8_t *	ciphertext,
		uint8_t *	key
	)

Function that does a DES encryption on one 64-bit data block.

Parameters

plaintext	Pointer to the plaintext that shall be encrypted.
ciphertext	Pointer to where in memory the ciphertext (answer) shall be stored.
key	Pointer to the DES key.

Referenced by main(), run_des_encryption(), and run_des_encryption_and_decryption_test().