cipher.h

00001 /**
00002  * \file cipher.h
00003  *
00004  * \brief This file contains an abstraction interface for use with the cipher
00005  * primitives provided by the library. It provides a common interface to all of
00006  * the available cipher operations.
00007  *
00008  * \author Adriaan de Jong <dejong@fox-it.com>
00009  */
00010 /*
00011  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
00012  *  SPDX-License-Identifier: Apache-2.0
00013  *
00014  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00015  *  not use this file except in compliance with the License.
00016  *  You may obtain a copy of the License at
00017  *
00018  *  http://www.apache.org/licenses/LICENSE-2.0
00019  *
00020  *  Unless required by applicable law or agreed to in writing, software
00021  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00022  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00023  *  See the License for the specific language governing permissions and
00024  *  limitations under the License.
00025  *
00026  *  This file is part of Mbed TLS (https://tls.mbed.org)
00027  */
00028 
00029 #ifndef MBEDTLS_CIPHER_H
00030 #define MBEDTLS_CIPHER_H
00031 
00032 #if !defined(MBEDTLS_CONFIG_FILE)
00033 #include "config.h"
00034 #else
00035 #include MBEDTLS_CONFIG_FILE
00036 #endif
00037 
00038 #include <stddef.h>
00039 
00040 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
00041 #define MBEDTLS_CIPHER_MODE_AEAD
00042 #endif
00043 
00044 #if defined(MBEDTLS_CIPHER_MODE_CBC)
00045 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
00046 #endif
00047 
00048 #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
00049     defined(MBEDTLS_CHACHA20_C)
00050 #define MBEDTLS_CIPHER_MODE_STREAM
00051 #endif
00052 
00053 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
00054     !defined(inline) && !defined(__cplusplus)
00055 #define inline __inline
00056 #endif
00057 
00058 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE  -0x6080  /**< The selected feature is not available. */
00059 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA       -0x6100  /**< Bad input parameters. */
00060 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED         -0x6180  /**< Failed to allocate memory. */
00061 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING      -0x6200  /**< Input data contains invalid padding and is rejected. */
00062 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED  -0x6280  /**< Decryption of block requires a full block. */
00063 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED          -0x6300  /**< Authentication failed (for AEAD modes). */
00064 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT      -0x6380  /**< The context is invalid. For example, because it was freed. */
00065 #define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED      -0x6400  /**< Cipher hardware accelerator failed. */
00066 
00067 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN     0x01    /**< Cipher accepts IVs of variable length. */
00068 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN    0x02    /**< Cipher accepts keys of variable length. */
00069 
00070 #ifdef __cplusplus
00071 extern "C" {
00072 #endif
00073 
00074 /**
00075  * \brief     Supported cipher types.
00076  *
00077  * \warning   RC4 and DES are considered weak ciphers and their use
00078  *            constitutes a security risk. Arm recommends considering stronger
00079  *            ciphers instead.
00080  */
00081 typedef enum {
00082     MBEDTLS_CIPHER_ID_NONE = 0,  /**< Placeholder to mark the end of cipher ID lists. */
00083     MBEDTLS_CIPHER_ID_NULL,      /**< The identity cipher, treated as a stream cipher. */
00084     MBEDTLS_CIPHER_ID_AES,       /**< The AES cipher. */
00085     MBEDTLS_CIPHER_ID_DES,       /**< The DES cipher. */
00086     MBEDTLS_CIPHER_ID_3DES,      /**< The Triple DES cipher. */
00087     MBEDTLS_CIPHER_ID_CAMELLIA,  /**< The Camellia cipher. */
00088     MBEDTLS_CIPHER_ID_BLOWFISH,  /**< The Blowfish cipher. */
00089     MBEDTLS_CIPHER_ID_ARC4,      /**< The RC4 cipher. */
00090     MBEDTLS_CIPHER_ID_ARIA,      /**< The Aria cipher. */
00091     MBEDTLS_CIPHER_ID_CHACHA20,  /**< The ChaCha20 cipher. */
00092 } mbedtls_cipher_id_t;
00093 
00094 /**
00095  * \brief     Supported {cipher type, cipher mode} pairs.
00096  *
00097  * \warning   RC4 and DES are considered weak ciphers and their use
00098  *            constitutes a security risk. Arm recommends considering stronger
00099  *            ciphers instead.
