700 lines
30 KiB
C
Executable file
700 lines
30 KiB
C
Executable file
/**
|
|
* \file aes.h
|
|
*
|
|
* \brief This file contains AES definitions and functions.
|
|
*
|
|
* The Advanced Encryption Standard (AES) specifies a FIPS-approved
|
|
* cryptographic algorithm that can be used to protect electronic
|
|
* data.
|
|
*
|
|
* The AES algorithm is a symmetric block cipher that can
|
|
* encrypt and decrypt information. For more information, see
|
|
* <em>FIPS Publication 197: Advanced Encryption Standard</em> and
|
|
* <em>ISO/IEC 18033-2:2006: Information technology -- Security
|
|
* techniques -- Encryption algorithms -- Part 2: Asymmetric
|
|
* ciphers</em>.
|
|
*
|
|
* The AES-XTS block mode is standardized by NIST SP 800-38E
|
|
* <https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-38e.pdf>
|
|
* and described in detail by IEEE P1619
|
|
* <https://ieeexplore.ieee.org/servlet/opac?punumber=4375278>.
|
|
*/
|
|
|
|
/*
|
|
* Copyright The Mbed TLS Contributors
|
|
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
*
|
|
* This file is provided under the Apache License 2.0, or the
|
|
* GNU General Public License v2.0 or later.
|
|
*
|
|
* **********
|
|
* Apache License 2.0:
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* **********
|
|
*
|
|
* **********
|
|
* GNU General Public License v2.0 or later:
|
|
*
|
|
* 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.
|
|
*
|
|
* **********
|
|
*/
|
|
|
|
#ifndef MBEDTLS_AES_H
|
|
#define MBEDTLS_AES_H
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
/* padlock.c and aesni.c rely on these values! */
|
|
#define MBEDTLS_AES_ENCRYPT 1 /**< AES encryption. */
|
|
#define MBEDTLS_AES_DECRYPT 0 /**< AES decryption. */
|
|
|
|
/* Error codes in range 0x0020-0x0022 */
|
|
#define MBEDTLS_ERR_AES_INVALID_KEY_LENGTH -0x0020 /**< Invalid key length. */
|
|
#define MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH -0x0022 /**< Invalid data input length. */
|
|
|
|
/* Error codes in range 0x0021-0x0025 */
|
|
#define MBEDTLS_ERR_AES_BAD_INPUT_DATA -0x0021 /**< Invalid input data. */
|
|
|
|
/* MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE is deprecated and should not be used. */
|
|
#define MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE -0x0023 /**< Feature not available. For example, an unsupported AES key size. */
|
|
|
|
/* MBEDTLS_ERR_AES_HW_ACCEL_FAILED is deprecated and should not be used. */
|
|
#define MBEDTLS_ERR_AES_HW_ACCEL_FAILED -0x0025 /**< AES hardware accelerator failed. */
|
|
|
|
#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
|
|
!defined(inline) && !defined(__cplusplus)
|
|
#define inline __inline
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#if !defined(MBEDTLS_AES_ALT)
|
|
// Regular implementation
|
|
//
|
|
|
|
/**
|
|
* \brief The AES context-type definition.
|
|
*/
|
|
typedef struct mbedtls_aes_context
|
|
{
|
|
int nr; /*!< The number of rounds. */
|
|
uint32_t *rk; /*!< AES round keys. */
|
|
uint32_t buf[68]; /*!< Unaligned data buffer. This buffer can
|
|
hold 32 extra Bytes, which can be used for
|
|
one of the following purposes:
|
|
<ul><li>Alignment if VIA padlock is
|
|
used.</li>
|
|
<li>Simplifying key expansion in the 256-bit
|
|
case by generating an extra round key.
|
|
</li></ul> */
|
|
}
|
|
mbedtls_aes_context;
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_XTS)
|
|
/**
|
|
* \brief The AES XTS context-type definition.
|
|
*/
|
|
typedef struct mbedtls_aes_xts_context
|
|
{
|
|
mbedtls_aes_context crypt; /*!< The AES context to use for AES block
|
|
encryption or decryption. */
|
|
mbedtls_aes_context tweak; /*!< The AES context used for tweak
|
|
computation. */
|
|
} mbedtls_aes_xts_context;
|
|
#endif /* MBEDTLS_CIPHER_MODE_XTS */
|
|
|
|
#else /* MBEDTLS_AES_ALT */
|
|
#include "aes_alt.h"
|
|
#endif /* MBEDTLS_AES_ALT */
|
|
|
|
/**
|
|
* \brief This function initializes the specified AES context.
