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polarssl/include/mbedtls/cipher.h
Max Fillinger c3cffae420 Document return value for IV size getter on NULL 
Signed-off-by: Max Fillinger <max@max-fillinger.net>
2021-11-28 14:13:43 +01:00

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/**
* \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 The Mbed TLS Contributors
* 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.
*/
#ifndef MBEDTLS_CIPHER_H
#define MBEDTLS_CIPHER_H
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include <stddef.h>
#include "mbedtls/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_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
/** The selected feature is not available. */
#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080
/** Bad input parameters. */
#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100
/** Failed to allocate memory. */
#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180
/** Input data contains invalid padding and is rejected. */
#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200
/** Decryption of block requires a full block. */
#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280
/** Authentication failed (for AEAD modes). */
#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300
/** The context is invalid. For example, because it was freed. */
#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380
#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 DES is considered weak cipher and its 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_ARIA, /**< The Aria cipher. */
MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
} mbedtls_cipher_id_t;
/**
* \brief Supported {cipher type, cipher mode} pairs.
*
* \warning DES is considered weak cipher and its 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_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_AES_128_CCM_STAR_NO_TAG, /**< AES cipher with 128-bit CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_AES_192_CCM_STAR_NO_TAG, /**< AES cipher with 192-bit CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_AES_256_CCM_STAR_NO_TAG, /**< AES cipher with 256-bit CCM_STAR_NO_TAG 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_CAMELLIA_128_CCM_STAR_NO_TAG, /**< Camellia cipher with 128-bit CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_CAMELLIA_192_CCM_STAR_NO_TAG, /**< Camellia cipher with 192-bit CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_CAMELLIA_256_CCM_STAR_NO_TAG, /**< Camellia cipher with 256-bit CCM_STAR_NO_TAG 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_ARIA_128_CCM_STAR_NO_TAG, /**< Aria cipher with 128-bit key and CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_ARIA_192_CCM_STAR_NO_TAG, /**< Aria cipher with 192-bit key and CCM_STAR_NO_TAG mode. */
MBEDTLS_CIPHER_ARIA_256_CCM_STAR_NO_TAG, /**< Aria cipher with 256-bit key and CCM_STAR_NO_TAG 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_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
} 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_CCM_STAR_NO_TAG, /**< The CCM*-no-tag cipher mode. */
MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
MBEDTLS_MODE_KWP, /**< The SP800-38F KWP 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. */
/* This should ideally be derived automatically from list of ciphers.
* This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
* in library/ssl_misc.h. */
#define MBEDTLS_MAX_IV_LENGTH 16
/** Maximum block size of any cipher, in Bytes. */
/* This should ideally be derived automatically from list of ciphers.
* This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
* in library/ssl_misc.h. */
#define MBEDTLS_MAX_BLOCK_LENGTH 16
/** Maximum key length, in Bytes. */
/* This should ideally be derived automatically from list of ciphers.
* For now, only check whether XTS is enabled which uses 64 Byte keys,
* and use 32 Bytes as an upper bound for the maximum key length otherwise.
* This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
* in library/ssl_misc.h, which however deliberately ignores the case of XTS
* since the latter isn't used in SSL/TLS. */
#if defined(MBEDTLS_CIPHER_MODE_XTS)
#define MBEDTLS_MAX_KEY_LENGTH 64
#else
#define MBEDTLS_MAX_KEY_LENGTH 32
#endif /* MBEDTLS_CIPHER_MODE_XTS */
/**
* 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.
*
* \note The library does not support custom cipher info structures,
* only built-in structures returned by the functions
* mbedtls_cipher_info_from_string(),
* mbedtls_cipher_info_from_type(),
* mbedtls_cipher_info_from_values(),
* mbedtls_cipher_info_from_psa().
*/
typedef struct mbedtls_cipher_info_t
{
/** Full cipher identifier. For example,
* MBEDTLS_CIPHER_AES_256_CBC.
*/
mbedtls_cipher_type_t MBEDTLS_PRIVATE(type);
/** The cipher mode. For example, MBEDTLS_MODE_CBC. */
mbedtls_cipher_mode_t MBEDTLS_PRIVATE(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 MBEDTLS_PRIVATE(key_bitlen);
/** Name of the cipher. */
const char * MBEDTLS_PRIVATE(name);
/** IV or nonce size, in Bytes.
* For ciphers that accept variable IV sizes,
* this is the recommended size.