00100  */
00101 typedef enum {
00102     MBEDTLS_CIPHER_NONE = 0,             /**< Placeholder to mark the end of cipher-pair lists. */
00103     MBEDTLS_CIPHER_NULL,                 /**< The identity stream cipher. */
00104     MBEDTLS_CIPHER_AES_128_ECB,          /**< AES cipher with 128-bit ECB mode. */
00105     MBEDTLS_CIPHER_AES_192_ECB,          /**< AES cipher with 192-bit ECB mode. */
00106     MBEDTLS_CIPHER_AES_256_ECB,          /**< AES cipher with 256-bit ECB mode. */
00107     MBEDTLS_CIPHER_AES_128_CBC,          /**< AES cipher with 128-bit CBC mode. */
00108     MBEDTLS_CIPHER_AES_192_CBC,          /**< AES cipher with 192-bit CBC mode. */
00109     MBEDTLS_CIPHER_AES_256_CBC,          /**< AES cipher with 256-bit CBC mode. */
00110     MBEDTLS_CIPHER_AES_128_CFB128,       /**< AES cipher with 128-bit CFB128 mode. */
00111     MBEDTLS_CIPHER_AES_192_CFB128,       /**< AES cipher with 192-bit CFB128 mode. */
00112     MBEDTLS_CIPHER_AES_256_CFB128,       /**< AES cipher with 256-bit CFB128 mode. */
00113     MBEDTLS_CIPHER_AES_128_CTR,          /**< AES cipher with 128-bit CTR mode. */
00114     MBEDTLS_CIPHER_AES_192_CTR,          /**< AES cipher with 192-bit CTR mode. */
00115     MBEDTLS_CIPHER_AES_256_CTR,          /**< AES cipher with 256-bit CTR mode. */
00116     MBEDTLS_CIPHER_AES_128_GCM,          /**< AES cipher with 128-bit GCM mode. */
00117     MBEDTLS_CIPHER_AES_192_GCM,          /**< AES cipher with 192-bit GCM mode. */
00118     MBEDTLS_CIPHER_AES_256_GCM,          /**< AES cipher with 256-bit GCM mode. */
00119     MBEDTLS_CIPHER_CAMELLIA_128_ECB,     /**< Camellia cipher with 128-bit ECB mode. */
00120     MBEDTLS_CIPHER_CAMELLIA_192_ECB,     /**< Camellia cipher with 192-bit ECB mode. */
00121     MBEDTLS_CIPHER_CAMELLIA_256_ECB,     /**< Camellia cipher with 256-bit ECB mode. */
00122     MBEDTLS_CIPHER_CAMELLIA_128_CBC,     /**< Camellia cipher with 128-bit CBC mode. */
00123     MBEDTLS_CIPHER_CAMELLIA_192_CBC,     /**< Camellia cipher with 192-bit CBC mode. */
00124     MBEDTLS_CIPHER_CAMELLIA_256_CBC,     /**< Camellia cipher with 256-bit CBC mode. */
00125     MBEDTLS_CIPHER_CAMELLIA_128_CFB128,  /**< Camellia cipher with 128-bit CFB128 mode. */
00126     MBEDTLS_CIPHER_CAMELLIA_192_CFB128,  /**< Camellia cipher with 192-bit CFB128 mode. */
00127     MBEDTLS_CIPHER_CAMELLIA_256_CFB128,  /**< Camellia cipher with 256-bit CFB128 mode. */
00128     MBEDTLS_CIPHER_CAMELLIA_128_CTR,     /**< Camellia cipher with 128-bit CTR mode. */
00129     MBEDTLS_CIPHER_CAMELLIA_192_CTR,     /**< Camellia cipher with 192-bit CTR mode. */
00130     MBEDTLS_CIPHER_CAMELLIA_256_CTR,     /**< Camellia cipher with 256-bit CTR mode. */
00131     MBEDTLS_CIPHER_CAMELLIA_128_GCM,     /**< Camellia cipher with 128-bit GCM mode. */
00132     MBEDTLS_CIPHER_CAMELLIA_192_GCM,     /**< Camellia cipher with 192-bit GCM mode. */
00133     MBEDTLS_CIPHER_CAMELLIA_256_GCM,     /**< Camellia cipher with 256-bit GCM mode. */
00134     MBEDTLS_CIPHER_DES_ECB,              /**< DES cipher with ECB mode. */
00135     MBEDTLS_CIPHER_DES_CBC,              /**< DES cipher with CBC mode. */
00136     MBEDTLS_CIPHER_DES_EDE_ECB,          /**< DES cipher with EDE ECB mode. */
00137     MBEDTLS_CIPHER_DES_EDE_CBC,          /**< DES cipher with EDE CBC mode. */
00138     MBEDTLS_CIPHER_DES_EDE3_ECB,         /**< DES cipher with EDE3 ECB mode. */
00139     MBEDTLS_CIPHER_DES_EDE3_CBC,         /**< DES cipher with EDE3 CBC mode. */
00140     MBEDTLS_CIPHER_BLOWFISH_ECB,         /**< Blowfish cipher with ECB mode. */
00141     MBEDTLS_CIPHER_BLOWFISH_CBC,         /**< Blowfish cipher with CBC mode. */
00142     MBEDTLS_CIPHER_BLOWFISH_CFB64,       /**< Blowfish cipher with CFB64 mode. */