|
|
*
|
|
* It must be the first API called before using
|
|
* the context.
|
|
*
|
|
* \param ctx The AES context to initialize. This must not be \c NULL.
|
|
*/
|
|
void mbedtls_aes_init( mbedtls_aes_context *ctx );
|
|
|
|
/**
|
|
* \brief This function releases and clears the specified AES context.
|
|
*
|
|
* \param ctx The AES context to clear.
|
|
* If this is \c NULL, this function does nothing.
|
|
* Otherwise, the context must have been at least initialized.
|
|
*/
|
|
void mbedtls_aes_free( mbedtls_aes_context *ctx );
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_XTS)
|
|
/**
|
|
* \brief This function initializes the specified AES XTS context.
|
|
*
|
|
* It must be the first API called before using
|
|
* the context.
|
|
*
|
|
* \param ctx The AES XTS context to initialize. This must not be \c NULL.
|
|
*/
|
|
void mbedtls_aes_xts_init( mbedtls_aes_xts_context *ctx );
|
|
|
|
/**
|
|
* \brief This function releases and clears the specified AES XTS context.
|
|
*
|
|
* \param ctx The AES XTS context to clear.
|
|
* If this is \c NULL, this function does nothing.
|
|
* Otherwise, the context must have been at least initialized.
|
|
*/
|
|
void mbedtls_aes_xts_free( mbedtls_aes_xts_context *ctx );
|
|
#endif /* MBEDTLS_CIPHER_MODE_XTS */
|
|
|
|
/**
|
|
* \brief This function sets the encryption key.
|
|
*
|
|
* \param ctx The AES context to which the key should be bound.
|
|
* It must be initialized.
|
|
* \param key The encryption key.
|
|
* This must be a readable buffer of size \p keybits bits.
|
|
* \param keybits The size of data passed in bits. Valid options are:
|
|
* <ul><li>128 bits</li>
|
|
* <li>192 bits</li>
|
|
* <li>256 bits</li></ul>
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
|
|
*/
|
|
int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
|
|
unsigned int keybits );
|
|
|
|
/**
|
|
* \brief This function sets the decryption key.
|
|
*
|
|
* \param ctx The AES context to which the key should be bound.
|
|
* It must be initialized.
|
|
* \param key The decryption key.
|
|
* This must be a readable buffer of size \p keybits bits.
|
|
* \param keybits The size of data passed. Valid options are:
|
|
* <ul><li>128 bits</li>
|
|
* <li>192 bits</li>
|
|
* <li>256 bits</li></ul>
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
|
|
*/
|
|
int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
|
|
unsigned int keybits );
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_XTS)
|
|
/**
|
|
* \brief This function prepares an XTS context for encryption and
|
|
* sets the encryption key.
|
|
*
|
|
* \param ctx The AES XTS context to which the key should be bound.
|
|
* It must be initialized.
|
|
* \param key The encryption key. This is comprised of the XTS key1
|
|
* concatenated with the XTS key2.
|
|
* This must be a readable buffer of size \p keybits bits.
|
|
* \param keybits The size of \p key passed in bits. Valid options are:
|
|
* <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
|
|
* <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
|
|
*/
|
|
int mbedtls_aes_xts_setkey_enc( mbedtls_aes_xts_context *ctx,
|
|
const unsigned char *key,
|
|
unsigned int keybits );
|
|
|
|
/**
|
|
* \brief This function prepares an XTS context for decryption and
|
|
* sets the decryption key.
|
|
*
|
|
* \param ctx The AES XTS context to which the key should be bound.
|
|
* It must be initialized.
|
|
* \param key The decryption key. This is comprised of the XTS key1
|
|
* concatenated with the XTS key2.
|
|
* This must be a readable buffer of size \p keybits bits.
