/**
* \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 (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved.
* SPDX-License-Identifier: GPL-2.0
*
* 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.
*
* This file is part of Mbed TLS (https://tls.mbed.org)
*/
#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 */