ccm.h

00001 /**
00002  * \file ccm.h
00003  *
00004  * \brief CCM combines Counter mode encryption with CBC-MAC authentication
00005  *        for 128-bit block ciphers.
00006  *
00007  * Input to CCM includes the following elements:
00008  * <ul><li>Payload - data that is both authenticated and encrypted.</li>
00009  * <li>Associated data (Adata) - data that is authenticated but not
00010  * encrypted, For example, a header.</li>
00011  * <li>Nonce - A unique value that is assigned to the payload and the
00012  * associated data.</li></ul>
00013  *
00014  */
00015 /*
00016  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
00017  *  SPDX-License-Identifier: Apache-2.0
00018  *
00019  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00020  *  not use this file except in compliance with the License.
00021  *  You may obtain a copy of the License at
00022  *
00023  *  http://www.apache.org/licenses/LICENSE-2.0
00024  *
00025  *  Unless required by applicable law or agreed to in writing, software
00026  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00027  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00028  *  See the License for the specific language governing permissions and
00029  *  limitations under the License.
00030  *
00031  *  This file is part of Mbed TLS (https://tls.mbed.org)
00032  */
00033 
00034 #ifndef MBEDTLS_CCM_H
00035 #define MBEDTLS_CCM_H
00036 
00037 #include "cipher.h"
00038 
00039 #define MBEDTLS_ERR_CCM_BAD_INPUT       -0x000D /**< Bad input parameters to the function. */
00040 #define MBEDTLS_ERR_CCM_AUTH_FAILED     -0x000F /**< Authenticated decryption failed. */
00041 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */
00042 
00043 #if !defined(MBEDTLS_CCM_ALT)
00044 // Regular implementation
00045 //
00046 
00047 #ifdef __cplusplus
00048 extern "C" {
00049 #endif
00050 
00051 /**
00052  * \brief    The CCM context-type definition. The CCM context is passed
00053  *           to the APIs called.
00054  */
00055 typedef struct {
00056     mbedtls_cipher_context_t cipher_ctx ;    /*!< The cipher context used. */
00057 }
00058 mbedtls_ccm_context;
00059 
00060 /**
00061  * \brief           This function initializes the specified CCM context,
00062  *                  to make references valid, and prepare the context
00063  *                  for mbedtls_ccm_setkey() or mbedtls_ccm_free().
00064  *
00065  * \param ctx       The CCM context to initialize.
00066  */
00067 void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
00068 
00069 /**
00070  * \brief           This function initializes the CCM context set in the
00071  *                  \p ctx parameter and sets the encryption key.
00072  *
00073  * \param ctx       The CCM context to initialize.
00074  * \param cipher    The 128-bit block cipher to use.
00075  * \param key       The encryption key.
00076  * \param keybits   The key size in bits. This must be acceptable by the cipher.
00077  *
00078  * \return          \c 0 on success, or a cipher-specific error code.
00079  */
00080 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
00081                         mbedtls_cipher_id_t cipher,
00082                         const unsigned char *key,
00083                         unsigned int keybits );
00084 
00085 /**
00086  * \brief   This function releases and clears the specified CCM context
00087  *          and underlying cipher sub-context.
00088  *
00089  * \param ctx       The CCM context to clear.
00090  */
00091 void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
00092 
00093 /**
00094  * \brief           This function encrypts a buffer using CCM.
00095  *
00096  * \param ctx       The CCM context to use for encryption.
00097  * \param length    The length of the input data in Bytes.
00098  * \param iv        Initialization vector (nonce).
00099  * \param iv_len    The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
00100  * \param add       The additional data field.
00101  * \param add_len   The length of additional data in Bytes.
00102  *                  Must be less than 2^16 - 2^8.
00103  * \param input     The buffer holding the input data.
00104  * \param output    The buffer holding the output data.
00105  *                  Must be at least \p length Bytes wide.
00106  * \param tag       The buffer holding the tag.
00107  * \param tag_len   The length of the tag to generate in Bytes:
00108  *                  4, 6, 8, 10, 12, 14 or 16.
00109  *
00110  * \note            The tag is written to a separate buffer. To concatenate
00111  *                  the \p tag with the \p output, as done in <em>RFC-3610:
00112  *                  Counter with CBC-MAC (CCM)</em>, use
00113  *                  \p tag = \p output + \p length, and make sure that the
00114  *                  output buffer is at least \p length + \p tag_len wide.
00115  *
00116  * \return          \c 0 on success.
00117  */
00118 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
00119                          const unsigned char *iv, size_t iv_len,
00120                          const unsigned char *add, size_t add_len,
00121                          const unsigned char *input, unsigned char *output,
00122                          unsigned char *tag, size_t tag_len );
00123 
00124 /**
00125  * \brief           This function performs a CCM authenticated decryption of a
00126  *                  buffer.
00127  *
00128  * \param ctx       The CCM context to use for decryption.
00129  * \param length    The length of the input data in Bytes.
00130  * \param iv        Initialization vector.
00131  * \param iv_len    The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
00132  * \param add       The additional data field.
00133  * \param add_len   The length of additional data in Bytes.
00134  *                  Must be less than 2^16 - 2^8.
00135  * \param input     The buffer holding the input data.
00136  * \param output    The buffer holding the output data.
00137  *                  Must be at least \p length Bytes wide.
00138  * \param tag       The buffer holding the tag.
00139  * \param tag_len   The length of the tag in Bytes.
00140  *                  4, 6, 8, 10, 12, 14 or 16.
00141  *
00142  * \return          0 if successful and authenticated, or
00143  *                  #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
00144  */
00145 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
00146                       const unsigned char *iv, size_t iv_len,
00147                       const unsigned char *add, size_t add_len,
00148                       const unsigned char *input, unsigned char *output,
00149                       const unsigned char *tag, size_t tag_len );
00150 
00151 #ifdef __cplusplus
00152 }
00153 #endif
00154 
00155 #else  /* MBEDTLS_CCM_ALT */
00156 #include "ccm_alt.h"
00157 #endif /* MBEDTLS_CCM_ALT */
00158 
00159 #ifdef __cplusplus
00160 extern "C" {
00161 #endif
00162 
00163 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
00164 /**
00165  * \brief          The CCM checkup routine.
00166  *
00167  * \return         \c 0 on success, or \c 1 on failure.
00168  */
00169 int mbedtls_ccm_self_test( int verbose );
00170 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
00171 
00172 #ifdef __cplusplus
00173 }
00174 #endif
00175 
00176 #endif /* MBEDTLS_CCM_H */