00143     MBEDTLS_CIPHER_BLOWFISH_CTR,         /**< Blowfish cipher with CTR mode. */
00144     MBEDTLS_CIPHER_ARC4_128,             /**< RC4 cipher with 128-bit mode. */
00145     MBEDTLS_CIPHER_AES_128_CCM,          /**< AES cipher with 128-bit CCM mode. */
00146     MBEDTLS_CIPHER_AES_192_CCM,          /**< AES cipher with 192-bit CCM mode. */
00147     MBEDTLS_CIPHER_AES_256_CCM,          /**< AES cipher with 256-bit CCM mode. */
00148     MBEDTLS_CIPHER_CAMELLIA_128_CCM,     /**< Camellia cipher with 128-bit CCM mode. */
00149     MBEDTLS_CIPHER_CAMELLIA_192_CCM,     /**< Camellia cipher with 192-bit CCM mode. */
00150     MBEDTLS_CIPHER_CAMELLIA_256_CCM,     /**< Camellia cipher with 256-bit CCM mode. */
00151     MBEDTLS_CIPHER_ARIA_128_ECB,         /**< Aria cipher with 128-bit key and ECB mode. */
00152     MBEDTLS_CIPHER_ARIA_192_ECB,         /**< Aria cipher with 192-bit key and ECB mode. */
00153     MBEDTLS_CIPHER_ARIA_256_ECB,         /**< Aria cipher with 256-bit key and ECB mode. */
00154     MBEDTLS_CIPHER_ARIA_128_CBC,         /**< Aria cipher with 128-bit key and CBC mode. */
00155     MBEDTLS_CIPHER_ARIA_192_CBC,         /**< Aria cipher with 192-bit key and CBC mode. */
00156     MBEDTLS_CIPHER_ARIA_256_CBC,         /**< Aria cipher with 256-bit key and CBC mode. */
00157     MBEDTLS_CIPHER_ARIA_128_CFB128,      /**< Aria cipher with 128-bit key and CFB-128 mode. */
00158     MBEDTLS_CIPHER_ARIA_192_CFB128,      /**< Aria cipher with 192-bit key and CFB-128 mode. */
00159     MBEDTLS_CIPHER_ARIA_256_CFB128,      /**< Aria cipher with 256-bit key and CFB-128 mode. */
00160     MBEDTLS_CIPHER_ARIA_128_CTR,         /**< Aria cipher with 128-bit key and CTR mode. */
00161     MBEDTLS_CIPHER_ARIA_192_CTR,         /**< Aria cipher with 192-bit key and CTR mode. */
00162     MBEDTLS_CIPHER_ARIA_256_CTR,         /**< Aria cipher with 256-bit key and CTR mode. */
00163     MBEDTLS_CIPHER_ARIA_128_GCM,         /**< Aria cipher with 128-bit key and GCM mode. */
00164     MBEDTLS_CIPHER_ARIA_192_GCM,         /**< Aria cipher with 192-bit key and GCM mode. */
00165     MBEDTLS_CIPHER_ARIA_256_GCM,         /**< Aria cipher with 256-bit key and GCM mode. */
00166     MBEDTLS_CIPHER_ARIA_128_CCM,         /**< Aria cipher with 128-bit key and CCM mode. */
00167     MBEDTLS_CIPHER_ARIA_192_CCM,         /**< Aria cipher with 192-bit key and CCM mode. */
00168     MBEDTLS_CIPHER_ARIA_256_CCM,         /**< Aria cipher with 256-bit key and CCM mode. */
00169     MBEDTLS_CIPHER_AES_128_OFB,          /**< AES 128-bit cipher in OFB mode. */
00170     MBEDTLS_CIPHER_AES_192_OFB,          /**< AES 192-bit cipher in OFB mode. */
00171     MBEDTLS_CIPHER_AES_256_OFB,          /**< AES 256-bit cipher in OFB mode. */
00172     MBEDTLS_CIPHER_AES_128_XTS,          /**< AES 128-bit cipher in XTS block mode. */
00173     MBEDTLS_CIPHER_AES_256_XTS,          /**< AES 256-bit cipher in XTS block mode. */
00174     MBEDTLS_CIPHER_CHACHA20,             /**< ChaCha20 stream cipher. */
00175     MBEDTLS_CIPHER_CHACHA20_POLY1305,    /**< ChaCha20-Poly1305 AEAD cipher. */
00176 } mbedtls_cipher_type_t;
00177 
00178 /** Supported cipher modes. */
00179 typedef enum {
00180     MBEDTLS_MODE_NONE = 0,               /**< None. */
00181     MBEDTLS_MODE_ECB,                    /**< The ECB cipher mode. */
00182     MBEDTLS_MODE_CBC,                    /**< The CBC cipher mode. */
00183     MBEDTLS_MODE_CFB,                    /**< The CFB cipher mode. */
00184     MBEDTLS_MODE_OFB,                    /**< The OFB cipher mode. */
00185     MBEDTLS_MODE_CTR,                    /**< The CTR cipher mode. */
00186     MBEDTLS_MODE_GCM,                    /**< The GCM cipher mode. */
00187     MBEDTLS_MODE_STREAM,                 /**< The stream cipher mode. */
