/**
* \file cipher.h
*
* \brief This file contains an abstraction interface for use with the cipher
* primitives provided by the library. It provides a common interface to all of
* the available cipher operations.
*
* \author Adriaan de Jong <dejong@fox-it.com>
*/
/*
* 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_CIPHER_H
#define MBEDTLS_CIPHER_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include <stddef.h>
#include "platform_util.h"
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
#define MBEDTLS_CIPHER_MODE_AEAD
#endif
#if defined(MBEDTLS_CIPHER_MODE_CBC)
#define MBEDTLS_CIPHER_MODE_WITH_PADDING
#endif
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
defined(MBEDTLS_CHACHA20_C)
#define MBEDTLS_CIPHER_MODE_STREAM
#endif
#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
!defined(inline) && !defined(__cplusplus)
#define inline __inline
#endif
#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters. */
#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid. For example, because it was freed. */
/* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
#define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400 /**< Cipher hardware accelerator failed. */
#define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Supported cipher types.
*
* \warning RC4 and DES are considered weak ciphers and their use
* constitutes a security risk. Arm recommends considering stronger
* ciphers instead.
*/
typedef enum {
MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */
MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
} mbedtls_cipher_id_t;
/**
* \brief Supported {cipher type, cipher mode} pairs.
*
* \warning RC4 and DES are considered weak ciphers and their use
* constitutes a security risk. Arm recommends considering stronger
* ciphers instead.
*/
typedef enum {
MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. */
MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. */
MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. */
MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. */
MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. */
MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. */
MBEDTLS_CIPHER_BLOWFISH_ECB, /**< Blowfish cipher with ECB mode. */
MBEDTLS_CIPHER_BLOWFISH_CBC, /**< Blowfish cipher with CBC mode. */
MBEDTLS_CIPHER_BLOWFISH_CFB64, /**< Blowfish cipher with CFB64 mode. */
MBEDTLS_CIPHER_BLOWFISH_CTR, /**< Blowfish cipher with CTR mode. */
MBEDTLS_CIPHER_ARC4_128, /**< RC4 cipher with 128-bit mode. */
MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
} mbedtls_cipher_type_t;
/** Supported cipher modes. */
typedef enum {
MBEDTLS_MODE_NONE = 0, /**< None. */
MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
} mbedtls_cipher_mode_t;
/** Supported cipher padding types. */
typedef enum {
MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
} mbedtls_cipher_padding_t;
/** Type of operation. */
typedef enum {
MBEDTLS_OPERATION_NONE = -1,
MBEDTLS_DECRYPT = 0,
MBEDTLS_ENCRYPT,
} mbedtls_operation_t;
enum {
/** Undefined key length. */
MBEDTLS_KEY_LENGTH_NONE = 0,
/** Key length, in bits (including parity), for DES keys. */
MBEDTLS_KEY_LENGTH_DES = 64,
/** Key length in bits, including parity, for DES in two-key EDE. */
MBEDTLS_KEY_LENGTH_DES_EDE = 128,
/** Key length in bits, including parity, for DES in three-key EDE. */
MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
};
/** Maximum length of any IV, in Bytes. */
#define MBEDTLS_MAX_IV_LENGTH 16
/** Maximum block size of any cipher, in Bytes. */
#define MBEDTLS_MAX_BLOCK_LENGTH 16
/**
* Base cipher information (opaque struct).
*/
typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
/**
* CMAC context (opaque struct).
*/
typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
/**
* Cipher information. Allows calling cipher functions
* in a generic way.
*/
typedef struct mbedtls_cipher_info_t
{
/** Full cipher identifier. For example,
* MBEDTLS_CIPHER_AES_256_CBC.
*/
mbedtls_cipher_type_t type;
/** The cipher mode. For example, MBEDTLS_MODE_CBC. */
mbedtls_cipher_mode_t mode;
/** The cipher key length, in bits. This is the
* default length for variable sized ciphers.
* Includes parity bits for ciphers like DES.
*/
unsigned int key_bitlen;
/** Name of the cipher. */
const char * name;
/** IV or nonce size, in Bytes.
* For ciphers that accept variable IV sizes,
* this is the recommended size.
*/
unsigned int iv_size;
/** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
* MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
* cipher supports variable IV or variable key sizes, respectively.