|
|
* \param keybits The size of \p key passed in bits. Valid options are:
|
|
* <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
|
|
* <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
|
|
*/
|
|
int mbedtls_aes_xts_setkey_dec( mbedtls_aes_xts_context *ctx,
|
|
const unsigned char *key,
|
|
unsigned int keybits );
|
|
#endif /* MBEDTLS_CIPHER_MODE_XTS */
|
|
|
|
/**
|
|
* \brief This function performs an AES single-block encryption or
|
|
* decryption operation.
|
|
*
|
|
* It performs the operation defined in the \p mode parameter
|
|
* (encrypt or decrypt), on the input data buffer defined in
|
|
* the \p input parameter.
|
|
*
|
|
* mbedtls_aes_init(), and either mbedtls_aes_setkey_enc() or
|
|
* mbedtls_aes_setkey_dec() must be called before the first
|
|
* call to this API with the same context.
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param mode The AES operation: #MBEDTLS_AES_ENCRYPT or
|
|
* #MBEDTLS_AES_DECRYPT.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and at least \c 16 Bytes long.
|
|
* \param output The buffer where the output data will be written.
|
|
* It must be writeable and at least \c 16 Bytes long.
|
|
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
|
|
int mode,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] );
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_CBC)
|
|
/**
|
|
* \brief This function performs an AES-CBC encryption or decryption operation
|
|
* on full blocks.
|
|
*
|
|
* It performs the operation defined in the \p mode
|
|
* parameter (encrypt/decrypt), on the input data buffer defined in
|
|
* the \p input parameter.
|
|
*
|
|
* It can be called as many times as needed, until all the input
|
|
* data is processed. mbedtls_aes_init(), and either
|
|
* mbedtls_aes_setkey_enc() or mbedtls_aes_setkey_dec() must be called
|
|
* before the first call to this API with the same context.
|
|
*
|
|
* \note This function operates on full blocks, that is, the input size
|
|
* must be a multiple of the AES block size of \c 16 Bytes.
|
|
*
|
|
* \note Upon exit, the content of the IV is updated so that you can
|
|
* call the same function again on the next
|
|
* block(s) of data and get the same result as if it was
|
|
* encrypted in one call. This allows a "streaming" usage.
|
|
* If you need to retain the contents of the IV, you should
|
|
* either save it manually or use the cipher module instead.
|
|
*
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param mode The AES operation: #MBEDTLS_AES_ENCRYPT or
|
|
* #MBEDTLS_AES_DECRYPT.
|
|
* \param length The length of the input data in Bytes. This must be a
|
|
* multiple of the block size (\c 16 Bytes).
|
|
* \param iv Initialization vector (updated after use).
|
|
* It must be a readable and writeable buffer of \c 16 Bytes.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and of size \p length Bytes.
|
|
* \param output The buffer holding the output data.
|
|
* It must be writeable and of size \p length Bytes.
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
|
|
* on failure.
|
|
*/
|
|
int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output );
|
|
#endif /* MBEDTLS_CIPHER_MODE_CBC */
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_XTS)
|
|
/**
|
|
* \brief This function performs an AES-XTS encryption or decryption
|
|
* operation for an entire XTS data unit.
|
|
*
|
|
* AES-XTS encrypts or decrypts blocks based on their location as
|
|
* defined by a data unit number. The data unit number must be
|
|
* provided by \p data_unit.
|
|
*
|
|
* NIST SP 800-38E limits the maximum size of a data unit to 2^20
|
|
* AES blocks. If the data unit is larger than this, this function
|
|
* returns #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH.
|
|
*
|
|
* \param ctx The AES XTS context to use for AES XTS operations.
|
|
* It must be initialized and bound to a key.
|
|
* \param mode The AES operation: #MBEDTLS_AES_ENCRYPT or
|
|
* #MBEDTLS_AES_DECRYPT.
|
|
* \param length The length of a data unit in Bytes. This can be any
|
|
* length between 16 bytes and 2^24 bytes inclusive
|
|
* (between 1 and 2^20 block cipher blocks).
|
|
* \param data_unit The address of the data unit encoded as an array of 16
|
|
* bytes in little-endian format. For disk encryption, this
|
|
* is typically the index of the block device sector that
|
|
* contains the data.
|
|
* \param input The buffer holding the input data (which is an entire
|
|
* data unit). This function reads \p length Bytes from \p
|
|
* input.
|
|
* \param output The buffer holding the output data (which is an entire
|
|
* data unit). This function writes \p length Bytes to \p
|
|
* output.