00188     MBEDTLS_MODE_CCM,                    /**< The CCM cipher mode. */
00189     MBEDTLS_MODE_XTS,                    /**< The XTS cipher mode. */
00190     MBEDTLS_MODE_CHACHAPOLY,             /**< The ChaCha-Poly cipher mode. */
00191 } mbedtls_cipher_mode_t;
00192 
00193 /** Supported cipher padding types. */
00194 typedef enum {
00195     MBEDTLS_PADDING_PKCS7 = 0,     /**< PKCS7 padding (default).        */
00196     MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding.         */
00197     MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding.             */
00198     MBEDTLS_PADDING_ZEROS,         /**< Zero padding (not reversible). */
00199     MBEDTLS_PADDING_NONE,          /**< Never pad (full blocks only).   */
00200 } mbedtls_cipher_padding_t;
00201 
00202 /** Type of operation. */
00203 typedef enum {
00204     MBEDTLS_OPERATION_NONE = -1,
00205     MBEDTLS_DECRYPT = 0,
00206     MBEDTLS_ENCRYPT,
00207 } mbedtls_operation_t;
00208 
00209 enum {
00210     /** Undefined key length. */
00211     MBEDTLS_KEY_LENGTH_NONE = 0,
00212     /** Key length, in bits (including parity), for DES keys. */
00213     MBEDTLS_KEY_LENGTH_DES  = 64,
00214     /** Key length in bits, including parity, for DES in two-key EDE. */
00215     MBEDTLS_KEY_LENGTH_DES_EDE = 128,
00216     /** Key length in bits, including parity, for DES in three-key EDE. */
00217     MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
00218 };
00219 
00220 /** Maximum length of any IV, in Bytes. */
00221 #define MBEDTLS_MAX_IV_LENGTH      16
00222 /** Maximum block size of any cipher, in Bytes. */
00223 #define MBEDTLS_MAX_BLOCK_LENGTH   16
00224 
00225 /**
00226  * Base cipher information (opaque struct).
00227  */
00228 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
00229 
00230 /**
00231  * CMAC context (opaque struct).
00232  */
00233 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
00234 
00235 /**
00236  * Cipher information. Allows calling cipher functions
00237  * in a generic way.
00238  */
00239 typedef struct mbedtls_cipher_info_t
00240 {
00241     /** Full cipher identifier. For example,
00242      * MBEDTLS_CIPHER_AES_256_CBC.
00243      */
00244     mbedtls_cipher_type_t type;
00245 
00246     /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
00247     mbedtls_cipher_mode_t mode;
00248 
00249     /** The cipher key length, in bits. This is the
00250      * default length for variable sized ciphers.
00251      * Includes parity bits for ciphers like DES.
00252      */
00253     unsigned int key_bitlen;
00254 
00255     /** Name of the cipher. */
00256     const char * name;
00257 
00258     /** IV or nonce size, in Bytes.
00259      * For ciphers that accept variable IV sizes,
00260      * this is the recommended size.
00261      */
00262     unsigned int iv_size;
00263 
00264     /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
00265      *  MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
00266      *  cipher supports variable IV or variable key sizes, respectively.
00267      */
00268     int flags;
00269 
00270     /** The block size, in Bytes. */
00271     unsigned int block_size;
00272 
00273     /** Struct for base cipher information and functions. */
00274     const mbedtls_cipher_base_t *base;
00275 
00276 } mbedtls_cipher_info_t;
00277 
00278 /**
00279  * Generic cipher context.
00280  */
00281 typedef struct mbedtls_cipher_context_t
00282 {
00283     /** Information about the associated cipher. */
00284     const mbedtls_cipher_info_t *cipher_info;
00285 
00286     /** Key length to use. */
00287     int key_bitlen;
00288 
00289     /** Operation that the key of the context has been
00290      * initialized for.