*/
int flags;
/** The block size, in Bytes. */
unsigned int block_size;
/** Struct for base cipher information and functions. */
const mbedtls_cipher_base_t *base;
} mbedtls_cipher_info_t;
/**
* Generic cipher context.
*/
typedef struct mbedtls_cipher_context_t
{
/** Information about the associated cipher. */
const mbedtls_cipher_info_t *cipher_info;
/** Key length to use. */
int key_bitlen;
/** Operation that the key of the context has been
* initialized for.
*/
mbedtls_operation_t operation;
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
/** Padding functions to use, if relevant for
* the specific cipher mode.
*/
void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
#endif
/** Buffer for input that has not been processed yet. */
unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
/** Number of Bytes that have not been processed yet. */
size_t unprocessed_len;
/** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
* for XTS-mode. */
unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
/** IV size in Bytes, for ciphers with variable-length IVs. */
size_t iv_size;
/** The cipher-specific context. */
void *cipher_ctx;
#if defined(MBEDTLS_CMAC_C)
/** CMAC-specific context. */
mbedtls_cmac_context_t *cmac_ctx;
#endif
} mbedtls_cipher_context_t;
/**
* \brief This function retrieves the list of ciphers supported by the generic
* cipher module.
*
* \return A statically-allocated array of ciphers. The last entry
* is zero.
*/
const int *mbedtls_cipher_list( void );
/**
* \brief This function retrieves the cipher-information
* structure associated with the given cipher name.
*
* \param cipher_name Name of the cipher to search for. This must not be
* \c NULL.
*
* \return The cipher information structure associated with the
* given \p cipher_name.
* \return \c NULL if the associated cipher information is not found.
*/
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
/**
* \brief This function retrieves the cipher-information
* structure associated with the given cipher type.
*
* \param cipher_type Type of the cipher to search for.
*
* \return The cipher information structure associated with the
* given \p cipher_type.
* \return \c NULL if the associated cipher information is not found.
*/
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
/**
* \brief This function retrieves the cipher-information
* structure associated with the given cipher ID,
* key size and mode.
*
* \param cipher_id The ID of the cipher to search for. For example,
* #MBEDTLS_CIPHER_ID_AES.
* \param key_bitlen The length of the key in bits.
* \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
*
* \return The cipher information structure associated with the
* given \p cipher_id.
* \return \c NULL if the associated cipher information is not found.
*/
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
int key_bitlen,
const mbedtls_cipher_mode_t mode );
/**
* \brief This function initializes a \p cipher_context as NONE.
*
* \param ctx The context to be initialized. This must not be \c NULL.
*/
void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
/**
* \brief This function frees and clears the cipher-specific
* context of \p ctx. Freeing \p ctx itself remains the
* responsibility of the caller.
*
* \param ctx The context to be freed. If this is \c NULL, the
* function has no effect, otherwise this must point to an
* initialized context.
*/
void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
/**
* \brief This function initializes and fills the cipher-context
* structure with the appropriate values. It also clears
* the structure.
*
* \param ctx The context to initialize. This must be initialized.
* \param cipher_info The cipher to use.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
* cipher-specific context fails.
*
* \internal Currently, the function also clears the structure.
* In future versions, the caller will be required to call
* mbedtls_cipher_init() on the structure first.
*/
int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
const mbedtls_cipher_info_t *cipher_info );
/**
* \brief This function returns the block size of the given cipher.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The block size of the underlying cipher.
* \return \c 0 if \p ctx has not been initialized.
*/
static inline unsigned int mbedtls_cipher_get_block_size(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
if( ctx->cipher_info == NULL )
return 0;
return ctx->cipher_info->block_size;
}
/**
* \brief This function returns the mode of operation for
* the cipher. For example, MBEDTLS_MODE_CBC.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The mode of operation.
* \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
*/
static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
if( ctx->cipher_info == NULL )
return MBEDTLS_MODE_NONE;
return ctx->cipher_info->mode;
}
/**
* \brief This function returns the size of the IV or nonce
* of the cipher, in Bytes.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The recommended IV size if no IV has been set.
* \return \c 0 for ciphers not using an IV or a nonce.
* \return The actual size if an IV has been set.
