diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h index 8585ce5e7..24e13dd80 100644 --- a/include/mbedtls/ccm.h +++ b/include/mbedtls/ccm.h @@ -102,7 +102,6 @@ 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 RFC-3610: * Counter with CBC-MAC (CCM), use @@ -132,6 +131,45 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, 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 RFC-3610: + * Counter with CBC-MAC (CCM), 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. + * \param length The length of the input data in Bytes. + * \param iv Initialization vector (nonce). + * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13. + * \param add The additional data field. + * \param add_len The length of additional data in Bytes. + * Must be less than 2^16 - 2^8. + * \param input The buffer holding the input data. + * \param output The buffer holding the output data. + * Must be at least \p length Bytes wide. + * \param tag The buffer holding the tag. + * \param tag_len The length of the tag to generate in Bytes: + * 0, 4, 6, 8, 10, 12, 14 or 16. + * + * \warning Passing 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 *add, size_t add_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. @@ -160,6 +198,42 @@ int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, 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. + * \param length The length of the input data in Bytes. + * \param iv Initialization vector. + * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13. + * \param add The additional data field. + * \param add_len The length of additional data in Bytes. + * Must be less than 2^16 - 2^8. + * \param input The buffer holding the input data. + * \param output The buffer holding the output data. + * Must be at least \p length Bytes wide. + * \param tag The buffer holding the tag. + * \param tag_len The length of the tag in Bytes. + * 0, 4, 6, 8, 10, 12, 14 or 16. + * + * \warning Passing 0 as \p tag_len means that the message is no + * longer authenticated. + * + * \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_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, + const unsigned char *iv, size_t iv_len, + const unsigned char *add, size_t add_len, + const unsigned char *input, unsigned char *output, + const unsigned char *tag, size_t tag_len ); #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) /**