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  * Definition of CCM:
00018  * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
00019  * RFC 3610 "Counter with CBC-MAC (CCM)"
00020  *
00021  * Related:
00022  * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
00023  *
00024  * Definition of CCM*:
00025  * IEEE 802.15.4 - IEEE Standard for Local and metropolitan area networks
00026  * Integer representation is fixed most-significant-octet-first order and
00027  * the representation of octets is most-significant-bit-first order. This is
00028  * consistent with RFC 3610.
00029  */
00030 /*
00031  *  Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
00032  *  SPDX-License-Identifier: Apache-2.0
00033  *
00034  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00035  *  not use this file except in compliance with the License.
00036  *  You may obtain a copy of the License at
00037  *
00038  *  http://www.apache.org/licenses/LICENSE-2.0
00039  *
00040  *  Unless required by applicable law or agreed to in writing, software
00041  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00042  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00043  *  See the License for the specific language governing permissions and
00044  *  limitations under the License.
00045  *
00046  *  This file is part of Mbed TLS (https://tls.mbed.org)
00047  */
00048 
00049 #ifndef MBEDTLS_CCM_H
00050 #define MBEDTLS_CCM_H
00051 
00052 #include "cipher.h"
00053 
00054 #define MBEDTLS_ERR_CCM_BAD_INPUT       -0x000D /**< Bad input parameters to the function. */
00055 #define MBEDTLS_ERR_CCM_AUTH_FAILED     -0x000F /**< Authenticated decryption failed. */
00056 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */
00057 
00058 
00059 #ifdef __cplusplus
00060 extern "C" {
00061 #endif
00062 
00063 #if !defined(MBEDTLS_CCM_ALT)
00064 // Regular implementation
00065 //
00066 
00067 /**
00068  * \brief    The CCM context-type definition. The CCM context is passed
00069  *           to the APIs called.
00070  */
00071 typedef struct mbedtls_ccm_context
00072 {
00073     mbedtls_cipher_context_t cipher_ctx ;    /*!< The cipher context used. */
00074 }
00075 mbedtls_ccm_context;
00076 
00077 #else  /* MBEDTLS_CCM_ALT */
00078 #include "ccm_alt.h"
00079 #endif /* MBEDTLS_CCM_ALT */
00080 
00081 /**
00082  * \brief           This function initializes the specified CCM context,
00083  *                  to make references valid, and prepare the context
00084  *                  for mbedtls_ccm_setkey() or mbedtls_ccm_free().
00085  *
00086  * \param ctx       The CCM context to initialize.
00087  */
00088 void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
00089 
00090 /**
00091  * \brief           This function initializes the CCM context set in the
00092  *                  \p ctx parameter and sets the encryption key.
00093  *
00094  * \param ctx       The CCM context to initialize.
00095  * \param cipher    The 128-bit block cipher to use.
00096  * \param key       The encryption key.
00097  * \param keybits   The key size in bits. This must be acceptable by the cipher.
00098  *
00099  * \return          \c 0 on success.
00100  * \return          A CCM or cipher-specific error code on failure.
00101  */
00102 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
00103                         mbedtls_cipher_id_t cipher,
00104                         const unsigned char *key,
00105                         unsigned int keybits );
00106 
00107 /**
00108  * \brief   This function releases and clears the specified CCM context
00109  *          and underlying cipher sub-context.
00110  *
00111  * \param ctx       The CCM context to clear.
00112  */
00113 void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
00114 
00115 /**
00116  * \brief           This function encrypts a buffer using CCM.
00117  *
00118  * \note            The tag is written to a separate buffer. To concatenate
00119  *                  the \p tag with the \p output, as done in <em>RFC-3610:
00120  *                  Counter with CBC-MAC (CCM)</em>, use
00121  *                  \p tag = \p output + \p length, and make sure that the
00122  *                  output buffer is at least \p length + \p tag_len wide.
00123  *
00124  * \param ctx       The CCM context to use for encryption.
00125  * \param length    The length of the input data in Bytes.
00126  * \param iv        Initialization vector (nonce).
00127  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
00128  *                  or 13. The length L of the message length field is
00129  *                  15 - \p iv_len.
00130  * \param add       The additional data field.
00131  * \param add_len   The length of additional data in Bytes.
00132  *                  Must be less than 2^16 - 2^8.
00133  * \param input     The buffer holding the input data.
00134  * \param output    The buffer holding the output data.
00135  *                  Must be at least \p length Bytes wide.
00136  * \param tag       The buffer holding the authentication field.
00137  * \param tag_len   The length of the authentication field to generate in Bytes:
00138  *                  4, 6, 8, 10, 12, 14 or 16.
00139  *
00140  * \return          \c 0 on success.
00141  * \return          A CCM or cipher-specific error code on failure.
00142  */
00143 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
00144                          const unsigned char *iv, size_t iv_len,
00145                          const unsigned char *add, size_t add_len,
00146                          const unsigned char *input, unsigned char *output,
00147                          unsigned char *tag, size_t tag_len );
00148 
00149 /**
00150  * \brief           This function encrypts a buffer using CCM*.
