Simon Butcher 8c0fd1e881 Add cipher abstraction and test cases for OFB block mode
Adds OFB as additional block mode in the cipher abstraction, and additional
test cases for that block mode.
2018-06-11 14:03:22 +01:00

796 lines
34 KiB
C

/**
* \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: Apache-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.
*
* 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>
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_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)
#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. */
#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_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,
MBEDTLS_CIPHER_AES_192_OFB,
MBEDTLS_CIPHER_AES_256_OFB
} 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 - unsupported. */
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_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 {
/** 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 {
/** 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. */
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.
*
* \return The cipher information structure associated with the
* given \p cipher_name.
* \return 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 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 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.
*/
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.
*/
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. May not be NULL.
* \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. Must be initialized.
*
* \return The size of the blocks of the cipher.
* \return 0 if \p ctx has not been initialized.
*/
static inline unsigned int mbedtls_cipher_get_block_size( const mbedtls_cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->name;
}
/**
* \brief This function returns the key length of the cipher.
*
* \param ctx The context of the cipher. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. 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 )
{
if( NULL == ctx || NULL == ctx->cipher_info )
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. May not be NULL. Must have
* been initialized using mbedtls_cipher_info_from_type()
* or mbedtls_cipher_info_from_string().
* \param key The key to use.
* \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.
* \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.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* \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.
*
* \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)
/**
* \brief This function adds additional data for AEAD ciphers.
* Only supported with GCM. Must be called
* exactly once, after mbedtls_cipher_reset().
*
* \param ctx The generic cipher context.
* \param ad The additional data to use.
* \param ad_len the Length of \p ad.
*
* \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 */
/**
* \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.
* \param input The buffer holding the input data.
* \param ilen The length of the input data.
* \param output The buffer for the output data. Must be able to hold at
* least \p ilen + block_size. Must not be the same buffer
* as input.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written.
*
* \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.
* \param output The buffer to write data to. Needs block_size available.
* \param olen The length of the data written to the \p output buffer.
*
* \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)
/**
* \brief This function writes a tag for AEAD ciphers.
* Only supported with GCM.
* Must be called after mbedtls_cipher_finish().
*
* \param ctx The generic cipher context.
* \param tag The buffer to write the tag to.
* \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.
* Only supported with GCM.
* Must be called after mbedtls_cipher_finish().
*
* \param ctx The generic cipher context.
* \param tag The buffer holding the tag.
* \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 */
/**
* \brief The generic all-in-one encryption/decryption function,
* for all ciphers except AEAD constructs.
*
* \param ctx The generic cipher context.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* \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.
* \param ilen The length of the input data.
* \param output The buffer for the output data. Must be able to hold at
* least \p ilen + block_size. Must not be the same buffer
* as input.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written.
*
* \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.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* \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.
* \param ad_len The length of \p ad.
* \param input The buffer holding the input data.
* \param ilen The length of the input data.
* \param output The buffer for the output data.
* Must be able to hold at least \p ilen.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written.
* \param tag The buffer for the authentication tag.
* \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.
* \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
* \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.
* \param ad_len The length of \p ad.
* \param input The buffer holding the input data.
* \param ilen The length of the input data.
* \param output The buffer for the output data.
* Must be able to hold at least \p ilen.
* \param olen The length of the output data, to be updated with the
* actual number of Bytes written.
* \param tag The buffer holding the authentication tag.
* \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 */