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH if \p length is
|
|
* smaller than an AES block in size (16 Bytes) or if \p
|
|
* length is larger than 2^20 blocks (16 MiB).
|
|
*/
|
|
int mbedtls_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
const unsigned char data_unit[16],
|
|
const unsigned char *input,
|
|
unsigned char *output );
|
|
#endif /* MBEDTLS_CIPHER_MODE_XTS */
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_CFB)
|
|
/**
|
|
* \brief This function performs an AES-CFB128 encryption or decryption
|
|
* operation.
|
|
*
|
|
* It performs the operation defined in the \p mode
|
|
* parameter (encrypt or decrypt), on the input data buffer
|
|
* defined in the \p input parameter.
|
|
*
|
|
* For CFB, you must set up the context with mbedtls_aes_setkey_enc(),
|
|
* regardless of whether you are performing an encryption or decryption
|
|
* operation, that is, regardless of the \p mode parameter. This is
|
|
* because CFB mode uses the same key schedule for encryption and
|
|
* decryption.
|
|
*
|
|
* \note Upon exit, the content of the IV is updated so that you can
|
|
* call the same function again on the next
|
|
* block(s) of data and get the same result as if it was
|
|
* encrypted in one call. This allows a "streaming" usage.
|
|
* If you need to retain the contents of the
|
|
* IV, you must either save it manually or use the cipher
|
|
* module instead.
|
|
*
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param mode The AES operation: #MBEDTLS_AES_ENCRYPT or
|
|
* #MBEDTLS_AES_DECRYPT.
|
|
* \param length The length of the input data in Bytes.
|
|
* \param iv_off The offset in IV (updated after use).
|
|
* It must point to a valid \c size_t.
|
|
* \param iv The initialization vector (updated after use).
|
|
* It must be a readable and writeable buffer of \c 16 Bytes.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and of size \p length Bytes.
|
|
* \param output The buffer holding the output data.
|
|
* It must be writeable and of size \p length Bytes.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_aes_crypt_cfb128( mbedtls_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
size_t *iv_off,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output );
|
|
|
|
/**
|
|
* \brief This function performs an AES-CFB8 encryption or decryption
|
|
* operation.
|
|
*
|
|
* It performs the operation defined in the \p mode
|
|
* parameter (encrypt/decrypt), on the input data buffer defined
|
|
* in the \p input parameter.
|
|
*
|
|
* Due to the nature of CFB, you must use the same key schedule for
|
|
* both encryption and decryption operations. Therefore, you must
|
|
* use the context initialized with mbedtls_aes_setkey_enc() for
|
|
* both #MBEDTLS_AES_ENCRYPT and #MBEDTLS_AES_DECRYPT.
|
|
*
|
|
* \note Upon exit, the content of the IV is updated so that you can
|
|
* call the same function again on the next
|
|
* block(s) of data and get the same result as if it was
|
|
* encrypted in one call. This allows a "streaming" usage.
|
|
* If you need to retain the contents of the
|
|
* IV, you should either save it manually or use the cipher
|
|
* module instead.
|
|
*
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param mode The AES operation: #MBEDTLS_AES_ENCRYPT or
|
|
* #MBEDTLS_AES_DECRYPT
|
|
* \param length The length of the input data.
|
|
* \param iv The initialization vector (updated after use).
|
|
* It must be a readable and writeable buffer of \c 16 Bytes.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and of size \p length Bytes.
|
|
* \param output The buffer holding the output data.
|
|
* It must be writeable and of size \p length Bytes.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_aes_crypt_cfb8( mbedtls_aes_context *ctx,
|
|
int mode,
|
|
size_t length,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output );
|
|
#endif /*MBEDTLS_CIPHER_MODE_CFB */
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_OFB)
|
|
/**
|
|
* \brief This function performs an AES-OFB (Output Feedback Mode)
|
|
* encryption or decryption operation.
|
|
*
|
|
* For OFB, you must set up the context with
|
|
* mbedtls_aes_setkey_enc(), regardless of whether you are
|
|
* performing an encryption or decryption operation. This is
|
|
* because OFB mode uses the same key schedule for encryption and
|
|
* decryption.