*/
unsigned int MBEDTLS_PRIVATE(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 MBEDTLS_PRIVATE(flags);
/** The block size, in Bytes. */
unsigned int MBEDTLS_PRIVATE(block_size);
/** Struct for base cipher information and functions. */
const mbedtls_cipher_base_t *MBEDTLS_PRIVATE(base);
} mbedtls_cipher_info_t;
/**
* Generic cipher context.
*/
typedef struct mbedtls_cipher_context_t
{
/** Information about the associated cipher. */
const mbedtls_cipher_info_t *MBEDTLS_PRIVATE(cipher_info);
/** Key length to use. */
int MBEDTLS_PRIVATE(key_bitlen);
/** Operation that the key of the context has been
* initialized for.
*/
mbedtls_operation_t MBEDTLS_PRIVATE(operation);
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
/** Padding functions to use, if relevant for
* the specific cipher mode.
*/
void (*MBEDTLS_PRIVATE(add_padding))( unsigned char *output, size_t olen, size_t data_len );
int (*MBEDTLS_PRIVATE(get_padding))( unsigned char *input, size_t ilen, size_t *data_len );
#endif
/** Buffer for input that has not been processed yet. */
unsigned char MBEDTLS_PRIVATE(unprocessed_data)[MBEDTLS_MAX_BLOCK_LENGTH];
/** Number of Bytes that have not been processed yet. */
size_t MBEDTLS_PRIVATE(unprocessed_len);
/** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
* for XTS-mode. */
unsigned char MBEDTLS_PRIVATE(iv)[MBEDTLS_MAX_IV_LENGTH];
/** IV size in Bytes, for ciphers with variable-length IVs. */
size_t MBEDTLS_PRIVATE(iv_size);
/** The cipher-specific context. */
void *MBEDTLS_PRIVATE(cipher_ctx);
#if defined(MBEDTLS_CMAC_C)
/** CMAC-specific context. */
mbedtls_cmac_context_t *MBEDTLS_PRIVATE(cmac_ctx);
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/** Indicates whether the cipher operations should be performed
* by Mbed TLS' own crypto library or an external implementation
* of the PSA Crypto API.
* This is unset if the cipher context was established through
* mbedtls_cipher_setup(), and set if it was established through
* mbedtls_cipher_setup_psa().
*/
unsigned char MBEDTLS_PRIVATE(psa_enabled);
#endif /* MBEDTLS_USE_PSA_CRYPTO */
} mbedtls_cipher_context_t;
/**
* \brief This function retrieves the list of ciphers supported
* by the generic cipher module.
*
* For any cipher identifier in the returned list, you can
* obtain the corresponding generic cipher information structure
* via mbedtls_cipher_info_from_type(), which can then be used
* to prepare a cipher context via mbedtls_cipher_setup().
*
*
* \return A statically-allocated array of cipher identifiers
* of type cipher_type_t. 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 Retrieve the identifier for a cipher info structure.
*
* \param[in] info The cipher info structure to query.
* This may be \c NULL.
*
* \return The full cipher identifier (\c MBEDTLS_CIPHER_xxx).
* \return #MBEDTLS_CIPHER_NONE if \p info is \c NULL.
*/
static inline mbedtls_cipher_type_t mbedtls_cipher_info_get_type(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( MBEDTLS_CIPHER_NONE );
else
return( info->MBEDTLS_PRIVATE(type) );
}
/**
* \brief Retrieve the operation mode for a cipher info structure.
*
* \param[in] info The cipher info structure to query.
* This may be \c NULL.
*
* \return The cipher mode (\c MBEDTLS_MODE_xxx).
* \return #MBEDTLS_MODE_NONE if \p info is \c NULL.
*/
static inline mbedtls_cipher_mode_t mbedtls_cipher_info_get_mode(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( MBEDTLS_MODE_NONE );
else
return( info->MBEDTLS_PRIVATE(mode) );
}
/**
* \brief Retrieve the key size for a cipher info structure.
*
* \param[in] info The cipher info structure to query.
* This may be \c NULL.
*
* \return The key length in bits.
* For variable-sized ciphers, this is the default length.
* For DES, this includes the parity bits.
* \return \c 0 if \p info is \c NULL.
*/
static inline size_t mbedtls_cipher_info_get_key_bitlen(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( 0 );
else
return( info->MBEDTLS_PRIVATE(key_bitlen) );
}
/**
* \brief Retrieve the human-readable name for a
* cipher info structure.
*
* \param[in] info The cipher info structure to query.
* This may be \c NULL.