00291      */
00292     mbedtls_operation_t operation;
00293 
00294 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
00295     /** Padding functions to use, if relevant for
00296      * the specific cipher mode.
00297      */
00298     void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
00299     int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
00300 #endif
00301 
00302     /** Buffer for input that has not been processed yet. */
00303     unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
00304 
00305     /** Number of Bytes that have not been processed yet. */
00306     size_t unprocessed_len;
00307 
00308     /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
00309      * for XTS-mode. */
00310     unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
00311 
00312     /** IV size in Bytes, for ciphers with variable-length IVs. */
00313     size_t iv_size;
00314 
00315     /** The cipher-specific context. */
00316     void *cipher_ctx;
00317 
00318 #if defined(MBEDTLS_CMAC_C)
00319     /** CMAC-specific context. */
00320     mbedtls_cmac_context_t *cmac_ctx;
00321 #endif
00322 } mbedtls_cipher_context_t;
00323 
00324 /**
00325  * \brief This function retrieves the list of ciphers supported by the generic
00326  * cipher module.
00327  *
00328  * \return      A statically-allocated array of ciphers. The last entry
00329  *              is zero.
00330  */
00331 const int *mbedtls_cipher_list( void );
00332 
00333 /**
00334  * \brief               This function retrieves the cipher-information
00335  *                      structure associated with the given cipher name.
00336  *
00337  * \param cipher_name   Name of the cipher to search for.
00338  *
00339  * \return              The cipher information structure associated with the
00340  *                      given \p cipher_name.
00341  * \return              NULL if the associated cipher information is not found.
00342  */
00343 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
00344 
00345 /**
00346  * \brief               This function retrieves the cipher-information
00347  *                      structure associated with the given cipher type.
00348  *
00349  * \param cipher_type   Type of the cipher to search for.
00350  *
00351  * \return              The cipher information structure associated with the
00352  *                      given \p cipher_type.
00353  * \return              NULL if the associated cipher information is not found.
00354  */
00355 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
00356 
00357 /**
00358  * \brief               This function retrieves the cipher-information
00359  *                      structure associated with the given cipher ID,
00360  *                      key size and mode.
00361  *
00362  * \param cipher_id     The ID of the cipher to search for. For example,
00363  *                      #MBEDTLS_CIPHER_ID_AES.
00364  * \param key_bitlen    The length of the key in bits.
00365  * \param mode          The cipher mode. For example, #MBEDTLS_MODE_CBC.
00366  *
00367  * \return              The cipher information structure associated with the
00368  *                      given \p cipher_id.
00369  * \return              NULL if the associated cipher information is not found.
00370  */
00371 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
00372                                               int key_bitlen,
00373                                               const mbedtls_cipher_mode_t mode );
00374 
00375 /**
00376  * \brief               This function initializes a \p cipher_context as NONE.
00377  */
00378 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
00379 
00380 /**
00381  * \brief               This function frees and clears the cipher-specific
00382  *                      context of \p ctx. Freeing \p ctx itself remains the
00383  *                      responsibility of the caller.
00384  */
00385 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
00386 
00387 
00388 /**
00389  * \brief               This function initializes and fills the cipher-context
00390  *                      structure with the appropriate values. It also clears
00391  *                      the structure.
00392  *
00393  * \param ctx           The context to initialize. May not be NULL.
00394  * \param cipher_info   The cipher to use.
00395  *
00396  * \return              \c 0 on success.
00397  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00398  *                      parameter-verification failure.
00399  * \return              #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
00400  *                      cipher-specific context fails.
00401  *
00402  * \internal Currently, the function also clears the structure.
00403  * In future versions, the caller will be required to call
00404  * mbedtls_cipher_init() on the structure first.
00405  */
00406 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info );
00407 
00408 /**
00409  * \brief        This function returns the block size of the given cipher.
00410  *
00411  * \param ctx    The context of the cipher. Must be initialized.
00412  *
00413  * \return       The size of the blocks of the cipher.
00414  * \return       0 if \p ctx has not been initialized.
00415  */
00416 static inline unsigned int mbedtls_cipher_get_block_size( const mbedtls_cipher_context_t *ctx )
00417 {
00418     if( NULL == ctx || NULL == ctx->cipher_info )
00419         return 0;
00420 
00421     return ctx->cipher_info->block_size;
00422 }
00423 
00424 /**
00425  * \brief        This function returns the mode of operation for
00426  *               the cipher. For example, MBEDTLS_MODE_CBC.
00427  *
00428  * \param ctx    The context of the cipher. Must be initialized.
00429  *
00430  * \return       The mode of operation.