*/
static inline int mbedtls_cipher_get_iv_size(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
if( ctx->cipher_info == NULL )
return 0;
if( ctx->iv_size != 0 )
return (int) ctx->iv_size;
return (int) ctx->cipher_info->iv_size;
}
/**
* \brief This function returns the type of the given cipher.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The type of the cipher.
* \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
*/
static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET(
ctx != NULL, MBEDTLS_CIPHER_NONE );
if( ctx->cipher_info == NULL )
return MBEDTLS_CIPHER_NONE;
return ctx->cipher_info->type;
}
/**
* \brief This function returns the name of the given cipher
* as a string.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The name of the cipher.
* \return NULL if \p ctx has not been not initialized.
*/
static inline const char *mbedtls_cipher_get_name(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
if( ctx->cipher_info == NULL )
return 0;
return ctx->cipher_info->name;
}
/**
* \brief This function returns the key length of the cipher.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The key length of the cipher in bits.
* \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
* initialized.
*/
static inline int mbedtls_cipher_get_key_bitlen(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET(
ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
if( ctx->cipher_info == NULL )
return MBEDTLS_KEY_LENGTH_NONE;
return (int) ctx->cipher_info->key_bitlen;
}
/**
* \brief This function returns the operation of the given cipher.
*
* \param ctx The context of the cipher. This must be initialized.
*
* \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
* \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
*/
static inline mbedtls_operation_t mbedtls_cipher_get_operation(
const mbedtls_cipher_context_t *ctx )
{
MBEDTLS_INTERNAL_VALIDATE_RET(
ctx != NULL, MBEDTLS_OPERATION_NONE );
if( ctx->cipher_info == NULL )
return MBEDTLS_OPERATION_NONE;
return ctx->operation;
}
/**
* \brief This function sets the key to use with the given context.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a cipher information structure.
* \param key The key to use. This must be a readable buffer of at
* least \p key_bitlen Bits.
* \param key_bitlen The key length to use, in Bits.
* \param operation The operation that the key will be used for:
* #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
const unsigned char *key,
int key_bitlen,
const mbedtls_operation_t operation );
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
/**
* \brief This function sets the padding mode, for cipher modes
* that use padding.
*
* The default passing mode is PKCS7 padding.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a cipher information structure.
* \param mode The padding mode.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
* if the selected padding mode is not supported.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
* does not support padding.
*/
int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
mbedtls_cipher_padding_t mode );
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
/**
* \brief This function sets the initialization vector (IV)
* or nonce.
*
* \note Some ciphers do not use IVs nor nonce. For these
* ciphers, this function has no effect.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a cipher information structure.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
* must be a readable buffer of at least \p iv_len Bytes.
* \param iv_len The IV length for ciphers with variable-size IV.
* This parameter is discarded by ciphers with fixed-size IV.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
*/
int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
const unsigned char *iv,
size_t iv_len );
/**
* \brief This function resets the cipher state.
*
* \param ctx The generic cipher context. This must be initialized.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
*/
int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
/**
* \brief This function adds additional data for AEAD ciphers.
* Currently supported with GCM and ChaCha20+Poly1305.
* This must be called exactly once, after
* mbedtls_cipher_reset().
*
* \param ctx The generic cipher context. This must be initialized.
* \param ad The additional data to use. This must be a readable
* buffer of at least \p ad_len Bytes.
* \param ad_len the Length of \p ad Bytes.
*
* \return \c 0 on success.
* \return A specific error code on failure.
*/
int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
const unsigned char *ad, size_t ad_len );
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
/**
* \brief The generic cipher update function. It encrypts or
* decrypts using the given cipher context. Writes as
* many block-sized blocks of data as possible to output.
* Any data that cannot be written immediately is either
* added to the next block, or flushed when
* mbedtls_cipher_finish() is called.
* Exception: For MBEDTLS_MODE_ECB, expects a single block
* in size. For example, 16 Bytes for AES.
*
* \note If the underlying cipher is used in GCM mode, all calls
* to this function, except for the last one before
* mbedtls_cipher_finish(), must have \p ilen as a
* multiple of the block size of the cipher.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a key.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes.
* \param ilen The length of the input data.
* \param output The buffer for the output data. This must be able to
* hold at least `ilen + block_size`. This must not be the
* same buffer as \p input.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written. This must not be
* \c NULL.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
* unsupported mode for a cipher.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
size_t ilen, unsigned char *output, size_t *olen );
/**
* \brief The generic cipher finalization function. If data still
* needs to be flushed from an incomplete block, the data
* contained in it is padded to the size of
* the last block, and written to the \p output buffer.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a key.