*
* \return The cipher name, which is a human readable string,
* with static storage duration.
* \return \c NULL if \c info is \p NULL.
*/
static inline const char *mbedtls_cipher_info_get_name(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( NULL );
else
return( info->MBEDTLS_PRIVATE(name) );
}
/**
* \brief This function returns the size of the IV or nonce
* for the cipher info structure, in bytes.
*
* \param info The cipher info structure. This may be \c NULL.
*
* \return The recommended IV size.
* \return \c 0 for ciphers not using an IV or a nonce.
* \return \c 0 if \p info is \c NULL.
*/
static inline size_t mbedtls_cipher_info_get_iv_size(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( 0 );
return( (size_t) info->MBEDTLS_PRIVATE(iv_size) );
}
/**
* \brief This function returns the block size of the given
* cipher info structure in bytes.
*
* \param info The cipher info structure. This may be \c NULL.
*
* \return The block size of the cipher.
* \return \c 1 if the cipher is a stream cipher.
* \return \c 0 if \p info is \c NULL.
*/
static inline size_t mbedtls_cipher_info_get_block_size(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( 0 );
return( (size_t) info->MBEDTLS_PRIVATE(block_size) );
}
/**
* \brief This function returns a non-zero value if the key length for
* the given cipher is variable.
*
* \param info The cipher info structure. This may be \c NULL.
*
* \return Non-zero if the key length is variable, \c 0 otherwise.
* \return \c 0 if the given pointer is \c NULL.
*/
static inline int mbedtls_cipher_info_has_variable_key_bitlen(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( 0 );
return( info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_KEY_LEN );
}
/**
* \brief This function returns a non-zero value if the IV size for
* the given cipher is variable.
*
* \param info The cipher info structure. This may be \c NULL.
*
* \return Non-zero if the IV size is variable, \c 0 otherwise.
* \return \c 0 if the given pointer is \c NULL.
*/
static inline int mbedtls_cipher_info_has_variable_iv_size(
const mbedtls_cipher_info_t *info )
{
if( info == NULL )
return( 0 );
return( info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_IV_LEN );
}
/**
* \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 prepares a cipher context for
* use with the given cipher primitive.
*
* \note After calling this function, you should call
* mbedtls_cipher_setkey() and, if the mode uses padding,
* mbedtls_cipher_set_padding_mode(), then for each
* message to encrypt or decrypt with this key, either:
* - mbedtls_cipher_crypt() for one-shot processing with
* non-AEAD modes;
* - mbedtls_cipher_auth_encrypt_ext() or
* mbedtls_cipher_auth_decrypt_ext() for one-shot
* processing with AEAD modes or NIST_KW;
* - for multi-part processing, see the documentation of
* mbedtls_cipher_reset().
*
* \param ctx The context to prepare. This must be initialized by
* a call to mbedtls_cipher_init() first.
* \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.
*/
int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
const mbedtls_cipher_info_t *cipher_info );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
/**
* \brief This function initializes a cipher context for
* PSA-based use with the given cipher primitive.
*
* \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
*
* \param ctx The context to initialize. May not be \c NULL.
* \param cipher_info The cipher to use.
* \param taglen For AEAD ciphers, the length in bytes of the
* authentication tag to use. Subsequent uses of
* mbedtls_cipher_auth_encrypt_ext() or
* mbedtls_cipher_auth_decrypt_ext() must provide
* the same tag length.
* For non-AEAD ciphers, the value must be \c 0.
*
* \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.
*/
int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
const mbedtls_cipher_info_t *cipher_info,
size_t taglen );
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/**
* \brief This function returns the block size of the given cipher
* in bytes.
*
* \param ctx The context of the cipher.
*
* \return The block size of the underlying cipher.
* \return \c 1 if the cipher is a stream 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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return 0;
return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return MBEDTLS_MODE_NONE;
return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return 0;
if( ctx->MBEDTLS_PRIVATE(iv_size) != 0 )
return (int) ctx->MBEDTLS_PRIVATE(iv_size);
return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return MBEDTLS_CIPHER_NONE;
return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return 0;
return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return MBEDTLS_KEY_LENGTH_NONE;
return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(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->MBEDTLS_PRIVATE(cipher_info) == NULL )
return MBEDTLS_OPERATION_NONE;
return ctx->MBEDTLS_PRIVATE(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.
*
* \note With non-AEAD ciphers, the order of calls for each message
* is as follows:
* 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
* 2. mbedtls_cipher_reset()
* 3. mbedtls_cipher_update() one or more times
* 4. mbedtls_cipher_finish()
* .
