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/**
* \file ccm.h
*
* \brief This file provides an API for the CCM authenticated encryption
* mode for block ciphers.
*
* CCM combines Counter mode encryption with CBC-MAC authentication
* for 128-bit block ciphers.
*
* Input to CCM includes the following elements:
* <ul><li>Payload - data that is both authenticated and encrypted.</li>
* <li>Associated data (Adata) - data that is authenticated but not
* encrypted, For example, a header.</li>
* <li>Nonce - A unique value that is assigned to the payload and the
* associated data.</li></ul>
*
* Definition of CCM:
* http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
* RFC 3610 "Counter with CBC-MAC (CCM)"
*
* Related:
* RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
*
* Definition of CCM*:
* IEEE 802.15.4 - IEEE Standard for Local and metropolitan area networks
* Integer representation is fixed most-significant-octet-first order and
* the representation of octets is most-significant-bit-first order. This is
* consistent with RFC 3610.
*/
/*
* 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_CCM_H
#define MBEDTLS_CCM_H
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include "mbedtls/cipher.h"
#define MBEDTLS_CCM_DECRYPT 0
#define MBEDTLS_CCM_ENCRYPT 1
#define MBEDTLS_CCM_STAR_DECRYPT 2
#define MBEDTLS_CCM_STAR_ENCRYPT 3
#define MBEDTLS_ERR_CCM_BAD_INPUT -0x000D /**< Bad input parameters to the function. */
#define MBEDTLS_ERR_CCM_AUTH_FAILED -0x000F /**< Authenticated decryption failed. */
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(MBEDTLS_CCM_ALT)
// Regular implementation
//
/**
* \brief The CCM context-type definition. The CCM context is passed
* to the APIs called.
*/
typedef struct mbedtls_ccm_context
{
mbedtls_cipher_context_t MBEDTLS_PRIVATE(cipher_ctx); /*!< The cipher context used. */
}
mbedtls_ccm_context;
#else /* MBEDTLS_CCM_ALT */
#include "ccm_alt.h"
#endif /* MBEDTLS_CCM_ALT */
/**
* \brief This function initializes the specified CCM context,
* to make references valid, and prepare the context
* for mbedtls_ccm_setkey() or mbedtls_ccm_free().
*
* \param ctx The CCM context to initialize. This must not be \c NULL.
*/
void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
/**
* \brief This function initializes the CCM context set in the
* \p ctx parameter and sets the encryption key.
*
* \param ctx The CCM context to initialize. This must be an initialized
* context.
* \param cipher The 128-bit block cipher to use.
* \param key The encryption key. This must not be \c NULL.
* \param keybits The key size in bits. This must be acceptable by the cipher.
*
* \return \c 0 on success.
* \return A CCM or cipher-specific error code on failure.
*/
int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
mbedtls_cipher_id_t cipher,
const unsigned char *key,
unsigned int keybits );
/**
* \brief This function releases and clears the specified CCM context
* and underlying cipher sub-context.
*
* \param ctx The CCM context to clear. If this is \c NULL, the function
* has no effect. Otherwise, this must be initialized.
*/
void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
/**
* \brief This function encrypts a buffer using CCM.
*
* \note The tag is written to a separate buffer. To concatenate
* the \p tag with the \p output, as done in <em>RFC-3610:
* Counter with CBC-MAC (CCM)</em>, use
* \p tag = \p output + \p length, and make sure that the
* output buffer is at least \p length + \p tag_len wide.
*
* \param ctx The CCM context to use for encryption. This must be
* initialized and bound to a key.
* \param length The length of the input data in Bytes.
* \param iv The initialization vector (nonce). This must be a readable
* buffer of at least \p iv_len Bytes.
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
* \param ad The additional data field. If \p ad_len is greater than
* zero, \p ad must be a readable buffer of at least that
* length.
* \param ad_len The length of additional data in Bytes.
* This must be less than `2^16 - 2^8`.
* \param input The buffer holding the input data. If \p length is greater
* than zero, \p input must be a readable buffer of at least
* that length.
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
* \param tag The buffer holding the authentication field. This must be a
* writable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
*
* \return \c 0 on success.
* \return A CCM or cipher-specific error code on failure.
*/
int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, unsigned char *output,
unsigned char *tag, size_t tag_len );
/**
* \brief This function encrypts a buffer using CCM*.
*
* \note The tag is written to a separate buffer. To concatenate
* the \p tag with the \p output, as done in <em>RFC-3610:
* Counter with CBC-MAC (CCM)</em>, use
* \p tag = \p output + \p length, and make sure that the
* output buffer is at least \p length + \p tag_len wide.
*
* \note When using this function in a variable tag length context,
* the tag length has to be encoded into the \p iv passed to
* this function.
*
* \param ctx The CCM context to use for encryption. This must be
* initialized and bound to a key.
* \param length The length of the input data in Bytes.
