ccm.h

00001 /**
00002  * \file ccm.h
00003  *
00004  * \brief This file provides an API for the CCM authenticated encryption
00005  *        mode for block ciphers.
00006  *
00007  * CCM combines Counter mode encryption with CBC-MAC authentication
00008  * for 128-bit block ciphers.
00009  *
00010  * Input to CCM includes the following elements:
00011  * <ul><li>Payload - data that is both authenticated and encrypted.</li>
00012  * <li>Associated data (Adata) - data that is authenticated but not
00013  * encrypted, For example, a header.</li>
00014  * <li>Nonce - A unique value that is assigned to the payload and the
00015  * associated data.</li></ul>
00016  *
00017  */
00018 /*
00019  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
00020  *  SPDX-License-Identifier: Apache-2.0
00021  *
00022  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00023  *  not use this file except in compliance with the License.
00024  *  You may obtain a copy of the License at
00025  *
00026  *  http://www.apache.org/licenses/LICENSE-2.0
00027  *
00028  *  Unless required by applicable law or agreed to in writing, software
00029  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00030  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00031  *  See the License for the specific language governing permissions and
00032  *  limitations under the License.
00033  *
00034  *  This file is part of Mbed TLS (https://tls.mbed.org)
00035  */
00036 
00037 #ifndef MBEDTLS_CCM_H
00038 #define MBEDTLS_CCM_H
00039 
00040 #include "cipher.h"
00041 
00042 #define MBEDTLS_ERR_CCM_BAD_INPUT       -0x000D /**< Bad input parameters to the function. */
00043 #define MBEDTLS_ERR_CCM_AUTH_FAILED     -0x000F /**< Authenticated decryption failed. */
00044 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */
00045 
00046 
00047 #ifdef __cplusplus
00048 extern "C" {
00049 #endif
00050 
00051 #if !defined(MBEDTLS_CCM_ALT)
00052 // Regular implementation
00053 //
00054 
00055 /**
00056  * \brief    The CCM context-type definition. The CCM context is passed
00057  *           to the APIs called.
00058  */
00059 typedef struct {
00060     mbedtls_cipher_context_t cipher_ctx ;    /*!< The cipher context used. */
00061 }
00062 mbedtls_ccm_context;
00063 
00064 #else  /* MBEDTLS_CCM_ALT */
00065 #include "ccm_alt.h"
00066 #endif /* MBEDTLS_CCM_ALT */
00067 
00068 /**
00069  * \brief           This function initializes the specified CCM context,
00070  *                  to make references valid, and prepare the context
00071  *                  for mbedtls_ccm_setkey() or mbedtls_ccm_free().
00072  *
00073  * \param ctx       The CCM context to initialize.
00074  */
00075 void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
00076 
00077 /**
00078  * \brief           This function initializes the CCM context set in the
00079  *                  \p ctx parameter and sets the encryption key.
00080  *
00081  * \param ctx       The CCM context to initialize.
00082  * \param cipher    The 128-bit block cipher to use.
00083  * \param key       The encryption key.
00084  * \param keybits   The key size in bits. This must be acceptable by the cipher.
00085  *
00086  * \return          \c 0 on success.
00087  * \return          A CCM or cipher-specific error code on failure.
00088  */
00089 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
00090                         mbedtls_cipher_id_t cipher,
00091                         const unsigned char *key,
00092                         unsigned int keybits );
00093 
00094 /**
00095  * \brief   This function releases and clears the specified CCM context
00096  *          and underlying cipher sub-context.
00097  *
00098  * \param ctx       The CCM context to clear.
00099  */
00100 void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
00101 
00102 /**
00103  * \brief           This function encrypts a buffer using CCM.
00104  *
00105  *
00106  * \note            The tag is written to a separate buffer. To concatenate
00107  *                  the \p tag with the \p output, as done in <em>RFC-3610:
00108  *                  Counter with CBC-MAC (CCM)</em>, use
00109  *                  \p tag = \p output + \p length, and make sure that the
00110  *                  output buffer is at least \p length + \p tag_len wide.
00111  *
00112  * \param ctx       The CCM context to use for encryption.
00113  * \param length    The length of the input data in Bytes.
00114  * \param iv        Initialization vector (nonce).
00115  * \param iv_len    The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
00116  * \param add       The additional data field.
00117  * \param add_len   The length of additional data in Bytes.
00118  *                  Must be less than 2^16 - 2^8.
00119  * \param input     The buffer holding the input data.
00120  * \param output    The buffer holding the output data.
00121  *                  Must be at least \p length Bytes wide.
00122  * \param tag       The buffer holding the tag.
00123  * \param tag_len   The length of the tag to generate in Bytes:
00124  *                  4, 6, 8, 10, 12, 14 or 16.
00125  *
00126  * \return          \c 0 on success.
00127  * \return          A CCM or cipher-specific error code on failure.
00128  */
00129 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
00130                          const unsigned char *iv, size_t iv_len,
00131                          const unsigned char *add, size_t add_len,
00132                          const unsigned char *input, unsigned char *output,
00133                          unsigned char *tag, size_t tag_len );
00134 
00135 /**
00136  * \brief           This function performs a CCM authenticated decryption of a
00137  *                  buffer.
00138  *
00139  * \param ctx       The CCM context to use for decryption.
00140  * \param length    The length of the input data in Bytes.
00141  * \param iv        Initialization vector.
00142  * \param iv_len    The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
00143  * \param add       The additional data field.
00144  * \param add_len   The length of additional data in Bytes.
00145  *                  Must be less than 2^16 - 2^8.
00146  * \param input     The buffer holding the input data.
00147  * \param output    The buffer holding the output data.
00148  *                  Must be at least \p length Bytes wide.
00149  * \param tag       The buffer holding the tag.
00150  * \param tag_len   The length of the tag in Bytes.
00151  *                  4, 6, 8, 10, 12, 14 or 16.
00152  *
00153  * \return          \c 0 on success. This indicates that the message is authentic.
00154  * \return          #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
00155  * \return          A cipher-specific error code on calculation failure.
00156  */
00157 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
00158                       const unsigned char *iv, size_t iv_len,
00159                       const unsigned char *add, size_t add_len,
00160                       const unsigned char *input, unsigned char *output,
00161                       const unsigned char *tag, size_t tag_len );
00162 
00163 
00164 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
00165 /**
00166  * \brief          The CCM checkup routine.
00167  *
00168  * \return         \c 0 on success.
00169  * \return         \c 1 on failure.
00170  */
00171 int mbedtls_ccm_self_test( int verbose );
00172 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
00173 
00174 #ifdef __cplusplus
00175 }
00176 #endif
00177 
00178 #endif /* MBEDTLS_CCM_H */