* This sequence can be repeated to encrypt or decrypt multiple
* messages with the same key.
*
* \note With AEAD ciphers, the order of calls for each message
* is as follows:
* 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
* 2. mbedtls_cipher_reset()
* 3. mbedtls_cipher_update_ad()
* 4. mbedtls_cipher_update() one or more times
* 5. mbedtls_cipher_finish()
* 6. mbedtls_cipher_check_tag() (for decryption) or
* mbedtls_cipher_write_tag() (for encryption).
* .
* This sequence can be repeated to encrypt or decrypt multiple
* messages with the same key.
*
* \param ctx The generic cipher context. This must be bound to a key.
*
* \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.
*
* \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 in 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.
*
* \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) || defined(MBEDTLS_NIST_KW_C)
/**
* \brief The authenticated encryption (AEAD/NIST_KW) function.
*
* \note For AEAD modes, the tag will be appended to the
* ciphertext, as recommended by RFC 5116.
* (NIST_KW doesn't have a separate tag.)
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a key, with an AEAD algorithm or NIST_KW.
* \param iv The nonce to use. This must be a readable buffer of
* at least \p iv_len Bytes and may be \c NULL if \p
* iv_len is \c 0.
* \param iv_len The length of the nonce. For AEAD ciphers, this must
* satisfy the constraints imposed by the cipher used.
* For NIST_KW, this must be \c 0.
* \param ad The additional data to authenticate. This must be a
* readable buffer of at least \p ad_len Bytes, and may
* be \c NULL is \p ad_len is \c 0.
* \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes, and may be
* \c NULL if \p ilen is \c 0.
* \param ilen The length of the input data.
* \param output The buffer for the output data. This must be a
* writable buffer of at least \p output_len Bytes, and
* must not be \c NULL.
* \param output_len The length of the \p output buffer in Bytes. For AEAD
* ciphers, this must be at least \p ilen + \p tag_len.
* For NIST_KW, this must be at least \p ilen + 8
* (rounded up to a multiple of 8 if KWP is used);
* \p ilen + 15 is always a safe value.
* \param olen This will be filled with the actual number of Bytes
* written to the \p output buffer. This must point to a
* writable object of type \c size_t.
* \param tag_len The desired length of the authentication tag. For AEAD
* ciphers, this must match the constraints imposed by
* the cipher used, and in particular must not be \c 0.
* For NIST_KW, this must be \c 0.
*
* \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_ext( 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 output_len,
size_t *olen, size_t tag_len );
/**
* \brief The authenticated encryption (AEAD/NIST_KW) 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.
*
* \note For AEAD modes, the tag must be appended to the
* ciphertext, as recommended by RFC 5116.
* (NIST_KW doesn't have a separate tag.)
*
* \param ctx The generic cipher context. This must be initialized and
* bound to a key, with an AEAD algorithm or NIST_KW.
* \param iv The nonce to use. This must be a readable buffer of
* at least \p iv_len Bytes and may be \c NULL if \p
* iv_len is \c 0.
* \param iv_len The length of the nonce. For AEAD ciphers, this must
* satisfy the constraints imposed by the cipher used.
* For NIST_KW, this must be \c 0.
* \param ad The additional data to authenticate. This must be a
* readable buffer of at least \p ad_len Bytes, and may
* be \c NULL is \p ad_len is \c 0.
* \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
* \param input The buffer holding the input data. This must be a
* readable buffer of at least \p ilen Bytes, and may be
* \c NULL if \p ilen is \c 0.
* \param ilen The length of the input data. For AEAD ciphers this
* must be at least \p tag_len. For NIST_KW this must be
* at least \c 8.
* \param output The buffer for the output data. This must be a
* writable buffer of at least \p output_len Bytes, and
* may be \c NULL if \p output_len is \c 0.
* \param output_len The length of the \p output buffer in Bytes. For AEAD
* ciphers, this must be at least \p ilen - \p tag_len.
* For NIST_KW, this must be at least \p ilen - 8.
* \param olen This will be filled with the actual number of Bytes
* written to the \p output buffer. This must point to a
* writable object of type \c size_t.
* \param tag_len The actual length of the authentication tag. For AEAD
* ciphers, this must match the constraints imposed by
* the cipher used, and in particular must not be \c 0.
* For NIST_KW, this must be \c 0.
*
* \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_ext( 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 output_len,
size_t *olen, size_t tag_len );
#endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_CIPHER_H */
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