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Diffstat (limited to 'include/mbedtls/cipher.h')
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diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h new file mode 100644 index 000000000..151da1d83 --- /dev/null +++ b/include/mbedtls/cipher.h @@ -0,0 +1,1166 @@ +/** + * \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 + +/** 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) +#if !defined(MBEDTLS_DEPRECATED_REMOVED) +/** + * \brief This function initializes a cipher context for + * PSA-based use with the given cipher primitive. + * + * \deprecated This function is deprecated and will be removed in a + * future version of the library. + * Please use psa_aead_xxx() / psa_cipher_xxx() directly + * instead. + * + * \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_DEPRECATED mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx, + const mbedtls_cipher_info_t *cipher_info, size_t taglen ); +#endif /* MBEDTLS_DEPRECATED_REMOVED */ +#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. + * + * \note For #MBEDTLS_CIPHER_CHACHA20, the nonce length must + * be 12, and the initial counter value is 0. + * + * \note For #MBEDTLS_CIPHER_CHACHA20_POLY1305, the nonce length + * must be 12. + * + * \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 */ |