00151  *
00152  * \note            The tag is written to a separate buffer. To concatenate
00153  *                  the \p tag with the \p output, as done in <em>RFC-3610:
00154  *                  Counter with CBC-MAC (CCM)</em>, use
00155  *                  \p tag = \p output + \p length, and make sure that the
00156  *                  output buffer is at least \p length + \p tag_len wide.
00157  *
00158  * \note            When using this function in a variable tag length context,
00159  *                  the tag length has to be encoded into the \p iv passed to
00160  *                  this function.
00161  *
00162  * \param ctx       The CCM context to use for encryption.
00163  * \param length    The length of the input data in Bytes.
00164  * \param iv        Initialization vector (nonce).
00165  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
00166  *                  or 13. The length L of the message length field is
00167  *                  15 - \p iv_len.
00168  * \param add       The additional data field.
00169  * \param add_len   The length of additional data in Bytes.
00170  *                  Must be less than 2^16 - 2^8.
00171  * \param input     The buffer holding the input data.
00172  * \param output    The buffer holding the output data.
00173  *                  Must be at least \p length Bytes wide.
00174  * \param tag       The buffer holding the authentication field.
00175  * \param tag_len   The length of the authentication field to generate in Bytes:
00176  *                  0, 4, 6, 8, 10, 12, 14 or 16.
00177  *
00178  * \warning         Passing 0 as \p tag_len means that the message is no
00179  *                  longer authenticated.
00180  *
00181  * \return          \c 0 on success.
00182  * \return          A CCM or cipher-specific error code on failure.
00183  */
00184 int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
00185                          const unsigned char *iv, size_t iv_len,
00186                          const unsigned char *add, size_t add_len,
00187                          const unsigned char *input, unsigned char *output,
00188                          unsigned char *tag, size_t tag_len );
00189 
00190 /**
00191  * \brief           This function performs a CCM authenticated decryption of a
00192  *                  buffer.
00193  *
00194  * \param ctx       The CCM context to use for decryption.
00195  * \param length    The length of the input data in Bytes.
00196  * \param iv        Initialization vector (nonce).
00197  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
00198  *                  or 13. The length L of the message length field is
00199  *                  15 - \p iv_len.
00200  * \param add       The additional data field.
00201  * \param add_len   The length of additional data in Bytes.
00202  *                  Must be less than 2^16 - 2^8.
00203  * \param input     The buffer holding the input data.
00204  * \param output    The buffer holding the output data.
00205  *                  Must be at least \p length Bytes wide.
00206  * \param tag       The buffer holding the authentication field.
00207  * \param tag_len   The length of the authentication field in Bytes.
00208  *                  4, 6, 8, 10, 12, 14 or 16.
00209  *
00210  * \return          \c 0 on success. This indicates that the message is authentic.
00211  * \return          #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
00212  * \return          A cipher-specific error code on calculation failure.
00213  */
00214 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
00215                       const unsigned char *iv, size_t iv_len,
00216                       const unsigned char *add, size_t add_len,
00217                       const unsigned char *input, unsigned char *output,
00218                       const unsigned char *tag, size_t tag_len );
00219 
00220 /**
00221  * \brief           This function performs a CCM* authenticated decryption of a
00222  *                  buffer.
00223  *
00224  * \note            When using this function in a variable tag length context,
00225  *                  the tag length has to be decoded from \p iv and passed to
00226  *                  this function as \p tag_len. (\p tag needs to be adjusted
00227  *                  accordingly.)
00228  *
00229  * \param ctx       The CCM context to use for decryption.
00230  * \param length    The length of the input data in Bytes.
00231  * \param iv        Initialization vector (nonce).
00232  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
00233  *                  or 13. The length L of the message length field is
00234  *                  15 - \p iv_len.
00235  * \param add       The additional data field.
00236  * \param add_len   The length of additional data in Bytes.
00237  *                  Must be less than 2^16 - 2^8.
00238  * \param input     The buffer holding the input data.
00239  * \param output    The buffer holding the output data.
00240  *                  Must be at least \p length Bytes wide.
00241  * \param tag       The buffer holding the authentication field.
00242  * \param tag_len   The length of the authentication field in Bytes.
00243  *                  0, 4, 6, 8, 10, 12, 14 or 16.
00244  *
00245  * \warning         Passing 0 as \p tag_len means that the message is no
00246  *                  longer authenticated.
00247  *
00248  * \return          \c 0 on success.
00249  * \return          #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
00250  * \return          A cipher-specific error code on calculation failure.
00251  */
00252 int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
00253                       const unsigned char *iv, size_t iv_len,
00254                       const unsigned char *add, size_t add_len,
00255                       const unsigned char *input, unsigned char *output,
00256                       const unsigned char *tag, size_t tag_len );
00257 
00258 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
00259 /**
00260  * \brief          The CCM checkup routine.
00261  *
00262  * \return         \c 0 on success.
00263  * \return         \c 1 on failure.
00264  */
00265 int mbedtls_ccm_self_test( int verbose );
00266 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
00267 
00268 #ifdef __cplusplus
00269 }
00270 #endif
00271 
00272 #endif /* MBEDTLS_CCM_H */