00431  * \return       #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
00432  */
00433 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode( const mbedtls_cipher_context_t *ctx )
00434 {
00435     if( NULL == ctx || NULL == ctx->cipher_info )
00436         return MBEDTLS_MODE_NONE;
00437 
00438     return ctx->cipher_info->mode;
00439 }
00440 
00441 /**
00442  * \brief       This function returns the size of the IV or nonce
00443  *              of the cipher, in Bytes.
00444  *
00445  * \param ctx   The context of the cipher. Must be initialized.
00446  *
00447  * \return      The recommended IV size if no IV has been set.
00448  * \return      \c 0 for ciphers not using an IV or a nonce.
00449  * \return      The actual size if an IV has been set.
00450  */
00451 static inline int mbedtls_cipher_get_iv_size( const mbedtls_cipher_context_t *ctx )
00452 {
00453     if( NULL == ctx || NULL == ctx->cipher_info )
00454         return 0;
00455 
00456     if( ctx->iv_size != 0 )
00457         return (int) ctx->iv_size;
00458 
00459     return (int) ctx->cipher_info->iv_size;
00460 }
00461 
00462 /**
00463  * \brief               This function returns the type of the given cipher.
00464  *
00465  * \param ctx           The context of the cipher. Must be initialized.
00466  *
00467  * \return              The type of the cipher.
00468  * \return              #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
00469  */
00470 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type( const mbedtls_cipher_context_t *ctx )
00471 {
00472     if( NULL == ctx || NULL == ctx->cipher_info )
00473         return MBEDTLS_CIPHER_NONE;
00474 
00475     return ctx->cipher_info->type;
00476 }
00477 
00478 /**
00479  * \brief               This function returns the name of the given cipher
00480  *                      as a string.
00481  *
00482  * \param ctx           The context of the cipher. Must be initialized.
00483  *
00484  * \return              The name of the cipher.
00485  * \return              NULL if \p ctx has not been not initialized.
00486  */
00487 static inline const char *mbedtls_cipher_get_name( const mbedtls_cipher_context_t *ctx )
00488 {
00489     if( NULL == ctx || NULL == ctx->cipher_info )
00490         return 0;
00491 
00492     return ctx->cipher_info->name;
00493 }
00494 
00495 /**
00496  * \brief               This function returns the key length of the cipher.
00497  *
00498  * \param ctx           The context of the cipher. Must be initialized.
00499  *
00500  * \return              The key length of the cipher in bits.
00501  * \return              #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
00502  *                      initialized.
00503  */
00504 static inline int mbedtls_cipher_get_key_bitlen( const mbedtls_cipher_context_t *ctx )
00505 {
00506     if( NULL == ctx || NULL == ctx->cipher_info )
00507         return MBEDTLS_KEY_LENGTH_NONE;
00508 
00509     return (int) ctx->cipher_info->key_bitlen;
00510 }
00511 
00512 /**
00513  * \brief          This function returns the operation of the given cipher.
00514  *
00515  * \param ctx      The context of the cipher. Must be initialized.
00516  *
00517  * \return         The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
00518  * \return         #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
00519  */
00520 static inline mbedtls_operation_t mbedtls_cipher_get_operation( const mbedtls_cipher_context_t *ctx )
00521 {
00522     if( NULL == ctx || NULL == ctx->cipher_info )
00523         return MBEDTLS_OPERATION_NONE;
00524 
00525     return ctx->operation;
00526 }
00527 
00528 /**
00529  * \brief               This function sets the key to use with the given context.
00530  *
00531  * \param ctx           The generic cipher context. May not be NULL. Must have
00532  *                      been initialized using mbedtls_cipher_info_from_type()
00533  *                      or mbedtls_cipher_info_from_string().
00534  * \param key           The key to use.
00535  * \param key_bitlen    The key length to use, in bits.
00536  * \param operation     The operation that the key will be used for:
00537  *                      #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
00538  *
00539  * \return              \c 0 on success.
00540  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00541  *                      parameter-verification failure.
00542  * \return              A cipher-specific error code on failure.
00543  */
00544 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *key,
00545                    int key_bitlen, const mbedtls_operation_t operation );
00546 
00547 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
00548 /**
00549  * \brief               This function sets the padding mode, for cipher modes
00550  *                      that use padding.
00551  *
00552  *                      The default passing mode is PKCS7 padding.
00553  *
00554  * \param ctx           The generic cipher context.
00555  * \param mode          The padding mode.
00556  *
00557  * \return              \c 0 on success.
00558  * \return              #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
00559  *                      if the selected padding mode is not supported.
00560  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
00561  *                      does not support padding.
