aes.h File Reference

Headers for the implementation of the AES cipher-algorithm. More...

Detailed Description

Headers for the implementation of the AES cipher-algorithm.

Author

Freie Universitaet Berlin, Computer Systems & Telematics

Nicolai Schmittberger nicol.nosp@m.ai.s.nosp@m.chmit.nosp@m.tber.nosp@m.ger@f.nosp@m.u-be.nosp@m.rlin..nosp@m.de

Fabrice Bellard

Zakaria Kasmi zkasm.nosp@m.i@in.nosp@m.f.fu-.nosp@m.berl.nosp@m.in.de

Definition in file aes.h.

#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include "crypto/ciphers.h"

Include dependency graph for aes.h:

Go to the source code of this file.

Data Structures
struct	aes_key_st
	AES key. More...
struct	aes_context_t
	the cipher_context_t-struct adapted for AES More...
#define	GETU32(pt)
#define	PUTU32(ct, st)
#define	AES_MAXNR   14
#define	AES_BLOCK_SIZE   16
#define	AES_KEY_SIZE   16
typedef uint32_t	u32
typedef uint16_t	u16
typedef uint8_t	u8
typedef struct aes_key_st	AES_KEY
int	aes_init (cipher_context_t *context, const uint8_t *key, uint8_t keySize)
	initializes the AES Cipher-algorithm with the passed parameters More...
int	aes_encrypt (const cipher_context_t *context, const uint8_t *plain_block, uint8_t *cipher_block)
	encrypts one plainBlock-block and saves the result in cipherblock. More...
int	aes_decrypt (const cipher_context_t *context, const uint8_t *cipher_block, uint8_t *plain_block)
	decrypts one cipher-block and saves the plain-block in plainBlock. More...

Macro Definition Documentation

GETU32

#define GETU32

(

pt

)

Value:

                     (((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ \
                     ((u32)(pt)[2] <<  8) ^ ((u32)(pt)[3]))

Definition at line 40 of file aes.h.

PUTU32

#define PUTU32	(		ct,
			st
	)

Value:

                          { (ct)[0] = (u8)((st) >> 24); \
                          (ct)[1] = (u8)((st) >> 16); \
                          (ct)[2] = (u8)((st) >>  8); \
                          (ct)[3] = (u8)(st); }

Definition at line 42 of file aes.h.

Function Documentation

aes_decrypt()

int aes_decrypt	(	const cipher_context_t *	context,
		const uint8_t *	cipher_block,
		uint8_t *	plain_block
	)

decrypts one cipher-block and saves the plain-block in plainBlock.

decrypts one blocksize long block of ciphertext pointed to by cipherBlock to one blocksize long block of plaintext and stores the plaintext in the memory-area pointed to by plainBlock

Parameters

context	the cipher_context_t-struct to use for this decryption
cipher_block	a pointer to the ciphertext-block (of size blocksize) to be decrypted
plain_block	a pointer to the place where the decrypted plaintext will be stored

Returns

1 on success

A negative value if the cipher key cannot be expanded with the AES key schedule

aes_encrypt()

int aes_encrypt	(	const cipher_context_t *	context,
		const uint8_t *	plain_block,
		uint8_t *	cipher_block
	)

encrypts one plainBlock-block and saves the result in cipherblock.

encrypts one blocksize long block of plaintext pointed to by plainBlock to one blocksize long block of ciphertext which will be written to the the memory-area pointed to by cipherBlock

Parameters

context	the cipher_context_t-struct to use for this encryption
plain_block	a pointer to the plaintext-block (of size blocksize)
cipher_block	a pointer to the place where the ciphertext will be stored

Returns

1 on success

A negative value if the cipher key cannot be expanded with the AES key schedule

aes_init()

int aes_init	(	cipher_context_t *	context,
		const uint8_t *	key,
		uint8_t	keySize
	)

initializes the AES Cipher-algorithm with the passed parameters

Parameters

context	the cipher_context_t-struct to save the initialization of the cipher in
keySize	the size of the key Must be 16, since this implementation does not support key lengths of 24 or 32 bytes
key	a pointer to the key

Returns

CIPHER_INIT_SUCCESS if the initialization was successful.

CIPHER_ERR_BAD_CONTEXT_SIZE if CIPHER_MAX_CONTEXT_SIZE has not been defined (which means that the cipher has not been included in the build)