|
|
*
|
|
* The OFB operation is identical for encryption or decryption,
|
|
* therefore no operation mode needs to be specified.
|
|
*
|
|
* \note Upon exit, the content of iv, the Initialisation Vector, is
|
|
* updated so that you can call the same function again on the next
|
|
* block(s) of data and get the same result as if it was encrypted
|
|
* in one call. This allows a "streaming" usage, by initialising
|
|
* iv_off to 0 before the first call, and preserving its value
|
|
* between calls.
|
|
*
|
|
* For non-streaming use, the iv should be initialised on each call
|
|
* to a unique value, and iv_off set to 0 on each call.
|
|
*
|
|
* If you need to retain the contents of the initialisation vector,
|
|
* you must either save it manually or use the cipher module
|
|
* instead.
|
|
*
|
|
* \warning For the OFB mode, the initialisation vector must be unique
|
|
* every encryption operation. Reuse of an initialisation vector
|
|
* will compromise security.
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param length The length of the input data.
|
|
* \param iv_off The offset in IV (updated after use).
|
|
* It must point to a valid \c size_t.
|
|
* \param iv The initialization vector (updated after use).
|
|
* It must be a readable and writeable buffer of \c 16 Bytes.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and of size \p length Bytes.
|
|
* \param output The buffer holding the output data.
|
|
* It must be writeable and of size \p length Bytes.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_aes_crypt_ofb( mbedtls_aes_context *ctx,
|
|
size_t length,
|
|
size_t *iv_off,
|
|
unsigned char iv[16],
|
|
const unsigned char *input,
|
|
unsigned char *output );
|
|
|
|
#endif /* MBEDTLS_CIPHER_MODE_OFB */
|
|
|
|
#if defined(MBEDTLS_CIPHER_MODE_CTR)
|
|
/**
|
|
* \brief This function performs an AES-CTR encryption or decryption
|
|
* operation.
|
|
*
|
|
* This function performs the operation defined in the \p mode
|
|
* parameter (encrypt/decrypt), on the input data buffer
|
|
* defined in the \p input parameter.
|
|
*
|
|
* Due to the nature of CTR, you must use the same key schedule
|
|
* for both encryption and decryption operations. Therefore, you
|
|
* must use the context initialized with mbedtls_aes_setkey_enc()
|
|
* for both #MBEDTLS_AES_ENCRYPT and #MBEDTLS_AES_DECRYPT.
|
|
*
|
|
* \warning You must never reuse a nonce value with the same key. Doing so
|
|
* would void the encryption for the two messages encrypted with
|
|
* the same nonce and key.
|
|
*
|
|
* There are two common strategies for managing nonces with CTR:
|
|
*
|
|
* 1. You can handle everything as a single message processed over
|
|
* successive calls to this function. In that case, you want to
|
|
* set \p nonce_counter and \p nc_off to 0 for the first call, and
|
|
* then preserve the values of \p nonce_counter, \p nc_off and \p
|
|
* stream_block across calls to this function as they will be
|
|
* updated by this function.
|
|
*
|
|
* With this strategy, you must not encrypt more than 2**128
|
|
* blocks of data with the same key.
|
|
*
|
|
* 2. You can encrypt separate messages by dividing the \p
|
|
* nonce_counter buffer in two areas: the first one used for a
|
|
* per-message nonce, handled by yourself, and the second one
|
|
* updated by this function internally.
|
|
*
|
|
* For example, you might reserve the first 12 bytes for the
|
|
* per-message nonce, and the last 4 bytes for internal use. In that
|
|
* case, before calling this function on a new message you need to
|
|
* set the first 12 bytes of \p nonce_counter to your chosen nonce
|
|
* value, the last 4 to 0, and \p nc_off to 0 (which will cause \p
|
|
* stream_block to be ignored). That way, you can encrypt at most
|
|
* 2**96 messages of up to 2**32 blocks each with the same key.
|
|
*
|
|
* The per-message nonce (or information sufficient to reconstruct
|
|
* it) needs to be communicated with the ciphertext and must be unique.