00562  */
00563 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode );
00564 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
00565 
00566 /**
00567  * \brief           This function sets the initialization vector (IV)
00568  *                  or nonce.
00569  *
00570  * \note            Some ciphers do not use IVs nor nonce. For these
00571  *                  ciphers, this function has no effect.
00572  *
00573  * \param ctx       The generic cipher context.
00574  * \param iv        The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
00575  * \param iv_len    The IV length for ciphers with variable-size IV.
00576  *                  This parameter is discarded by ciphers with fixed-size IV.
00577  *
00578  * \return          \c 0 on success.
00579  * \return          #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00580  *                  parameter-verification failure.
00581  */
00582 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
00583                    const unsigned char *iv, size_t iv_len );
00584 
00585 /**
00586  * \brief         This function resets the cipher state.
00587  *
00588  * \param ctx     The generic cipher context.
00589  *
00590  * \return        \c 0 on success.
00591  * \return        #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00592  *                parameter-verification failure.
00593  */
00594 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
00595 
00596 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
00597 /**
00598  * \brief               This function adds additional data for AEAD ciphers.
00599  *                      Currently supported with GCM and ChaCha20+Poly1305.
00600  *                      Must be called exactly once, after mbedtls_cipher_reset().
00601  *
00602  * \param ctx           The generic cipher context.
00603  * \param ad            The additional data to use.
00604  * \param ad_len        the Length of \p ad.
00605  *
00606  * \return              \c 0 on success.
00607  * \return              A specific error code on failure.
00608  */
00609 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
00610                       const unsigned char *ad, size_t ad_len );
00611 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
00612 
00613 /**
00614  * \brief               The generic cipher update function. It encrypts or
00615  *                      decrypts using the given cipher context. Writes as
00616  *                      many block-sized blocks of data as possible to output.
00617  *                      Any data that cannot be written immediately is either
00618  *                      added to the next block, or flushed when
00619  *                      mbedtls_cipher_finish() is called.
00620  *                      Exception: For MBEDTLS_MODE_ECB, expects a single block
00621  *                      in size. For example, 16 Bytes for AES.
00622  *
00623  * \note                If the underlying cipher is used in GCM mode, all calls
00624  *                      to this function, except for the last one before
00625  *                      mbedtls_cipher_finish(), must have \p ilen as a
00626  *                      multiple of the block size of the cipher.
00627  *
00628  * \param ctx           The generic cipher context.
00629  * \param input         The buffer holding the input data.
00630  * \param ilen          The length of the input data.
00631  * \param output        The buffer for the output data. Must be able to hold at
00632  *                      least \p ilen + block_size. Must not be the same buffer
00633  *                      as input.
00634  * \param olen          The length of the output data, to be updated with the
00635  *                      actual number of Bytes written.
00636  *
00637  * \return              \c 0 on success.
00638  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00639  *                      parameter-verification failure.
00640  * \return              #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
00641  *                      unsupported mode for a cipher.
00642  * \return              A cipher-specific error code on failure.
00643  */
00644 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
00645                    size_t ilen, unsigned char *output, size_t *olen );
00646 
00647 /**
00648  * \brief               The generic cipher finalization function. If data still
00649  *                      needs to be flushed from an incomplete block, the data
00650  *                      contained in it is padded to the size of
00651  *                      the last block, and written to the \p output buffer.
00652  *
00653  * \param ctx           The generic cipher context.
00654  * \param output        The buffer to write data to. Needs block_size available.
00655  * \param olen          The length of the data written to the \p output buffer.
00656  *
00657  * \return              \c 0 on success.
00658  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00659  *                      parameter-verification failure.
00660  * \return              #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
00661  *                      expecting a full block but not receiving one.
00662  * \return              #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
00663  *                      while decrypting.
00664  * \return              A cipher-specific error code on failure.
00665  */
00666 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
00667                    unsigned char *output, size_t *olen );
00668 
00669 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
00670 /**
00671  * \brief               This function writes a tag for AEAD ciphers.
00672  *                      Currently supported with GCM and ChaCha20+Poly1305.
00673  *                      Must be called after mbedtls_cipher_finish().
00674  *
00675  * \param ctx           The generic cipher context.
00676  * \param tag           The buffer to write the tag to.
00677  * \param tag_len       The length of the tag to write.
00678  *
00679  * \return              \c 0 on success.
00680  * \return              A specific error code on failure.
00681  */
00682 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
00683                       unsigned char *tag, size_t tag_len );
00684 
00685 /**
00686  * \brief               This function checks the tag for AEAD ciphers.
00687  *                      Currently supported with GCM and ChaCha20+Poly1305.
00688  *                      Must be called after mbedtls_cipher_finish().