* \param output The buffer to write data to. This needs to be a writable
* buffer of at least \p block_size Bytes.
* \param olen The length of the data written to the \p output buffer.
* This may not be \c NULL.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
* expecting a full block but not receiving one.
* \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
unsigned char *output, size_t *olen );
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
/**
* \brief This function writes a tag for AEAD ciphers.
* Currently supported with GCM and ChaCha20+Poly1305.
* This must be called after mbedtls_cipher_finish().
*
* \param ctx The generic cipher context. This must be initialized,
* bound to a key, and have just completed a cipher
* operation through mbedtls_cipher_finish() the tag for
* which should be written.
* \param tag The buffer to write the tag to. This must be a writable
* buffer of at least \p tag_len Bytes.
* \param tag_len The length of the tag to write.
*
* \return \c 0 on success.
* \return A specific error code on failure.
*/
int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
unsigned char *tag, size_t tag_len );
/**
* \brief This function checks the tag for AEAD ciphers.
* Currently supported with GCM and ChaCha20+Poly1305.
* This must be called after mbedtls_cipher_finish().
*
* \param ctx The generic cipher context. This must be initialized.
* \param tag The buffer holding the tag. This must be a readable
* buffer of at least \p tag_len Bytes.
* \param tag_len The length of the tag to check.
*
* \return \c 0 on success.
* \return A specific error code on failure.
*/
int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
const unsigned char *tag, size_t tag_len );
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
/**
* \brief The generic all-in-one encryption/decryption function,
* for all ciphers except AEAD constructs.
*
* \param ctx The generic cipher context. This must be initialized.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* This must be a readable buffer of at least \p iv_len
* Bytes.
* \param iv_len The IV length for ciphers with variable-size IV.
* This parameter is discarded by ciphers with fixed-size
* IV.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes.
* \param ilen The length of the input data in Bytes.
* \param output The buffer for the output data. This must be able to
* hold at least `ilen + block_size`. This must not be the
* same buffer as \p input.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written. This must not be
* \c NULL.
*
* \note Some ciphers do not use IVs nor nonce. For these
* ciphers, use \p iv = NULL and \p iv_len = 0.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
* expecting a full block but not receiving one.
* \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen );
#if defined(MBEDTLS_CIPHER_MODE_AEAD)
/**
* \brief The generic autenticated encryption (AEAD) function.
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a key.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* This must be a readable buffer of at least \p iv_len
* Bytes.
* \param iv_len The IV length for ciphers with variable-size IV.
* This parameter is discarded by ciphers with fixed-size IV.
* \param ad The additional data to authenticate. This must be a
* readable buffer of at least \p ad_len Bytes.
* \param ad_len The length of \p ad.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes.
* \param ilen The length of the input data.
* \param output The buffer for the output data. This must be able to
* hold at least \p ilen Bytes.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written. This must not be
* \c NULL.
* \param tag The buffer for the authentication tag. This must be a
* writable buffer of at least \p tag_len Bytes.
* \param tag_len The desired length of the authentication tag.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len );
/**
* \brief The generic autenticated decryption (AEAD) function.
*
* \note If the data is not authentic, then the output buffer
* is zeroed out to prevent the unauthentic plaintext being
* used, making this interface safer.
*
* \param ctx The generic cipher context. This must be initialized and
* and bound to a key.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* This must be a readable buffer of at least \p iv_len
* Bytes.
* \param iv_len The IV length for ciphers with variable-size IV.
* This parameter is discarded by ciphers with fixed-size IV.
* \param ad The additional data to be authenticated. This must be a
* readable buffer of at least \p ad_len Bytes.
* \param ad_len The length of \p ad.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes.
* \param ilen The length of the input data.
* \param output The buffer for the output data.
* This must be able to hold at least \p ilen Bytes.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written. This must not be
* \c NULL.
* \param tag The buffer holding the authentication tag. This must be
* a readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication tag.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
* parameter-verification failure.
* \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
const unsigned char *tag, size_t tag_len );
#endif /* MBEDTLS_CIPHER_MODE_AEAD */
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_CIPHER_H */