aes.h File Reference

AES block cipher. More...

#include <string.h>
#include <inttypes.h>

Go to the source code of this file.

Classes
struct	aes_context
	AES context structure. More...
Defines
#define	POLARSSL_CIPHER_MODE_CTR   1
#define	AES_ENCRYPT   1
#define	AES_DECRYPT   0
#define	POLARSSL_ERR_AES_INVALID_KEY_LENGTH   -0x0020
#define	POLARSSL_ERR_AES_INVALID_INPUT_LENGTH   -0x0022
Functions
void	aes_init (aes_context *ctx)
	Initialize AES context.
void	aes_free (aes_context *ctx)
	Clear AES context.
int	aes_setkey_enc (aes_context *ctx, const unsigned char *key, unsigned int keysize)
	AES key schedule (encryption).
int	aes_setkey_dec (aes_context *ctx, const unsigned char *key, unsigned int keysize)
	AES key schedule (decryption).
int	aes_crypt_ecb (aes_context *ctx, int mode, const unsigned char input[16], unsigned char output[16])
	AES-ECB block encryption/decryption.
int	aes_crypt_cbc (aes_context *ctx, int mode, size_t length, unsigned char iv[16], const unsigned char *input, unsigned char *output)
	AES-CBC buffer encryption/decryption Length should be a multiple of the block size (16 bytes).
int	aes_crypt_cfb128 (aes_context *ctx, int mode, size_t length, size_t *iv_off, unsigned char iv[16], const unsigned char *input, unsigned char *output)
	AES-CFB128 buffer encryption/decryption.
int	aes_crypt_cfb8 (aes_context *ctx, int mode, size_t length, unsigned char iv[16], const unsigned char *input, unsigned char *output)
	AES-CFB8 buffer encryption/decryption.
int	aes_crypt_ctr (aes_context *ctx, size_t length, size_t *nc_off, unsigned char nonce_counter[16], unsigned char stream_block[16], const unsigned char *input, unsigned char *output)
	AES-CTR buffer encryption/decryption.
int	aes_self_test (int verbose)
	Checkup routine.

---

Detailed Description

AES block cipher.

Copyright (C) 2006-2014, Brainspark B.V.

This file is part of PolarSSL (http://www.polarssl.org) Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>

All rights reserved.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

---

Define Documentation

#define POLARSSL_ERR_AES_INVALID_INPUT_LENGTH   -0x0022

Invalid data input length.

#define POLARSSL_ERR_AES_INVALID_KEY_LENGTH   -0x0020

Invalid key length.

---

Function Documentation

int aes_crypt_cbc	(	aes_context *	ctx,
		int	mode,
		size_t	length,
		unsigned char	iv[16],
		const unsigned char *	input,
		unsigned char *	output
	)

AES-CBC buffer encryption/decryption Length should be a multiple of the block size (16 bytes).

Parameters:

	ctx	AES context
	mode	AES_ENCRYPT or AES_DECRYPT
	length	length of the input data
	iv	initialization vector (updated after use)
	input	buffer holding the input data
	output	buffer holding the output data

Returns:

0 if successful, or POLARSSL_ERR_AES_INVALID_INPUT_LENGTH

int aes_crypt_cfb128	(	aes_context *	ctx,
		int	mode,
		size_t	length,
		size_t *	iv_off,
		unsigned char	iv[16],
		const unsigned char *	input,
		unsigned char *	output
	)

AES-CFB128 buffer encryption/decryption.

Note: Due to the nature of CFB you should use the same key schedule for both encryption and decryption. So a context initialized with aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.

Parameters:

	ctx	AES context
	mode	AES_ENCRYPT or AES_DECRYPT
	length	length of the input data
	iv_off	offset in IV (updated after use)
	iv	initialization vector (updated after use)
	input	buffer holding the input data
	output	buffer holding the output data

Returns:

0 if successful

int aes_crypt_cfb8	(	aes_context *	ctx,
		int	mode,
		size_t	length,
		unsigned char	iv[16],
		const unsigned char *	input,
		unsigned char *	output
	)

AES-CFB8 buffer encryption/decryption.

Note: Due to the nature of CFB you should use the same key schedule for both encryption and decryption. So a context initialized with aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.

Parameters:

	ctx	AES context
	mode	AES_ENCRYPT or AES_DECRYPT
	length	length of the input data
	iv	initialization vector (updated after use)
	input	buffer holding the input data
	output	buffer holding the output data

Returns:

0 if successful

int aes_crypt_ctr	(	aes_context *	ctx,
		size_t	length,
		size_t *	nc_off,
		unsigned char	nonce_counter[16],
		unsigned char	stream_block[16],
		const unsigned char *	input,
		unsigned char *	output
	)

AES-CTR buffer encryption/decryption.

Warning: You have to keep the maximum use of your counter in mind!

Note: Due to the nature of CTR you should use the same key schedule for both encryption and decryption. So a context initialized with aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.

Parameters:

	ctx	AES context
	length	The length of the data
	nc_off	The offset in the current stream_block (for resuming within current cipher stream). The offset pointer to should be 0 at the start of a stream.
	nonce_counter	The 128-bit nonce and counter.
	stream_block	The saved stream-block for resuming. Is overwritten by the function.
	input	The input data stream
	output	The output data stream

Returns:

0 if successful

int aes_crypt_ecb	(	aes_context *	ctx,
		int	mode,
		const unsigned char	input[16],
		unsigned char	output[16]
	)

AES-ECB block encryption/decryption.

Parameters:

	ctx	AES context
	mode	AES_ENCRYPT or AES_DECRYPT
	input	16-byte input block
	output	16-byte output block

Returns:

0 if successful

void aes_free

(

aes_context *

ctx

)

Clear AES context.

Parameters:

ctx

AES context to be cleared

void aes_init

(

aes_context *

ctx

)

Initialize AES context.

Parameters:

ctx

AES context to be initialized

int aes_self_test

(

int

verbose

)

Checkup routine.

Returns:

0 if successful, or 1 if the test failed

int aes_setkey_dec	(	aes_context *	ctx,
		const unsigned char *	key,
		unsigned int	keysize
	)

AES key schedule (decryption).

Parameters:

	ctx	AES context to be initialized
	key	decryption key
	keysize	must be 128, 192 or 256

Returns:

0 if successful, or POLARSSL_ERR_AES_INVALID_KEY_LENGTH

int aes_setkey_enc	(	aes_context *	ctx,
		const unsigned char *	key,
		unsigned int	keysize
	)

AES key schedule (encryption).

Parameters:

	ctx	AES context to be initialized
	key	encryption key
	keysize	must be 128, 192 or 256

Returns:

0 if successful, or POLARSSL_ERR_AES_INVALID_KEY_LENGTH