|
|
* The recommended way to ensure uniqueness is to use a message
|
|
* counter. An alternative is to generate random nonces, but this
|
|
* limits the number of messages that can be securely encrypted:
|
|
* for example, with 96-bit random nonces, you should not encrypt
|
|
* more than 2**32 messages with the same key.
|
|
*
|
|
* Note that for both stategies, sizes are measured in blocks and
|
|
* that an AES block is 16 bytes.
|
|
*
|
|
* \warning Upon return, \p stream_block contains sensitive data. Its
|
|
* content must not be written to insecure storage and should be
|
|
* securely discarded as soon as it's no longer needed.
|
|
*
|
|
* \param ctx The AES context to use for encryption or decryption.
|
|
* It must be initialized and bound to a key.
|
|
* \param length The length of the input data.
|
|
* \param nc_off The offset in the current \p stream_block, for
|
|
* resuming within the current cipher stream. The
|
|
* offset pointer should be 0 at the start of a stream.
|
|
* It must point to a valid \c size_t.
|
|
* \param nonce_counter The 128-bit nonce and counter.
|
|
* It must be a readable-writeable buffer of \c 16 Bytes.
|
|
* \param stream_block The saved stream block for resuming. This is
|
|
* overwritten by the function.
|
|
* It must be a readable-writeable buffer of \c 16 Bytes.
|
|
* \param input The buffer holding the input data.
|
|
* It must be readable and of size \p length Bytes.
|
|
* \param output The buffer holding the output data.
|
|
* It must be writeable and of size \p length Bytes.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_aes_crypt_ctr( mbedtls_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 );
|
|
#endif /* MBEDTLS_CIPHER_MODE_CTR */
|
|
|
|
/**
|
|
* \brief Internal AES block encryption function. This is only
|
|
* exposed to allow overriding it using
|
|
* \c MBEDTLS_AES_ENCRYPT_ALT.
|
|
*
|
|
* \param ctx The AES context to use for encryption.
|
|
* \param input The plaintext block.
|
|
* \param output The output (ciphertext) block.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_internal_aes_encrypt( mbedtls_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] );
|
|
|
|
/**
|
|
* \brief Internal AES block decryption function. This is only
|
|
* exposed to allow overriding it using see
|
|
* \c MBEDTLS_AES_DECRYPT_ALT.
|
|
*
|
|
* \param ctx The AES context to use for decryption.
|
|
* \param input The ciphertext block.
|
|
* \param output The output (plaintext) block.
|
|
*
|
|
* \return \c 0 on success.
|
|
*/
|
|
int mbedtls_internal_aes_decrypt( mbedtls_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] );
|
|
|
|
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
|
|
#if defined(MBEDTLS_DEPRECATED_WARNING)
|
|
#define MBEDTLS_DEPRECATED __attribute__((deprecated))
|
|
#else
|
|
#define MBEDTLS_DEPRECATED
|
|
#endif
|
|
/**
|
|
* \brief Deprecated internal AES block encryption function
|
|
* without return value.
|
|
*
|
|
* \deprecated Superseded by mbedtls_internal_aes_encrypt()
|
|
*
|
|
* \param ctx The AES context to use for encryption.
|
|
* \param input Plaintext block.
|
|
* \param output Output (ciphertext) block.
|
|
*/
|
|
MBEDTLS_DEPRECATED void mbedtls_aes_encrypt( mbedtls_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] );
|
|
|
|
/**
|
|
* \brief Deprecated internal AES block decryption function
|
|
* without return value.
|
|
*
|
|
* \deprecated Superseded by mbedtls_internal_aes_decrypt()
|
|
*
|
|
* \param ctx The AES context to use for decryption.
|
|
* \param input Ciphertext block.
|
|
* \param output Output (plaintext) block.
|
|
*/
|
|
MBEDTLS_DEPRECATED void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
|
|
const unsigned char input[16],
|
|
unsigned char output[16] );
|
|
|
|
#undef MBEDTLS_DEPRECATED
|
|
#endif /* !MBEDTLS_DEPRECATED_REMOVED */
|
|
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
/**
|
|
* \brief Checkup routine.
|
|
*
|
|
* \return \c 0 on success.
|
|
* \return \c 1 on failure.
|
|
*/
|
|
int mbedtls_aes_self_test( int verbose );
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* aes.h */
|