* \param iv The initialization vector (nonce). This must be a readable
* buffer of at least \p iv_len Bytes.
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
* \param ad The additional data field. This must be a readable buffer of
* at least \p ad_len Bytes.
* \param ad_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
* than zero, \p input must be a readable buffer of at least
* that length.
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
* \param tag The buffer holding the authentication field. This must be a
* writable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 0, 4, 6, 8, 10, 12, 14 or 16.
*
* \warning Passing \c 0 as \p tag_len means that the message is no
* longer authenticated.
*
* \return \c 0 on success.
* \return A CCM or cipher-specific error code on failure.
*/
int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, unsigned char *output,
unsigned char *tag, size_t tag_len );
/**
* \brief This function performs a CCM authenticated decryption of a
* buffer.
*
* \param ctx The CCM context to use for decryption. This must be
* initialized and bound to a key.
* \param length The length of the input data in Bytes.
* \param iv The initialization vector (nonce). This must be a readable
* buffer of at least \p iv_len Bytes.
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
* \param ad The additional data field. This must be a readable buffer
* of at least that \p ad_len Bytes..
* \param ad_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
* than zero, \p input must be a readable buffer of at least
* that length.
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
* \param tag The buffer holding the authentication field. This must be a
* readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
*
* \return \c 0 on success. This indicates that the message is authentic.
* \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
* \return A cipher-specific error code on calculation failure.
*/
int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, unsigned char *output,
const unsigned char *tag, size_t tag_len );
/**
* \brief This function performs a CCM* authenticated decryption of a
* buffer.
*
* \note When using this function in a variable tag length context,
* the tag length has to be decoded from \p iv and passed to
* this function as \p tag_len. (\p tag needs to be adjusted
* accordingly.)
*
* \param ctx The CCM context to use for decryption. This must be
* initialized and bound to a key.
* \param length The length of the input data in Bytes.
* \param iv The initialization vector (nonce). This must be a readable
* buffer of at least \p iv_len Bytes.
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
* \param ad The additional data field. This must be a readable buffer of
* at least that \p ad_len Bytes.
* \param ad_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
* than zero, \p input must be a readable buffer of at least
* that length.
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
* \param tag The buffer holding the authentication field. This must be a
* readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field in Bytes.
* 0, 4, 6, 8, 10, 12, 14 or 16.
*
* \warning Passing \c 0 as \p tag_len means that the message is nos
* longer authenticated.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
* \return A cipher-specific error code on calculation failure.
*/
int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, unsigned char *output,
const unsigned char *tag, size_t tag_len );
/**
* \brief This function starts a CCM encryption or decryption
* operation.
*
* This function and mbedtls_ccm_set_lengths() must be called
* before calling mbedtls_ccm_update_ad() or
* mbedtls_ccm_update(). This function can be called before
* or after mbedtls_ccm_set_lengths().
*
* \note This function is not implemented in Mbed TLS yet.
*
* \param ctx The CCM context. This must be initialized.
* \param mode The operation to perform: #MBEDTLS_CCM_ENCRYPT or
* #MBEDTLS_CCM_DECRYPT or #MBEDTLS_CCM_STAR_ENCRYPT or
* #MBEDTLS_CCM_STAR_DECRYPT.
* \param iv The initialization vector. This must be a readable buffer
* of at least \p iv_len Bytes.
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure:
* \p ctx is in an invalid state,
* \p mode is invalid,
* \p iv_len is invalid (lower than \c 7 or greater than
* \c 13).
*/
int mbedtls_ccm_starts( mbedtls_ccm_context *ctx,
int mode,
const unsigned char *iv,
size_t iv_len );
/**
* \brief This function declares the lengths of the message
* and additional data for a CCM encryption or decryption
* operation.
*
* This function and mbedtls_ccm_starts() must be called
* before calling mbedtls_ccm_update_ad() or
* mbedtls_ccm_update(). This function can be called before
* or after mbedtls_ccm_starts().
*
* \note This function is not implemented in Mbed TLS yet.
*
* \param ctx The CCM context. This must be initialized.
* \param total_ad_len The total length of additional data in bytes.
* This must be less than `2^16 - 2^8`.
* \param plaintext_len The length in bytes of the plaintext to encrypt or
* result of the decryption (thus not encompassing the
* additional data that are not encrypted).
* \param tag_len The length of the tag to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
* For CCM*, zero is also valid.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure:
* \p ctx is in an invalid state,
* \p total_ad_len is greater than \c 0xFF00.
*/
int mbedtls_ccm_set_lengths( mbedtls_ccm_context *ctx,
size_t total_ad_len,
size_t plaintext_len,
size_t tag_len );
/**
* \brief This function feeds an input buffer as associated data
* (authenticated but not encrypted data) in a CCM
* encryption or decryption operation.
