aes.h File Reference

AES block cipher. More...

#include "config.h"
#include <stddef.h>
#include <inttypes.h>

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Data Structures
struct	aes_context
	AES context structure. More...

Macros
#define	AES_ENCRYPT   1
#define	AES_DECRYPT   0
#define	POLARSSL_ERR_AES_INVALID_KEY_LENGTH   -0x0020
	Invalid key length. More...
#define	POLARSSL_ERR_AES_INVALID_INPUT_LENGTH   -0x0022
	Invalid data input length. More...

Functions
void	aes_init (aes_context *ctx)
	Initialize AES context. More...
void	aes_free (aes_context *ctx)
	Clear AES context. More...
int	aes_setkey_enc (aes_context *ctx, const unsigned char *key, unsigned int keysize)
	AES key schedule (encryption) More...
int	aes_setkey_dec (aes_context *ctx, const unsigned char *key, unsigned int keysize)
	AES key schedule (decryption) More...
int	aes_crypt_ecb (aes_context *ctx, int mode, const unsigned char input[16], unsigned char output[16])
	AES-ECB block encryption/decryption. More...
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) More...
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. More...
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. More...
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. More...
int	aes_self_test (int verbose)
	Checkup routine. More...

Detailed Description

AES block cipher.

Copyright (C) 2006-2014, ARM Limited, All Rights Reserved

This file is part of mbed TLS (https://tls.mbed.org)

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.

Definition in file aes.h.

Macro Definition Documentation

#define AES_DECRYPT   0

Definition at line 44 of file aes.h.

#define AES_ENCRYPT   1

Definition at line 43 of file aes.h.

#define POLARSSL_ERR_AES_INVALID_INPUT_LENGTH   -0x0022

Invalid data input length.

Definition at line 47 of file aes.h.

#define POLARSSL_ERR_AES_INVALID_KEY_LENGTH   -0x0020

Invalid key length.

Definition at line 46 of file aes.h.

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)

Note

Upon exit, the content of the IV is updated so that you can call the function same function again on the following block(s) of data and get the same result as if it was encrypted in one call. This allows a "streaming" usage. If on the other hand you need to retain the contents of the IV, you should either save it manually or use the cipher module instead.

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.

Note

Upon exit, the content of the IV is updated so that you can call the function same function again on the following block(s) of data and get the same result as if it was encrypted in one call. This allows a "streaming" usage. If on the other hand you need to retain the contents of the IV, you should either save it manually or use the cipher module instead.

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.

Note

Upon exit, the content of the IV is updated so that you can call the function same function again on the following block(s) of data and get the same result as if it was encrypted in one call. This allows a "streaming" usage. If on the other hand you need to retain the contents of the IV, you should either save it manually or use the cipher module instead.

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