00689  *
00690  * \param ctx           The generic cipher context.
00691  * \param tag           The buffer holding the tag.
00692  * \param tag_len       The length of the tag to check.
00693  *
00694  * \return              \c 0 on success.
00695  * \return              A specific error code on failure.
00696  */
00697 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
00698                       const unsigned char *tag, size_t tag_len );
00699 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
00700 
00701 /**
00702  * \brief               The generic all-in-one encryption/decryption function,
00703  *                      for all ciphers except AEAD constructs.
00704  *
00705  * \param ctx           The generic cipher context.
00706  * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
00707  * \param iv_len        The IV length for ciphers with variable-size IV.
00708  *                      This parameter is discarded by ciphers with fixed-size
00709  *                      IV.
00710  * \param input         The buffer holding the input data.
00711  * \param ilen          The length of the input data.
00712  * \param output        The buffer for the output data. Must be able to hold at
00713  *                      least \p ilen + block_size. Must not be the same buffer
00714  *                      as input.
00715  * \param olen          The length of the output data, to be updated with the
00716  *                      actual number of Bytes written.
00717  *
00718  * \note                Some ciphers do not use IVs nor nonce. For these
00719  *                      ciphers, use \p iv = NULL and \p iv_len = 0.
00720  *
00721  * \return              \c 0 on success.
00722  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00723  *                      parameter-verification failure.
00724  * \return              #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
00725  *                      expecting a full block but not receiving one.
00726  * \return              #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
00727  *                      while decrypting.
00728  * \return              A cipher-specific error code on failure.
00729  */
00730 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
00731                   const unsigned char *iv, size_t iv_len,
00732                   const unsigned char *input, size_t ilen,
00733                   unsigned char *output, size_t *olen );
00734 
00735 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
00736 /**
00737  * \brief               The generic autenticated encryption (AEAD) function.
00738  *
00739  * \param ctx           The generic cipher context.
00740  * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
00741  * \param iv_len        The IV length for ciphers with variable-size IV.
00742  *                      This parameter is discarded by ciphers with fixed-size IV.
00743  * \param ad            The additional data to authenticate.
00744  * \param ad_len        The length of \p ad.
00745  * \param input         The buffer holding the input data.
00746  * \param ilen          The length of the input data.
00747  * \param output        The buffer for the output data.
00748  *                      Must be able to hold at least \p ilen.
00749  * \param olen          The length of the output data, to be updated with the
00750  *                      actual number of Bytes written.
00751  * \param tag           The buffer for the authentication tag.
00752  * \param tag_len       The desired length of the authentication tag.
00753  *
00754  * \return              \c 0 on success.
00755  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00756  *                      parameter-verification failure.
00757  * \return              A cipher-specific error code on failure.
00758  */
00759 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
00760                          const unsigned char *iv, size_t iv_len,
00761                          const unsigned char *ad, size_t ad_len,
00762                          const unsigned char *input, size_t ilen,
00763                          unsigned char *output, size_t *olen,
00764                          unsigned char *tag, size_t tag_len );
00765 
00766 /**
00767  * \brief               The generic autenticated decryption (AEAD) function.
00768  *
00769  * \note                If the data is not authentic, then the output buffer
00770  *                      is zeroed out to prevent the unauthentic plaintext being
00771  *                      used, making this interface safer.
00772  *
00773  * \param ctx           The generic cipher context.
00774  * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
00775  * \param iv_len        The IV length for ciphers with variable-size IV.
00776  *                      This parameter is discarded by ciphers with fixed-size IV.
00777  * \param ad            The additional data to be authenticated.
00778  * \param ad_len        The length of \p ad.
00779  * \param input         The buffer holding the input data.
00780  * \param ilen          The length of the input data.
00781  * \param output        The buffer for the output data.
00782  *                      Must be able to hold at least \p ilen.
00783  * \param olen          The length of the output data, to be updated with the
00784  *                      actual number of Bytes written.
00785  * \param tag           The buffer holding the authentication tag.
00786  * \param tag_len       The length of the authentication tag.
00787  *
00788  * \return              \c 0 on success.
00789  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
00790  *                      parameter-verification failure.
00791  * \return              #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
00792  * \return              A cipher-specific error code on failure.
00793  */
00794 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
00795                          const unsigned char *iv, size_t iv_len,
00796                          const unsigned char *ad, size_t ad_len,
00797                          const unsigned char *input, size_t ilen,
00798                          unsigned char *output, size_t *olen,
00799                          const unsigned char *tag, size_t tag_len );
00800 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
00801 
00802 #ifdef __cplusplus
00803 }
00804 #endif
00805 
00806 #endif /* MBEDTLS_CIPHER_H */