*
* You may call this function zero, one or more times
* to pass successive parts of the additional data. The
* lengths \p ad_len of the data parts should eventually add
* up exactly to the total length of additional data
* \c total_ad_len passed to mbedtls_ccm_set_lengths(). You
* may not call this function after calling
* mbedtls_ccm_update().
*
* \note This function is not implemented in Mbed TLS yet.
*
* \param ctx The CCM context. This must have been started with
* mbedtls_ccm_starts(), the lengths of the message and
* additional data must have been declared with
* mbedtls_ccm_set_lengths() and this must not have yet
* received any input with mbedtls_ccm_update().
* \param ad The buffer holding the additional data, or \c NULL
* if \p ad_len is \c 0.
* \param ad_len The length of the additional data. If \c 0,
* \p ad may be \c NULL.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure:
* \p ctx is in an invalid state,
* total input length too long.
*/
int mbedtls_ccm_update_ad( mbedtls_ccm_context *ctx,
const unsigned char *ad,
size_t ad_len );
/**
* \brief This function feeds an input buffer into an ongoing CCM
* encryption or decryption operation.
*
* You may call this function zero, one or more times
* to pass successive parts of the input: the plaintext to
* encrypt, or the ciphertext (not including the tag) to
* decrypt. After the last part of the input, call
* mbedtls_ccm_finish(). The lengths \p input_len of the
* data parts should eventually add up exactly to the
* plaintext length \c plaintext_len passed to
* mbedtls_ccm_set_lengths().
*
* This function may produce output in one of the following
* ways:
* - Immediate output: the output length is always equal
* to the input length.
* - Buffered output: except for the last part of input data,
* the output consists of a whole number of 16-byte blocks.
* If the total input length so far (not including
* associated data) is 16 \* *B* + *A* with *A* < 16 then
* the total output length is 16 \* *B*.
* For the last part of input data, the output length is
* equal to the input length plus the number of bytes (*A*)
* buffered in the previous call to the function (if any).
* The function uses the plaintext length
* \c plaintext_len passed to mbedtls_ccm_set_lengths()
* to detect the last part of input data.
*
* In particular:
* - It is always correct to call this function with
* \p output_size >= \p input_len + 15.
* - If \p input_len is a multiple of 16 for all the calls
* to this function during an operation (not necessary for
* the last one) then it is correct to use \p output_size
* =\p input_len.
*
* \note This function is not implemented in Mbed TLS yet.
*
* \param ctx The CCM context. This must have been started with
* mbedtls_ccm_starts() and the lengths of the message and
* additional data must have been declared with
* mbedtls_ccm_set_lengths().
* \param input The buffer holding the input data. If \p input_len
* is greater than zero, this must be a readable buffer
* of at least \p input_len bytes.
* \param input_len The length of the input data in bytes.
* \param output The buffer for the output data. If \p output_size
* is greater than zero, this must be a writable buffer of
* at least \p output_size bytes.
* \param output_size The size of the output buffer in bytes.
* See the function description regarding the output size.
* \param output_len On success, \p *output_len contains the actual
* length of the output written in \p output.
* On failure, the content of \p *output_len is
* unspecified.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure:
* \p ctx is in an invalid state,
* total input length too long,
* or \p output_size too small.
*/
int mbedtls_ccm_update( mbedtls_ccm_context *ctx,
const unsigned char *input, size_t input_len,
unsigned char *output, size_t output_size,
size_t *output_len );
/**
* \brief This function finishes the CCM operation and generates
* the authentication tag.
*
* It wraps up the CCM stream, and generates the
* tag. The tag can have a maximum length of 16 Bytes.
*
* \note This function is not implemented in Mbed TLS yet.
*
* \param ctx The CCM context. This must have been started with
* mbedtls_ccm_starts() and the lengths of the message and
* additional data must have been declared with
* mbedtls_ccm_set_lengths().
* \param tag The buffer for holding the tag. If \p tag_len is greater
* than zero, this must be a writable buffer of at least \p
* tag_len Bytes.
* \param tag_len The length of the tag. Must match the tag length passed to
* mbedtls_ccm_set_lengths() function.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure:
* \p ctx is in an invalid state,
* invalid value of \p tag_len,
* the total amount of additional data passed to
* mbedtls_ccm_update_ad() was lower than the total length of
* additional data \c total_ad_len passed to
* mbedtls_ccm_set_lengths(),
* the total amount of input data passed to
* mbedtls_ccm_update() was lower than the plaintext length
* \c plaintext_len passed to mbedtls_ccm_set_lengths().
*/
int mbedtls_ccm_finish( mbedtls_ccm_context *ctx,
unsigned char *tag, size_t tag_len );
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/**
* \brief The CCM checkup routine.
*
* \return \c 0 on success.
* \return \c 1 on failure.
*/
int mbedtls_ccm_self_test( int verbose );
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_CCM_H */